Radon and radon daughters indoors, problems in the determination of the annual average

International Nuclear Information System (INIS)

Swedjemark, G.A.

1984-01-01

The annual average of the concentration of radon and radon daughters in indoor air is required both in studies such as determining the collective dose to a population and at comparing with limits. Measurements are often carried out during a time period shorter than a year for practical reasons. Methods for estimating the uncertainties due to temporal variations in an annual average calculated from measurements carried out during various lengths of the sampling periods. These methods have been applied to the results from long-term measurements of radon-222 in a few houses. The possibilities to use correction factors in order to get a more adequate annual average have also been studied and some examples have been given. (orig.)

National survey of indoor radon levels in Croatia

International Nuclear Information System (INIS)

Radolic, V.; Vukovic, B.; Stanic, D.; Katic, M.; Faj, Z.; Lukacevic, I.; Planinic, J.; Suveljak, B.; Faj, D.; Lukic, M.

2006-01-01

National survey of indoor radon was performed by a random sampling of thousand (782 realized) dwellings in Croatia. Radon concentrations were measured for one year with LR-115 SSNT detectors and arithmetic and geometric means of 68 and 50 Bq/m 3 were obtained, respectively. The arithmetic means of radon concentrations on 20 counties were from 33 to 198 Bq/m 3 . The percentage of dwellings with radon concentrations above 200 and 400 Bq/m 3 was 5.4% and 1.8%, respectively. The average annual effective dose of the indoor radon was estimated as 2.2 mSv. (author)

Influence of environmental factors on indoor radon concentration levels in the basement and ground floor of a building – A case study

International Nuclear Information System (INIS)

Xie, Dong; Liao, Maili; Kearfott, Kimberlee J.

2015-01-01

A series of experiments was conducted to measure indoor radon concentrations variations and observe any correlations with indoor and outdoor atmospheric parameters for over a period of one year. Indoor environmental parameters and radon concentrations were measured on an hourly basis in a two-story building both in a laboratory on the well-ventilated ground floor and in the basement below it which had negligible ventilation. The monthly average indoor radon concentration value of 29 ± 21 Bq m"−"3 in the laboratory was below the ICRP recommended limit of 200–300 Bq m"−"3. The monthly normalization factor for that location ranged from 0.5 to 2.0, while the seasonal normalization factor ranged from 0.78 to 2.0. In the unventilated basement, however, the average monthly indoor radon concentration was 1083 ± 6 Bq m"−"3 with little seasonal variation. The basement is only used for storage and thus the elevated radon concentration does not pose a serious health risk. The results indicated that indoor radon levels are higher in the autumn–winter season than in the spring–summer season. Analysis further showed that indoor radon concentrations negatively correlated with indoor humidity (correlation coefficient R = −0.14, p < 0.01), outdoor temperature (correlation coefficient R = −0.3, p < 0.01), outdoor dew point temperature (correlation coefficient R = −0.17, p < 0.01) and outdoor wind speeds (correlation coefficient R = −0.25, p < 0.05). Radon concentrations correlated positively with outdoor barometric pressure (correlation coefficient R = 0.35, p < 0.01), indoor–outdoor temperature difference (correlation coefficient R = 0.32, p < 0.05) and indoor–outdoor barometric pressure difference (correlation coefficient R = 0.67, p < 0.01). Indoor temperature, indoor barometric pressure and outdoor wind direction showed no clear correlations with indoor radon concentration. - Highlights: • Environmental variables and

Geologic controls on indoor radon in the Pacific Northwest

International Nuclear Information System (INIS)

Otton, J.K.; Duval, J.S.

1990-01-01

This paper reports on comparisons of average indoor radon levels, soil radium content (derived from aerial gamma-ray data), and soil characteristics for selected townships in Washington, Oregon, and Idaho which show that: soil radium content provides a first-order estimate of the relative amounts of indoor radon where soils are either of low to moderate intrinsic permeability or of permeability reduced by high moisture; in drier parts of the study area (east of the Cascade Mountains), unusually high average indoor radon levels are almost all characterized by soils that have high effective permeabilities (greater than 20 inches per hour), based on available country soil descriptions; and in the wetter parts of the study area (west of the Cascade Mountains), townships with unusually high indoor radon levels are characterized by steeply sloped soils

Unusually amplified summer or winter indoor levels of radon

International Nuclear Information System (INIS)

Gammage, R.B.; Dudney, C.S.; Wilson, D.L.

1993-01-01

The ratios of winter/summer indoor radon levels for houses in different regions of the southern Appalachians are characterized by individual log-normal distributions with geometric means both above and below unity. In some counties and cities, subpopulations of houses have unusually exaggerated winter/summer ratios of indoor radon, as well as high indoor radon levels, during periods of either warm or cool weather. It is proposed that in many instances, houses are communicating with larger than normal underground reservoirs of radon-bearing air in hilly karst terrains; differences between the outdoor and underground air temperatures are believed to provide density gradients producing aerostatic pressure differences for seasonally directed underground transport and subsequently elevated indoor radon. These seasonal movements of air are analogous to the well-known underground chimney effects, which produce interzonal flows of air inside caves

Inter-comparison of air pollutant concentrations in different indoor environments in Hong Kong

Science.gov (United States)

Lee, Shun-Cheng; Guo, Hai; Li, Wai-Ming; Chan, Lo-Yin

Indoor air quality in selected indoor environments in Hong Kong such as homes, offices, schools, shopping malls and restaurants were investigated. Average CO 2 levels and total bacteria counts in air-conditioned classrooms, shopping malls and restaurants were comparatively higher than those measured in occupied offices and homes. Elevated CO 2 levels exceeding 1000 ppm and total bacteria counts resulted from high occupancy combined with inadequate ventilation. Average PM 10 levels were usually higher indoors than outdoors in homes, shopping malls and restaurants. The highest indoor PM 10 levels were observed at investigated restaurants due to the presence of cigarette smoking and extensive use of gas stoves for cooking. The restaurants and shopping malls investigated had higher formaldehyde levels than other indoor environments when building material, smoking and internal renovation work were present. Volatile organic compounds (VOCs) in both indoor and outdoor environments mainly resulted from vehicle exhaust emissions. It was observed that interior decoration work and the use of industrial solvents in an indoor environment could significantly increase the indoor levels of VOCs.

Exposure to unusually high indoor radon levels

International Nuclear Information System (INIS)

Rasheed, F.N.

1993-01-01

Unusually high indoor radon concentrations were reported in a small village in western Tyrol, Austria. The authors have measured the seasonal course of indoor radon concentrations in 390 houses of this village. 71% of houses in winter and 33% in summer, showed radon values on the ground floor above the Austrian action level of 400 Bq/cm 3 . This proportion results in an unusually high indoor radon exposure of the population. The radon source was an 8,700-year-old rock slide of granite gneiss, the largest of the alpine crystalline rocks. It has a strong emanating power because its rocks are heavily fractured and show a slightly increased uranium content. Previous reports show increased lung cancer mortality, myeloid leukemia, kidney cancer, melanoma, and prostate cancer resulting from indoor radon exposure. However, many studies fail to provide accurate information on indoor radon concentrations, classifying them merely as low, intermediate, and high, or they record only minor increases in indoor radon concentrations. Mortality data for 1970-91 were used to calculate age and sex standardized mortality rates (SMR) for 51 sites of carcinoma. The total population of Tyrol were controls. A significantly higher risk was recorded for lung cancer. The high SMR for lung cancer in female subjects is especially striking. Because the numbers were low for the other cancer sites, these were combined in one group to calculate the SMR. No significant increase in SMR was found for this group

Indoor radon level measurements in Iran using AEOI passive dosimeters

International Nuclear Information System (INIS)

Sohrabi, M.; Solaymanian, A.R.

1988-01-01

A passive radon diffusion dosimeter was developed at the RPD of AEOI for nationwide indoor radon level measurements. Several parameters of the dosimeter were studied. Radon levels were determined in about 250 houses in Ramsar (a high natural radiation area), Tehran, Babolsar and Gonabad. In this paper, the results of some dosimeter parameters as well as radon levels in indoor air are reported

Indoor air quality at nine shopping malls in Hong Kong.

Science.gov (United States)

Li, W M; Lee, S C; Chan, L Y

2001-06-12

Hong Kong is one of the most attractive shopping paradises in the world. Many local people and international tourists favor to spend their time in shopping malls in Hong Kong. Good indoor air quality is, therefore, very essential to shoppers. In order to characterize the indoor air quality in shopping malls, nine shopping malls in Hong Kong were selected for this study. The indoor air pollutants included carbon dioxide (CO2), carbon monoxide (CO), total hydrocarbons (THC), formaldehyde (HCHO), respirable particulate matter (PM10) and total bacteria count (TBC). More than 40% of the shopping malls had 1-h average CO2 levels above the 1000 ppm of the ASHRAE standard on both weekdays and weekends. Also, they had average weekday PM10 concentrations that exceeded the Hong Kong Indoor Air Quality Objective (HKIAQO). The highest indoor PM10 level at a mall was 380 microg/m3. Of the malls surveyed, 30% had indoor airborne bacteria levels above 1000 cfu/m3 set by the HKIAQO. The elevated indoor CO2 and bacteria levels could result from high occupancy combined with insufficient ventilation. The increased PM10 levels could be probably attributed to illegal smoking inside these establishments. In comparison, the shopping malls that contained internal public transport drop-off areas, where vehicles were parked with idling engines and had major entry doors close to heavy traffic roads had higher CO and PM10 indoor levels. In addition, the extensive use of cooking stoves without adequate ventilation inside food courts could increase indoor CO2, CO and PM10 levels.

Correlation of indoor radon levels with physical properties of local soil in Khammam district, Andhra Pradesh, India

International Nuclear Information System (INIS)

Sreenivasa Reddy, B.; Bhaskar Reddy, G.; Sreenath Reddy, M.; Gopal Reddy, Ch; Yadagiri Reddy, P.; Rama Reddy, K.

2006-01-01

Indoor radon contributes significantly to the total radiation exposure caused to human beings. As might be expected, the physical characteristics of soil play key roles in determining the radon concentration in nearby buildings. The physical characteristics of soil, such as density, specific gravity and porosity in the vicinity of the dwellings of Khammam district, Andhra Pradesh, India, have been determined using core cutter and specific gravity bottle. In the present paper, these parameters are correlated with the average indoor radon levels estimated for a year using solid state nuclear track detectors. (author)

Indoor air quality in Brazilian universities.

Science.gov (United States)

Jurado, Sonia R; Bankoff, Antônia D P; Sanchez, Andrea

2014-07-11

This study evaluated the indoor air quality in Brazilian universities by comparing thirty air-conditioned (AC) (n = 15) and naturally ventilated (NV) (n = 15) classrooms. The parameters of interest were indoor carbon dioxide (CO2), temperature, relative humidity (RH), wind speed, viable mold, and airborne dust levels. The NV rooms had larger concentration of mold than the AC rooms (1001.30 ± 125.16 and 367.00 ± 88.13 cfu/m3, respectively). The average indoor airborne dust concentration exceeded the Brazilian standards (indoor air quality in Brazilian university classrooms affects the health of students. Therefore, indoor air pollution needs to be considered as an important public health problem.

Indoor radon measurements in the dwellings of Punjab and Himachal Pradesh, India

International Nuclear Information System (INIS)

Rani, A.; Singh, S.; Duggal, V.

2013-01-01

The measurement of indoor radon concentrations were performed in the dwellings of the Punjab and Himachal Pradesh, India by using LR-115 type II Solid-State Nuclear Track Detectors in the bare mode. The annual average indoor radon concentrations in the dwellings are found to vary from 114 to 400 Bq m -3 with an average of 194 Bq m -3 . In ∼22 % of the dwellings the indoor radon activity concentration values lies in the range of action level (200-300 Bq m -3 ) and in ∼11 % of the dwellings above the upper limit of action level recommended by the International Commission on Radiological Protection (ICRP). The annual effective dose (AED) varies from 2.88 to 10.08 mSv with an average of 4.88 mSv. In most of the villages, the AED lies in the range of action level (3-10 mSv) recommended by the ICRP. The seasonal variation in indoor radon reveals the maximum values in winter and minimum in summer. The winter/summer ratio of indoor radon ranges from 1.15 to 1.62 with an average of 1.31. Analysis of ventilation conditions reveal that the indoor radon concentration values are more in poorly ventilated dwellings compared with the well-ventilated ones. (authors)

Predictions of lung cancer based on county averages for indoor radon versus the historic incidence of regional lung cancer

International Nuclear Information System (INIS)

Mose, D.G.; Chrosniak, C.E.; Mushrush, G.W.

1992-01-01

After a decade of effort to determine the health risk associated with indoor radon, the efforts of the US Environmental Protection Agency have prevailed in the US, and 4 pCi/1 is commonly used as an Action Level. Proposals by other groups supporting lower or higher Action Levels have failed, largely due to paucity of information supporting any particular level of indoor radon. The authors' studies have compared indoor radon for zip code and county size areas with parameters such as geology, precipitation and home construction. Their attempts to verify the relative levels of lung cancer using US-EPA estimates of radon-vs-cancer have not been supportive of the EPA risk estimates. In general, when they compare the number of lung cancer cases in particular geological or geographical areas with the indoor radon levels in that area, they find the EPA predicted number of lung cancer cases to exceed the total number of lung cancer cases from all causes. Comparisons show a correlation between the incidence of lung cancer and indoor radon, but the level of risk is about 1/10 that proposed by the US-EPA. Evidently the assumptions used in their studies are flawed. Even though they find lower risk estimates using many counties in several states, fundamental flaws must be present in this type of investigation. Care must be taken in presenting health risks to the general population in cases, such as in indoor radon, where field data do not support risk estimates obtained by other means

Indoor radon levels in Riyadh city dwellings

International Nuclear Information System (INIS)

Alghamdi, Abdulrahman S.; Khalid, Aleissa; Ghazi, Alzeer

2008-01-01

Full text: Building materials used for construction of houses represent a major source of indoor radon. In this investigation, indoor radon concentrations are found to vary substantially among the different building materials, ventilation, cooling and heating systems used. This paper presents the effects of these factors on the radon concentration in Riyadh city dwellings. The measurements were obtained by using a passive integrating ionization system with an E-Perm Electret ion chamber. The study covered more than 700 houses and apartments, which were selected to cover the most common type of houses. The concentration range was found to be 1.02 to 196 Bq.m -3 , with an average value of 17.5 ± 3 Bq.m -3 . The results show that the radon concentration is higher in houses where the white bricks, no ventilation systems, plastic paint and Freon air conditioners are used, but relatively lower in houses where the red bricks, window ventilation, and water air conditioner is used. (author)

Health effects of indoor odorants.

Science.gov (United States)

Cone, J E; Shusterman, D

1991-11-01

People assess the quality of the air indoors primarily on the basis of its odors and on their perception of associated health risk. The major current contributors to indoor odorants are human occupant odors (body odor), environmental tobacco smoke, volatile building materials, bio-odorants (particularly mold and animal-derived materials), air fresheners, deodorants, and perfumes. These are most often present as complex mixtures, making measurement of the total odorant problem difficult. There is no current method of measuring human body odor, other than by human panel studies of expert judges of air quality. Human body odors have been quantitated in terms of the "olf" which is the amount of air pollution produced by the average person. Another quantitative unit of odorants is the "decipol," which is the perceived level of pollution produced by the average human ventilated by 10 L/sec of unpolluted air or its equivalent level of dissatisfaction from nonhuman air pollutants. The standard regulatory approach, focusing on individual constituents or chemicals, is not likely to be successful in adequately controlling odorants in indoor air. Besides the current approach of setting minimum ventilation standards to prevent health effects due to indoor air pollution, a standard based on the olf or decipol unit might be more efficacious as well as simpler to measure.

Immediate impact of smoke-free laws on indoor air quality.

Science.gov (United States)

Lee, Kiyoung; Hahn, Ellen J; Riker, Carol; Head, Sara; Seithers, Peggy

2007-09-01

Smoke-free laws significantly impact indoor air quality. However, the temporal effects of these laws on indoor air pollution have not been determined. This paper assesses the temporal impact of one smoke-free law on indoor air quality. This quasi-experimental study compared the indoor air quality of nine hospitality venues and one bingo hall in Georgetown, Kentucky, before and after implementation of a 100% smoke-free workplace law. We made real-time measurements of particulate matter with 2.5 microm aerodynamic diameter or smaller (PM2.5). Among the nine Georgetown hospitality venues, the average indoor PM2.5 concentration was 84 microg/m3 before the law took effect. The average indoor PM2.5 concentrations in nine compliant venues significantly decreased to 18 microg/m3 one week after the law took effect. Three venues having 82 microg/m3 before the law had significantly lower levels from the first day the law was implemented, and the low level was maintained. Compliance with the law is critical to achieving clean indoor air. Indoor air pollution in the bingo hall was not reduced until the establishment decided to comply with the law. The smoke-free law showed immediate impact on indoor air quality.

Contribution of 222Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

International Nuclear Information System (INIS)

Song Gang; Wang Xinming; Chen Diyun; Chen Yongheng

2011-01-01

This study investigates the contribution of radon ( 222 Rn)-bearing water to indoor 222 Rn in thermal baths. The 222 Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM 10 and PM 2.5 ) and carbon dioxide (CO 2 ) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m -3 of 222 Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which 222 Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average 222 Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor 222 Rn levels were influenced by the 222 Rn concentrations in the hot spring water and the bathing times. The average 222 Rn transfer coefficients from water to air were 6.2 x 10 -4 -4.1 x 10 -3 . The 24-h average levels of CO 2 and PM 10 in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM 2.5 . Radon and PM 10 levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: → 222 Rn-bearing water is the main contributor to indoor radon in hot spring hotel. → The PM 2.5 and CO 2 are also the main indoor pollutants in the hotel rooms. → Higher radon and PM levels might have significant negative health effects to human. → The radon transfer coefficients are consistent with the published data.

Indoor Air Quality in Brazilian Universities

Directory of Open Access Journals (Sweden)

Sonia R. Jurado

2014-07-01

Full Text Available This study evaluated the indoor air quality in Brazilian universities by comparing thirty air-conditioned (AC (n = 15 and naturally ventilated (NV (n = 15 classrooms. The parameters of interest were indoor carbon dioxide (CO2, temperature, relative humidity (RH, wind speed, viable mold, and airborne dust levels. The NV rooms had larger concentration of mold than the AC rooms (1001.30 ± 125.16 and 367.00 ± 88.13 cfu/m3, respectively. The average indoor airborne dust concentration exceeded the Brazilian standards (<80 µg/m3 in both NV and AC classrooms. The levels of CO2 in the AC rooms were significantly different from the NV rooms (1433.62 ± 252.80 and 520.12 ± 37.25 ppm, respectively. The indoor air quality in Brazilian university classrooms affects the health of students. Therefore, indoor air pollution needs to be considered as an important public health problem.

Reducing Indoor Noise Levels Using People's Perception on Greenery

Science.gov (United States)

Mediastika, Christina E.; Binarti, Floriberta

2013-12-01

Employees working in cubicles of open-plan offices in Indonesia were studied in regard to their perception on the ability of indoor greenery to reduce noise levels. Sansevieria trifasciata and Scindapsus sp were used. Each was placed in the cubicle and noise levels were measured without plants, with Sansevieria, and with Scindapsus in place. The meters showed very insignificant difference. However, responses to surveys indicated a perception of lower noise in the presence of greenery. This seemed to be supported by prior knowledge and preconception and may be useful in creating a "quieter" indoor environment.

Differences between Outdoor and Indoor Sound Levels for Open, Tilted, and Closed Windows.

Science.gov (United States)

Locher, Barbara; Piquerez, André; Habermacher, Manuel; Ragettli, Martina; Röösli, Martin; Brink, Mark; Cajochen, Christian; Vienneau, Danielle; Foraster, Maria; Müller, Uwe; Wunderli, Jean Marc

2018-01-18

Noise exposure prediction models for health effect studies normally estimate free field exposure levels outside. However, to assess the noise exposure inside dwellings, an estimate of indoor sound levels is necessary. To date, little field data is available about the difference between indoor and outdoor noise levels and factors affecting the damping of outside noise. This is a major cause of uncertainty in indoor noise exposure prediction and may lead to exposure misclassification in health assessments. This study aims to determine sound level differences between the indoors and the outdoors for different window positions and how this sound damping is related to building characteristics. For this purpose, measurements were carried out at home in a sample of 102 Swiss residents exposed to road traffic noise. Sound pressure level recordings were performed outdoors and indoors, in the living room and in the bedroom. Three scenarios-of open, tilted, and closed windows-were recorded for three minutes each. For each situation, data on additional parameters such as the orientation towards the source, floor, and room, as well as sound insulation characteristics were collected. On that basis, linear regression models were established. The median outdoor-indoor sound level differences were of 10 dB(A) for open, 16 dB(A) for tilted, and 28 dB(A) for closed windows. For open and tilted windows, the most relevant parameters affecting the outdoor-indoor differences were the position of the window, the type and volume of the room, and the age of the building. For closed windows, the relevant parameters were the sound level outside, the material of the window frame, the existence of window gaskets, and the number of windows.

Reconstruction of national distribution of indoor radon concentration in Russia using results of regional indoor radon measurement programs

International Nuclear Information System (INIS)

Yarmoshenko, I.; Malinovsky, G.; Vasilyev, A.; Zhukovsky, M.

2015-01-01

The aim of the paper is a reconstruction of the national distribution and estimation of the arithmetic average indoor radon concentration in Russia using the data of official annual 4-DOZ reports. Annual 4-DOZ reports summarize results of radiation measurements in 83 regions of Russian Federation. Information on more than 400 000 indoor radon measurements includes the average indoor radon isotopes equilibrium equivalent concentration (EEC) and number of measurements by regions and by three main types of houses: wooden, one-storey non-wooden, and multi-storey non-wooden houses. To reconstruct the national distribution, all-Russian model sample was generated by integration of sub-samples created using the results of each annual regional program of indoor radon measurements in each type of buildings. According to indoor radon concentration distribution reconstruction, all-Russian average indoor radon concentration is 48 Bq/m"3. Average indoor radon concentration by region ranges from 12 to 207 Bq/m"3. The 95-th percentile of the distribution is reached at indoor radon concentration 160 Bq/m"3. - Highlights: • Reconstruction of indoor radon concentration distribution in Russia was carried out. • Data of official annual 4-DOZ reports were used. • All-Russian average indoor radon concentration is 48 Bq/m"3. • The 95-th percentile is 160 Bq/m"3.

Seasonal and Spatial Variations of Indoor Pollen in a Hospital

Directory of Open Access Journals (Sweden)

Santiago Fernández-Rodríguez

2009-12-01

Full Text Available The airborne indoor pollen in a hospital of Badajoz (Spain was monitored over two years using a personal Burkard sampler. The air was sampled in four places indoors—one closed room and one open ward on each of the ground and the third floors—and one place outdoors at the entrance to the hospital. The results were compared with data from a continuous volumetric sampler. While 32 pollen types were identified, nearly 75% of the total counts were represented by just five of them. These were: Quercus, Cupressaceae, Poaceae, Olea, and Plantago. The average indoor concentration was 25.2 grains/m3, and the average indoor/outdoor ratio was 0.27. A strong seasonal pattern was found, with the highest levels in spring and winter, and the indoor concentrations were correlated with the outdoor one. Indoor air movement led to great homogeneity in the airborne pollen presence: the indoor results were not influenced by whether or not the room was isolated, the floor level, or the number of people in or transiting the site during sampling. The presence of ornamental vegetation in the area surrounding the building affected the indoor counts directly as sources of the pollen.

Differences between Outdoor and Indoor Sound Levels for Open, Tilted, and Closed Windows

Science.gov (United States)

Locher, Barbara; Piquerez, André; Habermacher, Manuel; Ragettli, Martina; Cajochen, Christian; Vienneau, Danielle; Foraster, Maria; Müller, Uwe; Wunderli, Jean Marc

2018-01-01

Noise exposure prediction models for health effect studies normally estimate free field exposure levels outside. However, to assess the noise exposure inside dwellings, an estimate of indoor sound levels is necessary. To date, little field data is available about the difference between indoor and outdoor noise levels and factors affecting the damping of outside noise. This is a major cause of uncertainty in indoor noise exposure prediction and may lead to exposure misclassification in health assessments. This study aims to determine sound level differences between the indoors and the outdoors for different window positions and how this sound damping is related to building characteristics. For this purpose, measurements were carried out at home in a sample of 102 Swiss residents exposed to road traffic noise. Sound pressure level recordings were performed outdoors and indoors, in the living room and in the bedroom. Three scenarios—of open, tilted, and closed windows—were recorded for three minutes each. For each situation, data on additional parameters such as the orientation towards the source, floor, and room, as well as sound insulation characteristics were collected. On that basis, linear regression models were established. The median outdoor–indoor sound level differences were of 10 dB(A) for open, 16 dB(A) for tilted, and 28 dB(A) for closed windows. For open and tilted windows, the most relevant parameters affecting the outdoor–indoor differences were the position of the window, the type and volume of the room, and the age of the building. For closed windows, the relevant parameters were the sound level outside, the material of the window frame, the existence of window gaskets, and the number of windows. PMID:29346318

Design and evaluation of representative indoor radon surveys

International Nuclear Information System (INIS)

Csige, I.; Csegzi, S.

2004-01-01

We have developed a procedure to design and evaluate representative indoor radon surveys. The procedure is based on random sampling of a population of houses and careful statistical analysis of measured indoor radon concentrations. The method is designed to estimate the fraction of houses in which annual average 222 Rn activity concentration may exceed a certain reference level. Measurements of annual average indoor 222 Rn activity concentration were done in sleeping rooms at pillow level using etched track type radon detectors. We applied the above procedure in an old fashioned village and in a fast developing small city in Transylvania, Romania. In the village almost all houses were single floor wooden made houses without cellar built with traditional technology on a geologically uniform area. The distribution of indoor 222 Rn activity concentration in a sample of 115 houses can almost perfectly be fitted with log-normal probability density function. The correlation coefficient of linear fitting on linearized scales was k = -0.9980. The percentages of houses expected to have annual average 222 Rn activity concentration higher than 400 Bq m -3 is less than 1 %, and of those higher than 600 Bq m -3 can be estimated to be around 0.1 %. The small city, on the other hand lies on a geologically inhomogeneous area, and house construction technology has also changed dramatically in past decades. The resulting distribution of measured indoor 222 Rn activity concentration in a sample of 116 houses cannot be fitted with any simple probability density function. Therefore the prediction of the fraction of houses in which the annual average 222 Rn activity concentration may exceed a certain reference level could not be done adequately. With certain assumptions we estimated that the percentages of houses expected to have annual average 222 Rn activity concentration higher than 400 Bq m -3 is between 3 and 7 %, and of those higher than 600 Bq m -3 can be estimated to be between

Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings.

Science.gov (United States)

Carneiro, G L; Braz, D; de Jesus, E F; Santos, S M; Cardoso, K; Hecht, A A; Dias da Cunha, Moore K

2013-06-01

The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.

Continuous weeklong measurements of indoor particle levels in a Minnesota Tribal Casino Resort.

Science.gov (United States)

Zhou, Zheng; Bohac, David; Boyle, Raymond G

2016-08-24

Secondhand smoke (SHS) exposure for workers and patrons in hospitality venues is a persistent and significant public health concern. We designed this study to provide a comprehensive assessment of SHS exposure inside an Indian Tribal Casino in Minnesota. Real-time fine particulate matter (PM2.5) concentrations were measured at multiple locations for up to 7 days. The field monitoring provided information on the day of week and time of day variation of SHS exposure, as well as comparisons between smoking and non-smoking areas. Indoor PM2.5 level was nearly 13 times the concurrent outdoor PM2.5 level. Gaming floor hourly PM2.5 level was highest on Saturday night, averaged at 62.9 μg/m(3). Highest PM2.5 concentration was observed in smoking-permitted employee break room, reaching 600 μg/m(3). PM2.5 readings in non-smoking sections exhibited same temporal pattern as the readings in smoking sections. The results show that indoor concentration of PM2.5 is substantially higher than the outdoor level, posing health risks to casino workers and patrons. SHS can migrate into adjacent non-smoking areas very quickly. The casino's ventilation system did not fully eliminate SHS. A completely smoke-free casino would be the only way to fully protect non-smoking patrons and employees from the dangers of tobacco smoke.

Study of indoor radon levels in some radioactive areas of Himachal Pradesh: an inter-comparison of active and passive techniques

International Nuclear Information System (INIS)

Bajwa, B.S.; Singh, S.; Sharma, N.; Virk, H.S.

2006-01-01

Full text of publication follows: Indoor radon levels measurements were carried using both the active and passive techniques in the dwellings of some villages, known to be located in the vicinity of uranium mineralized zones of Hamirpur district, Himachal Pradesh. Even in the passive technique using Solid State Nuclear Track Detectors (S.S.N.T.D.), both the bare-slide and twin chamber dosemeter cup modes were utilized. An attempt has also been made to assess the levels of the indoor radon in these dwellings and inhalation dose rates of the population living in these villages. The average value of radon concentration levels using the bare-slide mode varies from 109.0 to 741.5 Bq/m3 in these dwellings, where as the maximum radon level using the twin cup dosemeter technique was found to be 140.3 Bq/m3. As usual the radon concentrations were found to be varying with seasonal changes, building materials etc. The radon survey in the dwellings of these villages has also been carried out using the Alpha- Guard technique, which is based on the pulse ionization chamber. The indoor radon concentration levels measured using the active technique of Alpha Guard have been found to be quite different from those measured in these dwellings by the passive technique of S.S.N.T.D.; indicating the importance of the S.S.N.T.D. in the long-term integrated measurement of the indoor radon levels in the dwellings. (authors)

Study of indoor radon levels in some radioactive areas of Himachal Pradesh: an inter-comparison of active and passive techniques

International Nuclear Information System (INIS)

Bajwa, B.S.; Singh, S.; Sharma, N.; Virk, H.S.

2006-01-01

Full text of publication follows: Indoor radon levels measurements were carried using both the active and passive techniques in the dwellings of some villages, known to be located in the vicinity of uranium mineralized zones of Hamirpur district, Himachal Pradesh. Even in the passive technique using S.S.N.T.D., both the bare -slide and twin chamber dosemeter cup modes were utilized. An attempt has also been made to assess the levels of the indoor radon in these dwellings and inhalation dose rates of the population living in these villages. The average value of radon concentration levels using the bare-slide mode varies from 109.0 to 741.5 Bq/m3 in these dwellings, where as the maximum radon level using the twin cup dosemeter technique was found to be 140.3 Bq/m3. As usual the radon concentrations were found to be varying with seasonal changes, building materials etc. The radon survey in the dwellings of these villages has also been carried out using the Alpha-Guard technique, which is based on the pulse ionization chamber. The indoor radon concentration levels measured using the active technique of Alpha Guard have been found to be quite different from those measured in these dwellings by the passive technique of S.S.N.T.D.; indicating the importance of the S.S.N.T.D. in the long -term integrated measurement of the indoor radon levels in the dwellings. (authors)

Contribution of {sup 222}Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

Energy Technology Data Exchange (ETDEWEB)

Song Gang, E-mail: songg2005@126.co [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China); Wang Xinming [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Diyun; Chen Yongheng [School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006 (China)

2011-04-15

This study investigates the contribution of radon ({sup 222}Rn)-bearing water to indoor {sup 222}Rn in thermal baths. The {sup 222}Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM{sub 10} and PM{sub 2.5}) and carbon dioxide (CO{sub 2}) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m{sup -3} of {sup 222}Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which {sup 222}Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average {sup 222}Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor {sup 222}Rn levels were influenced by the {sup 222}Rn concentrations in the hot spring water and the bathing times. The average {sup 222}Rn transfer coefficients from water to air were 6.2 x 10{sup -4}-4.1 x 10{sup -3}. The 24-h average levels of CO{sub 2} and PM{sub 10} in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM{sub 2.5}. Radon and PM{sub 10} levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. - Highlights: {yields} {sup 222}Rn-bearing water is the main contributor to indoor radon in hot spring hotel. {yields} The PM{sub 2.5} and CO{sub 2} are also the main indoor pollutants in the hotel rooms. {yields} Higher radon and PM levels might have significant negative health effects to human. {yields} The radon transfer coefficients are consistent with the published data.

Assement on level of indoor air quality at kindergartens in Ampang ...

African Journals Online (AJOL)

This study identify the air pollutant that occurs in the kindergartens, to measure the level of indoor air quality and also to analyze the association between indoor air quality patterns with respiratory health symptoms. Three kindergartens were selected based on types of building (single house, terraced 2 floors and refurbished ...

A Comprehensive Real-Time Indoor Air-Quality Level Indicator

Directory of Open Access Journals (Sweden)

Jungho Kang

2016-09-01

Full Text Available The growing concern about Indoor Air-Quality has accelerated the development of small, low-cost air-quality monitoring systems. These systems are capable of monitoring various indoor air pollutants in real time, notifying users about the current air-quality status and gathering the information to the central server. However, most Internet of Things (IoT-based air-quality monitoring systems numerically present the sensed value per pollutant, making it difficult for general users to identify how polluted the air is. Therefore, in this paper, we first introduce a tiny air-quality monitoring system that we developed and, based on the system, we also test the applicability of the comprehensive Air-Quality Index (AQI, which is widely used all over the world, in terms of its capacity for a comprehensive indoor air-quality indication. We also develop design considerations for an IoT-based air-quality monitoring system and propose a real-time comprehensive indoor air-quality level indication method, which effectively copes with dynamic changes and is efficient in terms of processing and memory overhead.

Natural gamma radiation levels, indoor and water 222RN Concentrations in soil division of Kerio valley, kenya

International Nuclear Information System (INIS)

Nderitu, S.K.; Maina, D.M.; Kinyua, A.M.

2001-01-01

Human beings are constantly exposed to natural radioactivity. This radiation is mainly from natural gamma rays and radon and its decay products. The gamma rays are as a result of the decay of primordial nuclides and their daughter radioactive nuclides present in the earth's crust. Radon is produced from the decay of 226 Ra and it diffuses to the indoor environment through cracks on the floor or from building materials containing radium and hence radon problem is mainly indoors. In Kenya, some parts have been identified as having high gamma radiation causing exposure to the public. These areas include Mrima Hill (Kwale), Homa Bay, Bufayo, Weast Pokot, Kitui, Nanyuki, Kerio Valley and Tura. It is therefore necessary to carry out studies on the levels of radiation and determine whether they are within safe limits. Kerio valley, which is the area of study in this work, has been identified as one of the areas with uranium traces associated with fluorite mineralisation. In this study an assessment of the natural radiation levels in this area was carried out and in addition the radon concentrations indoor as well in water that the public is exposed were determined. To measure the radiation levels, soil samples were collected from the area of study, Kerio valley, and analysed for gamma levels using gamma spectroscopy technique. Indoor 222 Rn and radon in water concentrations were measured using the E-perm system. The activity concentrations of the radionuclides present, the doses as well as the annual effective dose equivalents were calculated for the soils using conversion factors adopted from the UNSCEAR (1988 and 1993) reports. Similarly, the dose equivalents and the annual effective doses for 222 Rn concentrations were evaluated. For natural gamma radiation 74 samples were analysed. The soil samples yielded activity concentrations ranging from 194.54??2.89 to 995.77??5.48 Bq Kg-1 for 40 K, 17.04??0.43 to 122.4??0.94 Bq Kg-1 for 232 Th which was evaluated from the 212

Indoor radon monitoring in the Mandi district of Himachal Pradesh, India, for health hazard assessment

International Nuclear Information System (INIS)

Kumar, G.; Kumar, A.; Walia, V.; Kumar, M.; Tuccu, M.A.; Prasher, S.

2016-01-01

In the present study, indoor radon equilibrium equivalent concentration monitoring was carried out using Solid-State Nuclear Track Detectors in some residential areas of the Mandi district, Himachal Pradesh, India. The average value of the indoor radon equilibrium equivalent concentration in the study area was found to be 94 Bq m -3 , with an annual effective dose of 1.61 mSv. The average value of the indoor radon equilibrium equivalent concentration in the studied areas was found to be higher than the world average indoor radon value of 40 Bq m -3 but lower than the value of the action level 300 Bq m -3 , except for two locations. (authors)

Reply to "Can the levels of Can f 1 in indoor environments be evaluated without considering passive transport of allergen indoors?"

NARCIS (Netherlands)

Krop, E.J.M.; Vredegoor, D.W.; Chapman, M.D.; Willemse, A.; Heederik, D.J.J.

2013-01-01

Response to Liccardi G, Salzillo A, Piccolo A, D’Amato M, D’Amato G. Can the levels of Can f 1 in indoor environments be evaluated without considering passive transport of allergen indoors? J Allergy Clin Immunol 2013;131:1258-9.

[Indoor volatile organic compounds: concentrations, sources, variation factors].

Science.gov (United States)

Palot, A; Charpin-Kadouch, C; Ercoli, J; Charpin, D

2008-06-01

Volatile organic compounds (V.O.C.) are part of urban air pollution and are also generated indoors from cleaning and maintenance products. VOC measurements are, on average, 10 times higher within homes than outside. Results of the national survey led by the Observatoire National de la Qualité de l'Air Intérieur demonstrated that up to 25% of French homes have very high or high concentrations of VOC. Indoor levels depend mainly on indoor sources. Aldehydes are included in many everyday life products. VOC originate from various household decorating and cleaning products. Some products are less detrimental to the environment and health and have special labelling. Indoor VOC levels also depend on the rate of air exchange and on household characteristics such as indoor temperature and humidity, age of the building, presence of smokers, and communication with a garage. The public may participate in maintaining good indoor air quality and the authorities should also improve regulations. VOC are part of everyday air pollution. Their sources and concentrations should be better monitored.

Continuous weeklong measurements of indoor particle levels in a Minnesota Tribal Casino Resort

Directory of Open Access Journals (Sweden)

Zheng Zhou

2016-08-01

Full Text Available Abstract Background Secondhand smoke (SHS exposure for workers and patrons in hospitality venues is a persistent and significant public health concern. We designed this study to provide a comprehensive assessment of SHS exposure inside an Indian Tribal Casino in Minnesota. Methods Real-time fine particulate matter (PM2.5 concentrations were measured at multiple locations for up to 7 days. The field monitoring provided information on the day of week and time of day variation of SHS exposure, as well as comparisons between smoking and non-smoking areas. Results Indoor PM2.5 level was nearly 13 times the concurrent outdoor PM2.5 level. Gaming floor hourly PM2.5 level was highest on Saturday night, averaged at 62.9 μg/m3. Highest PM2.5 concentration was observed in smoking-permitted employee break room, reaching 600 μg/m3. PM2.5 readings in non-smoking sections exhibited same temporal pattern as the readings in smoking sections. Conclusions The results show that indoor concentration of PM2.5 is substantially higher than the outdoor level, posing health risks to casino workers and patrons. SHS can migrate into adjacent non-smoking areas very quickly. The casino’s ventilation system did not fully eliminate SHS. A completely smoke-free casino would be the only way to fully protect non-smoking patrons and employees from the dangers of tobacco smoke.

Application of a radon model to explain indoor radon levels in a Swedish house

CERN Document Server

Font, L; Jönsson, G; Enge, W; Ghose, R

1999-01-01

Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75+-30 and 200+-80 Bq m sup - sup 3...

Soil as a source of indoor 220Rn

International Nuclear Information System (INIS)

Li, Y.; Schery, S.D.; Turk, B.

1992-01-01

Two suggestions for sources of indoor 220Rn (thoron) have appeared in the literature: (1) building materials and outside air, and (2) soil beneath the house. Due to the difficulty of 220Rn measurement and limited data, both suggestions lack sufficient supporting evidence. We have investigated sources of indoor 220Rn in seven occupied houses in northern New Mexico, U.S. A two-filter system was used to measure indoor 220Rn levels continuously, and 220Rn progeny were measured with single filters and specialized alpha-track detectors. The amount of 220Rn entry from soil was curtailed by cutting off soil gas flow to the indoor air with subfloor depressurization mitigation systems. Four of the houses showed significant reductions in 220Rn with mitigation systems on. The average effect for these houses was to reduce indoor 220Rn levels by 70%. The other three houses had no clear reductions but in one of these houses, the mitigation system was not effective for stopping soil gas flow. Our results provide some of the most clear evidence to date supporting soil as an important source of indoor 220Rn

Indoor radon survey in dwellings of some regions in Yemen

Energy Technology Data Exchange (ETDEWEB)

Khayrat, A.H. E-mail: akhayrat@yahoo.com; Al-Jarallah, M.I.; Fazal-ur-Rehman, X.; Abu-Jarad, F

2003-06-01

Indoor radon survey in a total of 241 dwellings, distributed in some regions of Yemen was performed, using CR-39 based radon monitors. The objective of this radon survey is to get representative indoor radon data of three regions, namely Dhamar, Taiz and Hodeidah, situated at different altitudes above sea level. The radon concentrations varied from 3 to 270 Bq m{sup -3} with an average of 42 Bq m{sup -3}. It was found that the average radon concentration in the surveyed areas increases with altitudes. The highest average radon concentration of 59 Bq m{sup -3} was found in Dhamar city while the lowest average concentration of 8 Bq m{sup -3} was found in Hodeidah city.

A new coating material for reducing indoor radon level

International Nuclear Information System (INIS)

Zhuo, W.; Tokonami, S.; Ichitsubo, H.; Yamada, Y.; Yamada, Y.

2002-01-01

In order to mitigate indoor radon level, a new fast-setting, solvent-free, polyurethane-based coating material was developed. The permeability of radon gas in the new material was estimated with a simple radon permeation test system set up in this study. It was found that the permeation velocity depended on the thickness of the coating material, and a thickness of 2.0 mm of the coating material seems sufficient for preventing radon permeation. The permeability of radon in the coating material was estimated to be (2.2± 0.8)x10 -10 m 2 ·s -1 for a thickness of about 1.0 mm. The value is much lower than those reported for membrane materials and caulking compounds. For its performance test, the coating material was used in an existing room with high radon level. By spraying a thickness of 1.5 mm of the material, the indoor radon level reduced by about 80%

Indoor pollutant levels from the use of unvented natural gas fireplaces in Boulder, Colorado.

Science.gov (United States)

Dutton, S J; Hannigan, M P; Miller, S L

2001-12-01

High CO and NO2 concentrations have been documented in homes with unvented combustion appliances, such as natural gas fireplaces. In addition, polycyclic aromatic hydrocarbons (PAH) are emitted from incomplete natural gas combustion. The acute health risks of CO and NO2 exposure have been well established for the general population and for certain high-risk groups, including infants, the elderly, and people with heart disease or asthma. Health effects from PAH exposure are less well known, but may include increased risk of cancer. We monitored CO emissions during the operation of unvented natural gas fireplaces in two residences in Boulder, CO, at various times between 1997 and 2000. During 1999, we expanded our tests to include measurements of NO2 and PAH. Results show significant pollutant accumulation indoors when the fireplaces were used for extended periods of time. In one case, CO concentrations greater than 100 ppm accumulated in under 2 hr of operation; a person at rest exposed for 10 hr to this environment would get a mild case of CO poisoning with an estimated 10% carboxyhemoglobin level. Appreciable NO2 concentrations were also detected, with a 4-hr time average reaching 0.36 ppm. Similar time-average total PAH concentrations reached 35 ng/m3. The results of this study provide preliminary insights to potential indoor air quality problems in homes operating unvented natural gas fireplaces in Boulder.

Application of a radon model to explain indoor radon levels in a Swedish house

International Nuclear Information System (INIS)

Font, LL.; Baixeras, C.; Joensson, G.; Enge, W.; Ghose, R.

1999-01-01

Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75±30 and 200±80 Bq m -3 . Results of the model adaptation to the house indicate that soil constitutes the most relevant radon source in both parts of the house. The radon concentration values predicted by the model indoors fall into the same range as the experimental results

Slovak Republic, indoor measurements

International Nuclear Information System (INIS)

Vicanova, M.; Daniel, S.

2006-01-01

In this report the annual average effective doses from indoor radon exposure were calculated for each district of Slovakia. The population-weighted arithmetic mean of indoor radon concentration was calculated for every district considering different types of houses.

Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China.

Science.gov (United States)

Song, Gang; Wang, Xinming; Chen, Diyun; Chen, Yongheng

2011-04-01

This study investigates the contribution of radon ((222)Rn)-bearing water to indoor (222)Rn in thermal baths. The (222)Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM(10) and PM(2.5)) and carbon dioxide (CO(2)) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m(-3) of (222)Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which (222)Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average (222)Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor (222)Rn levels were influenced by the (222)Rn concentrations in the hot spring water and the bathing times. The average (222)Rn transfer coefficients from water to air were 6.2 × 10(-4)-4.1 × 10(-3). The 24-h average levels of CO(2) and PM(10) in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM(2.5). Radon and PM(10) levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants. Copyright © 2011 Elsevier Ltd. All rights reserved.

Indoor air quality/air infiltration in selected low-energy houses

International Nuclear Information System (INIS)

Shohl Wagner, B.; Phillips, T.J.

1984-01-01

Indoor air quality and air infiltration were measured in 16 low-energy California houses. Eleven has gas stoves; all had average infiltration rates of 0.5 h -1 of less, recent construction dates, low natural ventilation, and no mechanical ventilation. HCHO levels in 12 houses and radon-222 and NO 2 levels in all houses were measured using passive monitors. Blower door measurements and local weather data were used to calculate average infiltration rates during the monitoring period. Correlation of pollutant concentrations with infiltration rates and building characteristics indicate that new houses with average heating season infiltration rates less than 0.5 h -1 do not necessarily experience poor indoor air quality, HCHO and radon-222 levels in new houses exceeded the lowest currently proposed standards or guidelines, and much higher levels probably exist elsewhere. Therefore, some strategy for identifying 'problem' houses is needed. We recommend an approach for future research in this area. (Author)

A study of indoor radon levels and radon effective dose in dwellings of some cities of Gezira State in Sudan

Directory of Open Access Journals (Sweden)

Elzain Abd-Elmoniem Ahmed

2014-01-01

Full Text Available Exposure to natural sources of radiation, especially 222Rn and its short-lived daughter products has become an important issue throughout the world because sustained exposure of humans to indoor radon may cause lung cancer. The indoor radon concentration level and radon effective dose rate were carried out in the dwellings of Medani, El Hosh, Elmanagil, Haj Abd Allah, and Wad Almahi cities, Gezira State - Central Sudan, in 393 measurements, using passive integrated solid-state nuclear track devices containing allyl diglycol carbonate plastic detectors. The radon concentration in the corresponding dwellings was found to vary from (57 ± 8 Bq/m3 in Medani to 41 ± 9 Bq/m3 in Wad Almahi, with an average of 49 ± 10 Bq/m3. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the annual effective dose rate from 222Rn in the studied dwellings ranges from 1.05 to 1.43 mSv per year and the relative lung cancer risk for radon exposure was 1.044%. In this research, we also correlated the relationship of radon concentration and building age. From our study, it is clear that the annual effective dose rate is larger than the “normal” background level as quoted by UNSCEAR, lower than the recommended action level of ICRP, and less than the maximum permissible dose defined by the International Atomic Energy Agency.

Evaluations of average level spacings

International Nuclear Information System (INIS)

Liou, H.I.

1980-01-01

The average level spacing for highly excited nuclei is a key parameter in cross section formulas based on statistical nuclear models, and also plays an important role in determining many physics quantities. Various methods to evaluate average level spacings are reviewed. Because of the finite experimental resolution, to detect a complete sequence of levels without mixing other parities is extremely difficult, if not totally impossible. Most methods derive the average level spacings by applying a fit, with different degrees of generality, to the truncated Porter-Thomas distribution for reduced neutron widths. A method that tests both distributions of level widths and positions is discussed extensivey with an example of 168 Er data. 19 figures, 2 tables

Procedure manual for the estimation of average indoor radon-daughter concentrations using the radon grab-sampling method

International Nuclear Information System (INIS)

George, J.L.

1986-04-01

The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center to provide standardization, calibration, comparability, verification of data, quality assurance, and cost-effectiveness for the measurement requirements of DOE remedial action programs. One of the remedial-action measurement needs is the estimation of average indoor radon-daughter concentration. One method for accomplishing such estimations in support of DOE remedial action programs is the radon grab-sampling method. This manual describes procedures for radon grab sampling, with the application specifically directed to the estimation of average indoor radon-daughter concentration (RDC) in highly ventilated structures. This particular application of the measurement method is for cases where RDC estimates derived from long-term integrated measurements under occupied conditions are below the standard and where the structure being evaluated is considered to be highly ventilated. The radon grab-sampling method requires that sampling be conducted under standard maximized conditions. Briefly, the procedure for radon grab sampling involves the following steps: selection of sampling and counting equipment; sample acquisition and processing, including data reduction; calibration of equipment, including provisions to correct for pressure effects when sampling at various elevations; and incorporation of quality-control and assurance measures. This manual describes each of the above steps in detail and presents an example of a step-by-step radon grab-sampling procedure using a scintillation cell

Indoor gamma radiation monitoring In Rawalpindi, Pakistan using TLD100

International Nuclear Information System (INIS)

Azam, Sana; Tufail, Muhammad; Sohail, Muhammad

2008-01-01

Full text: Natural radioactivity originates from extraterrestrial sources as well as from radioactive elements in earth's crust. The amount of radioactivity varies from place to place and with altitude. The aim of this study was to observe the indoor radiation level in Rawalpindi using TLD. For this purpose LiF:Mg:Ti (TLD100) chips were used. Chips were annealed and then calibrated using different sources and the calibration factor obtained by using Cs137 source was selected for dose estimation. Its value was 0.1403 μGy/TL response. Rawalpindi categorized into six regions. In each region, 5 cemented houses were selected and TLD 100 chips were placed at a distance of 0.5 m from ground the level. Chips were properly covered to protect them from ultraviolet light and moisture and were placed for three months. The average annual indoor dose rate for Rawalpindi was estimated to be 392.105μGy/yr and average dose to be 97.65μGy. Therefore, the effective dose for population of Rawalpindi from indoor gamma radiation was estimated to be 313.68μSv/yr using an indoor occupancy factor of 80%. (author)

Indoor radon measurements in Mexico City

Energy Technology Data Exchange (ETDEWEB)

Espinosa, G. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20364, 01000 Mexico, D.F. (Mexico)], E-mail: espinosa@fisica.unam.mx; Golzarri, J.I. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20364, 01000 Mexico, D.F. (Mexico); Bogard, J. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6480 (United States); Gaso, I. [Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, 11801 Mexico, D.F. (Mexico); Ponciano, G. [Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico); Mena, M.; Segovia, N. [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico, D.F. (Mexico)

2008-08-15

Mexico City is one of the most populated cities in the world with almost 22 million inhabitants, located at an altitude of 2200 m. The old city was founded on an ancient lake and the zone is known by its high seismicity; indoor radon determination is an important public health issue. In this paper the data of indoor radon levels in Mexico City, measured independently by two research groups, both using Nuclear Track Detector systems but different methodologies, are correlated. The measurements were done during similar exposure periods of time, at family houses from the political administrative regions of the city. The results indicate a correlation coefficient between the two sets of data of R=0.886. Most of the differences between the two sets of data are inherent to houses having extreme (very high or very low indoor radon) included in the statistics of each group. The total average indoor radon found in Mexico City considering the two methods was 87Bqm{sup -3}.

Assessment and predictor determination of indoor aldehyde levels in Paris newborn babies' homes.

Science.gov (United States)

Dassonville, C; Demattei, C; Laurent, A-M; Le Moullec, Y; Seta, N; Momas, I

2009-08-01

Exposure to indoor chemical air pollutants expected to be potentially involved in allergic respiratory diseases in infants is poorly documented. A specific environmental investigation included in a birth cohort study was carried out to first assess indoor airborne aldehyde levels, using passive devices and their variability within 1 year (1, 6, 9 and 12 months) in the bedroom of 196 Paris infants, and second, to identify predictors for aldehyde concentrations using interviewer administered questionnaires about housing factors. Comfort parameters and carbon dioxide levels were measured simultaneously. Aldehydes were detected in almost all dwellings and geometric mean levels (geometric standard deviation) at the first visit were respectively for formaldehyde, acetaldehyde, hexanal, and pentanal 19.4 (1.7) microg/m(3), 8.9 (1.8) microg/m(3), 25.3 (3.1) microg/m(3), 3.7 (2.3) microg/m(3), consistent with earlier published results. Generalized Estimating Equation multivariate analyses showed that, apart from comfort parameters, aeration and season, the main indoor aldehyde sources were either continuous (building materials and coverings especially when they were new) or discontinuous (smoking, use of air fresheners and cleaning products, DIY etc...). Finally, the data collected by questionnaires should be sufficient to enable us to classify each infant in our cohort study according to his/her degree of exposure to the main aldehydes. This analysis contributed to document indoor aldehyde levels in Parisian homes and to identify factors determining these levels. In the major part of newborn babies' homes, indoor formaldehyde levels were above the guideline value of 10 microg/m(3) proposed by the French Agency for Environmental and Occupational Health Safety for long-term exposure. Given this result, it is essential to study the health impact of exposure to aldehydes especially formaldehyde on the incidence of respiratory and allergic symptoms, particularly during the

Geologic influence on indoor radon concentrations and gamma radiation levels in Norwegian dwellings

Energy Technology Data Exchange (ETDEWEB)

Sundal, Aud Venche

2003-09-01

Indoor radon levels in 1618 Norwegian dwellings located in different geological settings were compared with geological information in order to determine potential correlations between geological factors and indoor radon concentrations in Norway and to establish whether geological information is useful in radon risk analysis. In two geographically limited areas, Kinsarvik and Fen, detailed geological and geochemical investigations were carried out in order to explain their elevated natural radiation environment. Significant correlations between geology and indoor radon concentrations in Norway are found when the properties of both the bedrock and the overburden are taken into account. Areas of high radon risk in Norway include 1) exposed bedrock with elevated levels of radium (mainly alum shale and granites) and b) highly permeable unconsolidated sediments derived from all rock types (mainly glaciofluvial and fluvial deposits) and moderately permeable sediments containing radium rich rock fragments (mainly basal till). More than 20 % of Norwegian dwellings located in the high-risk areas can be expected to contain radon levels exceeding 200 Bq/m3. The elevated radon risk related to penneable building grounds is illustrated in Kinsarvik where the highly permeable sediments and the large vadose zone underlying the Huse residential area enable the transport of radon from large volumes into the dwellings resulting in enhanced indoor radon concentrations. Subterranean air flows caused by temperature/pressure differences between soil air and atmospheric air and elevations differences within the Huse area are shown to strongly affect the annual variations in indoor radon concentrations. The marked contrasts in radon risk potential between different types of building grounds are clearly illustrated in the Fen area where outcrops of the radium rich Fen carbonatites represent areas of high radon risk while only low levels of both indoor radon concentrations and indoor gamma

Indoor particle levels in small- and medium-sized commercial buildings in California.

Science.gov (United States)

Wu, Xiangmei May; Apte, Michael G; Bennett, Deborah H

2012-11-20

This study monitored indoor and outdoor particle concentrations in 37 small and medium commercial buildings (SMCBs) in California with three buildings sampled on two occasions, resulting in 40 sampling days. Sampled buildings included offices, retail establishments, restaurants, dental offices, and hair salons, among others. Continuous measurements were made for both ultrafine and fine particulate matter as well as black carbon inside and outside of the building. Integrated PM(2.5), PM(2.5-10), and PM(10) samples were also collected inside and outside the building. The majority of the buildings had indoor/outdoor (I/O) particle concentration ratios less than 1.0, indicating that contributions from indoor sources are less than removal of outdoor particles. However, some of the buildings had I/O ratios greater than 1, indicating significant indoor particle sources. This was particularly true of restaurants, hair salons, and dental offices. The infiltration factor was estimated from a regression analysis of indoor and outdoor concentrations for each particle size fraction, finding lower values for ultrafine and coarse particles than for submicrometer particles, as expected. The I/O ratio of black carbon was used as a relative measure of the infiltration factor of particles among buildings, with a geometric mean of 0.62. The contribution of indoor sources to indoor particle levels was estimated for each building.

Normal and seasonally amplified indoor radon levels

International Nuclear Information System (INIS)

Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; King, D.

1995-01-01

Winter and summer indoor radon measurements are reported for 121 houses in Freehold, New Jersey. When presented as winter:summer ratios of indoor radon, the data closely approximate a lognormal distribution. The geometric mean is 1.49. Freehold is located on the fairly flat coastal plain. The winter:summer ratios are believed to represent the norm for regions of the U.S. with cold winters and hot summers. The Freehold data set can be compared to corresponding data sets from other locations to suggest seasonal perturbations of indoor radon arising from unusual causes

CONTRIBUTION TO INDOOR OZONE LEVELS OF AN OZONE GENERATOR

Science.gov (United States)

This report gives results of a study of a commonly used commercially available ozone generator, undertaken to determine its impact on indoor ozone levels. xperiment were conducted in a typical mechanically ventilated office and in a test house. he generated ozone and the in-room ...

Indoor radon and its progeny levels in new type houses in rural area of Hubei

International Nuclear Information System (INIS)

He Quan; Xiong Zhaoxing; He Zuan; Zheng Youqing

1993-01-01

Using Cluster Sampling method, indoor radon of 54 rooms and radon progeny potential alpha-energy concentrations of 200 rooms were measured in the new type brick-concrete 2-storey flats and old type brick-wood single-storey residences in the rural area. Instant and cumulative samplings and measurements were made. The average per capita residential area of the surveyed houses was 28.1 m 2 , clear height 3.6 m. The geometric means of indoor radon concentration were 18.22 Bq.m -3 and 15.93 Bq.m -3 for storied and single-storey buildings, respectively; radon progeny potential alpha-energy concentrations were 2.62 mWL and 2.54 mWL, correspondingly. In storied buildings, the arithmetic mean of indoor cumulative radon concentration was 25.56 Bq.m -3 in summer, and 37.94 Bq.m -3 in winter. The annual effective dose equivalent of radon progeny inhaled indoors and outdoors was 0.80 mSv. (orig.). (6 refs., 1 fig., 5 tabs.)

Implications in estimation of indoor thoron levels: season and ventilation effects

International Nuclear Information System (INIS)

Chauhan, R.P.; Amit Kumar

2015-01-01

The measurement of radon and thoron in dwellings and workplaces are most important for general public health point. Due to short half life of thoron, sometimes its contribution to radiation doses is assumed to be negligible, but their role is important for areas containing higher thorium content in soil and building materials. The thoron levels in dwellings were determined by various SSNTD detector using different cup geometry and dimensions along with bare mode in past at National and International level. These exercises were carried out in dwellings constructed with different building materials, different ventilation rates and seasons. Most of the times the results of radon and thoron levels were found same in spite of having different diffusion length in air due to different half life. This causes increase in uncertainty in measurement of thoron levels in different season and ventilation. Thus the problem of relative variation of thoron levels in different season and ventilation still exist in radiation field. In this work the measurement of indoor thoron levels from some selected dwelling having different ventilation and in different seasons using Pin hole based radon thoron dosimeters are reported. The results show that indoor thoron value is slightly lower in case of dwellings with poor ventilation, which is contrary to the results published in literature. An effort was made to explain the variation of thoron level under different season and ventilation. Some protocol suggestions are also given at the end of this work for future reference to carry out the measurement and mapping of indoor thoron. (author)

Winter-to-winter variations in indoor radon

International Nuclear Information System (INIS)

Mose, D.G.; Mushrush, G.W.; Kline, S.W.

1989-01-01

Indoor radon concentrations in northern Virginia and central Maryland show a strong dependence on weather. Winter tends to be associated with higher than average indoor radon, and summer with lower than average. However, compared to the winter of 1986-1987, the winter of 1987-1988 was warmer and drier. Consequently, winter-to-winter indoor radon decreased by about 25%. This winter-to-winter decrease is unexpectedly large, and simulates winter-to-summer variations that have been reported

Risk evaluation and control strategies for indoor radon: a brief discussion

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1994-01-01

Average risks of death estimated for radon are larger than those for many exposures in the outdoor environment, but similar to some in industrial settings. However, the indoor environment differs in regard to cost, benefit, responsibility, and distribution of risks from the outdoor and occupational settings, where frameworks for setting risk-limiting objectives and strategies have already been developed substantially. This indicates the need to develop a conceptual framework for evaluating risks in the indoor environment, within which the objectives of radon control strategies can be sensibly chosen. Nevertheless, the range of estimated radon risks and of recent radon control strategies suggest near-term elements of any strategy, i.e. accurate and effective public information, as well as reliable monitoring and control capabilities, and a focus on areas where most high residential levels occur. Developing a conceptual framework for evaluating indoor risks will permit the formulation of suitable aims on average indoor exposures and lower exposure situations. (author)

Procedure manual for the estimation of average indoor radon-daughter concentrations using the filtered alpha-track method

International Nuclear Information System (INIS)

George, J.L.

1988-04-01

One of the measurement needs of US Department of Energy (DOE) remedial action programs is the estimation of the annual-average indoor radon-daughter concentration (RDC) in structures. The filtered alpha-track method, using a 1-year exposure period, can be used to accomplish RDC estimations for the DOE remedial action programs. This manual describes the procedure used to obtain filtered alpha-track measurements to derive average RDC estimates from the measurrements. Appropriate quality-assurance and quality-control programs are also presented. The ''prompt'' alpha-track method of exposing monitors for 2 to 6 months during specific periods of the year is also briefly discussed in this manual. However, the prompt alpha-track method has been validated only for use in the Mesa County, Colorado, area. 3 refs., 3 figs

Indoor radon concentration levels, gamma dose rates and impact of geology - A case study in Kotli, State of Azad Jammu and Kashmir, sub-Himalayas, in Pakistan

International Nuclear Information System (INIS)

Iqbal, A.; Shahid Baig, M.; Akram, M.; Qureshi, A.A.

2012-01-01

Inhalation of indoor radon has been recognized as the largest contributor to the total effective dose received by human beings. Indoor radon data were collected from the dwellings lying on the sedimentary rocks (sandstones, siltstones and clays) of the Murree Formation, Nagri Formation, Dhok Pathan Formation, Mirpur conglomerate and surficial deposits of the Kotli area in Azad Jammu and Kashmir, Pakistan. Radon measurements were made using the passive time-integrated method using Kodak CN-85 Solid-State Nuclear Track Detectors. The radon concentration in dwellings varied from 13 ± 6 Bq.m -3 to 185 ± 23 Bq.m -3 , with an average of 73 ± 15 Bq.m -3 .The radon concentration in the Murree Formation, Nagri Formation, river terrace and Dhok Pathan Formation were 89.7 ± 16.5, 72 ± 15, 68.5 and 69 Bq.m -3 , respectively. The average value of all the measured concentrations (73 ± 15 Bq.m -3 ) within the framework of this study is more than the world average value of 40 Bq.m -3 given by UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation, report to the General Assembly, United Nations, New York, 2000) and is within the action level of 200-600 Bq.m -3 fixed by the ICRP (International Commission on Radiological Protection, ICRP publication 65, Protection against radon at home and at work, 1993). The ambient gamma dose rates both indoors and outdoors in different parts of Kotli were also measured. The average value of gamma absorbed dose rates prevailing in the indoor environment was 131.2 ± 16.6 nGy/h. The gamma exposure rates recorded outdoors were 35% lower than in the indoor environment. The measured gamma dose rates have a weak positive correlation with indoor radon concentration. The annual effective dose for inhabitants in Kotli due to radon ranged from 0.32 to 4.7 mSv.y -1 , with an average value of 1.8 mSv.y -1 . This dose is relatively higher than the world mean dose of 1.15 mSv/y. That is explained by the particular geology of the

Estimation of exposure to atmospheric pollutants during pregnancy integrating space-time activity and indoor air levels: does it make a difference?

Science.gov (United States)

Marion, OUIDIR; Lise, GIORGIS-ALLEMAND; Sarah, LYON-CAEN; Xavier, MORELLI; Claire, CRACOWSKI; Sabrina, PONTET; Isabelle, PIN; Johanna, LEPEULE; Valérie, SIROUX; Rémy, SLAMA

2016-01-01

Studies of air pollution effects during pregnancy generally only consider exposure in the outdoor air at the home address. We aimed to compare exposure models differing in their ability to account for the spatial resolution of pollutants, space-time activity and indoor air pollution levels. We recruited 40 pregnant women in the Grenoble urban area, France, who carried a Global Positioning System (GPS) during up to 3 weeks; in a subgroup, indoor measurements of fine particles (PM2.5) were conducted at home (n=9) and personal exposure to nitrogen dioxide (NO2) was assessed using passive air samplers (n=10). Outdoor concentrations of NO2, and PM2.5 were estimated from a dispersion model with a fine spatial resolution. Women spent on average 16 h per day at home. Considering only outdoor levels, for estimates at the home address, the correlation between the estimate using the nearest background air monitoring station and the estimate from the dispersion model was high (r=0.93) for PM2.5 and moderate (r=0.67) for NO2. The model incorporating clean GPS data was less correlated with the estimate relying on raw GPS data (r=0.77) than the model ignoring space-time activity (r=0.93). PM2.5 outdoor levels were not to moderately correlated with estimates from the model incorporating indoor measurements and space-time activity (r=−0.10 to 0.47), while NO2 personal levels were not correlated with outdoor levels (r=−0.42 to 0.03). In this urban area, accounting for space-time activity little influenced exposure estimates; in a subgroup of subjects (n=9), incorporating indoor pollution levels seemed to strongly modify them. PMID:26300245

Indoor aldehydes: measurement of contamination levels and identification of their determinants in Paris dwellings

International Nuclear Information System (INIS)

Clarisse, B.; Laurent, A.M.; Seta, N.; Le Moullec, Y.; El Hasnaoui, A.; Momas, I.

2003-01-01

The recent increased prevalence of childhood asthma and atopy has brought into question the impact of outdoor pollutants and indoor air quality. The contributory role of aldehydes to this problem and the fact that they are mainly derived from the domestic environment make them of particular interest. This study therefore measures six different aldehyde levels in Paris dwellings from potentially different sources and identifies their indoor determinants. The study was carried out in the three principal rooms of 61 flats with no previous history of complaint for olfactory nuisance or specific symptoms, two-thirds of the flats having been recently refurbished. Aldehydes were sampled in these rooms using passive samplers, and a questionnaire on potential aldehyde sources was filled out at the same time. A multiple linear regression model was used to investigate indoor aldehyde determinants. Our study revealed that propionaldehyde and benzaldehyde were of minor importance compared to formaldehyde, acetaldehyde, pentanal, and hexanal. We found that levels of these last four compounds depended on the age of wall or floor coverings (renovations less than 1 year old), smoking, and ambient parameters (carbon dioxide levels, temperature). These results could help in the assessment of indoor aldehyde emissions

Indoor NO{sub 2} levels in homes with different sources of air pollution - traffic, gas-use, smoking

Energy Technology Data Exchange (ETDEWEB)

Rudnai, P.; Farkas, I.; Bacskai, J.; Sarkany, E. [Bela Johan National Inst. of Hygiene, Budapest (Hungary); Somogyi, J. [Public Health Inst. of County Gyor-Moson-Sopron, Gyor (Hungary)

1993-12-31

Outdoor and indoor levels of NO{sub 2} in and around the homes of 300 children living in different parts of two Hungarian towns, Gyor and Sopron, were measured. Possible sources of NO{sub 2} pollution were assessed by questionnaires. NO{sub 2} levels in homes without any further known sources (like gas use for cooking and/or heating and smoking) varied according to the outdoor levels mainly depending on traffic density. Gas heaters had the strongest influence on the indoor NO{sub 2} levels measured in the children`s bedrooms while gas use for cooking and smoking proved to be the second and third most important source of indoor NO{sub 2} pollution. Different outdoor and indoor NO{sub 2} sources should be taken into account when planning the heating and ventilation systems of new buildings. (author)

Concentration levels of radon in air, indoors and outdoors in houses of Mexico City

International Nuclear Information System (INIS)

Pena Garcia, P.

1992-01-01

Concentration levels of radon in air, indoors and outdoors have been obtained in houses from Mexico City, with the purpose of relating them with the local environment. Measurements were performed both outdoors and indoors in 60 unifamiliar houses. Track detectors, LR-115, Type II, were used in several detection arrangements during four recording periods with times of exposure of three months each, with the purpose of analyzing the fluctuations due to seasonal changes. Data were obtained about the construction materials were the detection systems were located in order to establish a correlation of radon levels with the climatic parameters and the construction materials. The results of radon concentrations both indoors or outdoors were lower than the international recommendations (148 Bq/m 3 ) (Author)

Activity pattern and personal exposure to nitrogen dioxide in indoor and outdoor microenvironments.

Science.gov (United States)

Kornartit, C; Sokhi, R S; Burton, M A; Ravindra, Khaiwal

2010-01-01

People are exposed to air pollution from a range of indoor and outdoor sources. Concentrations of nitrogen dioxide (NO(2)), which is hazardous to health, can be significant in both types of environments. This paper reports on the measurement and analysis of indoor and outdoor NO(2) concentrations and their comparison with measured personal exposure in various microenvironments during winter and summer seasons. Furthermore, the relationship between NO(2) personal exposure in various microenvironments and including activities patterns were also studied. Personal, indoor microenvironments and outdoor measurements of NO(2) levels were conducted using Palmes tubes for 60 subjects. The results showed significant differences in indoor and outdoor NO(2) concentrations in winter but not for summer. In winter, indoor NO(2) concentrations were found to be strongly correlated with personal exposure levels. NO(2) concentration in houses using a gas cooker was higher in all rooms than those with an electric cooker during the winter campaign, whereas there was no significant difference noticed in summer. The average NO(2) levels in kitchens with a gas cooker were twice as high as those with an electric cooker, with no significant difference in the summer period. A time-weighted average personal exposure was calculated and compared with measured personal exposures in various indoor microenvironments (e.g. front doors, bedroom, living room and kitchen); including non-smokers, passive smokers and smoker. The estimated results were closely correlated, but showed some underestimation of the measured personal exposures to NO(2) concentrations. Interestingly, for our particular study higher NO(2) personal exposure levels were found during summer (14.0+/-1.5) than winter (9.5+/-2.4).

Hospital indoor PM10/PM2.5 and associated trace elements in Guangzhou, China

International Nuclear Information System (INIS)

Wang Xinhua; Bi Xinhui; Sheng Guoying; Fu Jiamo

2006-01-01

PM10 and PM2.5 samples were collected in the indoor environments of four hospitals and their adjacent outdoor environments in Guangzhou, China during the summertime. The concentrations of 18 target elements in particles were also quantified. The results showed that indoor PM2.5 levels with an average of 99 μg m -3 were significantly higher than outdoor PM2.5 standard of 65 μg m -3 recommended by USEPA [United States Environmental Protection Agency. Office of Air and Radiation, Office of Air Quality Planning and Standards, Fact Sheet. EPA's Revised Particulate Matter Standards, 17, July 1997] and PM2.5 constituted a large fraction of indoor respirable particles (PM10) by an average of 78% in four hospitals. High correlation between PM2.5 and PM10 (R 2 of 0.87 for indoors and 0.90 for outdoors) suggested that PM2.5 and PM10 came from similar particulate emission sources. The indoor particulate levels were correlated with the corresponding outdoors (R 2 of 0.78 for PM2.5 and 0.67 for PM10), demonstrating that outdoor infiltration could lead to direct transportation into indoors. In addition to outdoor infiltration, human activities and ventilation types could also influence indoor particulate levels in four hospitals. Total target elements accounted for 3.18-5.56% of PM2.5 and 4.38-9.20% of PM10 by mass, respectively. Na, Al, Ca, Fe, Mg, Mn and Ti were found in the coarse particles, while K, V, Cr, Ni, Cu, Zn, Cd, Sn, Pb, As and Se existed more in the fine particles. The average indoor concentrations of total elements were lower than those measured outdoors, suggesting that indoor elements originated mainly from outdoor emission sources. Enrichment factors (EF) for trace element were calculated to show that elements of anthropogenic origins (Zn, Pb, As, Se, V, Ni, Cu and Cd) were highly enriched with respect to crustal composition (Al, Fe, Ca, Ti and Mn). Factor analysis was used to identify possible pollution source-types, namely street dust, road traffic and

Hospital indoor PM10/PM2.5 and associated trace elements in Guangzhou, China.

Science.gov (United States)

Wang, Xinhua; Bi, Xinhui; Sheng, Guoying; Fu, Jiamo

2006-07-31

PM10 and PM2.5 samples were collected in the indoor environments of four hospitals and their adjacent outdoor environments in Guangzhou, China during the summertime. The concentrations of 18 target elements in particles were also quantified. The results showed that indoor PM2.5 levels with an average of 99 microg m(-3) were significantly higher than outdoor PM2.5 standard of 65 microg m(-3) recommended by USEPA [United States Environmental Protection Agency. Office of Air and Radiation, Office of Air Quality Planning and Standards, Fact Sheet. EPA's Revised Particulate Matter Standards, 17, July 1997] and PM2.5 constituted a large fraction of indoor respirable particles (PM10) by an average of 78% in four hospitals. High correlation between PM2.5 and PM10 (R(2) of 0.87 for indoors and 0.90 for outdoors) suggested that PM2.5 and PM10 came from similar particulate emission sources. The indoor particulate levels were correlated with the corresponding outdoors (R(2) of 0.78 for PM2.5 and 0.67 for PM10), demonstrating that outdoor infiltration could lead to direct transportation into indoors. In addition to outdoor infiltration, human activities and ventilation types could also influence indoor particulate levels in four hospitals. Total target elements accounted for 3.18-5.56% of PM2.5 and 4.38-9.20% of PM10 by mass, respectively. Na, Al, Ca, Fe, Mg, Mn and Ti were found in the coarse particles, while K, V, Cr, Ni, Cu, Zn, Cd, Sn, Pb, As and Se existed more in the fine particles. The average indoor concentrations of total elements were lower than those measured outdoors, suggesting that indoor elements originated mainly from outdoor emission sources. Enrichment factors (EF) for trace element were calculated to show that elements of anthropogenic origins (Zn, Pb, As, Se, V, Ni, Cu and Cd) were highly enriched with respect to crustal composition (Al, Fe, Ca, Ti and Mn). Factor analysis was used to identify possible pollution source-types, namely street dust, road traffic

Monitoring trends in civil engineering and their effect on indoor radon.

Science.gov (United States)

Ringer, W

2014-07-01

In this paper, the importance of monitoring new building concepts is discussed. The effect of energy-efficient construction technologies on indoor radon is presented in more detail. Comparing the radon levels of about 100 low-energy and passive houses in Austria with radon levels in conventional new houses show that, in energy-efficient new houses, the radon level is about one-third lower than in conventional new houses. Nevertheless, certain features or bad practice may cause high radon levels in energy-efficient new houses. Recommendations to avoid adverse effects were set up. Furthermore, the paper deals with the effect of thermal retrofitting on indoor radon. Results from a Swiss study where 163 dwellings were measured before and after thermal retrofit yield an increase of the radon level of 26% in average. Among the various retrofit measures, replacing windows has the greatest impact on the indoor radon level. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Novel Feature-Level Data Fusion Method for Indoor Autonomous Localization

Directory of Open Access Journals (Sweden)

Minxiang Liu

2013-01-01

Full Text Available We present a novel feature-level data fusion method for autonomous localization in an inactive multiple reference unknown indoor environment. Since monocular sensors cannot provide the depth information directly, the proposed method incorporates the edge information of images from a camera with homologous depth information received from an infrared sensor. Real-time experimental results demonstrate that the accuracies of position and orientation are greatly improved by using the proposed fusion method in an unknown complex indoor environment. Compared to monocular localization, the proposed method is found to have up to 70 percent improvement in accuracy.

Are neighborhood-level characteristics associated with indoor allergens in the household?

Science.gov (United States)

Rosenfeld, Lindsay; Rudd, Rima; Chew, Ginger L; Emmons, Karen; Acevedo-García, Dolores

2010-02-01

Individual home characteristics have been associated with indoor allergen exposure; however, the influence of neighborhood-level characteristics has not been well studied. We defined neighborhoods as community districts determined by the New York City Department of City Planning. We examined the relationship between neighborhood-level characteristics and the presence of dust mite (Der f 1), cat (Fel d 1), cockroach (Bla g 2), and mouse (MUP) allergens in the household. Using data from the Puerto Rican Asthma Project, a birth cohort of Puerto Rican children at risk of allergic sensitization (n = 261), we examined associations between neighborhood characteristics (percent tree canopy, asthma hospitalizations per 1,000 children, roadway length within 100 meters of buildings, serious housing code violations per 1000 rental units, poverty rates, and felony crime rates), and the presence of indoor allergens. Allergen cutpoints were used for categorical analyses and defined as follows: dust mite: >0.25 microg/g; cat: >1 microg/g; cockroach: >1 U/g; mouse: >1.6 microg/g. Serious housing code violations were statistically significantly positively associated with dust mite, cat, and mouse allergens (continuous variables), adjusting for mother's income and education, and all neighborhood-level characteristics. In multivariable logistic regression analyses, medium levels of housing code violations were associated with higher dust mite and cat allergens (1.81, 95%CI: 1.08, 3.03 and 3.10, 95%CI: 1.22, 7.92, respectively). A high level of serious housing code violations was associated with higher mouse allergen (2.04, 95%CI: 1.15, 3.62). A medium level of housing code violations was associated with higher cockroach allergen (3.30, 95%CI: 1.11, 9.78). Neighborhood-level characteristics, specifically housing code violations, appear to be related to indoor allergens, which may have implications for future research explorations and policy decisions.

Indoor radiation exposures from radon and its daughters: a view of the issue

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1981-08-01

Exposure to radon daughters indoors can result in significant risk to the general public, particularly those living in homes with much higher than average concentrations. This paper reviews what is known about indoor concentrations, associated risks, and the effect of measures to save energy by reducing ventilation rates. It concludes that, by employing appropriate control measures in homes having unacceptably high concentrations, the average exposure (and therefore risk) of the general public can remain at its present level, or even decrease, despite programs to save energy by tightening homes

Indoor organic and inorganic pollutants: In-situ formation and dry deposition in Southeastern Brazil

Science.gov (United States)

Allen, Andrew G.; Miguel, Antonio H.

We have measured indoor and outdoor levels of particle- and gas-phase pollutants, collected in offices, restaurants and a hotel at six different sites in and around the cities of São Paulo and Campinas, Brazil, during summer 1993. Gas-phase species included acetic acid, formic acid, nitrous acid, hydrochloric acid, sulfur dioxide, nitric acid, oxalic acid, and pyruvic acid. Fine mode ( 3 μm dp) species measured included chloride, potassium, acetate, nitrate, magnesium, formate, sodium, pyruvate, nitrite, calcium, sulfate, oxalate, and ammonium. One sample (˜ 6 h) was simultaneously collected indoors and outdoors at each site during regular working hours. Indoor samplers were located ca. 1.5 m from the floor, and the outdoors immediately outside the window. Indoor/outdoor concentration ratios suggest that fine potassium chloride was produced indoors in appreciable amounts at both restaurants studied and, to a lesser extent, in the three offices as well. Indoor fine nitrate particles found in restaurants appear to have been produced by fuel combustion; a small fraction may have resulted from dry deposition of nitric acid onto existing fine particles. Indoor and outdoor concentrations of fine- and coarse-mode acetate suggest their production at all sites. The average concentration of gas-phase acetic acid was 42 μg m -3 indoors compared to 9.0 μg m -3 outdoors. In-situ formation of nitrous acid and acetic acid appears to have occurred at all indoor sites. High levels of formic and acetic acids were produced indoors at a pizzeria that used wood for cooking. Nitrous acid average concentrations for all sites were 8.4 μm m -3 indoors and 3.2 μm m -3 outdoors. Indoor/outdoor ratios at all sites suggest that dry deposition indoors may have occurred for hydrochloric acid, nitric acid and sulfur dioxide and that fine-mode sulfate infiltrate buildings from outside at most sites.

A comprehensive air quality investigation at an aquatic centre: Indoor/outdoor comparisons.

Science.gov (United States)

Tolis, Evangelos I; Panaras, Giorgos; Bartzis, John G

2018-06-01

Air quality and comfort parameters in a naturally ventilated aquatic centre were studied in relation to the outdoor pollution levels. Simultaneous measurements of PM 2.5, as well as of volatile organic compounds, were carried out for the indoor and outdoor environment of the aquatic centre. The chemical analysis of ionic species and trace elements associated with particulate matter was also performed. In addition, automated analyzer for NO 2 and O 3 was used in order to record the indoor and outdoor levels of these pollutants. Analysis of diurnal variation of the pollutants' concentration was applied to the collected data, allowing the identification of potential variation on the sources affecting the indoor air quality. PM 2.5 concentration was almost two times higher indoors than outdoors with average values of 13.96 and 6.78 μg/m 3 , respectively. Concerning the ion fraction of PM 2.5, SO 4 2- and Ca 2+ were the ions with higher concentration indoors with values of 1.06 and 0.93 μg/m 3 , respectively, while the percentage of Cl - to the PM 2.5 fraction of the indoor atmosphere (9%) was too high than outdoor ones (1%). These results showed that indoor air of swimming pool concerning PM 2.5 and ionic species is mainly affected by the chlorination process along with the comfort conditions (high relative humidity) created during the operation of the facility. The common volatile organic compound concentrations at indoor air are generally in higher levels, compared to the outdoor air with p,m-xylene and toluene to be the substances with the higher concentration for indoor and outdoor area, respectively (7.80 and 1.57 μg/m 3 ); nevertheless, values were rather low compared with the findings of other studies. Also, they clearly demonstrate a diurnal variation as a result of poor ventilation during night. As it was expected, chloroform showed the highest concentration compared to the other volatile organic compounds with values ranging from 3.35 to 135.89 μg/m 3

Indoor thoron studies along the northeast coast of Andhra Pradesh, India

International Nuclear Information System (INIS)

Vinay Kumar Reddy, K.; Sudarshan, A.; Gopal Reddy, Ch.; Yadagiri Reddy, P.; Rama Reddy, K.

2013-01-01

The beach sands of the northeast coast of Andhra Pradesh are well known for heavy metal mineralization. The process of extraction of the metals can enhance the natural background radiation levels and hence it is essential to establish the radiological base-line data to take necessary remedial action to preserve and protect the coastal environment. The assessment of indoor radioactivity levels has been carried out by choosing 13 villages long the northeast coast of Andhra Pradesh covering around 150 km from Vishakapattanam to Kalingapattanam. The present paper discusses the indoor thoron levels in the areas along the northeast coast of Andhra Pradesh. The SSNTD based twin chamber dosimeters were employed for the assessment of the concentration of thoron and its progeny levels. The average indoor thoron concentrations in this area are found to be 44.1 ± 28.2 Bq.m -3 . The inhalation dose due to thoron has been evaluated using equilibrium factors and discussed in detail. (author)

Indoor environmental quality in Hellenic hospital operating rooms

Energy Technology Data Exchange (ETDEWEB)

Dascalaki, Elena G.; Gaglia, Athina G.; Balaras, Constantinos A. [Group Energy Conservation, Institute for Environmental Research and Sustainable Development, National Observatory of Athens, I. Metaxa and Vas. Pavlou, GR 152 36 P. Penteli (Greece); Lagoudi, Argyro [Terra Nova Ltd., Environmental Engineering Consultancy, Athens, Kaisareias 39, GR 115 27 Athens (Greece)

2009-05-15

Indoor environmental quality (IEQ) in hospital operating rooms (ORs) constitutes a major challenge for the proper design and operation of an energy efficient hospital. A subjective assessment of the indoor environment along with a short monitoring campaign was performed during the audits of 18 ORs at nine major Hellenic hospitals. A total of 557 medical personnel participated in an occupational survey, providing data for a subjective assessment of IEQ in the audited ORs. The OR personnel reported work related health symptoms and an assessment of indoor conditions (thermal, visual and acoustical comfort, and air quality). Overall, personnel reported an average of 2.24 work-related symptoms each, and 67.2% of respondents reported at least one. Women suffer more health symptoms than men. Special dispositions, such as smoking and allergies, increase the number of reported symptoms for male and female personnel. Personnel that perceive satisfactory indoor comfort conditions (temperature, humidity, ventilation, light, and noise) average 1.18 symptoms per person, while for satisfactory indoor air quality the average complaints are 0.99. The perception of satisfactory IEQ (satisfactory comfort conditions and air quality) reduces the average number of health complaints to 0.64 symptoms per person and improves working conditions, even in a demanding OR environment. (author)

Assessment of indoor levels of volatile organic compounds and carbon dioxide in schools in Kuwait.

Science.gov (United States)

Al-Awadi, Layla

2018-01-01

Indoor air quality (IAQ) in schools is a matter of concern because children are most vulnerable and sensitive to pollutant exposure. Conservation of energy at the expense of ventilation in heating, ventilation, and air conditioning (HVAC) systems adversely affects IAQ. Extensive use of new materials in building, fitting, and refurbishing emit various pollutants such that the indoor environment creates its own discomfort and health risks. Various schools in Kuwait were selected to assess their IAQ. Comprehensive measurements of volatile organic compounds (VOCs) consisting of 72 organic compounds consisting of aliphatic (C 3 -C 6 ), aromatic (C 6 -C 9 ), halogenated (C 1 -C 7 ), and oxygenated (C 2 -C 9 ) functional groups in indoor air were made for the first time in schools in Kuwait. The concentrations of indoor air pollutants revealed hot spots (science preparation rooms, science laboratories, arts and crafts classes/paint rooms, and woodworking shops/decoration rooms where local sources contributed to the buildup of pollutants in each school. The most abundant VOC pollutant was chlorodifluoromethane (R22; ClF 2 CH), which leaked from air conditioning (AC) systems due to improper operation and maintenance. The other copious VOCs were alcohols and acetone at different locations due to improper handling of the chemicals and their excessive uses as solvents. Indoor carbon dioxide (CO 2 ) levels were measured, and these levels reflected the performance of HVAC systems; a specific rate or lack of ventilation affected the IAQ. Recommendations are proposed to mitigate the buildup of indoor air pollutants at school sites. Indoor air quality in elementary schools has been a subject of extreme importance due to susceptibility and sensibility of children to air pollutants. The schools were selected based on their surrounding environment especially downwind direction from the highly industrialized zone in Kuwait. Extensive sampling from different sites in four schools for

Player Monitoring in Indoor Team Sports: Concurrent Validity of Inertial Measurement Units to Quantify Average and Peak Acceleration Values

Directory of Open Access Journals (Sweden)

Mareike Roell

2018-02-01

Full Text Available The increasing interest in assessing physical demands in team sports has led to the development of multiple sports related monitoring systems. Due to technical limitations, these systems primarily could be applied to outdoor sports, whereas an equivalent indoor locomotion analysis is not established yet. Technological development of inertial measurement units (IMU broadens the possibilities for player monitoring and enables the quantification of locomotor movements in indoor environments. The aim of the current study was to validate an IMU measuring by determining average and peak human acceleration under indoor conditions in team sport specific movements. Data of a single wearable tracking device including an IMU (Optimeye S5, Catapult Sports, Melbourne, Australia were compared to the results of a 3D motion analysis (MA system (Vicon Motion Systems, Oxford, UK during selected standardized movement simulations in an indoor laboratory (n = 56. A low-pass filtering method for gravity correction (LF and two sensor fusion algorithms for orientation estimation [Complementary Filter (CF, Kalman-Filter (KF] were implemented and compared with MA system data. Significant differences (p < 0.05 were found between LF and MA data but not between sensor fusion algorithms and MA. Higher precision and lower relative errors were found for CF (RMSE = 0.05; CV = 2.6% and KF (RMSE = 0.15; CV = 3.8% both compared to the LF method (RMSE = 1.14; CV = 47.6% regarding the magnitude of the resulting vector and strongly emphasize the implementation of orientation estimation to accurately describe human acceleration. Comparing both sensor fusion algorithms, CF revealed slightly lower errors than KF and additionally provided valuable information about positive and negative acceleration values in all three movement planes with moderate to good validity (CV = 3.9 – 17.8%. Compared to x- and y-axis superior results were found for the z-axis. These findings demonstrate that

An indoor air quality assessment for vulnerable populations exposed to volcanic vog from Kilauea Volcano.

Science.gov (United States)

Longo, Bernadette M; Yang, Wei; Green, Joshua B; Longo, Anthony A; Harris, Merylin; Bibilone, Renwick

2010-01-01

The Ka'u District of Hawaii is exposed to sulfurous air pollution called vog from the ongoing eruption of Kilauea Volcano. Increased volcanic activity in 2008 prompted an indoor air quality assessment of the district's hospital and schools. All indoor sulfur dioxide concentrations were above the World Health Organization's average 24-hour recommendation. Indoor penetration ratios were up to 94% of ambient levels and dependent upon building construction or the use of air-conditioning. Health-promotion efforts for vulnerable populations at the hospital and schools are under way to improve indoor air quality and respond to those affected by vog exposure.

Indoor Climate Quality Assessment -

DEFF Research Database (Denmark)

Ansaldi, Roberta; Asadi, Ehsan; Costa, José Joaquim

This Guidebook gives building professionals useful support in the practical measurements and monitoring of the indoor climate in buildings. It is evident that energy consumption in a building is directly influenced by required and maintained indoor comfort level. Wireless technologies for measure...... for measurement and monitoring have allowed a significantly increased number of possible applications, especially in existing buildings. The Guidebook illustrates several cases with the instrumentation of the monitoring and assessment of indoor climate.......This Guidebook gives building professionals useful support in the practical measurements and monitoring of the indoor climate in buildings. It is evident that energy consumption in a building is directly influenced by required and maintained indoor comfort level. Wireless technologies...

Indoor air pollution levels in public buildings in Thailand and exposure assessment.

Science.gov (United States)

Klinmalee, Aungsiri; Srimongkol, Kasama; Kim Oanh, Nguyen Thi

2009-09-01

Levels of pollutants including PM2.5 and PM2.5 composition (black carbon and water soluble ions), SO(2), NO(2), CO, CO(2), and BTEX (benzene, toluene, ethylbenzene, xylene) were monitored for indoor and outdoor air at a university campus and a shopping center, both located in the Northern suburb of Bangkok. Sampling was done during December 2005-February 2006 on both weekdays and weekends. At the university, indoor monitoring was done in two different air conditioned classrooms which shows the I/O ratios for all pollutants to be below 0.5-0.8 during the weekends. However, on weekdays the ratios for CO(2) and most detected BTEX were above 1.0. The concept of classroom occupancy was defined using a function of the student number in a lecture hour and the number of lecture hours per day. Classroom 2, which had a higher occupancy than classroom 1, was characterized by higher concentrations of most pollutants. PM2.5 was an exception and was higher in classroom 1 (37 microg/m(3), weekdays) as compared to classroom 2 (26 microg/m(3), weekdays) which was likely linked to the dust resuspension from the carpeted floor in the former. Monitoring was also done in the shopping mall at three different sites. Indoor pollutants levels and the I/O ratios at the shopping mall were higher than at the university. Levels of all pollutants measured at the car park, except for toluene and CO(2), were the highest. I/O ratios of the pollutants at the mall were above 1.0, which indicates the relatively higher influence of the indoor sources. However, the black carbon content in PM2.5 outdoor is higher than indoor, which suggest the important contribution from outdoor combustion sources such as the traffic. Major sources of outdoor air pollution in the areas were briefly discussed. Exposure modeling was applied using the time activity and measured pollutant concentrations to assess the exposure of different groups of people in the study areas. High exposure to PM2.5, especially for the people

Polluted air--outdoors and indoors.

Science.gov (United States)

Myers, I; Maynard, R L

2005-09-01

Many air pollutants which are considered important in ambient (outdoor) air are also found, sometimes at higher levels, in indoor air. With demanding standards having been set for many of these pollutants, both in the workplace and ambient air, consideration of the problems posed by indoor pollution is gaining pace. Studies on exposure to pollutants found in the indoor domestic environment are increasing and are contributing to an already significant compilation of datasets. Improvement in monitoring techniques has helped this process. Documented reports of fatalities from carbon monoxide poisonings are still worrying. However, studies on health effects of non-fatal, long term, low dose, indoor exposure to carbon monoxide and other pollutants, are still inconclusive and too infrequently documented. Of particular concern are the levels of air pollutants found in the domestic indoor environment in developing countries, despite simple interventions such as vented stoves having shown their value. Exposure to biomass smoke is still a level that would be considered unacceptable on health grounds in developed countries. As in the occupational environment, steps need to be taken to control the risks from exposure to the harmful constituents of indoor air in the home. However, the difficulty regarding regulation of the domestic indoor environment is its inherent privacy. Monitoring levels of pollutants in the home and ensuring regulations are adhered to, would likely prove difficult, especially when individual behaviour patterns and activities have the greatest influence on pollutant levels in indoor air. To this end, the Department of Health is developing guidance on indoor air pollution to encourage the reduction of pollutant levels in indoor domestic air. The importance of the effects of domestic indoor air on health and its contribution to the health of the worker are increasingly appreciated. Occupational physicians, by training and interest, are well placed to extend

Indoor radon distribution of subway stations in a Korean major city

International Nuclear Information System (INIS)

Yoon, Seokwon; Chang, Byung-Uck; Kim, Yongjae; Byun, Jong-In; Yun, Ju-Yong

2010-01-01

The overall survey on indoor radon concentration was conducted at all subway stations in a major city, Daejeon in the central part of Korea. It was quarterly performed from September 2007 to August 2008. The annual arithmetic mean of indoor radon concentration of all the stations was 34.1 ± 14.7 Bq m -3 , and the range of values was from 9.4 to 98.2 Bq m -3 . The radon concentrations in groundwater (average 31.0 ± 0.8 Bq m -3 ) were not significantly high in most stations, but the concentration (177.9 ± 2.3 Bq L -1 ) of one station was over the level of 148 Bq L -1 in drinking water proposed by U.S. EPA. Based on indoor survey results, the approximate average of the annual effective dose by radon inhalation to the employees and passengers were 0.24 mSv y -1 , and 0.02 mSv y -1 , respectively. Although the effective dose based on the UNSCEAR report was potentially estimated, for more accurate assessment, the additional survey on the influence by indoor radon will be necessary.

Indoor radon distribution of subway stations in a Korean major city

Energy Technology Data Exchange (ETDEWEB)

Yoon, Seokwon [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); Chang, Byung-Uck, E-mail: hafadai@kins.re.k [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); University of Science and Technology, Gwahak-ro 113, Yuseong-gu, 305-333 Daejeon (Korea, Republic of); Kim, Yongjae [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); Byun, Jong-In [University of Science and Technology, Gwahak-ro 113, Yuseong-gu, 305-333 Daejeon (Korea, Republic of); Yun, Ju-Yong [Korea Institute of Nuclear Safety, Gwahak-ro 34, Yuseong-gu, 305-338 Daejeon (Korea, Republic of); University of Science and Technology, Gwahak-ro 113, Yuseong-gu, 305-333 Daejeon (Korea, Republic of)

2010-04-15

The overall survey on indoor radon concentration was conducted at all subway stations in a major city, Daejeon in the central part of Korea. It was quarterly performed from September 2007 to August 2008. The annual arithmetic mean of indoor radon concentration of all the stations was 34.1 +- 14.7 Bq m{sup -3}, and the range of values was from 9.4 to 98.2 Bq m{sup -3}. The radon concentrations in groundwater (average 31.0 +- 0.8 Bq m{sup -3}) were not significantly high in most stations, but the concentration (177.9 +- 2.3 Bq L{sup -1}) of one station was over the level of 148 Bq L{sup -1} in drinking water proposed by U.S. EPA. Based on indoor survey results, the approximate average of the annual effective dose by radon inhalation to the employees and passengers were 0.24 mSv y{sup -1}, and 0.02 mSv y{sup -1}, respectively. Although the effective dose based on the UNSCEAR report was potentially estimated, for more accurate assessment, the additional survey on the influence by indoor radon will be necessary.

A 2-year study of seasonal indoor radon variations in northern Virginia

International Nuclear Information System (INIS)

Mose, D.G.; Mushrush, G.W.; Chrosniak, C.E.

1991-01-01

The concentrations of indoor radon in the basements of homes located in northern Virginia average about 1.4 times the first-floor radon concentrations. Basement indoor radon concentrations exhibit seasonal variations that can be related to home use patterns of the occupants. Little indoor radon difference was seen between homes that have concrete block basement walls and poured concrete basement walls, but homes that use oil or gas furnaces for heating have ∼ 25% lower indoor radon than homes that use electrical heating systems. Particular geological units seem to be associated with elevated indoor radon concentrations, and several units are associated with indoor radon concentrations that exceed 4 pCi/l (the U.S. Environmental Agency action level) at some time in more than 40% of the homes. Comparative studies between indoor radon and total gamma aeroradioactivity show that aeroradioactivity can be accurately used to estimate community radon hazards. When combined with information about the home heating system, geology and aeroradioactivity can be used to identify problem homes

Indoor air pollution

International Nuclear Information System (INIS)

Qureshi, I.H.

2001-01-01

Indoor air pollution is a potential risk to human health. Prolonged exposure to indoor pollutants may cause various infectious, allergic and other diseases. Indoor pollutants can emanate from a broad array of internal and external sources. Internal sources include building and furnishing materials, consumer and commercial products, office equipment, micro-organisms, pesticides and human occupants activities. External sources include soil, water supplies and outside makeup air. The main indoor air pollutants of concern are inorganic gases, formaldehyde and other volatile organic compounds, pesticides, radon and its daughters, particulates and microbes. The magnitude of human exposure to indoor pollutants can be estimated or predicted with the help of mathematical models which have been developed using the data from source emission testing and field monitoring of pollutants. In order to minimize human exposure to indoor pollutants, many countries have formulated guidelines / standards for the maximum permissible levels of main pollutants. Acceptable indoor air quality can be achieved by controlling indoor pollution sources and by effective ventilation system for removal of indoor pollutants. (author)

[Effect of large-scale repair work on indoor formaldehyde levels upon and subjective symptoms in, medical students during gross anatomy dissection course].

Science.gov (United States)

Mori, Mihoko; Hoshiko, Michiko; Hara, Kunio; Ishitake, Tatsuya; Saga, Tsuyoshi; Yamaki, Koichi

2012-01-01

To examine the effect of large-scale repair work on indoor formaldehyde (FA) levels and subjective symptoms in medical students during a gross anatomy dissection course. We measured the indoor FA levels, room air temperature, and room humidity during a gross anatomy dissection course. In addition, the prevalence of subjective symptoms, keeping allergy state, and wearing personal protective equipment were surveyed in two groups of students using a self-administered questionnaire. The mean indoor FA levels before and after repair work were 1.22 ppm and 0.14 ppm, respectively. The mean indoor FA level significantly decreased after repair work. The prevalences of most subjective symptoms before the anatomy practice were similar before and after the repair work. However, the prevalences of most subjective symptoms during the anatomy practice were lower after the repair work. The mean indoor FA levels and prevalences of subjective symptoms decreased after the repair work. We have to continuously monitor indoor FA levels, carry out private countermeasures to minimize exposure to FA, and maintain equipment for ventilation to be able to conduct practice in a comfortable environment.

Life time fatality risk assessment due to variation of indoor radon concentration in dwellings in western Haryana, India

International Nuclear Information System (INIS)

Kansal, Sandeep; Mehra, Rohit; Singh, N.P.

2012-01-01

Indoor radon measurements in 60 dwellings belonging to 12 villages of Sirsa, Fatehbad and Hisar districts of western Haryana, India, have been carried out, using LR-115 type II cellulose nitrate films in the bare mode. The annual average indoor radon value in the studied area varies from 76.00 to 115.46 Bq m −3 , which is well within the recommended action level 200–300 Bq m −3 (). The winter/summer ratio of indoor radon ranges from 0.78 to 2.99 with an average of 1.52. The values of annual average dose received by the residents and Life time fatality risk assessment due to variation of indoor radon concentration in dwellings of studied area suggests that there is no significance threat to the human beings due to the presence of natural radon in the dwellings. - Highlights: ► The radon concentration values in the dwellings are 2–3 times more than the world average of 40 Bq m −3 . ► These values are lower than the recommended action level of 200–300 Bq m −3 (). ► The annual effective dose is less than the recommended action level of 3–10 mSv per year (). ► The values of life time fatality risk determined for the studied area are within safe standards. ► There is no significant threat to the human beings due to the presence of natural radon in the dwellings.

Subjective annoyance caused by indoor low-level and low frequency noise and control method

Institute of Scientific and Technical Information of China (English)

DI Guo-qing; ZHANG Bang-jun; SHANG Qi

2005-01-01

The influence of low-level noise has not been widely noticed. This paper discovered that low-level and low frequency noise(Aweighted equivalent level Leq ＜ 45 dB) causes higher probability of subjective annoyance. The fuzzy mathematic principle was applied to deal with the threshold level of subjective annoyance from noise in this study; there is preferable relationship between the indoor noise and noise annoyance at low frequency noise level. Study indicated at the same centered noise level, the change of annoyance probability is mainly caused by the change of the frequency spectrum characteristic of the indoor noise. Under low noise level environment, without change of the medium-low frequency noise, the slight increase of medium-high frequency noise level with the help of noise sheltering effect can significantly reduce the noise annoyance. This discovery brings a new resolution on how to improve the environmental quality of working or living places. A noise control model is given in this study according to the acoustic analysis.

Indoor radon in a Spanish region with different gamma exposure levels

International Nuclear Information System (INIS)

Quindos, L.S.; Fernandez, P.L.; Sainz, C.; Fuente, I.; Nicolas, J.; Quindos, L.; Arteche, J.

2008-01-01

In the beginning of 1990s within the framework of a national radon survey of more than 1500 points, radon measurements were performed in more than 100 houses located in Galicia region, in the Northwest area of Spain. The houses were randomly selected only bearing in mind general geological aspects of the region. Subsequently, a nationwide project called MARNA dealt with external gamma radiation measurements in order to draw a Spanish natural radiation map. The comparison in Galicia between these estimations and the indoor radon levels previously obtained showed good agreement. With the purpose of getting a confirmation of this relationship and also of creating a radon map of the zone, a new set of measurements were carried out in 2005. A total of 300 external gamma radiation measurements were carried out as well as 300 measurements of 226 Ra, 232 Th and 40 K content in soil. Concerning radon, 300 1-m-depth radon measurements in soil were performed, and indoor radon concentration was determined in a total of 600 dwellings. Radon content in soil gave more accurate indoor radon predictions than external gamma radiation or 226 Ra concentration in soil

An investigation of factors influencing indoor radon concentrations

International Nuclear Information System (INIS)

Majborn, B.; Soerensen, A.; Nielsen, S.P.; Boetter-Jensen, L.

1988-05-01

Variations in indoor radon concentrations and some influencing factors have been studied during a two-year period (1986-1987) in 16 almost identical single-family houses.The annual average radon concentration in the houses varied from about 50 to about 400 Bq/m 3 . Variations in soil characteristics and radon concentration in soil gas could not be directly related to the variations of the average indoor radon concentrations. Most of the houses showed a ''normal'' seasonal variation of the radon concentration with a maximum in the winter and minimum in the summer. A deviating seasonal variation was found in three of the houses. Hourly data obtained in one unoccupied house during a period of 2-1/2 months showed no or only weak correlations between the indoor radon concentration and meteorological factors. However, for most of the houses, the seasonal variation of the indoor radon concentration was well correlated with the average indoor-outdoor temperature difference on a 2-month basis. It was demonstrated that the radon concentration can be strongly reduced in the Risoe houses if a district-heating duct, which is connected to all the houses, is ventilated, so that a slightly lowered pressure is maintained in the duct. 5 taps., 24 ill. (author)

Comparison of background levels of culturable fungal spore concentrations in indoor and outdoor air in southeastern Austria

Science.gov (United States)

Haas, D.; Habib, J.; Luxner, J.; Galler, H.; Zarfel, G.; Schlacher, R.; Friedl, H.; Reinthaler, F. F.

2014-12-01

Background concentrations of airborne fungi are indispensable criteria for an assessment of fungal concentrations indoors and in the ambient air. The goal of this study was to define the natural background values of culturable fungal spore concentrations as reference values for the assessment of moldy buildings. The concentrations of culturable fungi were determined outdoors as well as indoors in 185 dwellings without visible mold, obvious moisture problems or musty odor. Samples were collected using the MAS-100® microbiological air sampler. The study shows a characteristic seasonal influence on the background levels of Cladosporium, Penicillium and Aspergillus. Cladosporium sp. had a strong outdoor presence, whereas Aspergillus sp. and Penicillium sp. were typical indoor fungi. For the region of Styria, the median outdoor concentrations are between 100 and 940 cfu/m³ for culturable xerophilic fungi in the course of the year. Indoors, median background levels are between 180 and 420 cfu/m³ for xerophilic fungi. The I/O ratios of the airborne fungal spore concentrations were between 0.2 and 2.0. For the assessment of indoor and outdoor air samples the dominant genera Cladosporium, Penicillium and Aspergillus should receive special consideration.

Measurements of indoor radon concentration in Libyan cities

International Nuclear Information System (INIS)

Elarabiy, S. F.; Khalifa, M.; Misrati, N.; Chahboune, N.; Ahmed, M.

2012-12-01

Studies confirm that the risk of exposure to indor radon is attributable to lung cancer worldwide. The relationship between radon exposure and cancer is a linear one which necessitates for need for measurements of indoor radon concentration. This paper presents the results of measurements of indoor radon in several libya cities using CR-39 plastic. The results showed that the average radon concentration in the cities of Tripoli, Al-harcha and Alrajaban were 48.8 Bg/m 3 , 51.4 Bg/m 3 and 55.5 Bg/m 3 respectively. The average indoor radon concentration in Libya is low comparing with other studies. (Author)

Preliminary indoor radon and gamma measurements in kindergartens and schools in Bucharest

International Nuclear Information System (INIS)

Dumitrescu, A.; Milu, C.; Gheorghe, R.; Vaupotic, J.; Stegnar, P.

2001-01-01

A pilot study on indoor radon and gamma dose rates in schools and kindergartens (totalling one hundred buildings) in the Bucharest metropolitan area was performed jointly by the Institute of Public Health, Bucharest, Romania, and the J. Stefan Institute, Ljubljana, Slovenia. Because the geological structure of subsoil over the whole Bucharest area is uniform (a loess platform), the criteria for selecting a kindergarten or a school to be monitored were the age of the building and the building materials. Indoor radon concentrations were measured by a single one-month exposure of radon monitoring device based on etched track detectors in December 2000. Data show a lognormal distribution within the concentration range of 43/477 Bq/m 3 . An arithmetic mean of 146 Bq/m 3 and a geometric mean of 128 Bq/m 3 were obtained. Concomitant with indoor radon levels gamma dose rates were also measured, using thermoluminescent dosimeters. Values ranged from 54 to 100 μSv mo -1 , with a mean value of 74 μSv mo -1 . Having only a single average indoor radon concentration for a winter month, it is not possible to comment on our results, applying the ICRP Publication 65 methodology for indoor radon action level for the general public. Nevertheless, they give a preliminary picture of indoor radon and gamma dose rate levels in schools and kindergartens in Bucharest, and constitute a solid basis on which to design and perform a nation-wide radon survey programme.(author)

A passive integrating charcoal detector for indoor radon survey

International Nuclear Information System (INIS)

Lin Lianqing; Ren Tianshan; Li Guiyun

1986-01-01

This paper describes the principle, design, calibration and characteristics of a passive integrating charcoal detector for measuring average radon concentration indoors. The uncertainties of the detector are also evaluated. Under conditions of room temperature at 17 deg C and relative humidity at 30%, the minimum limit of detection is 0.16 pCi/1 for 72 hours exposure. Besides higher sensitivity, the other advantages of this detector are passive, simple and less expensive. It requires no power and makes no noise and gives no interference to daily activities of the residents of dwellings being surveyed. Therefore the detector is suitable for a large-scale survey of radon levels indoors

Indoor radon exposure in Norway and lung cancer risk

International Nuclear Information System (INIS)

Sanner, T.; Dybing, E.

1990-01-01

The risk for lung cancer due to indoor radon in Norway was estimated. The risk factor recommended by the World Health Organization was used. Corrections were made for time not spent at home and type of activity. On the basis of measurements by the Norwegian National Institute for Radiation Hygiene in 7,500 homes, Strand et al estimated that the average concentration of radon daughters in the bedroom of Norwegian dwellings was 26.5 Bq/m 3 (EER). The level of exposure during time spent outside the home was assumed to be 10% of that at home. It was calculated that indoor radon exposure may cause 75-225 lung cancer deaths per year. This corresponds to about 5-15% of all lung cancer deaths in Norway. The risk for lung cancer death per 1,000 deaths at an indoor radon decay product level of 100 Bq/m 3 was calculated on the basis of various reports in the paper. The results show that the present risk estimate is lower than most of the other estimates

Indoor air quality study of forty east Tennessee homes

Energy Technology Data Exchange (ETDEWEB)

Hawthorne, A.R.; Gammage, R.B.; Dudney, C.S.; Hingerty, B.E.; Schuresko, D.D.; Parzyck, D.C.; Womack, D.R.; Morris, S.A.; Westley, R.R.; White, D.A.

1984-12-01

Over a one-year period, measurements of indoor air pollutants (CO/sub x/, NO/sub x/, formaldehyde, volatile organics, particulates, and radon) were made in 40 homes in East Tennessee. The houses were of various ages with different types of insulation and heating. Over one-half of the houses exceeded the ASHRAE indoor ceiling guideline of 0.1 ppM for formaldehyde on at least one occasion. Over the duration of the study, older houses averaged 0.04 ppM of formaldehyde while houses less than 5 years old averaged 0.08 ppM (P < 0.01). The highest concentration of formaldehyde measured was 0.4 ppM in a new home. Diurnal and seasonal fluctuations in levels of formaldehyde in some homes were as much as twofold and tenfold, respectively. The highest levels of formaldehyde were usually recorded during summer months. The concentration in indoor air of various organics was at least tenfold higher than in outdoor air. Carbon monoxide and nitrgen oxides were usually <2 and <0.02 ppM, respectively, except when gas stoves or kerosene space heaters were operating, or when a car was running in the garage. In 30% of the houses, the annual indoor guideline for radon, 4 pCi/L, was exceeded. The mean radon level in houses built on the ridgelines was 4.4 pCi/L, while houses located in the valleys had a mean level of 1.7 pCi/L (P < 0.01). The factor having the most impact on infiltration was operation of the central duct fan of the heating, ventilation, and air conditioning system. The mean rate of air exchange increased from 0.39 to 0.74 h/sup -1/ when the duct fan was operated (measurements prior to December 1982). This report presents the study design and implementation, describes the monitoring protocols, and provides a complete set of the data collected during the project. 25 references, 29 figures, 42 tables.

Variation of annual effective dose due to radon level in indoor air in Marwar region of Rajasthan, India

Energy Technology Data Exchange (ETDEWEB)

Rani, Asha, E-mail: ashasachdeva78@gmail.com [Department of Applied Science, Ferozepur College of Engineering and Technology, Farozshah, Ferozepur-142052, Punjab (India); Mittal, Sudhir, E-mail: sudhirmittal03@gmail.com [Department of Applied Sciences, Punjab Technical University, Jalandhar-144601, Punjab (India); Mehra, Rohit [Department of Physics, Dr. B.R.Ambedkar National Institute of Technology, Jalandhar-144011 (India)

2015-08-28

In the present work, indoor radon and thoron measurements have been carried out from different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India using RAD7, a solid state alpha detector. The radon and thoron concentration in indoor air varies from 8.75 to 61.25 Bq m{sup −3} and 32.7 to 147.2 Bq m{sup −3} with the mean value of 32 and 73 Bq m{sup −3} respectively. The observed indoor radon concentration values are well below the action level recommended by International Commission on Radiological Protection (200-300 Bq m{sup −3}) and Environmental Protection Agency (148 Bq m{sup −3}). The survey reveals that the thoron concentration values in the indoor air are well within the International Commission on Radiological Protection (2005). The calculated total annual effective dose due to radon level in indoor air varies from 0.22 to 1.54 mSv y{sup −1} with the mean value of 0.81 mSv y{sup −1} which is less than even the lower limit of action level 3-10 mSv y{sup −1} recommended by International Commission on Radiological Protection (2005)

Nationwide survey of radon levels in indoor workplaces in Mexico using Nuclear Track Methodology

International Nuclear Information System (INIS)

Espinosa, G.; Golzarri, J.I.; Angeles, A.; Griffith, R.V.

2009-01-01

This report presents the preliminary results of an indoor workplace radon survey conducted during 2006-2007. Monitoring was carried out in 24 of the 32 federal entities of Mexico, incorporating 26 cities and 288 locations. The area monitored was divided into 8 regions for the purposes of the study: Chihuahua (a state with uranium mines), North-Central, South-Central, Southeast, South, Northeast, Northwest, and West. These regions differ in terms of geographic and geological characteristics, climate, altitude, and building materials and architectonic styles. Nuclear Track Methodology (NTM) was employed for the survey, using a passive closed-end cup device with Poly Allyl Diglycol Carbonate (PADC), known by its trade name CR-39 (Lantrack), as detector material. Well-established protocols for making continuous indoor radon measurements were followed, including one-step chemical etching in a 6.25 M KOH solution at 60 ± 1 deg. C with an etching time of 18 h. The track densities were determined with an automatic digital system at the Instituto de Fisica de la Universidad Nacional Autonoma de Mexico (IFUNAM) (Physics Institute of the National Autonomous University of Mexico), and calibrated in facilities at the Oak Ridge National Laboratory (ORNL). The importance of this survey lies in the fact that it represents the first time a nationwide survey of radon levels in indoor workplaces has been carried out in Mexico. Mean indoor radon levels from continuous measurements taken during and after working hours ranged from 13 Bq m -3 (the lower limit of detection) to 196 Bq m -3 . Analogous official controls or regulations for radon levels in indoor workplaces do not exist in Mexico. The survey described here contributes to knowledge of the natural radiological environment in workplaces, and will aid the relevant authorities in establishing appropriate regulations. The survey was made possible by the efforts of both a private institutions and the Dosimeter Application Project

Wintertime indoor air levels of PM10, PM2.5 and PM1 at public places and their contributions to TSP.

Science.gov (United States)

Liu, Yangsheng; Chen, Rui; Shen, Xingxing; Mao, Xiaoling

2004-04-01

From 26 October 2002 to 8 March 2003, particulate matter (PM) concentrations (total suspended particles [TSP], PM10, PM2.5 and PM1) were measured at 49 public places representing different environments in the urban area of Beijing. The objectives of this study were (1) to characterize the indoor PM concentrations in public places, (2) to evaluate the potential indoor sources and (3) to investigate the contribution of PM10 to TSP and the contributions of PM2.5 and PM1 to PM10. Additionally, The indoor and outdoor particle concentrations in the same type of indoor environment were employed to investigate the I/O level, and comparison was made between I/O levels in different types of indoor environment. Construction activities and traffic condition were the major outdoor sources to influence the indoor particle levels. The contribution of PM10 to TSP was even up to 68.8%, while the contributions of PM2.5 and PM1 to PM10 were not as much as that of PM10 to TSP.

Climate change and health: Indoor heat exposure in vulnerable populations

International Nuclear Information System (INIS)

White-Newsome, Jalonne L.; Sánchez, Brisa N.; Jolliet, Olivier; Zhang, Zhenzhen; Parker, Edith A.; Timothy Dvonch, J.; O'Neill, Marie S.

2012-01-01

Introduction: Climate change is increasing the frequency of heat waves and hot weather in many urban environments. Older people are more vulnerable to heat exposure but spend most of their time indoors. Few published studies have addressed indoor heat exposure in residences occupied by an elderly population. The purpose of this study is to explore the relationship between outdoor and indoor temperatures in homes occupied by the elderly and determine other predictors of indoor temperature. Materials and methods: We collected hourly indoor temperature measurements of 30 different homes; outdoor temperature, dewpoint temperature, and solar radiation data during summer 2009 in Detroit, MI. We used mixed linear regression to model indoor temperatures' responsiveness to weather, housing and environmental characteristics, and evaluated our ability to predict indoor heat exposures based on outdoor conditions. Results: Average maximum indoor temperature for all locations was 34.85 °C, 13.8 °C higher than average maximum outdoor temperature. Indoor temperatures of single family homes constructed of vinyl paneling or wood siding were more sensitive than brick homes to outdoor temperature changes and internal heat gains. Outdoor temperature, solar radiation, and dewpoint temperature predicted 38% of the variability of indoor temperatures. Conclusions: Indoor exposures to heat in Detroit exceed the comfort range among elderly occupants, and can be predicted using outdoor temperatures, characteristics of the housing stock and surroundings to improve heat exposure assessment for epidemiological investigations. Weatherizing homes and modifying home surroundings could mitigate indoor heat exposure among the elderly.

Indoor thermal environment, air exchange rates, and carbon dioxide concentrations before and after energy retro fits in Finnish and Lithuanian multi-family buildings.

Science.gov (United States)

Leivo, Virpi; Prasauskas, Tadas; Du, Liuliu; Turunen, Mari; Kiviste, Mihkel; Aaltonen, Anu; Martuzevicius, Dainius; Haverinen-Shaughnessy, Ulla

2018-04-15

Impacts of energy retrofits on indoor thermal environment, i.e. temperature (T) and relative humidity (RH), as well as ventilation rates and carbon dioxide (CO 2 ) concentrations, were assessed in 46 Finnish and 20 Lithuanian multi-family buildings, including 39 retrofitted case buildings in Finland and 15 in Lithuania (the remaining buildings were control buildings with no retrofits). In the Finnish buildings, high indoor T along with low RH levels was commonly observed both before and after the retrofits. Ventilation rates (l/s per person) were higher after the retrofits in buildings with mechanical exhaust ventilation than the corresponding values before the retrofits. Measured CO 2 levels were low in vast majority of buildings. In Lithuania, average indoor T levels were low before the retrofits and there was a significant increase in the average T after the retrofits. In addition, average ventilation rate was lower and CO 2 levels were higher after the retrofits in the case buildings (N=15), both in apartments with natural and mixed ventilation. Based on the results, assessment of thermal conditions and ventilation rates after energy retrofits is crucial for optimal indoor environmental quality and energy use. Copyright © 2017 Elsevier B.V. All rights reserved.

Variation of indoor radon concentration and ambient dose equivalent rate in different outdoor and indoor environments

Energy Technology Data Exchange (ETDEWEB)

Stojanovska, Zdenka; Janevik, Emilija; Taleski, Vaso [Goce Delcev University, Faculty of Medical Sciences, Stip (Macedonia, The Former Yugoslav Republic of); Boev, Blazo [Goce Delcev University, Faculty of Natural and Technical Sciences, Stip (Macedonia, The Former Yugoslav Republic of); Zunic, Zora S. [University of Belgrade, Institute of Nuclear Sciences ' ' Vinca' ' , Belgrade (Serbia); Ivanova, Kremena; Tsenova, Martina [National Center of Radiobiology and Radiation Protection, Sofia (Bulgaria); Ristova, Mimoza [University in Ss. Cyril and Methodius, Faculty of Natural Sciences and Mathematic, Institute of Physics, Skopje (Macedonia, The Former Yugoslav Republic of); Ajka, Sorsa [Croatian Geological Survey, Zagreb (Croatia); Bossew, Peter [German Federal Office for Radiation Protection, Berlin (Germany)

2016-05-15

Subject of this study is an investigation of the variations of indoor radon concentration and ambient dose equivalent rate in outdoor and indoor environments of 40 dwellings, 31 elementary schools and five kindergartens. The buildings are located in three municipalities of two, geologically different, areas of the Republic of Macedonia. Indoor radon concentrations were measured by nuclear track detectors, deployed in the most occupied room of the building, between June 2013 and May 2014. During the deploying campaign, indoor and outdoor ambient dose equivalent rates were measured simultaneously at the same location. It appeared that the measured values varied from 22 to 990 Bq/m{sup 3} for indoor radon concentrations, from 50 to 195 nSv/h for outdoor ambient dose equivalent rates, and from 38 to 184 nSv/h for indoor ambient dose equivalent rates. The geometric mean value of indoor to outdoor ambient dose equivalent rates was found to be 0.88, i.e. the outdoor ambient dose equivalent rates were on average higher than the indoor ambient dose equivalent rates. All measured can reasonably well be described by log-normal distributions. A detailed statistical analysis of factors which influence the measured quantities is reported. (orig.)

Indoor air quality

International Nuclear Information System (INIS)

Anon.

1993-01-01

Indoor Air Quality is rapidly becoming a major environmental concern because a significant amount of people spend a substantial amount of time in a variety of different indoor environments. Health effects from indoor pollutants fall into two categories: those that are experienced immediately after exposure and those that do not show up until years later. They are: radon, formaldehyde, asbestos, lead and household organic chemicals. The authors presented a source-by-source look at the most common indoor air pollutants, their potential health effects, and ways to reduce their levels in the home. There are three basic strategies to improve indoor air quality: one method is source control, another is through ventilation improvements, and the third is the utilization of some sort of mechanical device such as air cleaners

Influence of user behavior on unsatisfactory indoor thermal environment

International Nuclear Information System (INIS)

Yan, Biao; Long, Enshen; Meng, Xi; Zhang, Yuanze; Hou, Dongqi; Du, Xin

2014-01-01

Highlights: • The methodology of numerical simulation of 3D heat-flux visualization is proposed. • A full-scale model of prototype office for each influential factor was set up. • The simulation results were compared with the indoor occupant comfort levels. • The contrast of average temperature increase due to user behavior was presented. - Abstract: In areas of China that have hot summers and cold winters, the overall performance of HVAC systems in the poorly-insulated existing office buildings is generally not satisfactory, especially in extreme weather conditions. The reasons for the unsatisfactory indoor thermal environment were deduced, and to validate the findings, a methodology of numerical simulation for 3D heat-flux visualization was proposed. A full-scale model of a prototype office room was created, with representative working conditions for the characteristics of particular building. The results of the heat-flux visualization and temperature distribution showed that the overall effect was resulted from merged reasons, and that significance ranking of each reason varied when the outside environmental conditions changed. The simulation results were compared with the indoor occupant comfort levels of the volunteers who worked in the target room. Models of possible influential factors such as the outdoor temperature, opening or closing windows, and the effect of window shading devices (WSD) were set up. The influence of user behavior on indoor temperature in opening window, or not using WSD was proven to be significant in causing unfavorable indoor conditions. According to the visualized evaluation and analysis of the various factors, corresponding methods for both improving indoor thermal conditions and saving energy are proposed

Investigation of indoor air quality at residential homes in Hong Kong - case study

International Nuclear Information System (INIS)

Shun Cheng Lee; Waiming Li; Chiohang Ao

2002-01-01

Indoor air quality (IAQ) has been a matter of public concern in Hong Kong. Recently, the Hong Kong Government has recognized the potential risk and problems related to indoor air pollution, and it is striving to establish IAQ objectives for different types of indoor environments. This study attempts to provide more information about the present IAQ of local resident flats. Air pollutants measured in this study included carbon dioxide (CO 2 ), respirable suspended particulate matter (PM 10 ), formaldehyde (HCHO), volatile organic compounds (VOCs) and airborne bacteria. The results of this study indicate that the 8-h average concentrations of CO 2 and PM 10 in the domestic kitchens investigated were 14% and 67% higher than those measured in the living rooms. The indoor air pollution caused by PM 10 was more serious in domestic kitchens than in living rooms as almost all of the kitchens investigated had higher indoor levels of PM 10 . The majority of the domestic living rooms and kitchens studied had average concentrations of airborne bacteria higher than 500CFU/m 3 . The mean total bacteria count recorded in kitchens was greater than that obtained in living rooms by 23%. In homes where occupants smoke, the negative impact of benzene, toluene and m,p-xylene on the IAQ was greatly enhanced. The use of liquefied petroleum gas (LPG) stove has more significant impact on indoor VOCs than the use of cooking stoves with natural gas as cooking fuel. (Author)

Measurement and comparison of indoor radon levels in new and old buildings in the city of Muzaffarabad (Azad Kashmir), Pakistan. A pilot study

International Nuclear Information System (INIS)

Rafique, Muhammad; Jabeen, Shahida; Bukhari, Shujaht; Rahman, Saeed ur; Shahzad, Muhammad Ikram; Matiullah; Rahman, Said; Nasir, Tabassum

2009-01-01

Indoor radon concentrations have been measured in a limited number of dwellings in the state capital of Azad Jammu and Kashimir, Muzaffarabad city after the devastating earthquake of 2005. Radon detectors (CN-85 based box-type) were placed in the drawing rooms, bedrooms and kitchens of 35 houses, selected on the basis of their location and design as well as willingness and cooperation of householders from mid May to mid July 2007. The average radon concentrations were found to vary from 24 to 518 Bq m -3 , 41 to 380 Bq m -3 and 32 to 467 Bq m -3 in the bedrooms, drawing rooms and kitchens, respectively. The weighted average radon concentration in older houses was found to vary from 51 to 334 Bq m -3 and for newly constructed houses a considerable decrease in measured values (ranging from 14 to 102 Bq m -3 ) have been found. As Pakistan does not currently have a national reference (or action level) for radon in homes, therefore the present data has been compared with the data reported for other countries. Some of the houses studied were found to have higher radon concentrations. These higher values of indoor radon levels may be due to the poor ventilation and influence of the earthquake in creating new fissures and therefore new pathways for radon to enter into the buildings. (author)

Measurement and comparison of indoor radon levels in new and old buildings in the city of Muzaffarabad (Azad Kashmir), Pakistan. A pilot study

Energy Technology Data Exchange (ETDEWEB)

Rafique, Muhammad; Jabeen, Shahida; Bukhari, Shujaht [Dept. of Physics, Univ. of Azad Jammu and Kashmir Muzaffarabad, Azad Kashmir (Pakistan); Rahman, Saeed ur [Dept. of Physics, COMSATS Inst. of Information Technology, Islamabad (Pakistan); Shahzad, Muhammad Ikram; Matiullah, [Physics Division, PINSTECH, Islamabad (Pakistan); Rahman, Said [SPAS Division, SPARCENT, SUPARCO HQs, Karachi (Pakistan); Nasir, Tabassum [Dept. of Physics, Gomal Univ., Dera Ismail Khan (Pakistan)

2009-11-15

Indoor radon concentrations have been measured in a limited number of dwellings in the state capital of Azad Jammu and Kashimir, Muzaffarabad city after the devastating earthquake of 2005. Radon detectors (CN-85 based box-type) were placed in the drawing rooms, bedrooms and kitchens of 35 houses, selected on the basis of their location and design as well as willingness and cooperation of householders from mid May to mid July 2007. The average radon concentrations were found to vary from 24 to 518 Bq m{sup -3}, 41 to 380 Bq m{sup -3} and 32 to 467 Bq m{sup -3} in the bedrooms, drawing rooms and kitchens, respectively. The weighted average radon concentration in older houses was found to vary from 51 to 334 Bq m{sup -3} and for newly constructed houses a considerable decrease in measured values (ranging from 14 to 102 Bq m{sup -3}) have been found. As Pakistan does not currently have a national reference (or action level) for radon in homes, therefore the present data has been compared with the data reported for other countries. Some of the houses studied were found to have higher radon concentrations. These higher values of indoor radon levels may be due to the poor ventilation and influence of the earthquake in creating new fissures and therefore new pathways for radon to enter into the buildings. (author)

Indoor air quality in Portuguese schools: levels and sources of pollutants.

Science.gov (United States)

Madureira, J; Paciência, I; Pereira, C; Teixeira, J P; Fernandes, E de O

2016-08-01

Indoor air quality (IAQ) parameters in 73 primary classrooms in Porto were examined for the purpose of assessing levels of volatile organic compounds (VOCs), aldehydes, particulate matter, ventilation rates and bioaerosols within and between schools, and potential sources. Levels of VOCs, aldehydes, PM2.5 , PM10 , bacteria and fungi, carbon dioxide (CO2 ), carbon monoxide, temperature and relative humidity were measured indoors and outdoors and a walkthrough survey was performed concurrently. Ventilation rates were derived from CO2 and occupancy data. Concentrations of CO2 exceeding 1000 ppm were often encountered, indicating poor ventilation. Most VOCs had low concentrations (median of individual species <5 μg/m(3) ) and were below the respective WHO guidelines. Concentrations of particulate matter and culturable bacteria were frequently higher than guidelines/reference values. The variability of VOCs, aldehydes, bioaerosol concentrations, and CO2 levels between schools exceeded the variability within schools. These findings indicate that IAQ problems may persist in classrooms where pollutant sources exist and classrooms are poorly ventilated; source control strategies (related to building location, occupant behavior, maintenance/cleaning activities) are deemed to be the most reliable for the prevention of adverse health consequences in children in schools. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of Indoor Mercury Vapor in Common Areas of Residential Buildings with Outdoor Levels in a Community Where Mercury Is Used for Cultural Purposes

Science.gov (United States)

Garetano, Gary; Gochfeld, Michael; Stern, Alan H.

2006-01-01

Elemental mercury has been imbued with magical properties for millennia, and various cultures use elemental mercury in a variety of superstitious and cultural practices, raising health concerns for users and residents in buildings where it is used. As a first step in assessing this phenomenon, we compared mercury vapor concentration in common areas of residential buildings versus outdoor air, in two New Jersey cities where mercury is available and is used in cultural practices. We measured mercury using a portable atomic absorption spectrometer capable of quantitative measurement from 2 ng/m3 mercury vapor. We evaluated the interior hallways in 34 multifamily buildings and the vestibule in an additional 33 buildings. Outdoor mercury vapor averaged 5 ng/m3; indoor mercury was significantly higher (mean 25 ng/m3; p < 0.001); 21% of buildings had mean mercury vapor concentration in hallways that exceeded the 95th percentile of outdoor mercury vapor concentration (17 ng/m3), whereas 35% of buildings had a maximum mercury vapor concentration that exceeded the 95th percentile of outdoor mercury concentration. The highest indoor average mercury vapor concentration was 299 ng/m3, and the maximum point concentration was 2,022 ng/m3. In some instances, we were able to locate the source, but we could not specifically attribute the elevated levels of mercury vapor to cultural use or other specific mercury releases. However, these findings provide sufficient evidence of indoor mercury source(s) to warrant further investigation. PMID:16393659

Healthy indoors : achieving healthy indoor environments in Canada : Final report

International Nuclear Information System (INIS)

Anon

2002-01-01

A large proportion of the lives of Canadians is spent indoors, whether in vehicles, restaurants, shopping malls, offices or houses. The health of people working and living in those indoor settings might be damaged a a result, despite best efforts. Indoor pollution has been identified as one of the most serious risks to human health, according to numerous leading authorities, among them the American Lung Association, the United States Environmental Protection Agency, the Canada Mortgage and Housing Corporation (CMHC). A large number of cancer deaths are attributed to indoor pollution each year in the United States, as well as respiratory health problems. A causal link between certain indoor exposures and the development and provocation of asthma was established recently in a report on asthma and indoor air quality published by the National Academy of Sciences/Institute of Medicine. Exposure to indoor pollutants has also resulted in thousands of children experiencing elevated blood lead levels. Not enough attention is paid in Canada to pollution in buildings by government agencies, corporations and other non-governmental organizations and citizens. Not much seems to have changed in the past thirty years. An ambitious strategy by Pollution Probe was described in this document, listing the initial goals and measures required to achieve those goals. The creation of Healthy Indoors Partnership (HIP) was proposed to regroup all the stakeholders under the same umbrella. refs., tabs

Does natural gas increase the indoor radon levels?

International Nuclear Information System (INIS)

Abdel-Ghany, H.A.; Shabaan, D.H.

2015-01-01

The natural gas is naturally occurring hydrocarbon consists mainly of methane and includes varying amounts of other hydrocarbons, carbon dioxide and other impurities such as: nitrogen, and hydrogen sulfide. It is used domestically and industrially as a preferable energy source compared to coal and oil. Because natural gas is found in deep underground natural formations or associated with other underground hydrocarbon reservoirs, there is a potential to contain radon as a contaminant. This work was designated to measure indoor radon concentrations in dwellings supplied with natural gas compared with those not supplied with it, where radon level was estimated using solid state nuclear track detectors (CR-39). The results showed that radon concentration was significantly higher in dwellings supplied with natural gas, where it was 252.30 versus 136.19 Bqm -3 in dwelling not supplied with natural gas (P < 0.001). The mean values of radon exhalation rate was 0.02 ± 6.34 · 10 -4 Bq · m -2 · h -1 in dwellings supplied with natural gas and 0.01 +- 0.008 Bq · m -2 · h -1 in dwellings lacking it. In addition, a significant difference was observed in the mean annual effective doses (4.33 and 2.34 mSv · y -1 , respectively) between both groups. Conclusively, the data indicate that natural gas may represent a potential source of indoor radon

Indoor radon measurements in the Women College, Dammam, Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Al-Qahtani, Mona [Women College, P. O. Box 838, Dammam 31113 (Saudi Arabia); Al-Jarallah, M.I. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: mibrahim@kfupm.edu.sa; Fazal-ur-Rehman [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2005-11-15

Passive radon dosimeters, based on alpha particle etched track detectors, were used in the indoor radon survey of the College of Science for Girls in Dammam, Saudi Arabia. A total of 95 dosimeters were distributed in the academic departments and the administrative building in the College. The exposure time in all the buildings was one complete lunar year in the period October 2001-October 2002 to get the average annual indoor radon concentration. All the buildings were constructed with ready-made concrete, except the administrative building which constructed with ordinary concrete bricks. A significant difference in the average indoor radon concentrations in the two types of buildings was found. The average indoor radon concentration in the ready-made concrete buildings was 6+/-2Bqm{sup -3} whereas that for the ordinary concrete brick building was 24+/-2Bqm{sup -3}. This could be due to the fact that ready-made concrete has a significantly less voids for the radon to emanate compared with ordinary concrete bricks. The indoor radon concentration in the ground floor is slightly higher than that in the first and second floors.

Determination of indoor radon concentration levels and the associated annual effective dose rate in some Ghanaian dwellings

International Nuclear Information System (INIS)

Nsiah-Akoto, I.

2010-01-01

Radon and its decay products in indoor air are the main source of natural internal irradiation of man. In this present work, the indoor radon concentration, the annual exposure, the annual effective dose and the annual dose equivalent to the lung received by the population were estimated in the dwellings at Dome in the Ga-East District of the Greater Accra Region, Ghana using time-integrated passive radon detectors; LR-115 Type II solid state nuclear track detector (SSNTD) technique. The primary objective of this project was to assess the annual effective dose rate due to the indoor radon concentration levels and the associated level of risk. Measurements were carried out from December 2009 to March 2010. After the 3 months exposure, the detectors were subjected to chemical etching in a 2.5M analytical grade sodium hydroxide solution at (60 ±1) o C, for 90mins in a constant temperature water bath to enlarge the latent tracks produced by alpha particles from the decay of radon. The etched tracks were magnified using the microfiche reader and counted with a tally counter. The mean indoor radon concentration was found to be (466.9±1.2) Bqm -3 and the mean annual exposure was (2.03±0.08) WLM. Assuming an indoor occupancy factor of 0.4 and 0.4 for equilibrium factor for radon indoors, we found out that the mean Rn-222 effective dose rate and the annual equivalent dose rate to the lung in the present study dwellings was (14.13±0.22)mSvy -1 and (3.74 E-07 ±3.50 E-06)Svy -1 respectively. The mean values of radon concentrations at Dome, Kwabenya, Biakpa, and South-Eastern part of Ghana, Prestea and Kassena-Nakana District in the previous research ranged from (9.4±0.5) to (518.7±4.0) Bqm -3 . The mean annual exposure, annual effective dose rate and the annual equivalent for the previous work ranged from (0.04±0.03)WLM to (0.58±0.05)WLM, (0.28±0.08) to (15.54±0.69mSvy -1 ), (8.23E-12±4.33E-07) to (4.15E-07± 1.13E-04) respectively. Odds ratios (ORs) for lung

High indoor radon concentrations in some Swedish waterworks

International Nuclear Information System (INIS)

Aakerblom, G.; Hagberg, N.; Mjoenes, L.; Heiberg, A.

2002-01-01

High indoor radon concentrations in buildings used for water treatment are not uncommon. When raw water is processed in an open system radon escapes from the water to the indoor air of the premises. It is not unusual that the staff of the waterworks have their offices in the building where the water is processed. If large volumes of water are processed and the evaporated radon can reach the workplaces the indoor radon concentration can be very high even if the radon concentration of the raw water is moderate. Groundwaters from aquifers in bedrock and soil and surface water that has been infiltrated through deposits of sand or gravel have the potential to cause high indoor radon levels. In surface water emanating directly from a lake or a river the radon concentrations are normally too low to cause problems. Three waterworks in central Sweden have been studied, Ludvika, Fredriksberg and Kolbaeck. The radon concentrations in the raw water of these waterworks are from 85 Bq/l to 300 Bq/l. Average indoor radon concentrations exceeding 17,000 Bq/m 3 have been measured in Ludvika with peaks of almost 37,000 Bq/m 3 . In Kolbaeck radon concentrations up to 56,000 Bq/m 3 have been measured. It is quite possible that employees of waterworks can receive doses exceeding 20 mSv per year (calculated according to ICRP:s dose conversion convention). Measurements of radon and gamma radiation from the waterworks are reported and methods to lower the indoor radon concentrations are discussed. (author)

The measurement of the indoor absorbed dose rate in air in Beijing

International Nuclear Information System (INIS)

Guo Mingqiang; Pan Ziqiang; Yi Nanchang; Wei Zemin; Zhang Chao; Wang Huamin; Zhu Wencai

1985-01-01

This paper describes the indoor absorbed dose rate in air in Beijing. The average indoor absorbed dose rate in air is 8.29 μrad/h. The ratio of indoor to outdoor absorbed dose rate for 849 buildings is 1.51

Characterizing the source of radon indoors

International Nuclear Information System (INIS)

Nero, A.V.; Nazaroff, W.W.

1983-09-01

Average indoor radon concentrations range over more than two orders of magnitude, largely because of variability in the rate at which radon enters from building materials, soil, and water supplies. Determining the indoor source magnitude requires knowledge of the generation of radon in source materials, its movement within materials by diffusion and convection, and the means of its entry into buildings. This paper reviews the state of understanding of indoor radon sources and transport. Our understanding of generation rates in and movement through building materials is relatively complete and indicates that, except for materials with unusually high radionuclide contents, these sources can account for observed indoor radon concentrations only at the low end of the range observed. Our understanding of how radon enters buildings from surrounding soil is poorer, however recent experimental and theoretical studies suggest that soil may be the predominant source in many cases where the indoor radon concentration is high. 73 references, 3 figures, 1 table

Factors affecting yearly variations of indoor radon concentrations

International Nuclear Information System (INIS)

Steck, D.J.; Baynes, S.A.

1996-01-01

Since indoor radon exposures take place over many years while radon measurement periods are shorter, we are studying the yearly variation of indoor radon concentrations in approximately 100 houses located throughout Minnesota. Most houses were initially measured for one or more years in the late 1980's and for 5 consecutive years starting in 1990. Two houses have been monitored for 12 y. Each year, two alpha track detectors were placed on the two lowest livable levels. The year-to-year variations averaged about 35% (corrected for instrumental uncertainties) in both basements and first floors. The minimum observed variation was 5% and the maximum was 130%. Some homes have shown substantial variation associated with Structural modifications. While most homes show no obvious systematic trends, a few houses have shown temporal trends that may be associated with aging or climate. We are studying possible correlation between year-to-year radon variation, climatic variables (yearly-average and seasonal such as heating/cooling degree days, precipitation, soil moisture), and structural changes

Indoor air quality investigation at air-conditioned and non-air-conditioned markets in Hong Kong

International Nuclear Information System (INIS)

Guo, H.; Lee, S.C.; Chan, L.Y.

2004-01-01

To characterize indoor air quality at the markets in Hong Kong, three non-air-conditioned and two air-conditioned markets were selected for this study. The indoor air pollutants measured included PM 10 (particulate matters with aerodynamic diameter less than 10 μm), total bacteria count (TBC), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO 2 ) and sulfur dioxide (SO 2 ). The indoor and outdoor concentrations of these target air pollutants at these markets were measured and compared. The effects of air conditioning, temperature/relative humidity variation and different stalls on the indoor air quality were also investigated. The results indicated that all of the average indoor concentrations of PM 10 , TBC, CO and NO 2 at the markets were below the Hong Kong Indoor Air Quality Objectives (HKIAQO) standards with a few exceptions for PM 10 and TBC. The elevated PM 10 concentrations at Hung Hom, Ngau Tau Kok and Wan Chai markets were probably due to the air filtration of outdoor airborne particulates emitted from vehicular exhaust, whereas high concentrations of airborne bacteria at Sai Ying Pun and Tin Shing markets were linked to the use of air conditioning. Correlation analysis demonstrated that indoor bacteria concentrations were correlated with temperature and relative humidity. The operation of air conditioning did not significantly reduce the levels of air pollutants at the markets. However, the higher indoor/outdoor ratios demonstrated that the operation of air conditioning had influence on the levels of bacteria at the markets. It was found that average PM 10 concentration at poultry stalls was higher than the HKIAQO standard of 180 μg/m 3 , and was over two times that measured at vegetable, fish and meat stalls. Furthermore, the concentration of airborne bacteria at the poultry stalls was as high as 1031 CFU/m 3 , which was above the HKIAQO standard of 1000 CFU/m 3 . The bacteria levels at other three stalls were all below the HKIAQO standard

Incense, sparklers and cigarettes are significant contributors to indoor benzene and particle levels

Directory of Open Access Journals (Sweden)

Werner Tirler

2015-03-01

Full Text Available Introduction. The increased use of incense, magic candles and other flameless products often produces indoor pollutants that may represent a health risk for humans. Today, in fact, incense and air fresheners are used inside homes as well as in public places including stores, shopping malls and places of worship. As a source of indoor contamination, the impact of smoke, incense and sparklers on human health cannot be ignored. Aim. In the present work, we report the results of an emission study regarding particles (PM10 and particle number concentration, PNC and benzene, produced by various incense sticks and sparklers. Results and discussion.The results obtained for benzene, PM10 and PNC, showed a strong negative influence on air quality when these products were used indoors. Various incense sticks gave completely different benzene results: from a small increase of the benzene concentration in the air, just slightly above the background levels of ambient air, to very high concentrations, of more than 200 µg/m³ of benzene in the test room after the incense sticks had been tested.

Incense, sparklers and cigarettes are significant contributors to indoor benzene and particle levels.

Science.gov (United States)

Tirler, Werner; Settimo, Gaetano

2015-01-01

The increased use of incense, magic candles and other flameless products often produces indoor pollutants that may represent a health risk for humans. Today, in fact, incense and air fresheners are used inside homes as well as in public places including stores, shopping malls and places of worship. As a source of indoor contamination, the impact of smoke, incense and sparklers on human health cannot be ignored. In the present work, we report the results of an emission study regarding particles (PM10 and particle number concentration, PNC) and benzene, produced by various incense sticks and sparklers. The results obtained for benzene, PM10 and PNC, showed a strong negative influence on air quality when these products were used indoors. Various incense sticks gave completely different benzene results: from a small increase of the benzene concentration in the air, just slightly above the background levels of ambient air, to very high concentrations, of more than 200 µg/m of benzene in the test room after the incense sticks had been tested.

Indoor air quality in a restaurant kitchen using margarine for deep-frying.

Science.gov (United States)

Sofuoglu, Sait C; Toprak, Melis; Inal, Fikret; Cimrin, Arif H

2015-10-01

Indoor air quality has a great impact on human health. Cooking, in particular frying, is one of the most important sources of indoor air pollution. Indoor air CO, CO2, particulate matter (PM), and volatile organic compound (VOC) concentrations, including aldehydes, were measured in the kitchen of a small establishment where a special deep-frying margarine was used. The objective was to assess occupational exposure concentrations for cooks of such restaurants. While individual VOC and PM2.5 concentrations were measured before, during, and after frying events using active sampling, TVOC, PM10, CO, CO2, temperature, and relative humidity were continuously monitored through the whole period. VOC and aldehyde concentrations did not increase to considerable levels with deep-frying compared to the background and public indoor environment levels, whereas PM10 increased significantly (1.85 to 6.6 folds). The average PM2.5 concentration of the whole period ranged between 76 and 249 μg/m(3). Hence, considerable PM exposures could occur during deep-frying with the special margarine, which might be sufficiently high to cause health effects on cooks considering their chronic occupational exposures.

Indoor and Outdoor Levels and Sources of Submicron Particles (PM1) at Homes in Edmonton, Canada.

Science.gov (United States)

Bari, Md Aynul; Kindzierski, Warren B; Wallace, Lance A; Wheeler, Amanda J; MacNeill, Morgan; Héroux, Marie-Ève

2015-06-02

Exposure to submicron particles (PM1) is of interest due to their possible chronic and acute health effects. Seven consecutive 24-h PM1 samples were collected during winter and summer 2010 in a total of 74 nonsmoking homes in Edmonton, Canada. Median winter concentrations of PM1 were 2.2 μg/m(3) (interquartile range, IQR = 0.8-6.1 μg/m(3)) and 3.3 μg/m(3) (IQR = 1.5-6.9 μg/m(3)) for indoors and outdoors, respectively. In the summer, indoor (median 4.4 μg/m(3), IQR = 2.4-8.6 μg/m(3)) and outdoor (median 4.3 μg/m(3), IQR = 2.6-7.4 μg/m(3)) levels were similar. Positive matrix factorization (PMF) was applied to identify and apportion indoor and outdoor sources of elements in PM1 mass. Nine sources contributing to both indoor and outdoor PM1 concentrations were identified including secondary sulfate, soil, biomass smoke and environmental tobacco smoke (ETS), traffic, settled and mixed dust, coal combustion, road salt/road dust, and urban mixture. Three additional indoor sources were identified i.e., carpet dust, copper-rich, and silver-rich. Secondary sulfate, soil, biomass smoke and ETS contributed more than 70% (indoors: 0.29 μg/m(3), outdoors: 0.39 μg/m(3)) of measured elemental mass in PM1. These findings can aid understanding of relationships between submicron particles and health outcomes for indoor/outdoor sources.

Indoor radon measurements in dwellings of four Saudi Arabian cities

Energy Technology Data Exchange (ETDEWEB)

Al-Jarallah, M.I. E-mail: mibrahim@kfupm.edu.sa; Fazal-ur-Rehman; Abu-Jarad, F.; Al-Shukri, A

2003-06-01

An indoor radon survey of a total of 269 dwellings, with one dosimeter per house, distributed in four Saudi Arabian cities was carried out. The objective of this survey was to carry out indoor radon measurements of two cities in the Eastern Province, Khafji and Hafr Al-Batin and to compare this with two cities in the Western Province, Al-Madina and Taif. The survey provides additional information about indoor radon concentrations in Saudi Arabia. The results of the survey in these cities showed that the overall minimum, maximum and average radon concentration were 7,137 and 30 Bq m{sup -3}, respectively. The lowest average radon concentration (20 Bq m{sup -3}) was found in Hafr Al-Batin, while the highest average concentration was found in Khafji (40 Bq m{sup -3})

Current Indoor Air Quality in Japan.

Science.gov (United States)

Jinno, Hideto

2016-01-01

People spend more than two thirds of their daily time indoors. Hence, maintaining a healthy indoor environment is indispensable for the prevention of building related illness. In Japan, guidelines for indoor air quality have been established for 13 volatile/semi-volatile organic compounds (VOCs/SVOCs). These guidelines are now under revision by the Committee on Sick House Syndrome: Indoor Air Pollution. In order to gain information on the current indoor air pollutants and their levels, we carried out a nation-wide survey of VOCs and aldehydes in indoor residential air during 2012-2013. In this review, I concisely summarized the current indoor air quality of Japan.

Indoor radon survey in Eastern Sicily

International Nuclear Information System (INIS)

Catalano, R.; Immè, G.; Mangano, G.; Morelli, D.; Tazzer, A. Rosselli

2012-01-01

Inhalation of radon (Rn-222) and its progeny is one of the most significant sources of natural radiation exposure of the population. Nowadays, high radon exposures have been shown to cause lung cancer and many governments all over the world have therefore recommended that radon exposures in dwellings and indoor workplaces should be limited. Radon levels in buildings vary widely from area to area depending on local geology. This paper presents the results of a long-term survey of radon concentrations carried out from 2005 till 2010 in schools and dwellings of Eastern Sicily, using the solid-state nuclear track detector (SSNTD) technique. The investigated area shows medium-high indoor radon concentrations, higher than the Italian average of about 70 Bq/m 3 , with peaks of 500 Bq/m 3 or more in buildings near active faults. Fortunately, only a small fraction of the measurements, about 1.5% of total, was found greater than EU and Italian action limits for indoor and workplaces. - Highlights: ► In this paper we report radon monitoring survey carried out in the east Sicily in schools and dwellings. ► The detection methodology was the solid-state nuclear track detector one. ► The work was supported by a national projects financed by the National Institute of Nuclear Physics.

Simulasi Penggunaan Frekuensi Milimeter Wave Untuk Akses Komunikasi Jaringan 5G Indoor

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Toha Ardi Nugraha

2017-02-01

Full Text Available Millimeter Wave (mmWave is a solution to overcome of frequency limitations in 5G technology implementations using high frequency domain. This research discusses about mmWave frequency selection for 5G technology using empirical models in indoor propagation model. Several MmWave frequencies are simulated on indoor office environment. Based on simulation with InH placed in each room 5x5 meter size, it will be more effective using 60GHz, compared to 38Ghz, 28GHz, and 5GHz and also unlicenced 2.4. The average SIR will better at mmWave frequencies in the 60GHz with 33.97 dB and the average received signal is -73.87 dBm. Overall, it can also be concluded that the InH device with low frequency is not suitable applied indoors with massive deployement, it can be interference, for exampe using unlicenced 2.4GHz and 5GHz,  receiver only gets average SIR of approximately 5dB. Keywords-5G, Indoor, Milimeter Wave, Indoor Hotspot

Environmental and indoor study of Radon concentration in San Joaquin area, Queretaro, Mexico, first results

International Nuclear Information System (INIS)

Hinojo Alonso, N.A.; Kotsarenko, A.; Yutsis, V.; Hernandez Silva, G.; Perego, P.; Fazio, M.; Grimalsky, V.; Koshevaya, S.; Foglia, F.; Cortes Silva, A.; García Martínez, R.; Martínez Reyes, J.; Norini, G.; Groppelli, G.

2013-01-01

A highly contaminated zone with a maximum over 57,000 Bq/m 3 was discovered in a populated community “Agua de Venados” during the 2009–2011 soil Radon survey in San Joaquin, Queretaro State, Mexico. The indoor Radon monitoring accomplished in 2 different époques in a nearby 4 dwellings has shown an increased Radon hazard in 1 of the 4 buildings (about 300 Bq/m 3 ) during a rainy season and highly elevated indoor Radon levels (over 400 Bq/m 3 ) already in 3 buildings during a dry season. The averaged diurnal indoor Radon variations are in a correlation with the atmospheric pressure and the air humidity and are independent on the air temperature. The maximum indoor Radon hazard for dwellings is estimated for the morning interval 5–10 a.m. - Highlights: ► Emanative zone of 57,000 Bq/m 3 was found in area “Agua de Venados”. ► Indoor Radon level in a nearby dwellings elevates during a dry season. ► Maximum risk for residents was estimated during the daily interval 5–10 a.m

Airborne particle-bound brominated flame retardants: Levels, size distribution and indoor-outdoor exchange.

Science.gov (United States)

Zhu, Yue-Shan; Yang, Wan-Dong; Li, Xiu-Wen; Ni, Hong-Gang; Zeng, Hui

2018-02-01

The quality of indoor environments has a significant impact on public health. Usually, an indoor environment is treated as a static box, in which physicochemical reactions of indoor air contaminants are negligible. This results in conservative estimates for primary indoor air pollutant concentrations, while also ignoring secondary pollutants. Thus, understanding the relationship between indoor and outdoor particles and particle-bound pollutants is of great significance. For this reason, we collected simultaneous indoor and outdoor measurements of the size distribution of airborne brominated flame retardant (BFR) congeners. The time-dependent concentrations of indoor particles and particle-bound BFRs were then estimated with the mass balance model, accounting for the outdoor concentration, indoor source strength, infiltration, penetration, deposition and indoor resuspension. Based on qualitative observation, the size distributions of ΣPBDE and ΣHBCD were characterized by bimodal peaks. According to our results, particle-bound BDE209 and γ-HBCD underwent degradation. Regardless of the surface adsorption capability of particles and the physicochemical properties of the target compounds, the concentration of BFRs in particles of different size fractions seemed to be governed by the particle distribution. Based on our estimations, for airborne particles and particle-bound BFRs, a window-open ventilated room only takes a quarter of the time to reach an equilibrium between the concentration of pollutants inside and outside compared to a closed room. Unfortunately, indoor pollutants and outdoor pollutants always exist simultaneously, which poses a window-open-or-closed dilemma to achieve proper ventilation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Measurment of radon, thoron and their progeny in indoor environment of Mohali, Punjab, Northern India, using pinhole dosimeters

Directory of Open Access Journals (Sweden)

Mehta Vimal

2016-01-01

Full Text Available The health hazards of radon and its decay products above certain levels are well known. However, for any preventive measures to be taken, we have to be aware of radon levels of that particular area. Measurement of radon and its decay products in indoor environments is an important aspect of assessing indoor air quality and health conditions associated with it. Keeping this in mind, measurements of radon, thoron and their progeny concentrations were carried out in Mohali, Northern India, using pinhole-based twin cup dosimeters. Radon exhalation rates of soil samples in the dwellings/areas were measured via an active technique of a continuous radon monitor. The indoor radon concentration in Mohali varied from 15.03 ± 0.61 Bq/m3 to 39.21 ± 1.46 Bq/m3 with an average of 26.95 Bq/m3 ,while thoron concentration in the same dwellings varied from 9.62 ± 0.54 Bq/m3 to 52.84 ± 2.77 Bq/m3 with an average of 31.09 Bq/m3. Radon progeny levels in dwellings under study varied from 1.63 to 4.24 mWL, with an average of 2.94 mWL, while thoron progeny levels varied from 0.26 to 1.43 mWL , with an average of 0.84 mWL. The annual dose received by the inhabitants of dwellings under study varied from 0.78 to 2.36 mSv, with an average of 1.61 mSv. The in situ gamma dose rate varied from 0.12 to 0.32 mSv/h.

Indoor External Radiation Risk in Densely Populated Regions of Southern Nigeria

Science.gov (United States)

Ife-Adediran, Oluwatobi O.; Uwadiae, Iyobosa B.

2018-05-01

It is known that certain types of building materials contain significant concentrations of natural radionuclides; consequently, exposure to indoor background radiation is from the combined radioactivity from the soil as well as building materials; indoor exposures therefore have higher radiation hazard potentials than outdoor exposures in this regard and hence, need to be monitored. In this paper, an evaluation of background ionizing radiation from different buildings in Lagos and Ibadan, Southwestern Nigeria was carried out to determine the exposure rate of the general public to indoor ionizing radiation. 630 in situ measurements from the different buildings were taken using a Geiger Muller counter (model GQ-320 Plus). The indoor dose rates (i.e., 50-120 nGy/h) were within the world average values while the Annual Effective Dose for most of the buildings were above the world average AED for indoor gamma exposure from building materials. The mean AED for Lagos and Ibadan due to indoor exposures were 0.37 and 0.39 mSv/y with Excess Lifetime Cancer Risk of 0.99E-3 and 1.05E-3, respectively.

Contribution to the relation between volume activity of soil and indoor radon

International Nuclear Information System (INIS)

Mojzes, A.

1999-01-01

There were carried out some repeated manual measurements of volume activity of radon-222 (VAR) in both soil air of subsoil and also indoor air of buildings in two different areas in Bratislava. All measurements were done with a portable scintillation detector based on exchangeable Lucas cells. The measurements were repeated in different day and year intervals. There were repeated 259 measurements of volume activity of radon-222 in soil air with the average valuer 11.95 kBq/m 3 and the standard deviation 1.53 kBq/m 3 in the subsoil of the one-story house and 597 measurements of VAR in soil air of the subsoil of the second study building with the average 9.44 kBq/m 3 and the standard deviation 3.08 kBq/m 3 . Presented results of measurement of radon-222 volume activity in both soil and indoor air demonstrate that also in case of low radon concentrations in soil air of geological basement the level of radon in indoor air could be considerably high. It depends mainly on used technology of laying building foundations, on the distance from subsoil and on regime of ventilation. In case of older buildings the ventilation is very effective way to reduce the presence of radon in indoor air. (author)

Daily variation of the radon concentration indoors and outdoors and the influence of meteorological parameters

International Nuclear Information System (INIS)

Porstendoerfer, J.; Butterweck, G.; Reineking, A.

1994-01-01

Series of continuous radon measurements in the open atmosphere and in a dwelling, including the parallel measurement of meteorological parameters, were performed over a period of several weeks. The radon concentration in indoor and outdoor air depends on meteorological conditions. In the open atmosphere the radon concentration varies between 1 and 100 Bq m -3 , depending on weather conditions and time of day. During time periods of low turbulent air exchange (high pressure weather with clear night sky), especially in the night and early morning hours (night inversion layer), the diurnal variation of the radon concentration showed a pronounced maximum. Cloudy and windy weather conditions yield a small diurnal variation of the radon concentration. Indoors, the average level and the diurnal variation of the indoor radon concentration is also influenced by meteorological conditions. The measurements are consistent with a dependence of indoor radon concentrations on indoor-outdoor pressure differences. 11 refs., 4 figs

Indoor radon levels and inhalation doses in dwellings near the some sites of Himachal Pradesh, India

International Nuclear Information System (INIS)

Bajwa, B.S.; Singh, S.; Virk, H.S.

2005-01-01

In view of the fact that radon and its daughters are a major source of natural radiation exposure, the measurement of radon concentration levels in dwellings has assumed ever-increasing importance. Keeping this in view, the indoor radon level measurements were carried out in the dwellings of different villages known to be located in the vicinity of uranium-mineralized pockets of Hamirpur district, Himachal Pradesh. Track-etch technique, a passive method using the Solid State Nuclear Track Detectors (SSNTDs), LR-115 type II, was utilized for these measurements. An attempt has been made to assess the levels of the indoor radon in the dwellings and inhalation dose rates of the population living in these villages. The radon concentrations were found to be varying with seasonal changes, building materials and mode of construction of houses. The radon concentrations were found to be higher in houses made from local sandstone and with mud floor in comparison to the houses having cemented brick floors. The annual indoor radon concentration and thus annual effective dose in most of the dwellings of these villages is certainly quite higher and even in some of the dwellings it even exceeds the upper limit of the proposed action level of ICRP, 1993. The inhalation dose rates in dwellings of these villages located in the vicinity of uranium mineralized pockets of Hamirpur district, Himachal Pradesh have been found to be quite higher than dose rate in the dwellings in the Amritsar city, Punjab, which is located in a completely uranium free zone. The radon survey in the dwellings of these villages has also been carried out using the Alpha-Guard technique, which is based on the pulse ionization chamber. The indoor radon concentration levels measured using the active technique of Alpha Guard have been found to be quite different from those measured in these dwellings by the passive technique of SSNTDs; indicating the importance of the SSNTDs in the long-term integrated measurement

Indoor-outdoor nitric oxide and nitrogen dioxide concentrations at three sites in Riyadh, Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Rowe, D.R. (D.R. Rowe Engineering Services, Inc., Bowling Green, KY (United States)); Al-Dhowalia, K.H.; Mansour, M.E. (King Saud Univ., Riyadh (Saudi Arabia))

1991-08-01

The objective of this study was to evaluate the nitric oxide and nitrogen oxide concentrations indoors and outdoors at three sites in Riyadh, Saudi Arabia. Results show that the outdoor and indoor concentrations for NO were at least 270 and 16 times the reported average worldwide NO concentrations, respectively. The NO(sub 2) concentrations were about 14 times reported outdoor worldwide levels; however, NO(sub 2) concentrations indoors were generally below those reported in the literature. The data presented, in combination with information presented in previous articles, will provide a valuable background database for use in dispersion models to determine the effect of the Kuwaiti oil well fires on the air quality of Riyadh.

Indoor radon concentration and outdoor/indoor pressure difference correlation

International Nuclear Information System (INIS)

Cechak, T.; Fronka, A.; Moucka, L.

2004-01-01

In the current approach to the radon issue, the radon risk for people living in a building is estimated based on the average indoor radon concentration. Short-term measurements as usually applied fail to reflect the wide range of radon variations arising from ventilation, radon supply and, in particular, human activities in the building. For this reason, efforts are made to find a new approach to the assessment of the quality of a building as a radon barrier, independent of the weather conditions and residential habits. A simple model of radon volume activity entering the building at a constant rate and simultaneously ventilated at a constant rate is applicable to this task. The rate of radon ingress can be regarded as a parameter making it possible to quantify the leakage of structures provided the barrier against the radon in a soil gas. The ventilation rate, on the other hand, characterizes the leakage of the whole building envelope at a given outdoor/indoor pressure difference. A unique measuring technique called the blower door exists whereby a defined pressure difference between the indoor and outdoor atmosphere can be established. Under such conditions both the ventilation rate and the rate of radon ingress can be measured and expressed as a function of the pressure difference. An analysis of the model of a room with a constant ventilation and constant radon supply is presented and the relationship between radon supply and ventilation rate can be assumed. Some experimental results show how the model can be utilized. The real indoor-outdoor air pressure differences, the indoor-soil air pressure differences, and some effects of different ventilation regimes are given. Other experiments, which have been done by using the blower door method, illustrate the possible effects and some restrictions for a routine application are discussed

The association between estimated average glucose levels and fasting plasma glucose levels

Directory of Open Access Journals (Sweden)

Giray Bozkaya

2010-01-01

Full Text Available OBJECTIVE: The level of hemoglobin A1c (HbA1c, also known as glycated hemoglobin, determines how well a patient's blood glucose level has been controlled over the previous 8-12 weeks. HbA1c levels help patients and doctors understand whether a particular diabetes treatment is working and whether adjustments need to be made to the treatment. Because the HbA1c level is a marker of blood glucose for the previous 120 days, average blood glucose levels can be estimated using HbA1c levels. Our aim in the present study was to investigate the relationship between estimated average glucose levels, as calculated by HbA1c levels, and fasting plasma glucose levels. METHODS: The fasting plasma glucose levels of 3891 diabetic patient samples (1497 male, 2394 female were obtained from the laboratory information system used for HbA1c testing by the Department of Internal Medicine at the Izmir Bozyaka Training and Research Hospital in Turkey. These samples were selected from patient samples that had hemoglobin levels between 12 and 16 g/dL. The estimated glucose levels were calculated using the following formula: 28.7 x HbA1c - 46.7. Glucose and HbA1c levels were determined using hexokinase and high performance liquid chromatography (HPLC methods, respectively. RESULTS: A strong positive correlation between fasting plasma glucose levels and estimated average blood glucose levels (r=0.757, p<0.05 was observed. The difference was statistically significant. CONCLUSION: Reporting the estimated average glucose level together with the HbA1c level is believed to assist patients and doctors determine the effectiveness of blood glucose control measures.

Methods and measurements of indoor levels of radon and its daughter products

International Nuclear Information System (INIS)

Subba Ramu, M.C.; Muraleedharan, T.S.; Ramachandran, T.V.; Shaikh, G.N.

1988-01-01

General population is exposed, some times, to enhanced levels of radon (Rn) and its progeny concontrations in the indoor environment of dwellings, depending on various parameters like type of construction, location and ventilation features of the dwelling as well as on the occupancy factor. The risk involved in the indoor Rn exposure is briefly discussed in this report. Several methods are available for the measurement of Rn and its daughters in dwellings. This report describes in detail some of the suitable and convenient methods for the measurements. Methods for evluating ventilation rate in dwellings is also given. Grab sampling and time integrated measurements are described. The report also gives the results of some preliminary measurements carried out in some rooms and lecture halls of the Bhabha Atomic Research Centre, Bombay. The results are discussed and conclusions drawn with particular reference to a country-wide survey of Rn exposure. (author)

Indoor air quality in ice skating rinks in Hong Kong

International Nuclear Information System (INIS)

Guo, H.; Lee, S.C.; Chan, L.Y.

2004-01-01

Indoor air quality in ice skating rinks has become a public concern due to the use of propane- or gasoline-powered ice resurfacers and edgers. In this study, the indoor air quality in three ice rinks with different volumes and resurfacer power sources (propane and gasoline) was monitored during usual operating hours. The measurements included continuous recording of carbon monoxide (CO), carbon dioxide (CO 2 ), total volatile organic compounds (TVOC), particulate matter with a diameter less than 2.5 μm (PM 2.5 ), particulate matter with diameter less than 10 μm (PM 10 ), nitric oxide (NO), nitrogen dioxide (NO 2 ), nitrogen oxide (NO x ), and sulfur dioxide (SO 2 ). The average CO, CO 2 , and TVOC concentrations ranged from 3190 to 6749 μg/m 3 , 851 to 1329 ppm, and 550 to 765 μg/m 3 , respectively. The average NO and NO 2 concentrations ranged from 69 to 1006 μg/m 3 and 58 to 242 μg/m 3 , respectively. The highest CO and TVOC levels were observed in the ice rink which a gasoline-fueled resurfacer was used. The highest NO and NO 2 levels were recorded in the ice rink with propane-fueled ice resurfacers. The air quality parameters of PM 2.5 , PM 10 , and SO 2 were fully acceptable in these ice rinks according to HKIAQO standards. Overall, ice resurfacers with combustion engines cause indoor air pollution in ice rinks in Hong Kong. This conclusion is similar to those of previous studies in Europe and North America

Correlation between indoor radon and soil gas availability: Results of field studies

International Nuclear Information System (INIS)

Kothari, B.K.; Kunz, C.; Lilley, W.

1990-01-01

To correlate indoor radon concentrations with soil gas, the authors have carried out a field survey of surficial material in selected regions of New York State. The survey consisted of measurements of gamma radiation, Ra-226, Rn-222 and the permeability for gas flow in surficial material. Based on the data, three areas with a potential for above average indoor radon concentrations have been identified: (1) a black shale region in Onondaga County; (2) a granitic region in Orange County; and (3) a black shale region in Erie County. For an area with potential for below-average indoor radon concentrations, sandy deposits on Long Island with an average concentration of 0.7 pCi Ra-226/g and 160 pCi Rn-222/L at 2-feet depth, have been selected. Fifteen homes from each of these four areas are under test for indoor radon. Measurements of air infiltration rates and soil gas availability parameters are planned for all 60 homes

Association between State Assistance on the Topic of Indoor Air Quality and School District-Level Policies That Promote Indoor Air Quality in Schools

Science.gov (United States)

Everett Jones, Sherry; Doroski, Brenda; Glick, Sherry

2015-01-01

Nationally representative data from the 2012 School Health Policies and Practices Study examined whether state assistance on indoor air quality (IAQ) was associated with district-level policies and practices related to IAQ and integrated pest management (IPM). Districts in states that provided assistance on IAQ were more likely than districts not…

Indoor radon and environmental gamma radiation in Hong Kong

International Nuclear Information System (INIS)

Yu, K.N.; Young, E.C.M.; Stokes, M.J.; Luo, D.L.; Zhang, C.X.

1992-01-01

Activated charcoal canisters have been used to measured the indoor radon concentrations of 160 sites in different buildings in Hong Kong during the period from July to October 1990. The average value is 40.0 Bq.m -3 . Furthermore, CR-39 nuclear track detectors and two kinds of LiF TLDs have been used to measure the average indoor radon concentrations and the absorbed gamma dose rates in air of 71 sites over the period from January to April 1991. The results all show log-normal distribution. The indoor radon concentrations are respectively 72.2 Bq.m -3 and 155.4 Bq.m -3 for dwellings and offices, while the absorbed gamma dose rates in air are respectively 213.0 nGy.h -1 and 198.3 nGy.h -1 . (author)

[Global air monitoring study: a multi-country comparison of levels of indoor air pollution in different workplaces results from Tunisia].

Science.gov (United States)

Higbee, Cheryl; Travers, Mark; Hyland, Andrew; Cummings, K Michael; Dresler, Carolyn

2007-09-01

In 1986, a report of the U.S. Surgeon General concluded that second hand smoke is a cause of disease in healthy non smokers. Subsequent many nations including Tunisia implement smoke-free worksite regulations. The aim of our study is to test air quality in indoor ambient air venues in Tunisia. A TSI SidePak AM510 Personal Aerosol Monitor was used to sample, record the levels of respirable suspended particles (RSP) in the air and to assess the real-time concentration of particles less than 2.5 microm in micrograms per cubic meter, or PM2.5. Thirty three venues were sampled in Tunis. The venues were selected to get a broad range of size, location and type of venue. Venues included restaurants and cafés, bars, bus stations, hospitals, offices, and universities. The mean level of indoor air pollution was 296 microg/m3 ranged from 11 microg/m3 to 1,499 microg/m3. The level of indoor air pollution was 85% lower in venues that were smoke-free compared to venues where smoking was observed (ppollution were found in hospitals, offices and universities (52 microg/m3) and the highest level was found in a bar (1,499 micro/m3). Hospitality venues allowing indoor air smoking in Tunisia are significantly more polluted than both indoor smoke-free sites and outdoor air in Tunisia. This study demonstrates that workers and patrons are exposed to harmful levels of a known carcinogen and toxin. Policies that prohibit smoking in public worksites dramatically reduce second hand smoke exposure and improve worker and patron health.

A survey of indoor radon and particular concentration

International Nuclear Information System (INIS)

Ohta, Yukiko

1993-01-01

Lung disease risk from inhalation of radon can be enhanced by the presence of particular pollutants in indoor air. The indoor concentration of radon and particulates were measured in homes, a department store, and offices in a high building in Tokyo metropolis, as well as in homes in both northern and western Japan. Passive radon monitors were located in living rooms and offices for more than three months at 99 sites during the winter of 1988 and 1989. Indoor radon concentration ranged from 11.1 Bq/m 3 to 148 Bq/m 3 (n=99) and averaged value S.D. was 36.5±14.2 Bq/m 3 . However, the average concentration in air conditional buildings was 21.8±9.51 Bq/m 3 (n=17). Simultaneously at 65 of the radon sites, indoor particulates were collected using personal dust samplers by impaction methods. Deposited particulate concentrations on the sampler were measured and calculated in a unit of μm/m 3 . Concentrations were determined for particle sizes above and below 2.5 μm, for both smoking or non smoking sites. Consequently, concentration of particle size below 2.5 μm was high in smoking rooms. Finally, it was considered that smoking was a complex indoor pollutant as adherence of radon daughter to aerosols. (author)

Indoor radon -- a strategic perspective

International Nuclear Information System (INIS)

Nero, A.V.

1992-01-01

Even the average 222 Rn concentration in US homes corresponds to an estimated individual lifetime risk of fatal lung cancer between 0.1% and 1%, depending on whether one smokes or not. Perhaps 50,000 to 100,000 homes have ten times the average or more, implying radiation doses to the occupants at or above the occupational radiation limit. But even this picture has been exaggerated by information provided the public by the EPA and the media, associating with nonsmokers risk estimated for smokers, and -- due to a faulty monitoring protocol -- giving the impression that a large fraction of homes have elevated levels. The result has been a program that focuses in fact on slightly-above-average indoor levels, while having no program for rapidly identifying and assisting those living at genuinely high levels. A sensible and effective strategy, in contrast, would (1) rely on accurate and specific public information, (2) recommend a monitoring protocol yielding the annual-average concentration in living space, the parameter of health significance, (3) constitute a national program to identify systematically and rapidly the areas of the country where the bulk of the high-radon homes occur, (4) build a sensible long-term research and action program associated with lower concentrations. Accomplishing these purposes will require a commitment to careful analysis and planning, involving an effective interaction with the scientific community, that has so far not been demonstrated

MEASUREMENT OF INDOOR RADON-THORON IN AIR AND EXHALATION FROM SOIL IN THE ENVIRONMENT OF WESTERN HARYANA, INDIA.

Science.gov (United States)

Mann, Nisha; Kumar, Amit; Kumar, Sushil; Chauhan, R P

2016-10-01

Measurement of indoor radon and thoron is important because the inhalation of radon-thoron and their daughters contributes more than 50 % of the total dose from natural sources. One of the important parameters to find out the contribution of soil and building materials towards indoor radon is radon exhalation rates, which can be used for estimation of indoor radon levels. The indoor radon and thoron levels from the air and radon exhalation rates from soil samples collected from two districts (Hisar and Fatehabad) of Western Haryana are measured using pin-hole-based radon-thoron dosimeter and LR-115 solid-state nuclear track detector by canister technique. The results show that the indoor radon and thoron levels from Hisar district varied from 11 to 112 and 11 to 80 Bq m -3 , while for Fatehabad district from 5 to 24 and 59 to 105 Bq m -3 , respectively, in summer season. In winter season, indoor radon and thoron levels from Hisar district varied from 15 to 43 and 32 to 102 Bq m -3 , while for Fatehabad district from 18 to 31 and 11 to 80 Bq m -3 , respectively. The indoor radon levels of 95 % locations lie well below the limit recommended by International Commission of Radiation Protection, 2011. The radon mass exhalation rate varied from 6 to 56 mBq kg -1 h -1 The radon mass exhalation rates from the soil samples were lower than the worldwide average, i.e. 56 mBq kg -1 h -1 There exists a poor correlation between indoor radon and exhalation rates. More investigations of measurement of radionuclide contents from rock and stone of study area can improve the understanding. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Natural indoor gamma background in Coonoor environment of South India

International Nuclear Information System (INIS)

Sivakumar, R.; Selvasekarapandian, S.; Mugunthamanikand, N.; Raghunath, V.M.

2002-01-01

Indoor natural radiation dose existing in dwellings of Coonoor have been estimated using thermoluminescent dosimeters. TLDs are displayed in indoors and are replaced after three-month period. The seasonal averages of the dose rate and the annual effective dose equivalent are calculated from the measured results. Geographical and seasonal variations as well as the differences between indoor to outdoor dose rates have also been studied. Very good correlation exists between the indoor dose rates measured by LTD and environmental radiation dosimeter with correlation coefficient of 0.91. The annual effective dose equivalent to the Coonoor population due to indoor gamma radiation was estimated to be 970 μSv/y for the period of 1997-1998. (author)

Semivolatile organic compounds in indoor environments

DEFF Research Database (Denmark)

Weschler, Charles J.; Nazaroff, W.W.

2008-01-01

Semivolatile organic compounds (SVOCs) are ubiquitous in indoor environments, redistributing from their original sources to all indoor surfaces. Exposures resulting from their indoor presence contribute to detectable body burdens of diverse SVOCs, including pesticides, plasticizers, and flame ret...... remarkably well with levels measured in dermal hand wipes for SVOCs possessing a wide range of octanol-air partition coefficients....

Unscented Kalman Filter Algorithm for WiFi-PDR Integrated Indoor Positioning

Directory of Open Access Journals (Sweden)

CHEN GuoLiang

2015-12-01

Full Text Available Indoor positioning still faces lots of fundamental technical problems although it has been widely applied. A novel indoor positioning technology by using the smart phone with the assisting of the widely available and economically signals of WiFi is proposed. It also includes the principles and characteristics in indoor positioning. Firstly, improve the system's accuracy by fusing the WiFi fingerprinting positioning and PDR (ped estrian dead reckoning positioning with UKF (unscented Kalman filter. Secondly, improve the real-time performance by clustering the WiFi fingerprinting with k-means clustering algorithm. An investigation test was conducted at the indoor environment to learn about its performance on a HUAWEI P6-U06 smart phone. The result shows that compared to the pattern-matching system without clustering, an average reduction of 51% in the time cost can be obtained without degrading the positioning accuracy. When the state of personnel is walking, the average positioning error of WiFi is 7.76 m, the average positioning error of PDR is 4.57 m. After UKF fusing, the system's average positioning error is down to 1.24 m. It shows that the algorithm greatly improves the system's real-time and positioning accuracy.

Effect of local geology on indoor radon levels: a case study

International Nuclear Information System (INIS)

Hawthorne, A.R.; Gammage, R.B.; Dudney, C.S.

1984-01-01

This paper presents the results of radon monitoring in 40 East Tennessee homes that were a component of a larger study to evaluate indoor air quality. Measurements were conducted during two 3-month time periods with passive integrating track etch monitors in each of the forty homes. In a subset of homes, measurements were also conducted with a real-time monitor that provided readings on an hourly basis. The results of the monitoring indicate that about 30% of the homes had radon levels greater that 4 pCi/L in the living space. Homes with elevated radon levels were associated with local variations in geology; most of the homes having higher levels were located on the porous dolomite ridge partially surrounding Oad Ridge, Tennessee. (Author)

Polycyclic aromatic hydrocarbons and their derivatives in indoor and outdoor air in an eight-home study

Science.gov (United States)

Chuang, Jane C.; Mack, Gregory A.; Kuhlman, Michael R.; Wilson, Nancy K.

A pilot field study was performed in Columbus, OH, during the winter of 1986/1987. The objectives were to determine the feasibility of the use of a newly developed quiet sampler in indoor air sampling for particles and semivolatile organic compounds (SVOC) and to measure the concentrations of polycyclic aromatic hydrocarbons (PAH), PAH derivatives, and nicotine in air in selected residences. Eight homes were chosen for sampling on the basis of these characteristics: electric/gas heating system, electric/gas cooking appliances, and the absence/presence of environmental tobacco smoke (ETS). The indoor sampler was equipped with a quartz-fiber filter to collect particles followed by XAD-4 resin to trap SVOC. A PS-1 sampler with a similar sampling module was used outdoors. The indoor air was sampled in the kitchen and living room areas over two consecutive 8-h periods. The outdoor air was sampled concurrently with the indoor samples over a 16-h period. Fifteen PAH, five nitro-PAH, five oxygenated PAH, and three nitrogen heterocyclic compounds were determined in these samples. The most abundant PAH found indoors was naphthalene. The indoor concentrations of PAH derivatives were lower than those of their parent compounds. Average concentrations of all but three target compounds (naphthalene dicarboxylic acid anhydride, pyrene dicarboxylic acid anhydride, and 2-nitrofluoranthene) were higher indoors than outdoors. Environmental tobacco smoke was the most significant influence on indoor pollutant levels. Homes with gas heating systems had higher indoor pollutant levels than homes with electric heating systems. However, the true effects of heating and cooking systems were not characterized as accurately as the effects of ETS because of the small sample sizes and the lack of statistical significance for most pollutant differences in the absence of ETS. The concentrations of PAH marker compounds (phenanthrene, fluoranthene, and pyrene) correlated well with the concentrations

Indoor air quality in hospitality venues before and after implementation of a clean indoor air law--Western New York, 2003.

Science.gov (United States)

2004-11-12

Secondhand smoke (SHS) contains more than 50 carcinogens. SHS exposure is responsible for an estimated 3,000 lung cancer deaths and more than 35,000 coronary heart disease deaths among never smokers in the United States each year, and for lower respiratory infections, asthma, sudden infant death syndrome, and chronic ear infections among children. Even short-term exposures to SHS, such as those that might be experienced by a patron in a restaurant or bar that allows smoking, can increase the risk of experiencing an acute cardiovascular event. Although population-based data indicate declining SHS exposure in the United States over time, SHS exposure remains a common but preventable public health hazard. Policies requiring smoke-free environments are the most effective method of reducing SHS exposure. Effective July 24, 2003, New York implemented a comprehensive state law requiring almost all indoor workplaces and public places (e.g., restaurants, bars, and other hospitality venues) to be smoke-free. This report describes an assessment of changes in indoor air quality that occurred in 20 hospitality venues in western New York where smoking or indirect SHS exposure from an adjoining room was observed at baseline. The findings indicate that, on average, levels of respirable suspended particles (RSPs), an accepted marker for SHS levels, decreased 84% in these venues after the law took effect. Comprehensive clean indoor air policies can rapidly and effectively reduce SHS exposure in hospitality venues.

Effect of exhaust emissions on carbon monoxide levels in employees working at indoor car wash facilities.

Science.gov (United States)

Topacoglu, H; Katsakoglou, S; Ipekci, A

2014-01-01

Exhaust emissions from motor vehicles threaten the environment and human health. Carbon monoxide (CO) poisoning, especially the use of exhaust gas CO in suicidal attempts is well known in the literature. Recently, indoor car wash facilities established in large shopping malls with closed parking, lots is a new risk area that exposes car wash employees to prolonged periods of high level CO emissions from cars. The aim of this study was to investigate how carboxyhemoglobin (COHb) blood levels of employees get affected in confined areas with relatively poor air circulation. Twenty male volunteers working in indoor parking car wash facilities were included in the study. Participants were informed about the aim of this study and their consent was obtained. Their pulse COHb levels were measured twice, at the beginning and at the end of the working day using Rad-57 pulse CO-oximeter device, allowing non-invasive measurement of COHb blood levels to compare the changes in their COHb levels before and after work. The mean age of the male volunteers was 29.8 ± 11.9 (range 18-55). While the mean COHb levels measured at the start of the working day was 2.1 ± 2.0 (range 0-9), it was increased to 5.2 ± 3.3 (range 1-15) at the end of work shift (Wilcoxon test, p car wash facility employees is directly impacted and gets elevated by motor vechile exhaust emissions. For the health of the employees at indoor parking car wash facilities, stricter precautions are needed and the government should not give permit to such operations.

Usability analysis of indoor map application in a shopping centre

Science.gov (United States)

Dewi, R. S.; Hadi, R. K.

2018-04-01

Although indoor navigation is still new in Indonesia, its future development is very promising. Similar to the outdoor one, the indoor navigation technology provides several important functions to support route and landmark findings. Furthermore, there is also a need that indoor navigation can support the public safety especially during disaster evacuation process in a building. It is a common that the indoor navigation technologies are built as applications where users can access this technology using their smartphones, tablets, or personal computers. Therefore, a usability analysis is important to ensure the indoor navigation applications can be operated by users with highest functionality. Among several indoor map applications which were available in the market, this study chose to analyse indoor Google Maps due to its availability and popularity in Indonesia. The experiments to test indoor Google Maps was conducted in one of the biggest shopping centre building in Surabaya, Indonesia. The usability was measured by employing System Usability Scale (SUS) questionnaire. The result showed that the SUS score of indoor Google Maps was below the average score of other cellular applications to indicate the users still had high difficulty in operating and learning the features of indoor Google Maps.

Indoor radon concentrations in kindergartens from different regions of Yugoslavia

International Nuclear Information System (INIS)

Vaupotic, J.; Krizman, M.; Sutej, T.

1992-01-01

In the winter period of 1990-1991 instantaneous radon concentrations in air were measured in around 450 kindergartens from different regions from Yugoslavia. Alpha scintillation counting was used as a screening method, and the measurements were carried out in rooms where the children spent the majority of their time. All of the air grab samples were taken under the same conditions which excluded ventilation of the interior 12 h prior to sampling. In addition to indoor radon concentrations, gamma dose rate was measured using portable equipment. The indoor radon concentrations were generally low, in the range from 10 to 180 Bq.m -3 of air, with an overall average of about 100 Bq.m -3 . There were a few exceptions where indoor radon levels exceeded 150 Bq.m -3 ; mainly in old buildings containing higher contents of natural radionuclides in the building materials, and in the cellars or basements of the buildings. In all rooms with a level exceeding 150 Bq of 222 Rn per m 3 , solid-state nuclear track detectors were applied for long-term measurements. In order to investigate the equilibrium between radon and its short-lived daughters, mainly with respect to their contribution to the effective dose, alpha spectrometry is also being introduced in selected kindergartens with elevated radon concentrations. (author)

Survey of occupant behaviour, energy use and indoor air quality in Greenlandic dwellings

DEFF Research Database (Denmark)

Kotol, Martin

, they provide their occupants with poor indoor air quality. A questionnaire survey was performed in the town of Sisimiut-Greenland, which with its location and population represents Greenlandic conditions quite well. The aim of the survey was to investigate the energy consumption and indoor air quality...... in arctic dwellings and to study the influence of occupant behaviour of people living in arctic climates on energy consumption and indoor air quality. The results have shown that the average electricity consumption is 20% higher than in DK, ventilation systems are insufficient and that the inhabitants often......In cold arctic regions people usually spend over 70% of their time indoors. The effect of poor indoor air quality on occupants’ health and comfort is therefore considerable. Dwellings in Greenland consume very large amounts of energy (in average over 370 kWh/year per m2) and in addition...

Application of Bayesian approach to estimate average level spacing

International Nuclear Information System (INIS)

Huang Zhongfu; Zhao Zhixiang

1991-01-01

A method to estimate average level spacing from a set of resolved resonance parameters by using Bayesian approach is given. Using the information given in the distributions of both levels spacing and neutron width, the level missing in measured sample can be corrected more precisely so that better estimate for average level spacing can be obtained by this method. The calculation of s-wave resonance has been done and comparison with other work was carried out

DSCOVR Magnetometer Level 2 One Minute Averages

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Interplanetary magnetic field observations collected from magnetometer on DSCOVR satellite - 1-minute average of Level 1 data

DSCOVR Magnetometer Level 2 One Second Averages

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Interplanetary magnetic field observations collected from magnetometer on DSCOVR satellite - 1-second average of Level 1 data

Three-dimensional high-precision indoor positioning strategy using Tabu search based on visible light communication

Science.gov (United States)

Peng, Qi; Guan, Weipeng; Wu, Yuxiang; Cai, Ye; Xie, Canyu; Wang, Pengfei

2018-01-01

This paper proposes a three-dimensional (3-D) high-precision indoor positioning strategy using Tabu search based on visible light communication. Tabu search is a powerful global optimization algorithm, and the 3-D indoor positioning can be transformed into an optimal solution problem. Therefore, in the 3-D indoor positioning, the optimal receiver coordinate can be obtained by the Tabu search algorithm. For all we know, this is the first time the Tabu search algorithm is applied to visible light positioning. Each light-emitting diode (LED) in the system broadcasts a unique identity (ID) and transmits the ID information. When the receiver detects optical signals with ID information from different LEDs, using the global optimization of the Tabu search algorithm, the 3-D high-precision indoor positioning can be realized when the fitness value meets certain conditions. Simulation results show that the average positioning error is 0.79 cm, and the maximum error is 5.88 cm. The extended experiment of trajectory tracking also shows that 95.05% positioning errors are below 1.428 cm. It can be concluded from the data that the 3-D indoor positioning based on the Tabu search algorithm achieves the requirements of centimeter level indoor positioning. The algorithm used in indoor positioning is very effective and practical and is superior to other existing methods for visible light indoor positioning.

A comparative study of indoor radon levels and inhalation dose in some areas of Punjab and Haryana, India

International Nuclear Information System (INIS)

Bajwa, B.S.; Singh, Harmanjit; Singh, Joga; Singh, Surinder

2009-01-01

Indoor radon concentrations have been measured for two consecutive half-year periods in a wide range of dwellings of some regions of Punjab and Haryana states. The objective was to find correlation between the variations of indoor radon levels with the sub-soil, local geology, type of building materials, etc. of the two regions. So keeping this in view the indoor radon measurements have been carried out in the dwellings of different villages around the Tusham ring complex, Bhiwani District, Haryana, known to be composed of acidic volcanics and the associated granites along with some villages of Amritsar District, Punjab. The indoor radon concentration in the dwellings around Tusham (Haryana) have been found to be varying from 120.5±95 to 915.2±233 Bq m -3 , whereas it ranges from 60.0±37 to 235.6±96 Bq m -3 for the dwellings of Punjab. The 222 Rn concentration observed at most of locations particularly around Tusham ring complex region is higher than that of all the villages studied in Punjab region. Local geology including embedded granitic rocks, sub-soil, etc. as well as building materials having higher radioactive content are the major contributors for the higher indoor radon levels observed in the dwelling around Tusham, where few dwellings have higher radon concentrations than the ICRP, 1993 recommendations. The annual effective dose equivalent has also been estimated for each location of the both regions, which has been found to be varying from 1.0 to 17.2 mSv/y. (author)

Comparative study of short- and long-term indoor radon measurements

Energy Technology Data Exchange (ETDEWEB)

Al-Jarallah, M.I. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: mibrahim@kfupm.edu.sa; Fazal-ur-Rehman,; Abdalla, Khalid [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2008-08-15

Short-term indoor radon measurements are used widely. Therefore, it is interesting to find out a correlation between these measurements and long-term measurements which reflect a better average radon concentration of individual measurement. To find the correlation between the two measurements of indoor radon concentrations at low radon levels, a study was carried out at 34 locations of King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia using active and passive methods. In the short-term active method, a radon gas analyzer (AlphaGUARD) was used for a duration of 24 h in each measurement. In the long-term passive method, CR-39 based radon dosimeters were utilized for a period of 6 months, from January 2006 to June 2006. The short-term active measurements showed that the average, minimum and maximum radon concentrations were 19, 8 and 58Bqm{sup -3}, respectively, with a standard deviation of 8.6Bqm{sup -3}. The long-term passive measurements showed that the average, minimum and maximum radon concentrations were 25, 10 and 67Bqm{sup -3}, respectively, with a standard deviation of 12Bqm{sup -3}. The two measurements showed a poor correlation (R{sup 2}=0.38). The long-term measurements showed on the average higher concentrations by a factor of 1.3.

Residential indoor air quality guideline : ozone

International Nuclear Information System (INIS)

2010-01-01

Ozone (O 3 ) is a colourless gas that reacts rapidly on surfaces and with other constituents in the air. Sources of indoor O 3 include devices sold as home air cleaners, and some types of office equipment. Outdoor O 3 is also an important contributor to indoor levels of O 3 , depending on the air exchange rate with indoor environments. This residential indoor air quality guideline examined factors that affect the introduction, dispersion and removal of O 3 indoors. The health effects of prolonged exposure to O 3 were discussed, and studies conducted to evaluate the population health impacts of O 3 were reviewed. The studies demonstrated that there is a significant association between ambient O 3 and adverse health impacts. Exposure guidelines for residential indoor air quality were discussed. 14 refs.

Field study of the indoor environment in a Danish prison

DEFF Research Database (Denmark)

Dogbeh, Audrey; Jomaas, Grunde; Bjarløv, Søren Peter

2015-01-01

The indoor environment in a Danish prison was evaluated based on measurements made during the summer season of temperature, relative humidity and carbon dioxide, as well as through carefully conducted surveys among the inmates. The temperatures in the cells were high and well beyond common levels...... a compromise must be found to ensure that the building can comply with minimum health and comfort standards. The findings of this study can be used as background for recommendations for renovation of prison buildings.......The indoor environment in a Danish prison was evaluated based on measurements made during the summer season of temperature, relative humidity and carbon dioxide, as well as through carefully conducted surveys among the inmates. The temperatures in the cells were high and well beyond common levels...... in Danish buildings. The mean CO2 concentrations were generally low, but reached high maximum levels up to 5000 ppm. Thirty-one inmates responded to the questionnaire. They spent on average 19 h in the cell per day (range 12–23 h). Sixty-nine percent of the inmates expressed dissatisfaction...

Indoor radon measurements in the dwellings of Kangra District of Himachal Pradesh, India, using LR-115 nuclear track detectors

Energy Technology Data Exchange (ETDEWEB)

Dhiman, M. [Punjab Technical University (India); Mehra, R. [Department of Physics, Dr. B.R. Ambedkar National Institute of Technology (India); Tyagi, A.K. [Department of Applied Sciences, Shaheed Bhagat Singh College of Engineering and Technology (India)

2014-07-01

Study of indoor radon was carried out in the domestic environment of 15 villages of Kangra district of Himachal Pradesh, India. Time integrated track etch technique has been used for the measurement of indoor radon levels. Bare cellulose nitrate LR-115 type II films have been used as detectors in the survey of indoor radon for four seasons of three months each covering a period of one year from March 2012 to March 2013. The houses were chosen randomly in such a way that the dwellings constructed with different types of building materials such as soil, bricks, cement, marble, concrete, wood in different localities of the village are covered. It has been found that indoor radon concentration depends upon the type of house, ventilation condition etc. The calibration constant of 1 track cm{sup -2} day{sup -1} which is equal to 50 Bqm{sup -3} has been used to express radon concentration in Bqm{sup -3}. The conversion factors have been used to calculate the exposure (an exposure of an individual to radon progeny of 1 WLM is equivalent to 3.54 mJ h m{sup -3}), the annual effective dose (1 WLM=3.88 mSv) and the lifetime fatality risk (3 x 10{sup -4} WLM). Indoor radon concentrations were found to vary from 132.25 Bqm{sup -3} to 449.75 Bqm{sup -3} with an average value of 261.40 Bqm{sup -3}. Annual effective dose in these dwellings were found to vary form 2.78 mSv to 7.68 mSv with an average value of 4.5 mSv. The average radon concentration in dwellings in most of the villages falls in the action level (200-600 Bqm{sup -3}) recommended by International Commission on Radiological Protection. Document available in abstract form only. (authors)

Indoor air quality: a UK perspective

International Nuclear Information System (INIS)

Wadge, A.

1995-01-01

Outdoor air quality has generally improved in the UK over the last 2 decades but during this period changing conditions within the home have tended to reduce ventilation and increase the opportunity for accumulation of undesirable levels of indoor air pollutants. Information obtained from laboratory and epidemiological studies suggest that indoor air pollutants are an important cause of avoidable morbidity and mortality in the UK. This paper reviews the major indoor air pollutants of concern in the UK and considers some of the special issues relevant to indoor environment. (author) 3 figs., 37 refs

Indoor Radon Concentration Related to Different Radon Areas and Indoor Radon Prediction

Science.gov (United States)

Juhásová Šenitková, Ingrid; Šál, Jiří

2017-12-01

Indoor radon has been observed in the buildings at areas with different radon risk potential. Preventive measures are based on control of main potential radon sources (soil gas, building material and supplied water) to avoid building of new houses above recommended indoor radon level 200 Bq/m3. Radon risk (index) estimation of individual building site bedrock in case of new house siting and building protection according technical building code are obligatory. Remedial actions in buildings built at high radon risk areas were carried out principally by unforced ventilation and anti-radon insulation. Significant differences were found in the level of radon concentration between rooms where radon reduction techniques were designed and those where it was not designed. The mathematical model based on radon exhalation from soil has been developed to describe the physical processes determining indoor radon concentration. The model is focused on combined radon diffusion through the slab and advection through the gap from sub-slab soil. In this model, radon emanated from building materials is considered not having a significant contribution to indoor radon concentration. Dimensional analysis and Gauss-Newton nonlinear least squares parametric regression were used to simplify the problem, identify essential input variables and find parameter values. The presented verification case study is introduced for real buildings with respect to various underground construction types. Presented paper gives picture of possible mathematical approach to indoor radon concentration prediction.

Effect of home construction on indoor radon in Virginia and Maryland

International Nuclear Information System (INIS)

Mushrush, G.W.; Mose, D.G.

1988-01-01

The levels of indoor radon in approximately 500 homes located in two contiguous counties of northern Virginia and southern Maryland have been measured during four consecutive, three month seasonal intervals using alpha-track detectors. These two counties represent an area of about 700 square miles. Results from the winter period show that the indoor radon levels were about twice as high as anticipated. In some areas, more than 50% of the homes had winter indoor radon levels above 4 pCi/liter, the EPA's recommended action level. For the spring and fall periods, indoor radon levels showed a considerable drop with approximately 35% of the homes above 4 pCi/L. Summer values were even lower with approximately 25% of the homes above 4 pCi/L.Indoor radon can be related to the weather, but home construction demonstrably determines indoor radon levels

Understanding the origin of radon indoors: Building a predictive capability

International Nuclear Information System (INIS)

Sextro, R.G.

1985-12-01

Indoor radon concentrations one to two orders of magnitude higher than the US average of ∼60 Bq m -3 (∼1.5 pCi L -1 ) are not uncommon, and concentrations greater than 4000 Bq m -3 have been observed in houses in areas with no known artificially-enhanced radon sources. In general, source categories for indoor radon are well known: soil, domestic water, building materials, outdoor air, and natural gas. Soil is thought to be a major source of indoor radon, either through molecular diffusion (usually a minor component) or convective flow of soil gas. While soil gas flow into residences has been demonstrated, no detailed understanding of the important factors affecting the source strength of radon from soil has yet emerged. Preliminary work in this area has identified a number of likely issues, including the concentration of radium in the soil, the emanating fraction, soil type, soil moisture content, and other factors that would influence soil permeability and soil gas transport. Because a significant number of dwellings are expected to have indoor radon concentrations above guideline levels, a predictive capability is needed that would help identify geographical areas having the potential for high indoor concentrations. This paper reviews the preliminary work that has been done to identify important soil and building characteristics that influence the migration of radon and outlines the areas of further research necessary for development of a predictive method. 32 refs., 4 figs

Effect of local geology on indoor radon levels: a case study

Energy Technology Data Exchange (ETDEWEB)

Hawthorne, A.R.; Gammage, R.B.; Dudney, C.S.

1984-01-01

This paper presents the results of radon monitoring in 40 East Tennessee homes that were a component of a larger study to evaluate indoor air quality. Measurements were conducted during two 3-month time periods with passive integrating track etch monitors in each of the forty homes. In a subset of homes, measurements were also conducted with a real-time monitor that provided readings on an hourly basis. The results of the monitoring indicate that about 30% of the homes had radon levels were associated with local variations in geology; most of the homes having higher levels were located on the porous dolomite ridge partially surrounding Oak Ridge, Tennessee. 7 references, 3 figures, 2 tables.

Effect of local geology on indoor radon levels: a case study

International Nuclear Information System (INIS)

Hawthorne, A.R.; Gammage, R.B.; Dudney, C.S.

1984-01-01

This paper presents the results of radon monitoring in 40 East Tennessee homes that were a component of a larger study to evaluate indoor air quality. Measurements were conducted during two 3-month time periods with passive integrating track etch monitors in each of the forty homes. In a subset of homes, measurements were also conducted with a real-time monitor that provided readings on an hourly basis. The results of the monitoring indicate that about 30% of the homes had radon levels were associated with local variations in geology; most of the homes having higher levels were located on the porous dolomite ridge partially surrounding Oak Ridge, Tennessee. 7 references, 3 figures, 2 tables

Preventing Skin Cancer Through Reduction of Indoor Tanning

Science.gov (United States)

Watson, Meg; Holman, Dawn M.; Fox, Kathleen A.; Guy, Gery P.; Seidenberg, Andrew B.; Sampson, Blake P.; Sinclair, Craig; Lazovich, DeAnn

2015-01-01

Exposure to ultraviolet radiation from indoor tanning devices (tanning beds, booths, and sun lamps) or from the sun contributes to the risk of skin cancer, including melanoma, which is the type of skin cancer responsible for most deaths. Indoor tanning is common among certain groups, especially among older adolescents and young adults, adolescent girls and young women, and non-Hispanic whites. Increased understanding of the health risks associated with indoor tanning has led to many efforts to reduce use. Most environmental and systems efforts in the U.S. (e.g., age limits or requiring parental consent/accompaniment) have occurred at the state level. At the national level, the U.S. Food and Drug Administration and the Federal Trade Commission regulate indoor tanning devices and advertising, respectively. The current paper provides a brief review of (1) the evidence on indoor tanning as a risk factor for skin cancer; (2) factors that may influence use of indoor tanning devices at the population level; and (3) various environmental and systems options available for consideration when developing strategies to reduce indoor tanning. This information provides the context and background for the companion paper in this issue of the American Journal of Preventive Medicine, which summarizes highlights from an informal expert meeting convened by the CDC in August 2012 to identify opportunities to prevent skin cancer by reducing use of indoor tanning devices. PMID:23683987

Influence of surficial soil and bedrock on indoor radon in New York State homes. Task 2, Subtask 2 of an investigation of infiltration and indoor air quality in New York State homes

International Nuclear Information System (INIS)

Kunz, C.

1989-10-01

Radon can enter a building from soil and bedrock through cracks or openings in the basement. Extrapolation from data obtained from studies of miners exposed to high concentrations of radon and other carcinogens over long periods indicates that radon gas in the home poses an increased risk of lung cancer. The project was initiated to determine the characteristics of soil and bedrock that contribute to the availability of radon for infiltration into the home, and the feasibility of using soil characteristics in mapping areas at higher risk for above-average indoor radon in New York State. After conducting soil surveys across the State, the researchers choose four areas for further study. Fifteen homes in each area were tested for indoor air concentrations of radon, air infiltration into the home, radon concentrations in the soil, and the permeability of the soil for gas flow. The researchers concluded that these parameters could be combined to obtain a Radon Index Number to predict mean indoor radon levels for a given area with similar soil geology. However, this measure has a limited ability to predict indoor radon levels for a particular home due to variations in construction as well as differences in soil and bedrock

Indoor air pollution

International Nuclear Information System (INIS)

Anwar, J.; Hussain, F.

2005-01-01

Indoor air pollution after being a neglected subject for a number of years, is attracting attention recently because it is a side effect of energy crisis. About 50% of world's 6 billion population, mostly in developing countries, depend on biomass and coal in the form of wood, dung and crop residues for domestic energy because of poverty. These materials are burnt in simple stoves with incomplete combustion and infants, children and women are exposed to high levels of indoor air pollution for a considerable period, approximately between 2-4 hours daily. Current worldwide trade in wood fuel is over US $7 billion and about 2 million people are employed full time in production and marketing it. One of the most annoying and common indoor pollutant in both, developing and developed countries, is cigarette smoke. Children in gas-equipped homes had higher incidences of respiratory disease. Babies' DNA can be damaged even before they are born if their mothers breathe polluted air. Exposure to indoor air pollution may be responsible for nearly 2 million excess deaths in developing countries and for 4% of the global burden of the disease. Only a few indoor pollutants have been studied in detail. Indoor air pollution is a major health threat on which further research is needed to define the extent of the problem more precisely and to determine solutions by the policy-makers instead of neglecting it because sufferers mostly belong to Third World countries. (author)

Enhanced Photocatalytic Efficiency of N–F-Co-Embedded Titania under Visible Light Exposure for Removal of Indoor-Level Pollutants

Directory of Open Access Journals (Sweden)

Seung-Ho Shin

2014-12-01

Full Text Available N–F-co-embedded titania (N–F–TiO2 photocatalysts with varying N:F ratios were synthesized and tested for their ability to photocatalyze the degradation of pollutants present at indoor air levels using visible light. The synthesis was achieved using a solvothermal process with tetrabutyl titanate, urea and ammonium fluoride as sources of Ti, N and F, respectively. Three selected volatile organic compounds (toluene, ethyl benzene and o-xylene were selected as the test pollutants. The prepared composites were characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Ultra-violet (UV-visible spectroscopy. The photocatalytic degradation efficiencies of N–F–TiO2 composites were higher than those obtained using pure TiO2 and N–TiO2. Moreover, these efficiencies increased as the N:F ratio decreased from sixteen to eight, then decreased as it dropped further to three, indicating the presence of an optimal N:F ratio. Meanwhile, as retention time decreased from 12.4 to 0.62 s, the average photocatalytic efficiencies decreased from 65.4% to 21.7%, 91.5% to 37.8% and 95.8% to 44.7% for toluene, ethyl benzene and o-xylene, respectively. In contrast, the photocatalytic reaction rates increased as retention time decreased. In consideration of all of these factors, under optimized operational conditions, the prepared N–F–TiO2 composites could be utilized for the degradation of target pollutants at indoor air levels using visible light.

Dependence of indoor 222Rn level on building materials

International Nuclear Information System (INIS)

Tso, M.W.; Ng, C.; Leung, J.K.C.

1993-01-01

The radionuclide contents of typical building materials used in Hong Kong were studied by γ spectroscopic analysis. The physical properties of these building materials affecting the production and transportation of 222 Rn to the surrounding air were examined; these include the emanation coefficient of 2 '2 2 Rn of the material, the diffusion coefficient of 222 Rn in the material and the effect of surface coating and temperature on the rate of 222 Rn exhalation. Results obtained in this study explain the indoor 222 Rn concentration observed in our previous surveys and also suggest that the main source of indoor 222 Rn in Hong Kong is building material. (3 figs., 4 tabs.)

Association between Four-Level Categorisation of Indoor Exposure and Perceived Indoor Air Quality

Directory of Open Access Journals (Sweden)

Katja Tähtinen

2018-04-01

Full Text Available The aim of this study was to develop and test a tool for assessing urgency of indoor air quality (IAQ measures. The condition of the 27 buildings were investigated and results were categorized. Statistical test studied the differences between the categories and the employees’ complaints about their work environment. To study the employees’ experiences of the work premises, a validated indoor air (IA questionnaire was used. This study reveals a multifaceted problem: many factors affecting IAQ may also affect perceived IAQ, making it difficult to separate the impurity sources and ventilation system deficiencies affecting to employee experiences. An examination of the relationship between the categories and perceived IAQ revealed an association between the mould odour perceived by employees and mould detected by the researcher. A weak link was also found between the assessed categories and environmental complaints. However, we cannot make far-reaching conclusions regarding the assessed probability of abnormal IA exposure in the building on the basis of employee experiences. According to the results, categorising tool can partly support the assessment of the urgency for repairs when several factors that affect IAQ are taken into account.

Association between Four-Level Categorisation of Indoor Exposure and Perceived Indoor Air Quality.

Science.gov (United States)

Tähtinen, Katja; Lappalainen, Sanna; Karvala, Kirsi; Remes, Jouko; Salonen, Heidi

2018-04-04

The aim of this study was to develop and test a tool for assessing urgency of indoor air quality (IAQ) measures. The condition of the 27 buildings were investigated and results were categorized. Statistical test studied the differences between the categories and the employees’ complaints about their work environment. To study the employees’ experiences of the work premises, a validated indoor air (IA) questionnaire was used. This study reveals a multifaceted problem: many factors affecting IAQ may also affect perceived IAQ, making it difficult to separate the impurity sources and ventilation system deficiencies affecting to employee experiences. An examination of the relationship between the categories and perceived IAQ revealed an association between the mould odour perceived by employees and mould detected by the researcher. A weak link was also found between the assessed categories and environmental complaints. However, we cannot make far-reaching conclusions regarding the assessed probability of abnormal IA exposure in the building on the basis of employee experiences. According to the results, categorising tool can partly support the assessment of the urgency for repairs when several factors that affect IAQ are taken into account.

Indoor PAHs at schools, homes and offices in Rome, Italy

Science.gov (United States)

Romagnoli, P.; Balducci, C.; Perilli, M.; Gherardi, M.; Gordiani, A.; Gariazzo, C.; Gatto, M. P.; Cecinato, A.

2014-08-01

Indoor and outdoor concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with PM2.5 particles were monitored in three microenvironments (schools, homes and offices) in the city of Rome, Italy, between winter 2011 and summer 2012. Molecular signatures and indoor/outdoor concentration ratios of PAHs were investigated, with special emphasis on carcinogenic congeners. At indoor locations, total PAHs ranged, on average, from 1.8 to 8.4 ng/m3 in winter and from 0.30 to 1.35 ng/m3 in spring/summer. Outdoors, total PAH concentrations were found to reach 6.3-17.9 ng/m3 in winter and 0.42-1.74 ng/m3 in spring-summer. Indoors, the concentration of benzo[a]pyrene (BaP) was as high as 1.1 ng/m3 in winter and below 0.1 ng/m3 in the warm season, independently of site type; the yearly average remained below the European guideline value. The indoor/outdoor concentration ratios of individual compounds were lower than one for most of congeners, suggesting that outdoor sources were predominant. Nonetheless, the percentages of PAH compounds changed with sites and seasons; in particular, in spring/summer, the concentration of BaP at our sites was more than twice that recorded at the regional network stations.

Diffuse Scattering Model of Indoor Wideband Propagation

DEFF Research Database (Denmark)

Franek, Ondrej; Andersen, Jørgen Bach; Pedersen, Gert Frølund

2011-01-01

segments in total and approximately 2 min running time on average computer. Frequency independent power levels at the walls around the circumference of the room and at four receiver locations in the middle of the room are observed. It is demonstrated that after finite period of initial excitation the field...... radio coverage predictions.......This paper presents a discrete-time numerical algorithm for computing field distribution in indoor environment by diffuse scattering from walls. Calculations are performed for a rectangular room with semi-reflective walls. The walls are divided into 0.5 x 0.5 m segments, resulting in 2272 wall...

Diurnal variations of indoor radon progeny for Bangalore metropolitan, India

International Nuclear Information System (INIS)

Nagesh, V.; Sathish, L.A.; Nagaraja, K.; Sundareshan, S.

2010-01-01

Radon progenies are identified as major causes of the lung cancer if the activity is above its normal. It has not been clear whether radon poses a similar risk of causing lung cancer in humans exposed at generally lower levels found in homes, but a number of indoor radon survey have been carried out in recent years around the world. In view of this an attempt has been made for the measurement of diurnal variation of indoor radon levels for the environment of Bangalore metropolitan, India. The Radon progeny concentrations in terms of working level were measured using Kusnetz's method. The patterns of daily and annual changes in indoor Radon concentration have been observed in a general way for many years. However, understanding of the physical basis for these changes had to await the development of continuous monitors and a more complete knowledge of transport processes in the atmosphere. Over a continent, heating of the ground surface by the Sun during the day and cooling by radiation during the night causes a marked diurnal change in temperature near the surface. As a result cool air near the ground will accumulate radon isotopes from surface flux during the night; while during the day the warm air will be transported upward carrying radon with it. Many buildings show diurnal radon variations. Concentrations are relatively higher during night than daytime. This is influenced by the outdoor-indoor temperature contrast. This effect can be enhanced in buildings with strong diurnal use patterns. Buildings that have high average radon concentrations, but are only occupied for part of the day, may need to be measured during occupied periods to determine if there is significant diurnal radon variation. The results are discussed in detail. (author)

Influence of indoor formaldehyde pollution on respiratory system ...

African Journals Online (AJOL)

Background The decoration of interior spaces can lead to dangerous levels of indoor formaldehyde pollution. Exposure to indoor air pollution may be responsible for nearly 2 million deaths per year in developing countries. Objectives To assess the prevalence of indoor formaldehyde pollution caused by decoration and ...

Estimation of outdoor and indoor effective dose and excess lifetime cancer risk from Gamma dose rates in Gonabad, Iran

Energy Technology Data Exchange (ETDEWEB)

Jafaria, R.; Zarghania, H.; Mohammadia, A., E-mail: rvzreza@gmail.com [Paramedical faculty, Birjand University of Medical Sciences, Birjand (Iran, Islamic Republic of)

2017-07-01

Background gamma irradiation in the indoor and outdoor environments is a major concern in the world. The study area was Gonabad city. Three stations and buildings for background radiation measurement of outdoor and indoor were randomly selected and the Geiger-Muller detector (X5C plus) was used. All dose rates on display of survey meter were recorded and mean of all data in each station and buildings was computed and taken as measured dose rate of that particular station. The average dose rates of background radiation were 84.2 nSv/h for outdoor and 108.6 nSv/h for indoor, maximum and minimum dose rates were 88.9 nSv/h and 77.7 nSv/h for outdoor measurements and 125.4 nSv/h and 94.1 nSv/h for indoor measurements, respectively. Results show that the annual effective dose is 0.64 mSv, which compare to global level of the annual effective dose 0.48 mSv is high. Estimated excess lifetime cancer risk was 2.24×10{sup -3} , indicated that it is large compared to the world average value of 0.25×10{sup -3}. (author)

Microenvironmental air and soil monitoring of contaminants: An evaluation of indoor and outdoor levels in Chihuahua City

Science.gov (United States)

Delgado-Rios, Marcos

Like most of the cities around the world Chihuahua City suffers atmospheric and soil pollution. This is a problem that requires immediate attention from both public authorities and the scientific community. Although it is known that high levels of heavy metals are present in the airborne particulate matter, soil and dust in many urban regions, the information about personal exposure to these pollutants in Chihuahua City is nonexistent. This study focuses on the analysis and characterization of lead and arsenic in the airborne and soil particulate matter present in the interiors of households and their surrounding outdoor environments in the southern part of Chihuahua City. The sampling area chosen for this study was located in the southern part of Chihuahua City. An atmospheric sampling point selected by the Centro de Investigacion en Materiales Avanzados (CIMAV) was selected as a geographical center, with a 2 km radius forming the sampling area. The households selected for analyses were located on Lombardo Toledano Street, a high-traffic street. The main objectives of this study were to establish the maximum exposure level in outdoor and indoor environments for particulate matter less than 10 mum (PM 10), Pb, and As, to determine the background level of Chihuahua City for these same elements, to determine the isotopic ratios of Pb206 and Pb207 in the indoor and outdoor atmospheric samples, and to verify if the source of the pollution is from anthropogenic and/or natural sources. Additionally, a comparison of the analytical data from X-ray fluorescence (XRF) versus the analytical data from inductively coupled plasma with optical emission spectroscopy (ICP-OES) was conducted. The comparison of these techniques was based on sample preparation, speed of analysis, and accuracy of results. In the case of sample preparation, two extraction techniques were performed for a comparison of the extraction/leaching of Pb and As from the samples. These microwave

Indoor air quality – buildings design

Directory of Open Access Journals (Sweden)

Juhásová Šenitková Ingrid

2017-01-01

Full Text Available Growing attention is being paid to indoor air quality as one of the main health and well-being factors. The indoor research is concerned mostly to indoor air chemicals within indoor engineering related to building design. The providing good indoor air quality can be achieved effectively by avoiding or reducing indoor air pollution sources and by selecting low-polluting building materials, both being low-cost and energyefficient solutions. On the base of the last large experimental monitoring results, it was possible to know the level of selected indoor chemicals occurrence, rank them as well as to predict the tendencies of occurrence and establish the priorities for the future. There has been very limited attention to rigorous analysis of buildings actual environmental impacts to date. Healthy/green/sustainable building practices are typically applied in unsystematic and inconsistent ways often without resolution of inherent conflicts between and among such practices. Designers, products manufacturers, constructors, and owners declare their buildings and the applied technologies to be beneficial to the environment without validating those claims.

Radon concentration in indoor occupational environments in Aomori Prefecture, Japan

International Nuclear Information System (INIS)

Iyogi, T.; Ueda, S.; Hisamatsu, S.; Kondo, K.; Sakurai, N.; Inaba, J.

2003-01-01

The 222 Rn concentrations in indoor workplaces were measured in Aomori Prefecture, Japan, and the results are reported here. This survey was part of a program to measure background natural radiation dose rate in the prefecture where the first Japanese nuclear fuel cycling facilities are now under construction. The survey of the 222 Rn concentrations in indoor workplaces was carried out at 107 locations from 1996 to 1998. The 222 Rn concentrations were measured for approximately one year at each site with passive Rn detectors, which used a polycarbonate film for counting α-rays and could separate concentrations of 222 Rn from 220 Rn. Weeklong measurements of 222 Rn concentration and working level were carried out with active detectors to get the ratio of 222 Rn concentration during working hours to non-working hours as well as equilibrium factors in selected locations. Diurnal variation of 222 Rn concentration depended on building structure, air-conditioning, time of day and day of the week (week days or weekend). The 222 Rn concentration during working hours was generally lower than that in non-working hours. Although the annual average 222 Rn concentration in indoor occupational environments was higher than that in dwellings, radiation dose for Aomori Prefecture residents from Rn in the former was 14% of the total indoor dose by Rn because of the lower concentration in working hours and lower occupancy factor

Indoor aerosols

DEFF Research Database (Denmark)

Morawska, L.; Afshari, Alireza; N. Bae, G.

2013-01-01

Motivated by growing considerations of the scale, severity, and risks associated with human exposure to indoor particulate matter, this work reviewed existing literature to: (i) identify state-of-the-art experimental techniques used for personal exposure assessment; (ii) compare exposure levels...

Effect of fresh air ventilation on indoor radon concentration

International Nuclear Information System (INIS)

Sun Hao; Wu Jianhua; Fu Shi

2012-01-01

The radon concentration of laboratory for radon simulation (LRS) was measured by the RAD7 radon monitor, and the effect of the different fresh air ventilations on indoor radon concentration was studied and analyzed. The indoor radon concentration of LRS can be accumulated up to 2000 Bq/m 3 and the average radon exhalation rate of the LRS is 14.5 Bq · m -2 . h -1 . Furthermore, when the fresh air enters into the LRS continuously, the indoor radon concentration decreases exponentially with the increase of time. The equilibrium radon concentration and equilibrium time of LRS decrease exponentially with the increase of the rate of fresh air ventilation. In addition, the indoor radon concentration increases by accumulation with the decrease of the rate of fresh air ventilation. (authors)

INDOOR SUBSPACING TO IMPLEMENT INDOORGML FOR INDOOR NAVIGATION

Directory of Open Access Journals (Sweden)

H. Jung

2015-10-01

Full Text Available According to an increasing demand for indoor navigation, there are great attempts to develop applicable indoor network. Representation for a room as a node is not sufficient to apply complex and large buildings. As OGC established IndoorGML, subspacing to partition the space for constructing logical network is introduced. Concerning subspacing for indoor network, transition space like halls or corridors also have to be considered. This study presents the subspacing process for creating an indoor network in shopping mall. Furthermore, categorization of transition space is performed and subspacing of this space is considered. Hall and squares in mall is especially defined for subspacing. Finally, implementation of subspacing process for indoor network is presented.

Indoor Subspacing to Implement Indoorgml for Indoor Navigation

Science.gov (United States)

Jung, H.; Lee, J.

2015-10-01

According to an increasing demand for indoor navigation, there are great attempts to develop applicable indoor network. Representation for a room as a node is not sufficient to apply complex and large buildings. As OGC established IndoorGML, subspacing to partition the space for constructing logical network is introduced. Concerning subspacing for indoor network, transition space like halls or corridors also have to be considered. This study presents the subspacing process for creating an indoor network in shopping mall. Furthermore, categorization of transition space is performed and subspacing of this space is considered. Hall and squares in mall is especially defined for subspacing. Finally, implementation of subspacing process for indoor network is presented.

Radon and aldehyde concentrations in the indoor environment. Final report

International Nuclear Information System (INIS)

Moschandreas, D.J.; Rector, H.E.

1981-04-01

Findings regarding indoor air contaminants in the energy-efficient residence (EER) in Mt. Airy, Maryland are reported. The objectives of the study were to collect and analyze relevant air quality samples (specifically radon and aldehydes), characterize the indoor air quality with respect to radon and aldehydes, and develop relationships between air infiltration rates and contaminant levels. One-fifth of the measured formaldehyde concentrations were in the range that may cause health concerns. Although indoor temperature and relative humidity affect indoor HCHO concentration, the elevated formaldehyde concentrations were measured under very low air infiltration rates. The data show that ventilation of the indoor air space is somewhat effective in reducing high HCHO concentrations. The operation of the heat exchanger led to an increase of the air infiltration rate which in turn resulted in substantial reduction of formaldehyde concentrations. A considerable number of the collected samples of indoor air displayed radon concentrations at levels higher than 1.0 to 4.0 nCim -3 (assuming an equilibrium factor of 0.5, these radon levels would correspond to working levels above the health guidelines suggested by the US EPA for homes in Florida built on land reclaimed from phosphate mining). As in the case of indoor formaldehyde concentrations, elevated indoor concentrations are substantially reduced when the infiltration rate is increased. The data base shows that the use of the air to air heat exchanger leads to reduction of indoor radon concentration by increasing the residential ventilation rate

Biomass fuel use and indoor air pollution in homes in Malawi

Science.gov (United States)

Fullerton, D G; Semple, S; Kalambo, F; Suseno, A; Malamba, R; Henderson, G; Ayres, J G; Gordon, S B

2009-01-01

Background: Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure from biomass fuel in Malawian homes. Methods: Markers of indoor air quality were measured in 62 homes (31 rural and 31 urban) over a typical 24 h period. Four different devices were used (one gravimetric device, two photometric devices and a carbon monoxide (HOBO) monitor. Gravimetric samples were analysed for transition metal content. Data on cooking and lighting fuel type together with information on indicators of socioeconomic status were collected by questionnaire. Results: Respirable dust levels in both the urban and rural environment were high with the mean (SD) 24 h average levels being 226 μg/m3 (206 μg/m3). Data from real-time instruments indicated respirable dust concentrations were >250 μg/m3 for >1 h per day in 52% of rural homes and 17% of urban homes. Average carbon monoxide levels were significantly higher in urban compared with rural homes (6.14 ppm vs 1.87 ppm; p<0.001). The transition metal content of the smoke was low, with no significant difference found between urban and rural homes. Conclusions: Indoor air pollution levels in Malawian homes are high. Further investigation is justified because the levels that we have demonstrated are hazardous and are likely to be damaging to health. Interventions should be sought to reduce exposure to concentrations less harmful to health. PMID:19671533

Effectiveness of Indoor Plant to Reduce CO2 in Indoor Environment

Directory of Open Access Journals (Sweden)

Suhaimi Mohd Mahathir

2017-01-01

Full Text Available Modern country strongly emphasizes on indoor air quality (IAQ because it can effect on human health and productivity. Numerous efforts were performed to make sure that sustainability of IAQ is guaranteed. In the last 4th decade, researchers discover that indoor plants have abilities to reduce indoor air pollution. Generally, plants, carbon dioxide (CO2, light, and temperature involve in the photosynthesis process. This paper intends to study the effectiveness of seven indoor plants (Anthurium, Dumb Cane, Golden Pothos, Kadaka Fern, Prayer Plant, Spider Plant, and Syngonium to reduce CO2 with different light level. This study was conducted in one cubic meter of chamber, and each plant was put into the chamber individually with CO2 concentration in the chamber is set at 1000±50ppm, and light intensities is set at 300 and 700 lux, while temperature were fixed at 25±1°C. Based on the results, only the Spider Plant was not able to absorb CO2 during the test at 300 lux of light intensity. Meanwhile, Prayer Plant performed well when tested at 300 or 700 lux of light intensity compare to other investigates plants. This study can conclude that light intensity play an important role for the plant to absorb CO2 effectively. All the indoor plants absorbed more CO2, when the light intensity is increased.

Microscopic description of average level spacing in even-even nuclei

International Nuclear Information System (INIS)

Huong, Le Thi Quynh; Hung, Nguyen Quang; Phuc, Le Tan

2017-01-01

A microscopic theoretical approach to the average level spacing at the neutron binding energy in even-even nuclei is proposed. The approach is derived based on the Bardeen-Cooper-Schrieffer (BCS) theory at finite temperature and projection M of the total angular momentum J , which is often used to describe the superfluid properties of hot rotating nuclei. The exact relation of the J -dependent total level density to the M -dependent state densities, based on which the average level spacing is calculated, was employed. The numerical calculations carried out for several even-even nuclei have shown that in order to reproduce the experimental average level spacing, the M -dependent pairing gaps as well as the exact relation of the J -dependent total level density formula should be simultaneously used. (paper)

Investigations on indoor radon in Austria, Part 1: Seasonality of indoor radon concentration

International Nuclear Information System (INIS)

Bossew, Peter; Lettner, Herbert

2007-01-01

In general, indoor radon concentration is subject to seasonal variability. The reasons are to be found (1) in meteorological influence on the transport properties of soil, e.g. through temperature, frozen soil layers and soil water saturation; and (2) in living habits, e.g. the tendency to open windows in summer and keep them closed in winter, which in general leads to higher accumulation of geogenic Rn in closed rooms in winter. If one wants to standardize indoor Rn measurements originally performed at different times of the year, e.g. in order to make them comparable, some correction transform as a function of measurement time which accounts for these effects must be estimated. In this paper, the seasonality of indoor Rn concentration measured in Austria is investigated as a function of other factors that influence indoor Rn. Indoor radon concentration is clearly shown to have seasonal variability, with higher Rn levels in winter. However, it is complicated to quantify the effect because, as a consequence of the history of an Rn survey, the measurement season maybe correlated to geological regions, which may introduce a bias in the estimate of the seasonality amplitude

Reducing indoor residential exposures to outdoor pollutants

Energy Technology Data Exchange (ETDEWEB)

Sherman, Max H.; Matson, Nance E.

2003-07-01

The basic strategy for providing indoor air quality in residences is to dilute indoor sources with outdoor air. This strategy assumes that the outdoor air does not have pollutants at harmful levels or that the outdoor air is, at least, less polluted than the indoor air. When this is not the case, different strategies need to be employed to ensure adequate air quality in the indoor environment. These strategies include ventilation systems, filtration and other measures. These strategies can be used for several types of outdoor pollution, including smog, particulates and toxic air pollutants. This report reviews the impacts that typical outdoor air pollutants can have on the indoor environment and provides design and operational guidance for mitigating them. Poor quality air cannot be used for diluting indoor contaminants, but more generally it can become an indoor contaminant itself. This paper discusses strategies that use the building as protection against potentially hazardous outdoor pollutants, including widespread pollutants, accidental events, and potential attacks.

Impact of operating wood-burning stoves on indoor air quality

DEFF Research Database (Denmark)

Afshari, Alireza; Jensen, Ole Michael; Bergsøe, Niels Christian

2011-01-01

A field study on the impact of operating and reloading wood-burning stoves on the indoor air quality was carried out during two consecutive winters. In contrast to the majority of recent studies, which focussed on the ambient air quality and the penetration of particles to the indoor air......, this study aims to understand to what extent the operation of a stove contributes to the generation of concentration of ultrafine particles in the indoor air. Therefore, different stoves were ignited in one session by the owner of the stove and in a subsequent session by an expert on wood-burning stoves....... The study was conducted in seven typical Danish detached houses without other indoor activities taking place. In each house the average air change rate during one week was measured (using passive tracer gas technique) and the indoor and outdoor temperature and relative humidity were recorded continuously...

Radon gas. A review with emphasis on site investigations and measurements of soil gas and indoor house levels

International Nuclear Information System (INIS)

Mitchell, Seamus.

1992-09-01

A review of radon gas, with particular reference to its source and transport through soils and into buildings is examined. The principal parameters affecting the movement of radon has been discussed. The levels of radon gas in soils and in dwelling houses has been examined. Radon levels in the soil gas were highest in mineral soils with pear soils giving low readings but there was no significant differences between the results. Houses situated over granite and limestone bedrock gave similar results for indoor radon concentrations, with no significant differences being recorded. Results were expected to be much higher in houses over granite areas, in view of the higher uranium series activity in granites. It is concluded that high radon gas levels in soils under and in he vicinity of houses is the probable explanation for the indoor radon levels found. The influence of the underlying bedrock is not the most important parameter as was surmised before the study. (author)

Indoor air quality and infiltration in multifamily naval housing

International Nuclear Information System (INIS)

Parker, G.B.; Wilfert, G.L.; Dennis, G.W.

1984-11-01

Measurements of indoor air quality and air infiltration were taken in three units of a multifamily housing complex at the Naval Submarine base in Bangor, Washington, over 5 consecutive days during the heating season of 1983. Three dwelling units of identical size constructed in 1978 were monitored, each in a separate two-story four-unit complex. One unit was a downstairs unit and the other two units were upstairs units. Two of the units were occupied by smokers (one downstairs and one upstairs). None of the units had combustion appliances. Pollutants monitored indoors included radon, formaldehyde, carbon monoxide, particulate matter, and nitrogen dioxide. Indoor and outdoor temperature and windspeed were also recorded. Outdoor formaldehyde and nitrogen dioxide were also measured. Air exchange was measured about three times during each 24-h period, using a perfluorocarbon tracer with automatic tracer sampling. The daily average air exchange rate ranged from 0.22 to 0.91 air changes per hour (ACH). Pollutant concentrations were generally low except for particulate matter in the units with smokers, which were two to four times higher than in the unit with nonsmokers. Levels of carbon monoxide were also slightly elevated in one of the units with a smoker compared to the unit with nonsmokers. 5 references, 4 figures, 4 tables

Effects of ERV Filter Degradation on Indoor CO2 Levels of a Classroom

Directory of Open Access Journals (Sweden)

Jae-Sol Choi

2018-04-01

Full Text Available Energy recovery ventilators (ERVs are widely used to reduce energy losses caused by ventilation and improve indoor air quality for recently-constructed buildings. It is important for spaces with high occupancy density and longer residence times, such as classrooms. In classrooms, the ERV size is typically estimated by the target number of students in the design phase, but the design air volume flow rates (m3/h of the ERV can decrease over time owing to filter degradation such as increased dust loading. In this study, field tests are conducted in a classroom to investigate filter degradation through a visual inspection and by measuring the air volume flow rates at the diffusers connected to the ERV. In addition, variations in carbon dioxide (CO2 concentrations are also measured to verify the effects of filter degradation on the indoor CO2 levels over the entire test period, which includes filter replacement, as well. As the tests are conducted during classes, several adjusting methodologies are proposed to match the different test conditions. The results show that the total air volume flow rate of the ERV increases after the filter replacement (546 to 766 m3/h, but it again decreases as time elapses (659 m3/h. Accordingly, the indoor CO2 concentration decreases after the filter replacement by more than 300 ppm (1404 to 1085 ppm, clearly showing the effect of filter degradation. However, this CO2 concentration remains similar for four months after the replacement, and the total air volume rate decreases again. An interpretation is made using computational fluid dynamics analysis that the measured CO2 concentrations are affected by airflow patterns. The airflow in the cooling system may dilute CO2 concentrations at the measuring location. Thus, periodic filter replacement and management are important to ensure the desired ERV air volume rates and consequently the desired indoor CO2 concentrations.

[Measurement of Chemical Compounds in Indoor and Outdoor Air in Chiba City Using Diffusive Sampling Devices].

Science.gov (United States)

Sakamoto, Hironari; Uchiyama, Shigehisa; Kihara, Akiko; Tsutake, Toyoshige; Bekki, Kanae; Inaba, Yohei; Nakagome, Hideki; Kunugita, Naoki

2015-01-01

Indoor air quality (IAQ) is a major concern, because people on average spend the vast majority of their time indoors and they are repeatedly exposed to indoor air pollutants. In this study, to assess indoor air quality in Chiba City, gaseous chemical compounds were surveyed using four types of diffusive sampler. Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor air of 50 houses throughout Chiba City in winter and summer. Four types of diffusive sampler were used in this study: DSD-BPE/DNPH packed with 2,4-dinitrophenyl hydrazine and trans-1,2-bis(2-pyridyl)ethylene-coated silica for ozone and carbonyls; VOC-SD packed with Carboxen 564 particles for volatile organic compounds; DSD-TEA packed with triethanolamine-impregnated silica for acid gases; and DSD-NH3 packed with phosphoric acid-impregnated silica for basic gases. Almost all compounds in indoor air were detected at higher concentrations in summer than in winter. However, the nitrogen dioxide concentration in indoor air particularly increased only in winter, which well correlated with the formic acid concentration (correlation coefficient=0.974). The compound with the highest concentrations in indoor air was p-dichlorobenzene, with recorded levels of 13,000 μg m(-3) in summer and 1,100 μg m(-3) in winter in indoor air. p-Dichlorobenzene in summer and nitrogen dioxide in winter are detected at markedly high concentrations. Pollution control and continuous monitoring of IAQ are indispensable for human health.

Distribution of indoor radon concentrations and elements of a strategy for control

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1986-05-01

Indoor radon concentrations vary widely in the US housing stock, with normal concentrations estimated to cause a significant risk of lung cancer by comparison with environmental exposures normally considered, and high concentrations causing risks that exceed even those from cigarette smoking. The probability distribution, i.e., the number of houses at various concentrations, can be estimated from an analysis of the US indoor radon data accumulated to date. Such an analysis suggests that in about a million houses, occupants are receiving exposures greater than those experienced by uranium miners. The form of the frequency distribution, including not only the average concentration, but also the number of houses with high levels, has substantial influence on strategies for control of indoor radon. Such strategies require three major elements: formulation of control objectives in terms of guidelines for remedial action and for new houses; selection of means for identifying homes with high concentrations; and a framework for deciding what types of control measures are appropriate to particular circumstances and how rapidly they should be employed

Measurements of indoor radon concentration in italian red cross workplaces: preliminary results

International Nuclear Information System (INIS)

Fontana, C.; Musumeci, R.G.; Valeriani, F.; Tonnarini, S.; Trevisi, R.

2002-01-01

In August 2000 in Italy the D.Lgs.241/00 law was passed to implement the 96/29 Euratom Directive (BSS Directive, EC 1996). D.Lgs.241/00 states that workers cannot be exposed to decay products of radon, thoron and gamma radiation at a level higher than action level. The law became effective January 1, 2001. Italian action level of 500 Bq/m3 is the annual average indoor radon concentration. Work activities in zones with greater probability of high indoor radon concentration have to be identified. According to the law, a Commission must establish criteria for clarifying areas at risk. The actual work of classification is then done by the regions. A three year time period was given to define areas at risk. As the normative still must be completed, the Italian Red Cross and the Italian National Institute for Occupational Prevention and Safety initiated this study both because the Red Cross has always been sensitive to health problems and also to offer the Commission further experimental data regarding radon in Italy

Identifying areas with potential for high indoor radon levels: analysis of the national airborne radiometric reconnaissance data for California and the Pacific Northwest

Energy Technology Data Exchange (ETDEWEB)

Moed, B.A.; Nazaroff, W.W.; Nero, A.V.; Schwehr, M.B.; Van Heuvelen, A.

1984-04-01

Radon-222 is an important indoor air pollutant which, through the inhalation of its radioactive decay products, accounts for nearly half of the effective dose equivalent to the public from natural ionizing radiation. Indoor radon concentrations vary widely, largely because of local and regional differences in the rate of entry from sources. The major sources are soil and rock near building foundations, earth-based building materials, and domestic water; of these, soil and rock are thought to be predominant in many buildings with higher-than-average concentrations. Thus, one key factor in determining radon source potential is the concentration of radium, the progenitor of radon, in surficial rocks and soils. Aerial radiometric data were analyzed, collected for the National Uranium Resource Evaluation Program, for seven Western states to: (1) provide information on the spatial distribution of radium contents in surficial geologic materials for those states; and (2) investigate approaches for using the aerial data, which have been collected throughout the contiguous United States and Alaska, to identify areas where high indoor radon levels may be common. Radium concentrations were found to be relatively low in central and western portions of Washington, Oregon, and northern California; they were found to be relatively high in central and southern California. A field validation study, conducted along two flight-line segments near Spokane, Washington, showed close correspondence between the aerial data, in situ measurements of both radium content and radon flux from soil, and laboratory measurements of both radium content of and radon emanation rate from soil samples. 99 references, 11 figures, 3 tables.

Identifying areas with potential for high indoor radon levels: analysis of the national airborne radiometric reconnaissance data for California and the Pacific Northwest

International Nuclear Information System (INIS)

Moed, B.A.; Nazaroff, W.W.; Nero, A.V.; Schwehr, M.B.; Van Heuvelen, A.

1984-04-01

Radon-222 is an important indoor air pollutant which, through the inhalation of its radioactive decay products, accounts for nearly half of the effective dose equivalent to the public from natural ionizing radiation. Indoor radon concentrations vary widely, largely because of local and regional differences in the rate of entry from sources. The major sources are soil and rock near building foundations, earth-based building materials, and domestic water; of these, soil and rock are thought to be predominant in many buildings with higher-than-average concentrations. Thus, one key factor in determining radon source potential is the concentration of radium, the progenitor of radon, in surficial rocks and soils. Aerial radiometric data were analyzed, collected for the National Uranium Resource Evaluation Program, for seven Western states to: (1) provide information on the spatial distribution of radium contents in surficial geologic materials for those states; and (2) investigate approaches for using the aerial data, which have been collected throughout the contiguous United States and Alaska, to identify areas where high indoor radon levels may be common. Radium concentrations were found to be relatively low in central and western portions of Washington, Oregon, and northern California; they were found to be relatively high in central and southern California. A field validation study, conducted along two flight-line segments near Spokane, Washington, showed close correspondence between the aerial data, in situ measurements of both radium content and radon flux from soil, and laboratory measurements of both radium content of and radon emanation rate from soil samples. 99 references, 11 figures, 3 tables

Measurements of MIMO Indoor Channels at 1800 MHz with Multiple Indoor and Outdoor Base Stations

Directory of Open Access Journals (Sweden)

Jaldén Niklas

2007-01-01

Full Text Available This paper proposes several configurations for multiple base stations in indoor MIMO systems and compares their performance. The results are based on channel measurements realized with a MIMO testbed. The receiver was moved along several routes and floors on an office building. Both outdoor and indoor locations are considered for the transmitters or base stations, which allow the analysis of not only indoor but also outdoor-to-indoor environment. The use of 2 base stations with different system level combinations of the two is analyzed. We show that the configuration with base station selection provides almost as good performance as a full water-filling scheme when the 2 base stations are placed at different locations. Also the spatial correlation properties for the different configurations are analyzed and the importance of considering path loss when evaluating capacity is highlighted.

Prediction of indoor radon concentration based on residence location and construction

International Nuclear Information System (INIS)

Maekelaeinen, I.; Voutilainen, A.; Castren, O.

1992-01-01

We have constructed a model for assessing indoor radon concentrations in houses where measurements cannot be performed. It has been used in an epidemiological study and to determine the radon potential of new building sites. The model is based on data from about 10,000 buildings. Integrated radon measurements were made during the cold season in all the houses; their geographic coordinates were also known. The 2-mo measurement results were corrected to annual average concentrations. Construction data were collected from questionnaires completed by residents; geological data were determined from geological maps. Data were classified according to geographical, geological, and construction factors. In order to describe different radon production levels, the country was divided into four zones. We assumed that the factors were multiplicative, and a linear concentration-prediction model was used. The most significant factor in determining radon concentration was the geographical region, followed by soil type, year of construction, and type of foundation. The predicted indoor radon concentrations given by the model varied from 50 to 440 Bq m -3 . The lower figure represents a house with a basement, built in the 1950s on clay soil, in the region with the lowest radon concentration levels. The higher value represents a house with a concrete slab in contact with the ground, built in the 1980s, on gravel, in the region with the highest average radon concentration

[Indoor air pollution in southeast Santiago, Chile].

Science.gov (United States)

Pino, P; Oyarzún, M; Walter, T; von Baer, D; Romieu, I

1998-04-01

Indoor air pollution could play an important role in the susceptibility to respiratory diseases of vulnerable individuals, such as elders and infants. To evaluate indoor air pollution in a low income population of South East Santiago. A domiciliary survey of contaminant sources was carried out in the bouses of a cohort of 522 children less than one year old. Using a case-control design, 121 children consulting for respiratory diseases were considered as cases and 131 healthy infants of the same age and sex were considered as controls. In the houses of both groups, active monitors for particulate matter (PM10) and passive monitors for NO2 were installed. Forty two percent of fathers and 30% of mothers were smokers, and in two thirds of the families there was at least one smoker. Eighty five percent used portable heaters in winter. Of these, 77% used kerosene as fuel. Only 27% had water heating appliances. The rest heated water on the kitchen store or on bonfires. Most kitchen stoves used liquid gas as fuel. Twenty four hour PM10 was 109 +/- 3.2 micrograms/m3. Mean indoor and outdoor NO2 in 24 h was 108 +/- 76.3 and 84 +/- 53.6 micrograms/m3 respectively. Indoor NO2 levels were related to the use of heating devices and smoking. No differences in PM10 and NO2 levels were observed between cases and controls. There is a clear relationship between indoor pollution and contaminating sources. Indoor NO2 levels are higher than outdoors.

Geologic factors and house construction practices affecting indoor radon in Onondaga County, New York

International Nuclear Information System (INIS)

Laymon, C.; Kunz, C.

1990-01-01

Indoor radon in Onondaga County, New York is largely controlled by bedrock and surficial geology. At more local scales, these alone are insufficient to characterize indoor radon potential. This paper reports on a detailed study of the concentration of indoor radon, soil radium, soil-gas radon, soil and bedrock type, permeability, and home construction practices indicates that above-average indoor radon concentrations are associated with gravelly moraine and glaciofluvial deposits, the radium-bearing Marcellus Shale, and high permeability zones around the substructure of houses built into limestone bedrock

A study on seasonal variations of indoor gamma dose in Bangladesh

International Nuclear Information System (INIS)

Miah, M. Idrish

2005-01-01

Monthly variation of gamma dose rate measured in indoor air of buildings of Bangladesh was found to vary cosinusoidally through a period of 1 year. Significant seasonal variations were observed. Maximum dose rate, however, was observed in January and a minimum in July. Dose rate in January was 32% higher than the annual average, whereas dose rate in July was 50% lower. Seasonally varied ventilation and air exchange rates of the houses might play an important role in the observed variation. The average reduction with respect to winter dose was 59% in summer. Because of lower ventilation and air exchange rates between indoor and outdoor atmosphere, it is expected that the indoor dose rate would be higher in basements than that of upper floors. Monthly dose rate was also found to be influenced by the meteorological conditions. Correlations between dose rate and temperature (r 2 =0.85), rainfall (r=-0.83) and atmospheric pressure (r=0.92) were obtained, but no significant correlation (r=-0.45) was seen between dose rate and humidity. The results show that the seasonal variations of indoor dose rates should be taken into account to estimate annual effective dose equivalent. (author)

Indoor wayfinding and navigation

CERN Document Server

2015-01-01

Due to the widespread use of navigation systems for wayfinding and navigation in the outdoors, researchers have devoted their efforts in recent years to designing navigation systems that can be used indoors. This book is a comprehensive guide to designing and building indoor wayfinding and navigation systems. It covers all types of feasible sensors (for example, Wi-Fi, A-GPS), discussing the level of accuracy, the types of map data needed, the data sources, and the techniques for providing routes and directions within structures.

Design an Indoor Air Quality Controller Based on LPC2478

Directory of Open Access Journals (Sweden)

Shi Shuheng

2014-07-01

Full Text Available Indoor air quality is very important to our lives, because we spend most of our time indoor. In order to improve the air quality of indoor, this paper designs an indoor environment quality monitoring and controlling system based on ARM microcontroller LPC2478. It will do a real-time monitoring work for detecting the indoor environmental factors and comprehensively evaluate its air quality level. While the indoor air quality status is "poor", this intelligent system will automatically start the heat exchange ventilator for indoor environmental quality improvement. The results compared to traditional natural ventilation method show the better performance of proposed system.

Assessments of activated carbon prepared from date stones in adsorption of indoor radon

International Nuclear Information System (INIS)

Abudaia, J.I.; Al-Ezzaby, Suliman M.; Dawad, E.; Alawar, A.; Al-Shreide, A.

2015-01-01

Radiochemical department (RCD) at Tajoura Nuclear Research Center (TNRC) in Tripoli city is one of the fewest workplaces which have experienced indoor level evaluation. In this present study, it is intended to investigate the efficiency of domestic activated carbons (AC) derived from most locally available agricultural by products date stones (DS) in the adsorption of indoor radon-222 (' 222 Rn) at different oriented sites of RCD. The average indoor radon concentration values in the study areas varied from (34±3.0) Bq/m 3 to (192.7±9.1) Bq/m 3 , while the values of the annual effective dose varied from (0.355) mSv/y to (0.974) mSv/y. All obtained values were within the recommended action levels of (200 - 300) Bq/m 3 and 2.4 mSv/y which are given by International Commission on Radiological Protection (ICRP) in 1993 and 1987 respectively. A designed set up of portable ACDS canisters are proposed to be utilized in other different workplaces such as schools, where educational buildings are considered as locations of ventilation deficiency and high occupancy times for children and such naturally occurring radio-active radon is distinguished as a second leading cause of lung cancer worldwide.(author)

Indoor air quality of houses located in the urban environment of Agra, India.

Science.gov (United States)

Taneja, Ajay; Saini, Renuka; Masih, Amit

2008-10-01

Increased concern over the adverse health effects of air pollution has highlighted the need for air-pollution measurements, especially in urban areas, where many sources of air pollutants are normally monitored outdoors as part of obligations under the National Air Quality Strategies. Very little is known about air pollution indoors. In fact, the largest exposure to health-damaging indoor pollution probably occurs in the developing world, not in households, schools, and offices of developed countries where most research and control efforts have been focused to date. As a result much of the health impacts from air pollution worldwide seem to occur among the poorest and most vulnerable populations. The authors in their earlier studies have confirmed the importance of ambient air in determining the quality of air indoors. In this study an observation of air quality indoors and outdoors of domestic homes located in an urban environment from October 2004 to December 2005 in Agra, north central India, is performed. The purpose of this study was to characterize the indoor/outdoor (I/O) relationship of airborne pollutants and recognize their probable source in all three seasons, that is, winter, summer, and rainy season. Concentrations of SO(2), NO(2), CO(2), Cl(2), H(2)S, NH(3), RSPM, and PAH were monitored simultaneously and I/O ratios were calculated. In order to investigate the effect of seasonality on indoor and ambient air quality, winter to summer and winter to monsoon average ratios were calculated. It is apparent that there is a general pattern of increasing levels from monsoon to summer to winter, and similarly from outdoor to indoor air. Regressions analysis had been done to further investigate the influence of outdoor air-pollutant concentrations on indoor concentrations. The most probable categories of sources for these pollutants have been identified by using principal-component analysis. Indoor air pollution is a complex function of energy housing and

Indoor air-quality measurements in energy-efficient residential buildings

Energy Technology Data Exchange (ETDEWEB)

Berk, J.V.; Hollowell, C.D.; Pepper, J.H.; Young, R.

1980-05-01

The potential impact on indoor air quality of energy-conserving measures that reduce ventilation is being assessed in a field-monitoring program conducted by the Lawrence Berkeley Laboratory. Using a mobile laboratory, on-site monitoring of infiltration rate, carbon dioxide, carbon monoxide, nitrogen dioxide, nitric oxide, ozone, sulfur dioxide, formaldehyde, total aldehydes, and particulates was conducted in three houses designed to be energy-efficient. Preliminary results show that energy-conserving design features that reduce air-exchange rates compromise indoor air quality; specifically, indoor levels of several pollutants were found to exceed levels detected outdoors. Although the indoor levels of most pollutants are within limits established by present outdoor air-quality standards, considerable work remains to be accomplished before health-risk effects can be accurately assessed and broad-scale regulatory guidelines revised to comply with energy-conservation goals.

The carbon footprint of indoor Cannabis production

International Nuclear Information System (INIS)

Mills, Evan

2012-01-01

The emergent industry of indoor Cannabis production – legal in some jurisdictions and illicit in others – utilizes highly energy intensive processes to control environmental conditions during cultivation. This article estimates the energy consumption for this practice in the United States at 1% of national electricity use, or $6 billion each year. One average kilogram of final product is associated with 4600 kg of carbon dioxide emissions to the atmosphere, or that of 3 million average U.S. cars when aggregated across all national production. The practice of indoor cultivation is driven by criminalization, pursuit of security, pest and disease management, and the desire for greater process control and yields. Energy analysts and policymakers have not previously addressed this use of energy. The unchecked growth of electricity demand in this sector confounds energy forecasts and obscures savings from energy efficiency programs and policies. While criminalization has contributed to the substantial energy intensity, legalization would not change the situation materially without ancillary efforts to manage energy use, provide consumer information via labeling, and other measures. Were product prices to fall as a result of legalization, indoor production using current practices could rapidly become non-viable. - Highlights: ► The emergent industry of indoor Cannabis production utilizes highly energy intensive processes and is highly inefficient. ► In the United States, this represents an annual energy expenditure of $6 billion. ► One kg of final product is associated with emissions of 4600 kg of CO 2 emissions to the atmosphere. ► Aggregate U.S. emissions are equivalent those of 3 million cars. ► Energy analysts and policymakers have not previously addressed this use of energy.

Indoor and outdoor PM10 levels at schools located near mine dumps in Gauteng and North West Provinces, South Africa

Directory of Open Access Journals (Sweden)

Vusumuzi Nkosi

2017-01-01

Full Text Available Abstract Background Few studies in South Africa have investigated the exposure of asthmatic learners to indoor and outdoor air pollution at schools. This study compared outdoor PM10 and SO2 exposure levels in exposed (1–2 km from gold mine dumps and unexposed schools (5 km or more from gold mine dumps. It also examined exposure of asthmatic children to indoor respirable dust at exposed and unexposed schools. Methods The study was conducted between 1 and 31 October 2012 in five schools from exposed and five from unexposed communities. Outdoor PM10 and SO2 levels were measured for 8-h at each school. Ten asthmatic learners were randomly selected from each school for 8-h personal respirable dust sampling during school hours. Results The level of outdoor PM10 for exposed was 16.42 vs. 11.47 mg.m−3 for the unexposed communities (p < 0.001. The outdoor SO2 for exposed was 0.02 ppb vs. 0.01 ppb for unexposed communities (p < 0.001. Indoor respirable dust in the classroom differed significantly between exposed (0.17 mg.m−3 vs. unexposed (0.01 mg.m−3 children with asthma at each school (p < 0.001. Conclusion The significant differences between exposed and unexposed schools could reveal a serious potential health hazard for school children, although they were within the South African Air Quality Standards’ set by the Department of Environmental Affairs. The indoor respirable dust levels in exposed schools could have an impact on children with asthma, as they were significantly higher than the unexposed schools, although there are no published standards for environmental exposure for children with asthma.

Office of radiation and indoor air: Program description

International Nuclear Information System (INIS)

1993-06-01

The goal of the Environmental Protection Agency's (EPA) Office of Radiation and Indoor Air is to protect the public and the environment from exposures to radiation and indoor air pollutants. The Office develops protection criteria, standards, and policies and works with other programs within EPA and other agencies to control radiation and indoor air pollution exposures; provides technical assistance to states through EPA's regional offices and other agencies having radiation and indoor air protection programs; directs an environmental radiation monitoring program; responds to radiological emergencies; and evaluates and assesses the overall risk and impact of radiation and indoor air pollution. The Office is EPA's lead office for intra- and interagency activities coordinated through the Committee for Indoor Air Quality. It coordinates with and assists the Office of Enforcement in enforcement activities where EPA has jurisdiction. The Office disseminates information and works with state and local governments, industry and professional groups, and citizens to promote actions to reduce exposures to harmful levels of radiation and indoor air pollutants

High blood pressure and long-term exposure to indoor noise and air pollution from road traffic.

Science.gov (United States)

Foraster, Maria; Künzli, Nino; Aguilera, Inmaculada; Rivera, Marcela; Agis, David; Vila, Joan; Bouso, Laura; Deltell, Alexandre; Marrugat, Jaume; Ramos, Rafel; Sunyer, Jordi; Elosua, Roberto; Basagaña, Xavier

2014-11-01

Traffic noise has been associated with prevalence of hypertension, but reports are inconsistent for blood pressure (BP). To ascertain noise effects and to disentangle them from those suspected to be from traffic-related air pollution, it may be essential to estimate people's noise exposure indoors in bedrooms. We analyzed associations between long-term exposure to indoor traffic noise in bedrooms and prevalent hypertension and systolic (SBP) and diastolic (DBP) BP, considering long-term exposure to outdoor nitrogen dioxide (NO2). We evaluated 1,926 cohort participants at baseline (years 2003-2006; Girona, Spain). Outdoor annual average levels of nighttime traffic noise (Lnight) and NO2 were estimated at postal addresses with a detailed traffic noise model and a land-use regression model, respectively. Individual indoor traffic Lnight levels were derived from outdoor Lnight with application of insulations provided by reported noise-reducing factors. We assessed associations for hypertension and BP with multi-exposure logistic and linear regression models, respectively. Median levels were 27.1 dB(A) (indoor Lnight), 56.7 dB(A) (outdoor Lnight), and 26.8 μg/m3 (NO2). Spearman correlations between outdoor and indoor Lnight with NO2 were 0.75 and 0.23, respectively. Indoor Lnight was associated both with hypertension (OR = 1.06; 95% CI: 0.99, 1.13) and SBP (β = 0.72; 95% CI: 0.29, 1.15) per 5 dB(A); and NO2 was associated with hypertension (OR = 1.16; 95% CI: 0.99, 1.36), SBP (β = 1.23; 95% CI: 0.21, 2.25), and DBP (β⊇= 0.56; 95% CI: -0.03, 1.14) per 10 μg/m3. In the outdoor noise model, Lnight was associated only with hypertension and NO2 with BP only. The indoor noise-SBP association was stronger and statistically significant with a threshold at 30 dB(A). Long-term exposure to indoor traffic noise was associated with prevalent hypertension and SBP, independently of NO2. Associations were less consistent for outdoor traffic Lnight and likely affected by

Wi-Fi/MARG Integration for Indoor Pedestrian Localization.

Science.gov (United States)

Tian, Zengshan; Jin, Yue; Zhou, Mu; Wu, Zipeng; Li, Ze

2016-12-10

With the wide deployment of Wi-Fi networks, Wi-Fi based indoor localization systems that are deployed without any special hardware have caught significant attention and have become a currently practical technology. At the same time, the Magnetic, Angular Rate, and Gravity (MARG) sensors installed in commercial mobile devices can achieve highly-accurate localization in short time. Based on this, we design a novel indoor localization system by using built-in MARG sensors and a Wi-Fi module. The innovative contributions of this paper include the enhanced Pedestrian Dead Reckoning (PDR) and Wi-Fi localization approaches, and an Extended Kalman Particle Filter (EKPF) based fusion algorithm. A new Wi-Fi/MARG indoor localization system, including an Android based mobile client, a Web page for remote control, and a location server, is developed for real-time indoor pedestrian localization. The extensive experimental results show that the proposed system is featured with better localization performance, with the average error 0.85 m, than the one achieved by using the Wi-Fi module or MARG sensors solely.

A 'delayed' counting method to determine indoor Rn-222 levels indirectly

CERN Document Server

Iannopollo, V; Trimarchi, M; Tripepi, M G; Vermiglio, G

2001-01-01

A new indirect and 'delayed' way is presented to determine indoor concentration of Rn-222 by best-fitting methods. If a rapid knowledge of Rn-222 levels is required and if a detection system is not available in situ, it is possible to obtain concentration of radioactive gas by determining of 'delayed' counts of Po-214. The 'delay' time consists of two or three hours. The method is based on the use of cellulose filters for particulate collection and on the analysis of samples by alpha spectroscopy. It is also possible to obtain concentrations of short-lived radon daughters Po-218, Pb-214, Bi-214, which are very important quantities in a medical framework.

Soil radium, soil gas radon and indoor radon empirical relationships to assist in post-closure impact assessment related to near-surface radioactive waste disposal.

Science.gov (United States)

Appleton, J D; Cave, M R; Miles, J C H; Sumerling, T J

2011-03-01

Least squares (LS), Theil's (TS) and weighted total least squares (WTLS) regression analysis methods are used to develop empirical relationships between radium in the ground, radon in soil and radon in dwellings to assist in the post-closure assessment of indoor radon related to near-surface radioactive waste disposal at the Low Level Waste Repository in England. The data sets used are (i) estimated ²²⁶Ra in the < 2 mm fraction of topsoils (eRa226) derived from equivalent uranium (eU) from airborne gamma spectrometry data, (ii) eRa226 derived from measurements of uranium in soil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. For models comparing indoor radon and (i) eRa226 derived from airborne eU data and (ii) soil gas radon data, some of the geological groupings have significant slopes. For these groupings there is reasonable agreement in slope and intercept between the three regression analysis methods (LS, TS and WTLS). Relationships between radon in dwellings and radium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given radium or soil gas radon concentration in the ground. The regression models comparing indoor radon with soil gas radon have intercepts close to 5 Bq m⁻³ whilst the intercepts for those comparing indoor radon with eRa226 from airborne eU vary from about 20 Bq m⁻³ for a moderately permeable geological unit to about 40 Bq m⁻³ for highly permeable limestone, implying unrealistically high contributions to indoor radon from sources other than the ground. An intercept value of 5 Bq m⁻³ is assumed as an appropriate mean value for the UK for sources of indoor radon other than radon from the ground, based on examination of UK data. Comparison with published data used to derive an average indoor radon: soil ²²⁶Ra ratio shows that whereas the published data are

Preventing skin cancer through reduction of indoor tanning: current evidence.

Science.gov (United States)

Watson, Meg; Holman, Dawn M; Fox, Kathleen A; Guy, Gery P; Seidenberg, Andrew B; Sampson, Blake P; Sinclair, Craig; Lazovich, DeAnn

2013-06-01

Exposure to ultraviolet radiation from indoor tanning devices (tanning beds, booths, and sun lamps) or from the sun contributes to the risk of skin cancer, including melanoma, which is the type of skin cancer responsible for most deaths. Indoor tanning is common among certain groups, especially among older adolescents and young adults, adolescent girls and young women, and non-Hispanic whites. Increased understanding of the health risks associated with indoor tanning has led to many efforts to reduce use. Most environmental and systems efforts in the U.S. (e.g., age limits or requiring parental consent/accompaniment) have occurred at the state level. At the national level, the U.S. Food and Drug Administration and the Federal Trade Commission regulate indoor tanning devices and advertising, respectively. The current paper provides a brief review of (1) the evidence on indoor tanning as a risk factor for skin cancer; (2) factors that may influence use of indoor tanning devices at the population level; and (3) various environmental and systems options available for consideration when developing strategies to reduce indoor tanning. This information provides the context and background for the companion paper in this issue of the American Journal of Preventive Medicine, which summarizes highlights from an informal expert meeting convened by the CDC in August 2012 to identify opportunities to prevent skin cancer by reducing use of indoor tanning devices. Published by Elsevier Inc.

Energy use and indoor environment in new and existing dwellings in Arctic climates

DEFF Research Database (Denmark)

Kotol, Martin

2014-01-01

on indoor air quality performed in Sisimiut, Greenland. A questionnaire as part of the study found that over 30 % of respondents experience cold discomfort during winter months (i.e. cold floors, cold draft or too low indoor temperature), 35 % of the respondents reported frequent condensation on windows...... dwellings inhabited by the questionnaire respondents. The winter measurements indicate that 73 % of the monitored bedrooms experienced average additional moisture higher than 2.5 g/kg or average night CO2 concentration above 1000 ppm and 59 % of bedrooms had experienced both. This indicates...

Indoor and Outdoor Air Pollution- related Health Problem in Ethiopia: Review of Related Literature.

Science.gov (United States)

Tefera, Worku; Asfaw, Araya; Gilliland, Frank; Worku, Alemayehu; Wondimagegn, Mehari; Kumie, Abera; Samet, Jonathan; Berhane, Kiros

2016-01-01

The health effects of air pollution are generally global problems, but they have, since recently become issues of particular concern for developing countries. This review assessed the situation of air pollution and related health effects in the context of Ethiopia. The materials reviewed in this publication are published scientific papers from online search engines, unpublished government reports and academic theses/dissertations. In addition, interview data obtained from authorities and experts involved in the management of air quality were analyzed, interpreted and reported in the article. Review of the few studies conducted in Ethiopia showed that average concentrations of PM 2.5 reached as high as 280 µg/m 3 for 24-hour measurements (range: 2,417-12,739 µg/m 3 ). Indoor carbon monoxide (CO) levels were universally higher than regulatory limits for the United States and were found to be much higher among households using traditional stoves and solid biomass fuels. The use of traditional stoves and solid biomass fuels was reported in >95% of the households considered. High average levels of NO 2 (97 ppb) were reported in a large longitudinal study. The ambient PM 10 level was below the WHO guideline values in the majority of the samples. About 50% of the on-road CO samples taken from traffic roads in Addis Ababa were found to be less than the guideline values while the number of motor vehicles in Ethiopia is reported to be increasing by more than 9% per annum. There is a very limited air quality monitoring capacity in the country. The co-ordination between stakeholders in this regard is also inadequate. The limited evidence available on health effects of air pollution indicates that the prevalence of acute respiratory illness among children living in households using crude biomass fuels is significantly higher than the national average figures. The limited evidence reviewed and reported in this article indicates high levels of indoor air pollution and trends of

Indoor Chemistry

DEFF Research Database (Denmark)

Weschler, Charles J.; Carslaw, Nicola

2018-01-01

This review aims to encapsulate the importance, ubiquity, and complexity of indoor chemistry. We discuss the many sources of indoor air pollutants and summarize their chemical reactions in the air and on surfaces. We also summarize some of the known impacts of human occupants, who act as sources...... and sinks of indoor chemicals, and whose activities (e.g., cooking, cleaning, smoking) can lead to extremely high pollutant concentrations. As we begin to use increasingly sensitive and selective instrumentation indoors, we are learning more about chemistry in this relatively understudied environment....

Indoor and outdoor poly- and perfluoroalkyl substances (PFASs) in Korea determined by passive air sampler

International Nuclear Information System (INIS)

Kim, Seung-Kyu; Shoeib, Mahiba; Kim, Kyeong-Soo; Park, Jong-Eun

2012-01-01

Despite concerns to their increasing contribution to ecological and human exposure, the atmospheric levels of poly- and perfluoroalkyl substances (PFASs) have been determined mainly in Europe and North America. This study presents the indoor and outdoor air concentrations of volatile PFASs [fluorotelomer alcohols (FTOHs), and perfluoroalkyl sulfonamides/sulfonamidoethanols/sulfonamide ethyl acetate (FOSAs/FOSEs/FOSEA)] for the first time in Korean cities. In contrast to the good agreement observed for indoor FTOHs levels in Korea and Europea/North America, FOSAs/FOSEs levels were 10–100-fold lower in Korean indoor air, representing a cultural difference of indoor source. Korean outdoor air contained higher PFAS levels than indoor air, and additionally showed different PFAS composition profile from indoor air. Thus, indoor air would not likely be a main contributor to atmospheric PFAS contamination in Korea, in contrast to western countries. Inhalation exposure of volatile PFASs was estimated to be a minor contributor to PFOA and PFOS exposure in Korea. - Highlights: ► Volatile PFASs were measured in indoor and outdoor airs of Korea, for the first time. ► Cultural difference in indoor source was observed for Korea v.s. western countries. ► Furthermore, PFASs concentrations were higher in indoor air than outdoor air. ► Indoor air was not a major contributor to atmospheric PFASs contamination in Korea. ► Release from industrial activities was considered a possible source. - Korean outdoor air showed not only different PFAS composition profile but higher PFAS levels than indoor airs, indicating indoor air would not be a main source to Korean atmospheric PFASs.

Radiation exposure of man in the indoor environment

International Nuclear Information System (INIS)

Steinhaeusler, F.; Pohl, E.

1982-01-01

Indoor exposure of man represents the major component of the dose from the natural radiation environment (NRE). The different sources of the NRE and their complex superposition are discussed. Due to the use of radiologically disadvantageous material in or near the building, radon-rich tap water, specific architectural styles and decreased ventilation rates NRE-levels indoors have been found to even exceed the upper limit for professional exposure. The inadequacy of the existing international regulatory framework and specific local problems resulted in the establishment of national exposure limits. In general, no remedial action is recommended at levels below 50 μR/h for external gamma radiation, 10 mWL for internal radon daughter exposure. Several technical countermeasures reducing indoor gamma dose rates and radon levels have been developed for existing buildings. However, the use of some of the techniques is limited due to low cost-effectiveness or lack of long-term stability. Different techniques in order to achieve low indoor exposures for new buildings and financial aspects associated the application of radiation protection concepts are discussed

Research on Integration of Indoor and Outdoor Positioning in Professional Athletic Training

Directory of Open Access Journals (Sweden)

Yongqing Liu

2018-02-01

Full Text Available GNSS is widely used in professional athletic training as an outdoor location based services, and the indoor positioning technology has gradually flourished in the gymnasium. To keep up with the demand for athletic training in indoor and outdoor environment, integration of indoor and outdoor positioning technology can achieve a seamless indoor/outdoor position solution. The proposed method uses GPS/BEIDOU with IMU-MEMS technology for outdoor positioning and UWB with IMU-MEMS technology for indoor positioning to provide high precision positioning services. The experimental results show that the proposed method can achieve meter level position accuracy in outdoor environment and centimeter level position accuracy in indoor environment, it can provide precise and real-time positioning service for effective athletic training aid.

Indoor Environment Program

International Nuclear Information System (INIS)

Daisey, J.M.

1993-06-01

This paper reports progress during the year 1992 in the Indoor Environment Program in the Energy and Environment Division of Lawrence Berkeley Laboratory. Studies in the following areas are reported: energy performance and ventilation in buildings; physical and chemical characterization of indoor air pollutants; indoor radon; indoor air quality; exposure to indoor air pollutants and risk analysis. Pollutants of particular interest include: radon; volatile, semi-volatile and particulate organic compounds; and combustion emissions including environmental tobacco smoke, carbon monoxide, and nitrogen oxides

Method for Improving Indoor Positioning Accuracy Using Extended Kalman Filter

Directory of Open Access Journals (Sweden)

Seoung-Hyeon Lee

2016-01-01

Full Text Available Beacons using bluetooth low-energy (BLE technology have emerged as a new paradigm of indoor positioning service (IPS because of their advantages such as low power consumption, miniaturization, wide signal range, and low cost. However, the beacon performance is poor in terms of the indoor positioning accuracy because of noise, motion, and fading, all of which are characteristics of a bluetooth signal and depend on the installation location. Therefore, it is necessary to improve the accuracy of beacon-based indoor positioning technology by fusing it with existing indoor positioning technology, which uses Wi-Fi, ZigBee, and so forth. This study proposes a beacon-based indoor positioning method using an extended Kalman filter that recursively processes input data including noise. After defining the movement of a smartphone on a flat two-dimensional surface, it was assumed that the beacon signal is nonlinear. Then, the standard deviation and properties of the beacon signal were analyzed. According to the analysis results, an extended Kalman filter was designed and the accuracy of the smartphone’s indoor position was analyzed through simulations and tests. The proposed technique achieved good indoor positioning accuracy, with errors of 0.26 m and 0.28 m from the average x- and y-coordinates, respectively, based solely on the beacon signal.

Indoor air quality levels in a University Hospital in the Eastern Province of Saudi Arabia

Directory of Open Access Journals (Sweden)

Mahmoud F El-Sharkawy

2014-01-01

Full Text Available Aim of the Study: The complex hospital environment requires special attention to ensure a healthy indoor air quality (IAQ to protect patients and healthcare workers against hospital-acquired infections and occupational diseases. Poor hospital IAQ may cause outbreaks of building-related illness such as headaches, fatigue, eye, and skin irritations, and other symptoms. The general objective for this study was to assess IAQ inside a large University hospital at Al-Khobar City in the Eastern Province of Saudi Arabia. Materials and Methods: Different locations representing areas where most activities and tasks are performed were selected as sampling points for air pollutants in the selected hospital. In addition, several factors were studied to determine those that were most likely to affect the IAQ levels. The temperature and relative percent humidity of different air pollutants were measured simultaneously at each location. Results: The outdoor levels of all air pollutant levels, except volatile organic compounds (VOCs, were higher than the indoor levels which meant that the IAQ inside healthcare facilities (HCFs were greatly affected by outdoor sources, particularly traffic. The highest levels of total suspended particulates (TSPs and those less than 10 microns (PM 10 inside the selected hospital were found at locations that are characterized with m4ore human activity. Conclusions:Levels of particulate matter (both PM 10 and TSP were higher than the Air Quality Guidelines (AQGs. The highest concentrations of the fungal species recorded were Cladosporium and Penicillium. Education of occupants of HCF on IAQ is critical. They must be informed about the sources and effects of contaminants and the proper operation of the ventilation system.

Exploring the consequences of climate change for indoor air quality

International Nuclear Information System (INIS)

Nazaroff, William W

2013-01-01

Climate change will affect the concentrations of air pollutants in buildings. The resulting shifts in human exposure may influence public health. Changes can be anticipated because of altered outdoor pollution and also owing to changes in buildings effected in response to changing climate. Three classes of factors govern indoor pollutant levels in occupied spaces: (a) properties of pollutants; (b) building factors, such as the ventilation rate; and (c) occupant behavior. Diversity of indoor conditions influences the public health significance of climate change. Potentially vulnerable subpopulations include not only the young and the infirm but also those who lack resources to respond effectively to changing conditions. Indoor air pollutant levels reflect the sum of contributions from indoor sources and from outdoor pollutants that enter with ventilation air. Pollutant classes with important indoor sources include the byproducts of combustion, radon, and volatile and semivolatile organic compounds. Outdoor pollutants of special concern include particulate matter and ozone. To ensure good indoor air quality it is important first to avoid high indoor emission rates for all pollutants and second to ensure adequate ventilation. A third factor is the use of air filtration or air cleaning to achieve further improvements where warranted. (letter)

Hidden Markov Model based Mobility Learning for Improving Indoor Tracking of Mobile Users

DEFF Research Database (Denmark)

Pedersen, Nikolaj Bisgaard; Laursen, Troels; Nielsen, Jimmy Jessen

2012-01-01

Indoors, a user's movements are typically confined by walls, corridors, and doorways, and further he is typically repeating the same movements such as walking between certain points in the building. Conventional indoor localization systems do usually not take these properties of the user's moveme......Indoors, a user's movements are typically confined by walls, corridors, and doorways, and further he is typically repeating the same movements such as walking between certain points in the building. Conventional indoor localization systems do usually not take these properties of the user...... likely trajectory is then calculated using and extended version of the Viterbi algorithm. The results show significant improvements of the proposed algorithm compared to a simpler moving average smoothing....

Effects of types of ventilation system on indoor particle concentrations in residential buildings.

Science.gov (United States)

Park, J S; Jee, N-Y; Jeong, J-W

2014-12-01

The objective of this study was to quantify the influence of ventilation systems on indoor particle concentrations in residential buildings. Fifteen occupied, single-family apartments were selected from three sites. The three sites have three different ventilation systems: unbalanced mechanical ventilation, balanced mechanical ventilation, and natural ventilation. Field measurements were conducted between April and June 2012, when outdoor air temperatures were comfortable. Number concentrations of particles, PM2.5 and CO2 , were continuously measured both outdoors and indoors. In the apartments with natural ventilation, I/O ratios of particle number concentrations ranged from 0.56 to 0.72 for submicron particles, and from 0.25 to 0.60 for particles larger than 1.0 μm. The daily average indoor particle concentration decreased to 50% below the outdoor level for submicron particles and 25% below the outdoor level for fine particles, when the apartments were mechanically ventilated. The two mechanical ventilation systems reduced the I/O ratios by 26% for submicron particles and 65% for fine particles compared with the natural ventilation. These results showed that mechanical ventilation can reduce exposure to outdoor particles in residential buildings. Results of this study confirm that mechanical ventilation with filtration can significantly reduce indoor particle levels compared with natural ventilation. The I/O ratios of particles substantially varied at the naturally ventilated apartments because of the influence of variable window opening conditions and unsteadiness of wind flow on the penetration of outdoor air particles. For better prediction of the exposure to outdoor particles in naturally ventilated residential buildings, it is important to understand the penetration of outdoor particles with variable window opening conditions. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

An Indoor Continuous Positioning Algorithm on the Move by Fusing Sensors and Wi-Fi on Smartphones.

Science.gov (United States)

Li, Huaiyu; Chen, Xiuwan; Jing, Guifei; Wang, Yuan; Cao, Yanfeng; Li, Fei; Zhang, Xinlong; Xiao, Han

2015-12-11

Wi-Fi indoor positioning algorithms experience large positioning error and low stability when continuously positioning terminals that are on the move. This paper proposes a novel indoor continuous positioning algorithm that is on the move, fusing sensors and Wi-Fi on smartphones. The main innovative points include an improved Wi-Fi positioning algorithm and a novel positioning fusion algorithm named the Trust Chain Positioning Fusion (TCPF) algorithm. The improved Wi-Fi positioning algorithm was designed based on the properties of Wi-Fi signals on the move, which are found in a novel "quasi-dynamic" Wi-Fi signal experiment. The TCPF algorithm is proposed to realize the "process-level" fusion of Wi-Fi and Pedestrians Dead Reckoning (PDR) positioning, including three parts: trusted point determination, trust state and positioning fusion algorithm. An experiment is carried out for verification in a typical indoor environment, and the average positioning error on the move is 1.36 m, a decrease of 28.8% compared to an existing algorithm. The results show that the proposed algorithm can effectively reduce the influence caused by the unstable Wi-Fi signals, and improve the accuracy and stability of indoor continuous positioning on the move.

Influence of indoor air conditions on radon concentration in a detached house

International Nuclear Information System (INIS)

Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

2013-01-01

Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50–60%. - Highlights: ► We use CFD to simulate indoor radon concentration and distribution. ► The effects of ventilation rate, temperature and moisture are investigated. ► Model validation is performed through analytical solution and measurement results. ► Results show that ventilation rate is inversely proportional to radon level. ► There is a range of temperature and relative humidity that minimize radon level.

Indoor Air Pollution by Methylsiloxane in Household and Automobile Settings.

Directory of Open Access Journals (Sweden)

Fanyong Meng

Full Text Available This study examines characteristics of atmospheric methylsiloxane pollution in indoor settings where interior renovation/redecoration is being undertaken, in addition to ordinary family homes and inside family cars. Concentrations of atmospheric methylsiloxane in these locations were approximately one order of magnitude higher than that in outdoor areas. The average indoor concentration of methylsiloxane where renovation was being undertaken was 9.4 μg/m3, which is slightly higher than that in an ordinary family home (7.88 μg/m3, while samples from family cars showed lower concentration (3.10 μg/m3. The indoor atmospheric concentration during renovation/redecoration work was significantly positively correlated with the duration of the work. The structure of atmospheric methylsiloxane pollution is basically the same in these three venues. The concentration of annulus siloxane was much higher than that of linear compounds (85% of the total methylsiloxane concentrations. Household dust in average family homes showed total methylsiloxane concentration of 9.5 μg/m3 (average; the structure mainly consisted of linear siloxane (approximately 98% of total concentration, thereby differing from that of atmospheric methylsiloxane pollution. The comparatively high concentration of methylsiloxane in these three venues indicates that interior renovation and decoration work, and even travelling in cars, can involve exposure to more serious siloxane contamination during everyday activities.

Indoor air quality study of forty east Tennessee homes

International Nuclear Information System (INIS)

Hawthorne, A.R.; Gammage, R.B.; Dudney, C.S.

1984-12-01

Over a one-year period, measurements of indoor air pollutants (CO/sub x/, NO/sub x/, formaldehyde, volatile organics, particulates, and radon) were made in 40 homes in East Tennessee. The houses were of various ages with different types of insulation and heating. Over one-half of the houses exceeded the ASHRAE indoor ceiling guideline of 0.1 ppM for formaldehyde on at least one occasion. Over the duration of the study, older houses averaged 0.04 ppM of formaldehyde while houses less than 5 years old averaged 0.08 ppM (P -1 when the duct fan was operated (measurements prior to December 1982). This report presents the study design and implementation, describes the monitoring protocols, and provides a complete set of the data collected during the project. 25 references, 29 figures, 42 tables

[Indoor air pollution by volatile organic compounds in large buildings: pollution levels and remaining issues after revision of the Act on Maintenance of Sanitation in Buildings in 2002].

Science.gov (United States)

Sakai, Kiyoshi; Kamijima, Michihiro; Shibata, Eiji; Ohno, Hiroyuki; Nakajima, Tamie

2010-09-01

This study aimed to clarify indoor air pollution levels of volatile organic compounds (VOCs), especially 2-ethyl-1-hexanol (2E1H) in large buildings after revising of the Act on Maintenance of Sanitation in Buildings in 2002. We measured indoor air VOC concentrations in 57 (97%) out of a total of 61 large buildings completed within one year in half of the area of Nagoya, Japan, from 2003 through 2007. Airborne concentrations of 13 carbonyl compounds were determined with diffusion samplers and high-performance liquid chromatography, and of the other 32 VOCs with diffusion samplers and gas chromatography with a mass spectrometer. Formaldehyde was detected in all samples of indoor air but the concentrations were lower than the indoor air quality standard value set in Japan (100 microg/m3). Geometric mean concentrations of the other major VOCs, namely toluene, xylene, ethylbenzene, styrene, p-dichlorobenzene and acetaldehyde were also low. 2E1H was found to be one of the predominating VOCs in indoor air of large buildings. A few rooms in a small number of buildings surveyed showed high concentrations of 2E1H, while low concentrations were observed in most rooms of those buildings as well as in other buildings. It was estimated that about 310 buildings had high indoor air pollution levels of 2E1H, with increase during the 5 years from 2003 in Japan. Indoor air pollution levels of VOCs in new large buildings are generally good, although a few rooms in a small number of buildings showed high concentrations in 2E1H, a possible causative chemical in sick building symptoms. Therefore, 2E1H needs particular attention as an important indoor air pollutant.

Indoor radon concentration in Poland

International Nuclear Information System (INIS)

Mamont-Ciesla, K.; Jagielak, J.; Rosinski, S.W.; Sosinka, A.; Bysiek, M.; Henschke, J.

1996-01-01

Preliminary survey of Rn concentration indoors by means of track detectors and y-ray dose rate with the use of TLD in almost 500 homes in selected areas of Poland was performed in the late 1980s. It was concluded that radon contributes 1.16 mSv i.e. about 46 per cent of the total natural environment ionizing radiation dose to the Polish population. Comparison of the average radon concentrations in 4 seasons of a year and in 3 groups of buildings: masonry, concrete and wood, revealed that the ground beneath the building structure is likely the dominant source of radon indoors. Since the National Atomic Energy Agency in its regulations of 1988-03-31 set up the permissible limit of the equilibrium equivalent concentration of radon in new buildings (equal 100 Bq/m3), the nation-scale survey project for radon in buildings has been undertaken. These regulations were supposed to take effect in 1995-01-01. The project has 3 objectives: to estimate the radiation exposure due to radon daughters received by Polish population to identify radon-prone areas in Poland to investigate dependence of the indoor radon concentrations on such parameters as: type of construction material, presence (or absence) of cellar under the building, number of floor

A Critical Review of Naphthalene Sources and Exposures Relevant to Indoor and Outdoor Air

Directory of Open Access Journals (Sweden)

Chunrong Jia

2010-07-01

Full Text Available Both the recent classification of naphthalene as a possible human carcinogen and its ubiquitous presence motivate this critical review of naphthalene’s sources and exposures. We evaluate the environmental literature on naphthalene published since 1990, drawing on nearly 150 studies that report emissions and concentrations in indoor, outdoor and personal air. While naphthalene is both a volatile organic compound and a polycyclic aromatic hydrocarbon, concentrations and exposures are poorly characterized relative to many other pollutants. Most airborne emissions result from combustion, and key sources include industry, open burning, tailpipe emissions, and cigarettes. The second largest source is off-gassing, specifically from naphthalene’s use as a deodorizer, repellent and fumigant. In the U.S., naphthalene’s use as a moth repellant has been reduced in favor of para-dichlorobenzene, but extensive use continues in mothballs, which appears responsible for some of the highest indoor exposures, along with off-label uses. Among the studies judged to be representative, average concentrations ranged from 0.18 to 1.7 μg m-3 in non-smoker’s homes, and from 0.02 to 0.31 μg m-3 outdoors in urban areas. Personal exposures have been reported in only three European studies. Indoor sources are the major contributor to (non-occupational exposure. While its central tendencies fall well below guideline levels relevant to acute health impacts, several studies have reported maximum concentrations exceeding 100 μg m-3, far above guideline levels. Using current but draft estimates of cancer risks, naphthalene is a major environmental risk driver, with typical individual risk levels in the 10-4 range, which is high and notable given that millions of individuals are exposed. Several factors influence indoor and outdoor concentrations, but the literature is inconsistent on their effects. Further investigation is needed to better characterize naphthalene�

Design Criteria for Achieving Acceptable Indoor Radon Concentration

DEFF Research Database (Denmark)

Rasmussen, Torben Valdbjørn

2016-01-01

Design criteria for achieving an acceptable indoor radon concentration are presented in this paper. The paper suggests three design criteria. These criteria have to be considered at the early stage of the building design phase to meet the latest recommendations from the World Health Organization...... in most countries. The three design criteria are; first, establishing a radon barrier facing the ground; second, lowering the air pressure in the lower zone of the slab on ground facing downwards; third, diluting the indoor air with outdoor air. The first two criteria can prevent radon from infiltrating...... from the ground, and the third criteria can dilute the indoor air. By combining these three criteria, the indoor radon concentration can be lowered achieving an acceptable level. In addition, a cheap and reliable method for measuring the radon concentration in the indoor air is described. The provision...

Performance Analysis of Classification Methods for Indoor Localization in Vlc Networks

Science.gov (United States)

Sánchez-Rodríguez, D.; Alonso-González, I.; Sánchez-Medina, J.; Ley-Bosch, C.; Díaz-Vilariño, L.

2017-09-01

Indoor localization has gained considerable attention over the past decade because of the emergence of numerous location-aware services. Research works have been proposed on solving this problem by using wireless networks. Nevertheless, there is still much room for improvement in the quality of the proposed classification models. In the last years, the emergence of Visible Light Communication (VLC) brings a brand new approach to high quality indoor positioning. Among its advantages, this new technology is immune to electromagnetic interference and has the advantage of having a smaller variance of received signal power compared to RF based technologies. In this paper, a performance analysis of seventeen machine leaning classifiers for indoor localization in VLC networks is carried out. The analysis is accomplished in terms of accuracy, average distance error, computational cost, training size, precision and recall measurements. Results show that most of classifiers harvest an accuracy above 90 %. The best tested classifier yielded a 99.0 % accuracy, with an average error distance of 0.3 centimetres.

PERFORMANCE ANALYSIS OF CLASSIFICATION METHODS FOR INDOOR LOCALIZATION IN VLC NETWORKS

Directory of Open Access Journals (Sweden)

D. Sánchez-Rodríguez

2017-09-01

Full Text Available Indoor localization has gained considerable attention over the past decade because of the emergence of numerous location-aware services. Research works have been proposed on solving this problem by using wireless networks. Nevertheless, there is still much room for improvement in the quality of the proposed classification models. In the last years, the emergence of Visible Light Communication (VLC brings a brand new approach to high quality indoor positioning. Among its advantages, this new technology is immune to electromagnetic interference and has the advantage of having a smaller variance of received signal power compared to RF based technologies. In this paper, a performance analysis of seventeen machine leaning classifiers for indoor localization in VLC networks is carried out. The analysis is accomplished in terms of accuracy, average distance error, computational cost, training size, precision and recall measurements. Results show that most of classifiers harvest an accuracy above 90 %. The best tested classifier yielded a 99.0 % accuracy, with an average error distance of 0.3 centimetres.

Assessing future trends in indoor air quality

International Nuclear Information System (INIS)

van de Wiel, H.J.; Lebret, E.; van der Lingen, W.K.; Eerens, H.C.; Vaas, L.H.; Leupen, M.J.

1990-01-01

Several national and international health organizations have derived concentration levels below which adverse effects on men are not expected or levels below which the excess risk for individuals is less than a specified value. For every priority pollutant indoor concentrations below this limit are considered healthy. The percentage of Dutch homes exceeding such a limit is taken as a measure of indoor air quality for that component. The present and future indoor air quality of the Dutch housing stock is described for fourteen air pollutants. The highest percentages are scored by radon, environmental tobacco smoke, nitrogen dioxide from unvented combustion, and the potential presence of housedust mite and mould allergen in damp houses. Although the trend for all priority pollutants is downward the most serious ones remain high in the coming decades if no additional measures will be instituted

In search of the comfortable indoor environment: A comparison of the utility of objective and subjective indicators of indoor comfort

Energy Technology Data Exchange (ETDEWEB)

Fransson, Niklas; Skoog, Jennie [Building Services Engineering, Department of Energy and Environment, Chalmers University of Technology, Gothenburg (Sweden); Vaestfjaell, Daniel [Department of Psychology, Goeteborg University (Sweden)

2007-05-15

Today, many procedures for assessing the indoor environment rely on both subjective and objective indicators (e.g. ANSI/ASHRAE 55-2004; ISO 10551). It is however unclear how these two types of measurements are related to perceived comfort. This article aims at assessing the relative utility of subjective (rating scale measures) and objective indicators of perceived comfort of indoor environments. In a hospital setting, physical environmental variables (e.g. temperature, relative humidity and noise level) were simultaneously measured as respondents (both patients and staff) rated their perception of the indoor environment. Regression analyses indicated that the subjective sensory ratings were significantly better than objective indicators at predicting overall rated indoor comfort. These results are discussed in relation to existing measurement procedures and standards. (author)

Indoor air quality

DEFF Research Database (Denmark)

Jensen, Trine Susanne; Recevska, Ieva

 The objective of the 35th specific agreement is to provide support to the EEA activities in Environment and Health (E&H) on the topic of indoor air quality. The specific objectives have been to provide an overview of indoor air related projects in EU and indoor air related policies as well...... as idenfiying "good practices" to reduce health impact of indoor air exposure and suggest areas for future improvements....

Indoor multipath mitigation

DEFF Research Database (Denmark)

Dragünas, Kostas; Borre, Kai

2010-01-01

There are many applications that require continuous positioning in combined outdoor urban and indoor environments. GNSS has been used for a long time in outdoor environments, while indoor positioning is still a challenging task. One of the major degradations that GNSS receivers experience indoors...

Development of a model for radon concentration in indoor air

International Nuclear Information System (INIS)

Jelle, Bjørn Petter

2012-01-01

A model is developed for calculation of the radon concentration in indoor air. The model takes into account various important parameters, e.g. radon concentration in ground, radon diffusion resistance of radon barrier, air permeance of ground, air pressure difference between outdoor ground and indoor at ground level, ventilation of the building ground and number of air changes per hour due to ventilation. Characteristic case studies are depicted in selected 2D and 3D graphical plots for easy visualization and interpretation. The radon transport into buildings might be dominated by diffusion, pressure driven flow or a mixture of both depending on the actual values of the various parameters. The results of our work indicate that with realistic or typical values of the parameters, most of the transport of radon from the building ground to the indoor air is due to air leakage driven by pressure differences through the construction. By incorporation of various and realistic values in the radon model, valuable information about the miscellaneous parameters influencing the indoor radon level is gained. Hence, the presented radon model may be utilized as a simple yet versatile and powerful tool for examining which preventive or remedial measures should be carried out to achieve an indoor radon level below the reference level as set by the authorities. - Highlights: ► Model development for calculation of radon concentration in indoor air. ► Radon model accounting for various important parameters. ► Characteristic case studies depicted in 2D and 3D graphical plots. ► May be utilized for examining radon preventive measures.

Indoor air. Seminar of Zentrale Informationsstelle, Umweltberatung Bayern. Vol. 2

International Nuclear Information System (INIS)

Koller, U.; Haury, H.J.

1994-02-01

This seminar dealt with the subject of indoor air pollution and welcomed participants from environmental consultancy agencies and authorities and institutions related with environmental protection. Leading scientists from research and authorities presented the current state of knowledge abut the risks of indoorair pollution. The papers contained in these proceedings addressed: room climate and sick-building syndrome; allergens in indoor spaces; pollutants emitted by exemplary building materials; pollutant levels of organic compounds in indoor spaces; air quality in motor vehicle interiors; indoor air pollution - risk assessment and need for actions. (Uhe) [de

Indoor 222Rn measurements in the region of Beijing, People's Republic of China

International Nuclear Information System (INIS)

Ren, T.S.; Lin, L.Q.; Chen, Z.P.; Li, G.Y.; Chen, A.M.

1987-01-01

Passive integrating activated C detectors were used to study the regional distribution and temporal variation of 222 Rn in indoor air in dwellings in the Beijing region. Measurements were made in 537 dwellings, which were either detached houses or multi-family apartments. The city-wide study was completed in 1985. The distributions are approximately log-normal with 90% of the dwellings having 222 Rn levels less than 60 Bq m-3. The weighted average 222 Rn concentration has been found to be 22.4 Bq m-3. Averages for detached houses and multi-family dwellings are 25.9 and 15.2 Bq m-3, respectively. Assuming an equilibrium factor of 0.5 and an occupancy factor of 0.8, the average equilibrium equivalent concentration of 222 Rn progeny is 11.2 Bq m-3 and the annual average effective dose equivalent is 1.1 mSv

Indoor air pollution

International Nuclear Information System (INIS)

Spengler, J.D.

1985-01-01

Although official efforts to control air pollution have traditionally focused on outdoor air, it is now apparent that elevated contaminant concentrations are common inside some private and public buildings. Concerns about potential public health problems due to indoor air pollution are based on evidence that urban residents typically spend more than 90 percent of their time indoors, concentrations of some contaminants are higher indoors than outdoors, and for some pollutants personal exposures are not characterized adequately by outdoor measurements. Among the more important indoor contaminants associated with health or irritation effects are passive tobacco smoke, radon decay products, carbon monoxide, nitrogen dioxide, formaldehyde, asbestos fibers, microorganisms and aeroallergens. Efforts to assess health risks associated with indoor air pollution are limited by insufficient information about the number of people exposed, the pattern and severity of exposures, and the health consequences of exposures. An overall strategy should be developed to investigate indoor exposures, health effects, control options, and public policy alternatives

Radon measurements in air in waterworks and indoor swimming pools - a primary mapping project

International Nuclear Information System (INIS)

Marinko, J.; Mjoenes, L.; Soederman, A.-L.

2004-01-01

In 2001 the Swedish Work Environment Authority asked five regional offices around the country; Falun, Malmoe, Vaexjoe, Umeaa and Oerebro, to measure radon in air in workplaces where water was likely to enhance radon levels indoors. Track etch detectors were used and placed in workplaces according to the SSI measurement protocol for determining the annual average radon concentration in homes. Rooms that are frequently used by employees were measured. The detectors were exposed between 1 to 3 months. 225 detectors were used in the project and analysed at the same laboratory. The results showed that the radon concentration in waterworks often is high. Measurements were made in 60 waterworks. Levels exceeding 1000 Bq/m 3 were found in 49 of them and levels exceeding 4000 Bq/m 3 were found in 21 waterworks. The variation between waterworks may be a result of the radon concentration in the raw water, the amount of radon gas escaping to the air when water is treated, the air exchange rate in the building and where the detectors were deployed. Measurements were made in 28 indoor swimming baths. The maximum level was 290 Bq/m 3 , but most concentrations were between 30 to 70 Bq/m 3 . The conclusion is that high radon levels do not seem to be a problem in indoor swimming baths. Maybe this is due to good ventilation or the fact that water often has been treated for radon before it is used in swimming pools. The results from measurement in food industries such as breweries showed no extreme radon levels except for a fish farm where levels over 1000 Bq/m 3 were measured in the farming room and 790 Bq/m 3 in the office. The radon concentrations in laundries were relatively low, between 30 and 170 Bq/m 3

Effects of Using Light-Weight Concrete on Indoor Radon Concentration in High-Rise Buildings

Energy Technology Data Exchange (ETDEWEB)

Yu, K.N.; Cheung, T.; Koo, S.Y

1999-07-01

Light-weight concrete (LWC) (or drywall construction) has been used for partition walls in public housing in Hong Kong for about 10 years. A previous laboratory investigation showed that all types of LWC had considerably smaller Rn exhalation rates than those from normal concrete (NC), and could thus theoretically reduce the indoor Rn concentrations and the corresponding radiation dose from Rn. In the present investigation, a survey of Rn exhalation rates and indoor Rn concentrations at 39 dwelling sites built using LWC were carried out using charcoal canisters and {gamma}-spectroscopy. The mean Rn exhalation rate and the mean Rn concentration were around 1.6 mBq.s{sup -1}.m{sup -2} and 19 Bq.m{sup -3}, respectively, which were significantly smaller thanthe corresponding values of 12 mBq.s{sup -1}.m{sup -2} and 33 Bq.m{sup -3} for NC sites. The statistical t-test showed that both the mean Rn exhalation rate and the mean Rn concentration for NC and LWC sites walls were different at the 100% confidence level. The Rn exhalation rate from an LWC surface was, on average, only about 14% of that from an NC surface, while the Rn concentration in an LWC site was, on average, about 58% of that in an NC site, which were significant. A person living at an LWC site receives an average annual equivalent dose smaller than one living at an NC site by an amount as large as 1 mSv. Therefore, the use of LWC for partition walls can be a simple and economical way to reduce the indoor Rn concentrations and the corresponding radiation dose from Rn. Furthermore, the mean Rn concentration theoretically predicted from the mean Rn exhalation rate agreed excellently with that from measurements. (author)

The effects of an energy efficiency retrofit on indoor air quality.

Science.gov (United States)

Frey, S E; Destaillats, H; Cohn, S; Ahrentzen, S; Fraser, M P

2015-04-01

To investigate the impacts of an energy efficiency retrofit, indoor air quality and resident health were evaluated at a low-income senior housing apartment complex in Phoenix, Arizona, before and after a green energy building renovation. Indoor and outdoor air quality sampling was carried out simultaneously with a questionnaire to characterize personal habits and general health of residents. Measured indoor formaldehyde levels before the building retrofit routinely exceeded reference exposure limits, but in the long-term follow-up sampling, indoor formaldehyde decreased for the entire study population by a statistically significant margin. Indoor PM levels were dominated by fine particles and showed a statistically significant decrease in the long-term follow-up sampling within certain resident subpopulations (i.e. residents who report smoking and residents who had lived longer at the apartment complex). © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sampling strategies for indoor radon investigations

International Nuclear Information System (INIS)

Prichard, H.M.

1983-01-01

Recent investigations prompted by concern about the environmental effects of residential energy conservation have produced many accounts of indoor radon concentrations far above background levels. In many instances time-normalized annual exposures exceeded the 4 WLM per year standard currently used for uranium mining. Further investigations of indoor radon exposures are necessary to judge the extent of the problem and to estimate the practicality of health effects studies. A number of trends can be discerned as more indoor surveys are reported. It is becoming increasingly clear that local geological factors play a major, if not dominant role in determining the distribution of indoor radon concentrations in a given area. Within a giving locale, indoor radon concentrations tend to be log-normally distributed, and sample means differ markedly from one region to another. The appreciation of geological factors and the general log-normality of radon distributions will improve the accuracy of population dose estimates and facilitate the design of preliminary health effects studies. The relative merits of grab samples, short and long term integrated samples, and more complicated dose assessment strategies are discussed in the context of several types of epidemiological investigations. A new passive radon sampler with a 24 hour integration time is described and evaluated as a tool for pilot investigations

The distribution of indoor radon in Transylvania (Romania) - influence of the natural and anthropogenic factors

Science.gov (United States)

Cucos Dinu, Alexandra; Baciu, Calin; Dicu, Tiberius; Papp, Botond; Moldovan, Mircea; Bety Burghele, Denissa; Tenter, Ancuta; Szacsvai, Kinga

2017-04-01

(residential, soil, water) was observed, both as individual values, average values over the grid or county level. The highest concentrations of indoor radon were found in Bihor, Mures, Brasov, and Cluj. In these regions further investigation is needed on the factors influencing the accumulation of radon in high concentrations in indoor air, such as soil type and geology, ventilation, or constructive and architectural features. Acknowledgements: The research is supported by the project ID P_37_229, Contract No. 22/01.09.2016, with the title „Smart Systems for Public Safety through Control and Mitigation of Residential Radon linked with Energy Efficiency Optimization of Buildings in Romanian Major Urban Agglomerations SMART-RAD-EN" of the POC Programme.

A View Indoors, Indoor Environment Division's e-Article Series

Science.gov (United States)

The Indoor Environments Division has created partnership with public and private sector entities to help encourage the public to take action to minimize their risk and mitigate indoor air quality problems.

Indoor and outdoor sources of size-resolved mass concentration of particulate matter in a school gym-implications for exposure of exercising children.

Science.gov (United States)

Braniš, Martin; Safránek, Jiří; Hytychová, Adéla

2011-05-01

It has been noticed many times that schools are buildings with high levels of particulate matter concentrations. Several authors documented that concentrations of particulate matter in indoor school microenvironments exceed limits recommended by WHO namely when school buildings are situated near major roads with high traffic densities. In addition, exercise under conditions of high particulate concentrations may increase the adverse health effects, as the total particle deposition increases in proportion to minute ventilation, and the deposition fraction nearly doubles from rest to intense exercise. Mass concentrations of size-segregated aerosol were measured simultaneously in an elementary school gym and an adjacent outdoor site in the central part of Prague by two pairs of collocated aerosol monitors-a fast responding photometer DusTrak and a five stage cascade impactor. To encompass seasonal and annual differences, 89 days of measurements were performed during ten campaigns between 2005 and 2009. The average (all campaigns) outdoor concentration of PM(2.5) (28.3 μg m(-3)) measured by the cascade impactors was higher than the indoor value (22.3 μg m(-3)) and the corresponding average from the nearest fixed site monitor (23.6 μg m(-3)). Indoor and outdoor PM(2.5) concentrations exceeded the WHO recommended 24-h limit in 42% and 49% of the days measured, respectively. The correlation coefficient (r) between corresponding outdoor and indoor aerosol sizes increased with decreasing aerodynamic diameter of the collected particles (r = 0.32-0.87), suggesting a higher infiltration rate of fine and quasi-ultrafine particles. Principal component analysis revealed five factors explaining more than 82% of the data variability. The first two factors reflected a close association between outdoor and indoor fine and quasi-ultrafine particles confirming the hypothesis of high infiltration rate of particles from outdoors. The third factor indicated that human

Potential exposures associated with indoor marijuana growing operations.

Science.gov (United States)

Martyny, John W; Serrano, Kate A; Schaeffer, Joshua W; Van Dyke, Mike V

2013-01-01

We entered a total of 30 indoor marijuana grow operations (IMGO) with law enforcement investigators in order to determine potential exposures to first responders. Samples for airborne fungal spores, volatile organic compounds, carbon dioxide, carbon monoxide, and delta-9-tetrahydrocannabinol (THC) were obtained as well as the identification of chemicals utilized in the IMGO. The chemicals utilized within the IMGOs were primarily pesticides and fertilizers with none showing high toxicity. Although several of the IMGOs had CO2 enrichment processes involving combustion, CO levels were not elevated. THC levels were identified on surfaces within the IMGOs and on the hands of the investigators. Surface levels ranged from indoor and outdoor samples with Cladosporium sp. the predominant outdoor species and Penicillium sp. the predominant indoor species. We concluded that the potential increase in fungal spore concentrations associated with the investigation and especially removal of the marijuana plants could potentially expose responders to levels of exposure consistent with those associated with mold remediation processes and that respiratory protection is advisable.

Computing transient exposure to indoor pollutants

International Nuclear Information System (INIS)

Owczarski, P.C.; Parker, G.B.

1983-03-01

A computer code, CORRAL, is used to compute the transient levels of gases and respirable particulates in a residence. Predictions of time-varying exposure to radon (from the outside air, soil and well water) and respirable particulates (from outside air, wood stove operation and cigarette smoke) for a mother and child over 24 hours are made. Average 24-hour radon exposures are 13 times background (0.75 pCi/l) for the child and 4.5 times background for the mother. Average 24-hour respirable particulate exposures are 5.6 times background (100 μg/m 3 ) for the mother and 4.2 times background for the child. The controlling parameters examined are source location, flow rates between rooms, air infiltration rate and lifestyle. The first three are shown to influence the formation of local pockets of high concentration of radon and particulates, and the last parameter shows that lifestyle patterns ultimately govern individual exposure to these pockets of high concentrations. The code is useful for examination of mitigation measures to reduce exposure and examination of the effects that the controlling parameters have on exposure to indoor pollutants

Environmental radiation levels around Nuclear Fuel Complex, Hyderabad during 1981-1988

International Nuclear Information System (INIS)

Mehta, Navnit; Lakshmanan, A.R.; Kathuria, S.P.; Nambi, K.S.V.

1989-01-01

This report presents environmental radiation monitoring results around Nuclear Ffuel Complex (NFC) at Hyderabad for the period, 1981-'88. During 1981-'83 only indoor radiations were monitored at 12 locations in the region of about 15 km. radius around NFC plant. However, during 1984-'88 both indoor and outdoor monitoring was done in a standardised manner at 8 locations. In this routine monitoring programme, environmental thermoluminescent dosimeters were used in quarterly integrating cycles. The average outdoor natural radiation level around NFC during 1984-'88 is found to be 227 ± 34 (σ) mR/y, which is the highest among the various sites in the country where DAE units are located. Such a high level of natural background radiation in and around Hyderabad is due to granitic terrains which normally have significant amounts of primordial radioactivity. The indoor to outdoor radiation ratio is found to be 1.35 ± 0.1 (σ). Application of this ratio on all the available indoor radiation monitoring results of 1981-'88 gives an estimate of 230 ± 26 mR/y as the average outdoor radiation level, and this is in very close agreement with the directly measured value mentioned earlier. The temporal variations seen in the quarterly results of each location have been tested for Normal and Log-Normal distributions and found to yield satisfactory correlations, although the plots reveal slight skewness; the latter however, could not be attributed to the NFC operations. (author). 7 refs., 4 tabs., 12 figs

Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, Chile.

Science.gov (United States)

Jorquera, Héctor; Barraza, Francisco; Heyer, Johanna; Valdivia, Gonzalo; Schiappacasse, Luis N; Montoya, Lupita D

2018-05-01

Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; however, little is known about the indoor air quality in this region. A field measurement campaign at 63 households in the Temuco urban area was conducted in winter 2014 and is reported here. In this study, indoor and outdoor (24-hr) PM 2.5 and its elemental composition were measured and compared. Infiltration parameters and outdoor/indoor contributions to indoor PM 2.5 were also determined. A statistical evaluation of how various air quality interventions and household features influence indoor PM 2.5 was also performed. This study determined median indoor and outdoor PM 2.5 concentrations of 44.4 and 41.8 μg/m 3 , respectively. An average infiltration factor (0.62 ± 0.06) was estimated using sulfur as a tracer species. Using a simple mass balance approach, median indoor and outdoor contributions to indoor PM 2.5 concentrations were then estimated as 12.5 and 26.5 μg/m 3 , respectively; therefore, 68% of indoor PM 2.5 comes from outdoor infiltration. This high percentage is due to high outdoor pollution and relatively high household air exchange rates (median: 1.06 h -1 ). This study found that S, Br and Rb were dominated by outdoor contributions, while Si, Ca, Ti, Fe and As originated from indoor sources. Using continuous indoor and outdoor PM 2.5 measurements, a median indoor source strength of 75 μg PM 2.5 /min was estimated for the diurnal period, similar to literature results. For the evening period, the median estimate rose to 135 μg PM 2.5 /min, reflecting a more intense wood burning associated to cooking and space heating at night. Statistical test results (at the 90% confidence level) support the ongoing woodstove replacement program (reducing emissions) and household weatherization subsidies (reducing heating demand) for improving indoor air quality in southern Chile, and suggest that a cookstove improvement program might be helpful as well

Experimental Evaluation of UWB Indoor Positioning for Sport Postures.

Science.gov (United States)

Ridolfi, Matteo; Vandermeeren, Stef; Defraye, Jense; Steendam, Heidi; Gerlo, Joeri; De Clercq, Dirk; Hoebeke, Jeroen; De Poorter, Eli

2018-01-09

Radio frequency (RF)-based indoor positioning systems (IPSs) use wireless technologies (including Wi-Fi, Zigbee, Bluetooth, and ultra-wide band (UWB)) to estimate the location of persons in areas where no Global Positioning System (GPS) reception is available, for example in indoor stadiums or sports halls. Of the above-mentioned forms of radio frequency (RF) technology, UWB is considered one of the most accurate approaches because it can provide positioning estimates with centimeter-level accuracy. However, it is not yet known whether UWB can also offer such accurate position estimates during strenuous dynamic activities in which moves are characterized by fast changes in direction and velocity. To answer this question, this paper investigates the capabilities of UWB indoor localization systems for tracking athletes during their complex (and most of the time unpredictable) movements. To this end, we analyze the impact of on-body tag placement locations and human movement patterns on localization accuracy and communication reliability. Moreover, two localization algorithms (particle filter and Kalman filter) with different optimizations (bias removal, non-line-of-sight (NLoS) detection, and path determination) are implemented. It is shown that although the optimal choice of optimization depends on the type of movement patterns, some of the improvements can reduce the localization error by up to 31%. Overall, depending on the selected optimization and on-body tag placement, our algorithms show good results in terms of positioning accuracy, with average errors in position estimates of 20 cm. This makes UWB a suitable approach for tracking dynamic athletic activities.

Experimental Evaluation of UWB Indoor Positioning for Sport Postures

Directory of Open Access Journals (Sweden)

Matteo Ridolfi

2018-01-01

Full Text Available Radio frequency (RF-based indoor positioning systems (IPSs use wireless technologies (including Wi-Fi, Zigbee, Bluetooth, and ultra-wide band (UWB to estimate the location of persons in areas where no Global Positioning System (GPS reception is available, for example in indoor stadiums or sports halls. Of the above-mentioned forms of radio frequency (RF technology, UWB is considered one of the most accurate approaches because it can provide positioning estimates with centimeter-level accuracy. However, it is not yet known whether UWB can also offer such accurate position estimates during strenuous dynamic activities in which moves are characterized by fast changes in direction and velocity. To answer this question, this paper investigates the capabilities of UWB indoor localization systems for tracking athletes during their complex (and most of the time unpredictable movements. To this end, we analyze the impact of on-body tag placement locations and human movement patterns on localization accuracy and communication reliability. Moreover, two localization algorithms (particle filter and Kalman filter with different optimizations (bias removal, non-line-of-sight (NLoS detection, and path determination are implemented. It is shown that although the optimal choice of optimization depends on the type of movement patterns, some of the improvements can reduce the localization error by up to 31%. Overall, depending on the selected optimization and on-body tag placement, our algorithms show good results in terms of positioning accuracy, with average errors in position estimates of 20 cm. This makes UWB a suitable approach for tracking dynamic athletic activities.

Dynamic behavior of semivolatile organic compounds in indoor air

Energy Technology Data Exchange (ETDEWEB)

Loy, Michael David Van [Univ. of California, Berkeley, CA (United States)

1998-12-09

Exposures to a wide range of air pollutants are often dominated by those occurring in buildings because of three factors: 1) most people spend a large fraction of their time indoors, 2) many pollutants have strong indoor sources, and 3) the dilution volume in buildings is generally several orders of magnitude smaller than that of an urban airshed. Semivolatile organic compounds (SVOCS) are emitted by numerous indoor sources, including tobacco combustion, cooking, carpets, paints, resins, and glues, so indoor gasphase concentrations of these compounds are likely to be elevated relative to ambient levels. The rates of uptake and release of reversibly sorbing SVOCS by indoor materials directly affect both peak concentrations and persistence of the pollutants indoors after source elimination. Thus, accurate predictions of SVOC dynamics in indoor air require an understanding of contaminant sorption on surface materials such as carpet and wallboard. The dynamic behaviors of gas-phase nicotine and phenanthrene were investigated in a 20 ms stainless steel chamber containing carpet and painted wallboard. Each compound was studied independently, first in the empty chamber, then with each sorbent individually, and finally with both sorbents in the chamber.

An RFID Indoor Positioning Algorithm Based on Bayesian Probability and K-Nearest Neighbor.

Science.gov (United States)

Xu, He; Ding, Ye; Li, Peng; Wang, Ruchuan; Li, Yizhu

2017-08-05

The Global Positioning System (GPS) is widely used in outdoor environmental positioning. However, GPS cannot support indoor positioning because there is no signal for positioning in an indoor environment. Nowadays, there are many situations which require indoor positioning, such as searching for a book in a library, looking for luggage in an airport, emergence navigation for fire alarms, robot location, etc. Many technologies, such as ultrasonic, sensors, Bluetooth, WiFi, magnetic field, Radio Frequency Identification (RFID), etc., are used to perform indoor positioning. Compared with other technologies, RFID used in indoor positioning is more cost and energy efficient. The Traditional RFID indoor positioning algorithm LANDMARC utilizes a Received Signal Strength (RSS) indicator to track objects. However, the RSS value is easily affected by environmental noise and other interference. In this paper, our purpose is to reduce the location fluctuation and error caused by multipath and environmental interference in LANDMARC. We propose a novel indoor positioning algorithm based on Bayesian probability and K -Nearest Neighbor (BKNN). The experimental results show that the Gaussian filter can filter some abnormal RSS values. The proposed BKNN algorithm has the smallest location error compared with the Gaussian-based algorithm, LANDMARC and an improved KNN algorithm. The average error in location estimation is about 15 cm using our method.

Indoor and outdoor particulate matter in primary school classrooms with fan-assisted natural ventilation in Singapore.

Science.gov (United States)

Chen, Ailu; Gall, Elliott T; Chang, Victor W C

2016-09-01

We conducted multiday continuous monitoring of indoor and outdoor particulate matter (PM) in classrooms with fan-assisted natural ventilation (NV) at five primary schools in Singapore. We monitored size-resolved number concentration of PM with diameter 0.3-10 μm at all schools and alveolar deposited surface area concentrations of PM with diameter 0.01-1.0 μm (SA0.01-1.0) at two schools. Results show that, during the monitoring period, schools closer to expressways and in the downtown area had 2-3 times higher outdoor PM0.3-1.0 number concentrations than schools located in suburban areas. Average indoor SA0.01-1.0 was 115-118 μm(2) cm(-3) during periods of occupancy and 72-87 μm(2) cm(-3) during unoccupied periods. There were close indoor and outdoor correlations for fine PM during both occupied and unoccupied periods (Pearson's r = 0.84-1.0) while the correlations for coarse PM were weak during the occupied periods (r = 0.13-0.74). Across all the schools, the size-resolved indoor/outdoor PM ratios (I/O ratios) were 0.81 to 1.58 and 0.61 to 0.95 during occupied and unoccupied periods, respectively, and average infiltration factors were 0.64 to 0.94. Average PM net emission rates, calculated during periods of occupancy in the classrooms, were lower than or in the lower range of emission rates reported in the literature. This study also reveals that indoor fine and submicron PM predominantly come from outdoor sources, while indoor sources associated with occupancy may be important for coarse PM even when the classrooms have high air exchange rates.

EML indoor radon workshop, 1982

International Nuclear Information System (INIS)

George, A.C.; Lowder, W.; Fisenne, I.; Knutson, E.O.; Hinchliffe, L.

1983-07-01

A workshop on indoor radon, held at the Environmental Measurements Laboratory (EML) on November 30 and December 1, 1982, covered recent developments in radon daughter research and development. Thirty papers were presented dealing with standardization and quality assurance measurement methods, surveys, measurements strategy, physical mechanisms of radon and radon daughter transport and development of guidance standards for indoor exposures. The workshop concluded with a planning session that identified the following needs: (1) national and international intercomparisons of techniques for measuring radon and radon daughter concentrations, working level and radon exhalation flux density; (2) development and refinement of practical measurement techniques for thoron and its daughter products; (3) quantitative definition of the sources of indoor radon and the mechanisms of transport into structures; (4) better knowledge of the physical properties of radon daughters; (5) more complete and accurate data on the population exposure to radon, which can only be met by broadly based surveys; and (6) more international cooperation and information exchange among countries with major research programs

Radon in indoor air. Health risk, measurement methods and remedial measures

International Nuclear Information System (INIS)

Strand, T.

1996-02-01

Radon in indoor air is the main source of ionizing radiation in Norway. The booklet contains a presentation of radon sources, measurement methods, indoor radon concentrations, action levels, health risk and remedial measures

Conceptual spatial representations for indoor mobile robots

OpenAIRE

Zender, Henrik; Mozos, Oscar Martinez; Jensfelt, Patric; Kruijff, Geert-Jan M.; Wolfram, Burgard

2008-01-01

We present an approach for creating conceptual representations of human-made indoor environments using mobile robots. The concepts refer to spatial and functional properties of typical indoor environments. Following findings in cognitive psychology, our model is composed of layers representing maps at different levels of abstraction. The complete system is integrated in a mobile robot endowed with laser and vision sensors for place and object recognition. The system also incorporate...

Investigation on Moisture and Indoor Environment in Eight Danish Houses

DEFF Research Database (Denmark)

Jensen, Kasper Risgaard; Jensen, Rasmus Lund; Nørgaard, Jesper

2011-01-01

then need to be ventilated actively either by natural or mechanical ventilation. Increased focus on energy reduction together with requirements for e.g. thermal comfort indoors may lead to reduced indoor air quality and moisture problems which in turn may cause mould problems. This paper describes...... an investigation of the indoor air quality, relative humidity and air change rate in eight Danish houses. The houses were selected as they are all having recurrent problems with condensation on the windows. The houses were built between 1930 and 2007. Some of them have been only slightly renovated where others......, to indoor air quality in terms of CO2 concentration, and to the use of the house in terms of the level of the relative humidity and indoor moisture excess. Furthermore, the moisture production in the houses was estimated and compared to values provided in the literature. A better indoor air quality...

Study of high levels indoor air mercury contamination from mercury amalgam use in dentistry

International Nuclear Information System (INIS)

Khwaja, M.A.; Abbasi, M.S.; Mehmood, F.; Jahangir, S.

2014-01-01

In 2005, United Nations Environment Programme (UNEP) estimated that 362 tonnes of dental mercury are consumed annually worldwide. Dental mercury amalgams also called silver fillings and amalgam fillings are widely done. These fillings gave off mercury vapours. Estimated average absorbed concentrations of mercury vapours from dental fillings vary from 3,000 to 17,000 ng Hg. Mercury (Hg) also known as quick silver is an essential constituent of dental amalgam. It is a toxic substance of global concern. A persistent pollutant, mercury is not limited to its source but it travels, on time thousands of kilometers away from the source. Scientific evidence, including, UNEP Global Mercury report, establishes mercury as an extremely toxic substance, which is a major threat to wildlife, ecosystem and human health, at a global scale. Children are more at risk from mercury poisoning which affects their neurological development and brain. Mercury poisoning diminishes memory, attention, thinking and sight. In the past, a number of studies at dental sites in many countries have been carried out and reported which have been reviewed and briefly described. This paper describes and discusses the recent investigations, regarding mercury vapours level in air, carried out at 18 dental sites in Pakistan and other countries. It is evident from the data of 42 dental sites in 17 countries, including, selected dental sites in five main cities of Pakistan, described and discussed in this paper that at most dental sites in many countries including Pakistan, the indoor mercury vapours levels exceed far above the permissible limit, recommended for safe physical and mental health. At these sites, public, in general, and the medical, paramedical staff and vulnerable population, in particular, are at most serious risk to health resulting from exposure to toxic and hazardous mercury. (author)

The association between estimated average glucose levels and fasting plasma glucose levels in a rural tertiary care centre

Directory of Open Access Journals (Sweden)

Raja Reddy P

2013-01-01

Full Text Available The level of hemoglobin A1c (HbA1c, also known as glycated hemoglobin, determines how well a patient’s blood glucose level has been controlled over the previous 8-12 weeks. HbA1c levels help patients and doctors understand whether a particular diabetes treatment is working and whether adjustments need to be made to the treatment. Because the HbA1c level is a marker of blood glucose for the previous 60- 90 days, average blood glucose levels can be estimated using HbA1c levels. Aim in the present study was to investigate the relationship between estimated average glucose levels, as calculated by HbA1c levels, and fasting plasma glucose levels. Methods: Type 2 diabetes patients attending medicine outpatient department of RL Jalappa hospital, Kolar between March 2010 and July 2012 were taken. The estimated glucose levels (mg/dl were calculated using the following formula: 28.7 x HbA1c-46.7. Glucose levels were determined using the hexokinase method. HbA1c levels were determined using an HPLC method. Correlation and independent t- test was the test of significance for quantitative data. Results: A strong positive correlation between fasting plasma glucose level and estimated average blood glucose levels (r=0.54, p=0.0001 was observed. The difference was statistically significant. Conclusion: Reporting the estimated average glucose level together with the HbA1c level is believed to assist patients and doctors determine the effectiveness of blood glucose control measures.

Visual Positioning Indoors: Human Eyes vs. Smartphone Cameras.

Science.gov (United States)

Wu, Dewen; Chen, Ruizhi; Chen, Liang

2017-11-16

Artificial Intelligence (AI) technologies and their related applications are now developing at a rapid pace. Indoor positioning will be one of the core technologies that enable AI applications because people spend 80% of their time indoors. Humans can locate themselves related to a visually well-defined object, e.g., a door, based on their visual observations. Can a smartphone camera do a similar job when it points to an object? In this paper, a visual positioning solution was developed based on a single image captured from a smartphone camera pointing to a well-defined object. The smartphone camera simulates the process of human eyes for the purpose of relatively locating themselves against a well-defined object. Extensive experiments were conducted with five types of smartphones on three different indoor settings, including a meeting room, a library, and a reading room. Experimental results shown that the average positioning accuracy of the solution based on five smartphone cameras is 30.6 cm, while that for the human-observed solution with 300 samples from 10 different people is 73.1 cm.

Exposure caused by wireless technologies used for short-range indoor communication in homes and offices.

Science.gov (United States)

Schmid, G; Lager, D; Preiner, P; Uberbacher, R; Cecil, S

2007-01-01

In order to estimate typical radio frequency exposures from indoor used wireless communication technologies applied in homes and offices, WLAN, Bluetooth and Digital Enhanced Cordless Telecommunications systems, as well as baby surveillance devices and wireless headphones for indoor usage, have been investigated by measurements and numerical computations. Based on optimised measurement methods, field distributions and resulting exposure were assessed on selected products and real exposure scenarios. Additionally, generic scenarios have been investigated on the basis of numerical computations. The obtained results demonstrate that under usual conditions the resulting spatially (over body dimensions) averaged and 6-min time-averaged exposure for persons in the radio frequency fields of the considered applications is below approximately 0.1% of the reference level for power density according to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines published in 1998. Spatial and temporal peak values can be considerably higher by 2-3 orders of magnitude. In case of some transmitting devices operated in close proximity to the body (e.g. WLAN transmitters), local exposure can reach the same order of magnitude as the basic restriction; however, none of the devices considered in this study exceeded the limits according to the ICNIRP guidelines.

Coping with Indoor Air Pollution

Science.gov (United States)

... Pollution > Coping with Indoor Air Pollution Font: Outdoor Pollution Indoor Air Pollution Asthma Triggers For Kids and Teachers Coping with Indoor Air Pollution Indoor air pollution is irritating to everyone: But people who ...

Indoor radon concentration data: Its geographic and geologic distribution, an example from the Capital District, NY

International Nuclear Information System (INIS)

Thomas, J.J.; Overeynder, H.M.; Thomas, B.R.

1995-01-01

Most studies of the geographic distribution of indoor radon levels are plotted by county or ZIP code. This method is used for the radon potential maps produced by the U.S. Environmental Protection Agency (EPA) and the New York State Department of Health (NYSDOH). The basis for the mapping is the mean or median indoor radon count for all the data provided by NYSDOH within each geographic area. While testing the indoor radon analyses provided to the authors by CMT Independent Laboratories, we discovered data that deviated markedly from the EPA and NYSDOH means for the Capital District of New York (Albany and surrounding counties). Their screening indoor radon average concentrations in pCi/L, indicate low potential for Schenectady (3.0), Saratoga (3.2), and Albany (3.7) counties; and moderate potential for Rensselaer (6.4) and Columbia (7.0) counties. Our database of over 3,000 analyses contains over 800 records of indoor radon counts above 4 pCi/L (14-47% of each county's analyses), many high enough to be rated as a serious health hazard. In order to obtain greater precision of information, the authors plotted their indoor radon data by street address using MapInfo, a geographic Information System (GIS), and StreetInfo, MapInfo's TIGER address database. We compared the geographic distribution of our data to both the Bedrock Geology and Surficial Geology Maps of New York State. The results show a striking relationship of radon concentrations to bedrock, faults and permeability of surficial material. Data being compiled and mapped by street address by the NYSDOH in Erie County in western New York, confirm our results

[IMPACT OF PERIOPERATIVE AVERAGE BLOOD-GLUCOSE LEVEL ON PROGNOSIS OF PATIENTS WITH HIP FRACTURE AND DIABETES MELLITUS].

Science.gov (United States)

Wang, Guoqi; Long, Anhua; Zhang, Lihai; Zhang, Hao; Yin, Peng; Tang, Peifu

2014-07-01

To explore the impact of perioperative average blood-glucose level on the prognosis of patients with hip fracture and diabetes mellitus. A retrospective analysis was made on the clinical data of 244 patients with hip fracture and diabetes mellitus who accorded with the inclusion criteria between September 2009 and September 2012. Of 244 patients, 125 patients with poorly controlled fasting blood-glucose (average fasting blood-glucose level > 7.8 mmol/L) were assigned in group A, and 119 patients with well controlled fasting blood-glucose (average fasting blood-glucose level ≤ 7.8 mmol/L) were assigned in group B according to "China guideline for type 2 diabetes" criteria. There was no significant difference in gender, age, disease duration of diabetes mellitus, serum albumin, fracture type and disease duration, surgical procedure, anaesthesia, and complications between 2 groups (P > 0.05). Group A had a higher hemoglobin level and fewer patients who can do some outdoor activities than group B (t = -2.353, P = 0.020; χ2 = 4.333, P = 0.037). The hospitalization time, days to await surgery, stitch removal time, the postoperative complication rate, the mortality at 1 month and 1 year after operation, and ambulatory ability at 1 year after operation were compared between the 2 groups. A total of 223 patients (114 in group A and 109 in group B) were followed up 12-15 months (mean, 13.5 months). The days to await surgery of group A were significantly more than those of group B (t = -2.743, P=0.007), but no significant difference was found in hospitalization time and stitch removal time between 2 groups (P > 0.05). The postoperative complication rate of group A (19.2%, 24/125) was significantly higher than that of group B (8.4%, 10/119) (χ2 =5.926, P = 0.015). Group A had a higher mortality at 1 month after operation than group B (6.1% vs. 0) (χ2 = 5.038, P = 0.025), but no significant difference was shown at 1 year after operation between groups A and B (8.8% vs. 4

Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

Science.gov (United States)

Johnston, James D; Tuttle, Steven C; Nelson, Morgan C; Bradshaw, Rebecca K; Hoybjerg, Taylor G; Johnson, Julene B; Kruman, Bryce A; Orton, Taylor S; Cook, Ryan B; Eggett, Dennis L; Weber, K Scott

2016-01-01

Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr) and summer (July-Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.

School Policies and Practices that Improve Indoor Air Quality

Science.gov (United States)

Jones, Sherry Everett; Smith, Alisa M.; Wheeler, Lani S.; McManus, Tim

2010-01-01

Background: To determine whether schools with a formal indoor air quality management program were more likely than schools without a formal program to have policies and practices that promote superior indoor air quality. Methods: This study analyzed school-level data from the 2006 School Health Policies and Programs Study, a national study of…

Indoor Tanning

Science.gov (United States)

... proof that indoor tanning is safer than tanning outdoors. Indoor tanning systems give concentrated UV exposure regardless ... For example, it’s essential for promoting good bone health. While UV ... a tan to get that benefit. According to the Surgeon General, fair and light- ...

Behaviors of radon in indoor environment

International Nuclear Information System (INIS)

Mochizuki, Sadamu; Shimo, Michikuni.

1987-01-01

The source of radon ( 222 Rn) in the atmosphere is radioactive nuclide, uranium ( 238 U), which exists fairly common throughout the earth's crust. Radium ( 226 Ra) descended from uranium produce radon ( 222 Rn) of noble gas by decay. After formation in the ground, radon diffuses into the atmosphere. Without exception radon decay products are heavy metals which soon become attached to natural aerosols. Therefore, radon and its daughters (decay products) appear also in indoor environment, and generally, their concentration levels become higher than that of outdoor air due to build-up effects in the closed indoor environments. With the progress of the study on the influence of radon and its daughers on human health, it has become clear that they act effectively as an exciting cause of lung cancer. So, the study on the risk evaluation of them in room air has become to be very important. Concequently, the behaviors of radon and its daughters in indoor environment, first of all, should be studied in detail for the accurate estimation of the risk caused by them. In this special edition, fundamental characteristics of radon and its daughters, some measuring methods, theoretical considerations and some observational evidences obtained from various circumstances of indoor environment are described inorder to grasp and understand the behaviors of radon and its daughters in the indoor environment. (author)

Indoor air quality in urban and rural kindergartens: short-term studies in Silesia, Poland.

Science.gov (United States)

Błaszczyk, Ewa; Rogula-Kozłowska, Wioletta; Klejnowski, Krzysztof; Kubiesa, Piotr; Fulara, Izabela; Mielżyńska-Švach, Danuta

2017-01-01

More than 80% of people living in urban areas who monitor air pollution are exposed to air quality levels that exceed limits defined by the World Health Organization (WHO). Although all regions of the world are affected, populations in low-income cities are the most impacted. According to average annual levels of fine particulate matter (PM2.5, ambient particles with aerodynamic diameter of 2.5 μm or less) presented in the urban air quality database issued by WHO in 2016, as many as 33 Polish cities are among the 50 most polluted cities in the European Union (EU), with Silesian cities topping the list. The aim of this study was to characterize the indoor air quality in Silesian kindergartens based on the concentrations of gaseous compounds (SO 2 , NO 2 ), PM2.5, and the sum of 15 PM2.5-bound polycyclic aromatic hydrocarbons (PAHs), including PM2.5-bound benzo(a)pyrene (BaP), as well as the mutagenic activity of PM2.5 organic extracts in Salmonella assay (strains: TA98, YG1024). The assessment of the indoor air quality was performed taking into consideration the pollution of the atmospheric air (outdoor). I/O ratios (indoor/outdoor concentration) for each investigated parameter were also calculated. Twenty-four-hour samples of PM2.5, SO 2 , and NO 2 were collected during spring in two sites in southern Poland (Silesia), representing urban and rural areas. Indoor samples were taken in naturally ventilated kindergartens. At the same time, in the vicinity of the kindergarten buildings, the collection of outdoor samples of PM2.5, SO 2 , and NO 2 was carried out. The content of BaP and the sum of 15 studied PAHs was determined in each 24-h sample of PM2.5 (indoor and outdoor). In the urban site, statistically lower concentrations of SO 2 and NO 2 were detected indoors compared to outdoors, whereas in the rural site, such a relationship was observed only for NO 2 . No statistically significant differences in the concentrations of PM2.5, PM2.5-bound BaP, and Σ15 PAHs

A numerical study on the performance evaluation of ventilation systems for indoor radon reduction

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Eun; Park, Hoon Chae; Choi, Hang Seok; Cho, Seung Yeon; Jeong, Tae Young; Roh, Sung Cheoul [Yonsei University, Wonju (Korea, Republic of)

2016-03-15

Numerical simulations were conducted using computational fluid dynamics to evaluate the effect of ventilation conditions on radon ({sup 222}Rn) reduction performance in a residential building. The results indicate that at the same ventilation rate, a mechanical ventilation system is more effective in reducing indoor radon than a natural ventilation system. For the same ventilation type, the indoor radon concentration decreases as the ventilation rate increases. When the air change per hour (ACH) was 1, the indoor radon concentration was maintained at less than 100 Bq/m{sup 3}. However, when the ACH was lowered to 0.01, the average indoor radon concentration in several rooms exceeded 148 Bq/ m{sup 3}. The angle of the inflow air was found to affect the indoor air stream and consequently the distribution of the radon concentration. Even when the ACH was 1, the radon concentrations of some areas were higher than 100 Bq/m{sup 3} for inflow air angles of 5 .deg. and 175 .deg.

Observations on persistent organic pollutants in indoor and outdoor air using passive polyurethane foam samplers

Science.gov (United States)

Bohlin, Pernilla; Jones, Kevin C.; Tovalin, Horacio; Strandberg, Bo

Air quality data of persistent organic pollutants (POPs) indoors and outdoors are sparse or lacking in several parts of the world, often hampered by the cost and inconvenience of active sampling techniques. Cheap and easy passive air sampling techniques are therefore helpful for reconnaissance surveys. As a part of the Megacity Initiative: Local and Global Research Observations (MILAGRO) project in Mexico City Metropolitan Area in 2006, a range of POPs (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs)) were analyzed in polyurethane foam (PUF) disks used as passive samplers in indoor and outdoor air. Results were compared to those from samplers deployed simultaneously in Gothenburg (Sweden) and Lancaster (United Kingdom). Using sampling rates suggested in the literature, the sums of 13 PAHs in the different sites were estimated to be 6.1-180 ng m -3, with phenanthrene as the predominant compound. Indoor PAH levels tended to be higher in Gothenburg and outdoor levels higher in Mexico City. The sum of PCBs ranged 59-2100 ng m -3, and seemed to be highest indoors in Gothenburg and Lancaster. PBDE levels (sum of seven) ranged 0.68-620 ng m -3, with the highest levels found in some indoor locations. OCPs (i.e. DDTs, HCHs, and chlordanes) were widely dispersed both outdoors and indoors at all three studied areas. In Gothenburg all POPs tended to be higher indoors than outdoors, while indoor and outdoor levels in Mexico City were similar. This could be due to the influence of indoor and outdoor sources, air exchange rates, and lifestyle factors. The study demonstrates how passive samplers can provide quick and cheap reconnaissance data simultaneously at many locations which can shed light on sources and other factors influencing POP levels in air, especially for the gaseous fractions.

Sources and concentrations of indoor nitrogen dioxide in Hamburg (west Germany) and Erfurt (east Germany)

International Nuclear Information System (INIS)

Cyrys, J.; Woelke, G.; Wichmann, H.E.; Heinrich, J.; Richter, K.

2000-01-01

Here we report indoor and outdoor concentrations of NO 2 for Erfurt and Hamburg and assess the contribution of the most important indoor sources (e.g. the presence of gas cooking ranges, smoking) and outdoor sources (traffic exhaust emissions). We examined the relative contribution of the different sources of NO 2 to the total indoor NO 2 levels in Erfurt and Hamburg. NO 2 indoor concentrations in Hamburg were slightly higher than those in Erfurt (i.e. living room: 15 μg m -3 for Erfurt and 17 μg m -3 for Hamburg). A linear regression model including the variables, place of residence, season and outdoor NO 2 levels, location of the home within the city, housing and occupant characteristics accounted for 38% of the NO 2 variance. The most important predictors of indoor NO 2 concentrations were gas in cooking followed by other characteristics, such as ventilation or outdoor NO 2 level. Residences in which gas was used for cooking, or in which occupants smoked, had substantially higher indoor NO 2 concentrations (41 or 18% increase, respectively). An increase in the outdoor NO 2 concentration from the 25th to the 75th-percentile (17 μg m -3 ) was associated with a 33% increase in the living room NO 2 concentration. Multiple regression analysis for both cities separately illustrated that use of gas for cooking was the major indoor source of NO 2 . This variable caused a similar increase in the indoor NO 2 levels in each city (43% in Erfurt and 47% in Hamburg). However, outdoor sources of NO 2 (motor vehicle traffic) contributed more to indoor NO 2 levels in Hamburg than in Erfurt

Hybrid daylight/light-emitting diode illumination system for indoor lighting.

Science.gov (United States)

Ge, Aiming; Qiu, Peng; Cai, Jinlin; Wang, Wei; Wang, Junwei

2014-03-20

A hybrid illumination method using both daylight and light-emitting diodes (LEDs) for indoor lighting is presented in this study. The daylight can be introduced into the indoor space by a panel-integration system. The daylight part and LEDs are combined within a specific luminaire that can provide uniform illumination. The LEDs can be turned on and dimmed through closed-loop control when the daylight illuminance is inadequate. We simulated the illumination and calculated the indoor lighting efficiency of our hybrid daylight and LED lighting system, and compared this with that of LED and fluorescent lighting systems. Simulation results show that the efficiency of the hybrid daylight/LED illumination method is better than that of LED and traditional lighting systems, under the same lighting conditions and lighting time; the method has hybrid lighting average energy savings of T5 66.28%, and that of the LEDs is 41.62%.

Enabling Indoor Location-Based Services

DEFF Research Database (Denmark)

Radaelli, Laura

Indoor spaces have always attracted interest from different scientific disciplines. Relatively recent interest in indoor settings by computer scientists is driven in part by the increasing use of smartphones, which serve as a platform for service delivery and can generate extensive volumes...... of trajectory data that can be used to study how people actually use indoor spaces. In this dissertation, we contribute partial solutions that address challenges in indoor positioning and indoor trajectory management and analysis. The key enabler of indoor location-based services and indoor movement analysis...... is a well-functioning positioning system that can be easily deployed in most public places. Different technologies are able to provide indoor positioning with different accuracy and coverage, but it is difficult to find a technology that by itself can provide good positioning in the many different layouts...

Indoor radon measurements in dwellings of Mizoram

International Nuclear Information System (INIS)

Lalramengzami, R.; Laldawngliana, C.; Sinha, D.; Ghosh, S.; Dwivedi, K.K.

1995-01-01

The concentration of indoor radon has been measured in some dwellings of Mizoram state by employing time integrated method using solid state nuclear track detector. This state is located in the north eastern region of India which has been identified as a high background area. The indoor radon levels determined in this work are compared with data obtained from other regions of India and the Environmental Protection Agency (EPA) prescribed safe limit. (author). 7 refs., 2 figs

Wifi-friendly building, enabling wifi signal indoor: an initial study

Science.gov (United States)

Suherman; Mubarakah, Naemah; Sagala, Romulo S.; Prayitno, Hendra

2018-03-01

The 802.11 network (wireless fidelity/WiFi) is the most common wireless infrastructure applied for internet access indoor. Widespread devices and installation simplicity make it better than similar technologies such as 802.16 and other 802.xx series. The access points are the most influential devices for indoor access. However, building indoor architectures contribute to the signal quality. Since WiFi installation in buildings becomes prevalent, the architecture should consider WiFi-friendliness into consideration. The more friendly the building to WiFi signal, the more efficient the 802.11 based wireless infrastructure. This paper present preliminary study how the building, specially the obstacle material, effects the WiFi signal propagation indoor. The study was performed by using ESP8266-based WiFi signal reader, to determine the impact indoor obstacles to WiFi signal propagation. The initial study shows that simple reflecting materials increase signal level about 1.14 dBm. WiFi-friendly building can be achieved by transforming building properties into signal interconnector. A simple photo frame with aluminium sheet insertion increase signal level on the second floor up to 6.56dBm.

Variance of indoor radon concentration: Major influencing factors

Energy Technology Data Exchange (ETDEWEB)

Yarmoshenko, I., E-mail: ivy@ecko.uran.ru [Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg (Russian Federation); Vasilyev, A.; Malinovsky, G. [Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg (Russian Federation); Bossew, P. [German Federal Office for Radiation Protection (BfS), Berlin (Germany); Žunić, Z.S. [Institute of Nuclear Sciences “Vinca”, University of Belgrade (Serbia); Onischenko, A.; Zhukovsky, M. [Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg (Russian Federation)

2016-01-15

Variance of radon concentration in dwelling atmosphere is analysed with regard to geogenic and anthropogenic influencing factors. Analysis includes review of 81 national and regional indoor radon surveys with varying sampling pattern, sample size and duration of measurements and detailed consideration of two regional surveys (Sverdlovsk oblast, Russia and Niška Banja, Serbia). The analysis of the geometric standard deviation revealed that main factors influencing the dispersion of indoor radon concentration over the territory are as follows: area of territory, sample size, characteristics of measurements technique, the radon geogenic potential, building construction characteristics and living habits. As shown for Sverdlovsk oblast and Niška Banja town the dispersion as quantified by GSD is reduced by restricting to certain levels of control factors. Application of the developed approach to characterization of the world population radon exposure is discussed. - Highlights: • Influence of lithosphere and anthroposphere on variance of indoor radon is found. • Level-by-level analysis reduces GSD by a factor of 1.9. • Worldwide GSD is underestimated.

Indoor air quality and health in schools.

Science.gov (United States)

Ferreira, Ana Maria da Conceição; Cardoso, Massano

2014-01-01

To determine whether indoor air quality in schools is associated with the prevalence of allergic and respiratory diseases in children. We evaluated 1,019 students at 51 elementary schools in the city of Coimbra, Portugal. We applied a questionnaire that included questions regarding the demographic, social, and behavioral characteristics of students, as well as the presence of smoking in the family. We also evaluated the indoor air quality in the schools. In the indoor air of the schools evaluated, we identified mean concentrations of carbon dioxide (CO2) above the maximum reference value, especially during the fall and winter. The CO2 concentration was sometimes as high as 1,942 ppm, implying a considerable health risk for the children. The most prevalent symptoms and respiratory diseases identified in the children were sneezing, rales, wheezing, rhinitis, and asthma. Other signs and symptoms, such as poor concentration, cough, headache, and irritation of mucous membranes, were identified. Lack of concentration was associated with CO2 concentrations above the maximum recommended level in indoor air (p = 0.002). There were no other significant associations. Most of the schools evaluated presented with reasonable air quality and thermal comfort. However, the concentrations of various pollutants, especially CO2, suggest the need for corrective interventions, such as reducing air pollutant sources and improving ventilation. There was a statistically significant association between lack of concentration in the children and exposure to high levels of CO2. The overall low level of pollution in the city of Coimbra might explain the lack of other significant associations.

Community-Based Investigation of Radon and Indoor Air Quality in Northeast Denver Neighborhoods

Science.gov (United States)

Pfotenhauer, D.; Iwasaki, P. G.; Ware, G. E.; Collier, A.; Hannigan, M.

2017-12-01

In 2015, Taking Neighborhood Health to Heart (TNH2H), a community-based organization based in Northeast Denver, and researchers from the University of Colorado, Boulder jointly piloted a project to investigate indoor air quality within Denver communities. This pilot study was carried out across 2015-2016 and found higher than actionable-levels for radon across a majority of its participants. These results inspired a continued collaboration between the community group and academic researchers from CU Boulder. The partnership went on to conduct a similar project this last year in which the team again employed a community-based participatory research (CBPR) framework to investigate indoor air pollutants across a broader geographical footprint in Denver's Northeast Neighborhoods. The collaboration sampled 30 participant houses across 5 neighborhoods for radon and volatile organic compounds (VOCs). Although VOC levels were found to be well under thresholds for concern, for the second year of this investigation, radon levels were found on average to be significantly above the EPA's threshold for hazardous levels. Additionally, in collecting survey data on the participants' house characteristics, certain identifiable trends emerged that signal which house types have greater risk of radon intrusion. Having found in two consecutive studies that a majority of homes in these neighborhoods are burdened with dangerous levels of radon, the partnership is now moving towards developing educational and political actions to address the results from these projects and disseminate the information regarding radon levels and threats to these neighborhood communities.

Indoor radon concentration and its possible dependence on ventilation rate and flooring type

International Nuclear Information System (INIS)

Ashok, G. V.; Nagaiah, N.; Shiva Prasad, N. G.

2012-01-01

The results of radon concentration measurements carried out in dwellings with natural ventilation for 1 y in Bangalore are reported. Measurements, covering three sessions of the day (morning, afternoon, night) were performed two times in a month for 1 y at a fixed place of each dwelling at a height of 1 m above the ground surface in selected dwellings. The low-level radon detection system (LLRDS), an active method, was used for the estimation of radon concentration. The measurements were aimed to understand the diurnal variation and the effect of ventilation rate and flooring type on indoor radon concentration. The geometric mean (±geometric standard deviation) of indoor radon concentration from about 500 measurements carried out in 20 dwellings is found to be 25.4 ±1.54 Bq m -3 . The morning, afternoon and night averages were found to be 42.6 ±2.05, 15.3 ±2.18 and 28.5 ±2.2 Bq m -3 , respectively. The approximate natural ventilation rates of the dwellings were calculated using the PHPAIDA-the on-line natural ventilation, mixed mode and air infiltration rate calculation algorithm and their effects on indoor radon concentrations were studied. The inhalation dose and the lung cancer risk due to indoor radon exposure were found to be 0.66 mSv y -1 and 11.9 per 10 6 persons, respectively. The gamma exposure rate was also measured in all the dwellings and its correlation with the inhalation dose rate was studied. (authors)

Survey of indoor radon concentrations in Fukuoka and Kagoshima prefectures

International Nuclear Information System (INIS)

Kunugita, Naoki; Norimura, Toshiyuki; Tsuchiya, Takehiko

1990-01-01

It is now well established that radon and its daughter products account for nearly half of the average population exposure to ionizing radiations and that radon is the greatest single source of natural radiation to the population. Radon and its daughters are alpha-emitters, which are more biologically damaging than beta- and gamma-radiations. A nationwide survey of radon concentration was conducted by the National Institute of Radiological Sciences in order to estimate the contribution of radon and its daughters to the population dose in Japan. Authors surveyed indoor radon concentrations in Fukuoka and Kagoshima prefectures as part of this project. A passive type radon dosimeter, in which a sheet of polycarbonate film as the alpha-ray detector was mounted, was used to measure indoor radon concentrations. The resulting distribution of the average annual indoor radon concentrations in both prefectures can be characterized by an arithmetic mean of 24.4 Bq/m 3 and a standard deviation of 13.1 Bq/m 3 , by a geometric mean of 22.2 Bq/m 3 , and by a median of 20.7 Bq/m 3 . The geometric means of the distributions for Fukuoka and Kagoshima were 25.4, and 18.4 Bq/m 3 , respectively. Radon concentrations were also generally high in winter and low in summer. Regarding the analysis of correlations between the concentrations and construction materials, radon concentrations were generally high in Japanese houses with earthen walls and in concrete structures. These results showed that seasons, the type of building materials, and regional differences were significant factors in the variation of indoor radon concentration. (author)

Indoor radon and childhood leukaemia

International Nuclear Information System (INIS)

Raaschou-Nielsen, O.

2008-01-01

This paper summarises the epidemiological literature on domestic exposure to radon and risk for childhood leukaemia. The results of 12 ecological studies show a consistent pattern of higher incidence and mortality rates for childhood leukaemia in areas with higher average indoor radon concentrations. Although the results of such studies are useful to generate hypotheses, they must be interpreted with caution, as the data were aggregated and analysed for geographical areas and not for individuals. The seven available case - control studies of childhood leukaemia with measurement of radon concentrations in the residences of cases and controls gave mixed results, however, with some indication of a weak (relative risk < 2) association with acute lymphoblastic leukaemia. The epidemiological evidence to date suggests that an association between indoor exposure to radon and childhood leukaemia might exist, but is weak. More case - control studies are needed, with sufficient statistical power to detect weak associations and based on designs and methods that minimise misclassification of exposure and provide a high participation rate and low potential selection bias. (authors)

Review of the health risks associated with nitrogen dioxide and sulfur dioxide in indoor air

International Nuclear Information System (INIS)

Brauer, M.; Henderson, S.; Kirkham, T.; Lee, K.S.; Rich, R.; Teschke, K.

2002-01-01

The scientific literature on the health effects of nitrogen dioxide (NO 2 ) and sulfur dioxide (SO 2 ) were reviewed with particular focus on the chemical and physical properties of the 2 gases and the toxicological characteristics identified in animal studies at exposure concentrations near the rate of ambient human exposures. The study also examined the expected levels of non-industrial indoor exposure of Canadians compared to other regions with similar climates. The sources of indoor pollution were also reviewed, along with the contribution of outdoor pollution to indoor levels. Results from epidemiological studies of indoor exposures in homes, offices and schools were also presented. For each pollutant, the study identified anthropogenic sources, indoor sources, toxicological characteristics, biochemistry, pulmonary effects, immune response, and other effects. Indoor sources of NO 2 include gas-fired appliances, pilot lights, hot water heaters, kerosene heaters, and tobacco smoke. The impact of ventilation on both NO 2 and SO 2 levels was also examined. Outdoor sources such as traffic can also contribute to indoor levels, particularly in urban areas. In the case of SO 2 , coal heating and cooling appear to be associated in increased indoor levels. The epidemiological studies that were reviewed failed in general to indicate an association between NO 2 exposure and a wide range of health impacts. The studies, however, indicate that asthmatics are more susceptible to the effects of NO 2 exposure. In the case of SO 2 , evidence suggests that it has a chronic effect on lung function and respiratory symptoms and disease. 243 refs., 13 tabs

An RFID Indoor Positioning Algorithm Based on Bayesian Probability and K-Nearest Neighbor

Directory of Open Access Journals (Sweden)

He Xu

2017-08-01

Full Text Available The Global Positioning System (GPS is widely used in outdoor environmental positioning. However, GPS cannot support indoor positioning because there is no signal for positioning in an indoor environment. Nowadays, there are many situations which require indoor positioning, such as searching for a book in a library, looking for luggage in an airport, emergence navigation for fire alarms, robot location, etc. Many technologies, such as ultrasonic, sensors, Bluetooth, WiFi, magnetic field, Radio Frequency Identification (RFID, etc., are used to perform indoor positioning. Compared with other technologies, RFID used in indoor positioning is more cost and energy efficient. The Traditional RFID indoor positioning algorithm LANDMARC utilizes a Received Signal Strength (RSS indicator to track objects. However, the RSS value is easily affected by environmental noise and other interference. In this paper, our purpose is to reduce the location fluctuation and error caused by multipath and environmental interference in LANDMARC. We propose a novel indoor positioning algorithm based on Bayesian probability and K-Nearest Neighbor (BKNN. The experimental results show that the Gaussian filter can filter some abnormal RSS values. The proposed BKNN algorithm has the smallest location error compared with the Gaussian-based algorithm, LANDMARC and an improved KNN algorithm. The average error in location estimation is about 15 cm using our method.

The impacts of balanced and exhaust mechanical ventilation on indoor radon

International Nuclear Information System (INIS)

Fisk, W.J.; Mowris, R.J.

1987-02-01

Models for estimating radon entry rates, indoor radon concentrations, and ventilation rates in houses with a basement or a vented crawl-space and ventilated by natural infiltration, mechanical exhaust ventilation, or balanced mechanical ventilation are described. Simulations are performed for a range of soil and housing characteristics using hourly weather data for the heating season in Spokane, WA. For a house with a basement, we show that any ventilation technique should be acceptable when the soil permeability is less than approximately 10 -12 m 2 . However, exhaust ventilation leads to substantially higher indoor radon concentrations than infiltration or balanced ventilation with the same average air exchange rate when the soil permeability is 10 -10 m 2 or greater. For houses with a crawl-space, indoor radon concentrations are lowest with balanced ventilation, intermediate with exhaust ventilation, and highest with infiltration

Per- and polyfluorinated compounds (PFCs) in house dust and indoor air in Catalonia, Spain: implications for human exposure.

Science.gov (United States)

Ericson Jogsten, I; Nadal, M; van Bavel, B; Lindström, G; Domingo, J L

2012-02-01

A total of 27 per- and polyfluorinated compounds (PFCs) were determined in both house dust (n=10) and indoor air (n=10) from selected homes in Catalonia, Spain. Concentrations were found to be similar or lower than those previously reported for household microenvironments in other countries. Ten PFCs were detected in all house dust samples. The highest mean concentrations corresponded to perfluorodecanoic acid (PFDA) and perfluorononanoic acid (PFNA), 10.7 ng/g (median: 1.5 ng/g) and 10.4 ng/g (median: 5.4 ng/g), respectively, while the 8:2 fluorotelomer alcohol (FTOH) was the dominating neutral PFC at a concentration of 0.41 ng/g (median: 0.35 ng/g). The indoor air was dominated by the FTOHs, especially the 8:2 FTOH at a mean (median) concentration of 51 pg/m(3) (median: 42 pg/m(3)). A limited number of ionic PFCs were also detected in the indoor air samples. Daily intakes of PFCs were estimated for average and worst case scenarios of human exposure from indoor sources. For toddlers, this resulted in average intakes of ∑ionic PFCs of 4.9ng/day (0.33 ng/kg(bw)/day for a 15 kg toddlers) and ∑neutral PFCs of 0.072 ng/day (0.005 ng/kg(bw)/day) from house dust. For adults, the average daily intakes of dust were 3.6 and 0.053 ng/day (0.05 and 0.001 ng/kg(bw)/day for a 70 kg adult) for ∑ionic and ∑neutral PFCs, respectively. The average daily inhalation of ∑neutral PFCs was estimated to be 0.9 and 1.3 ng/day (0.06 and 0.02 ng/kg(bw)/day) for toddlers and adults, respectively. For PFOS, the main ionic PFC detected in indoor air samples, the median intakes (based on those samples where PFOS was detected), resulted in indoor exposures of 0.06 and 0.11 ng/day (0.004 and 0.002 ng/kg(bw)/day) for toddlers and adults, respectively. Based on previous studies on dietary intake and drinking water consumption, both house dust and indoor air contribute significantly less to PFC exposure within this population. Copyright © 2011 Elsevier Ltd. All rights reserved.

Source specific risk assessment of indoor aerosol particles

Energy Technology Data Exchange (ETDEWEB)

Koivisto, A.J.

2013-05-15

In the urban environment, atmospheric aerosols consist mainly of pollutants from anthropogenic sources. The majority of these originate from traffic and other combustion processes. A fraction of these pollutants will penetrate indoors via ventilation. However, indoor air concentrations are usually predominated by indoor sources due to the small amount of dilution air. In modern societies, people spend most of their time indoors. Thus, their exposure is controlled mainly by indoor concentrations from indoor sources. During the last decades, engineering of nanosized structures has created a new field of material science. Some of these materials have been shown to be potentially toxic to human health. The greatest potential for exposure to engineered nanomaterials (ENMs) occurs in the workplace during production and handling of ENMs. In an exposure assessment, both gaseous and particulate matter pollutants need to be considered. The toxicities of the particles usually depend on the source and age. With time, particle morphology and composition changes due to their tendency to undergo coagulation, condensation and evaporation. The PM exposure risk is related to source specific emissions, and thus, in risk assessment one needs to define source specific exposures. This thesis describes methods for source specific risk assessment of airborne particulate matter. It consists of studies related to workers' ENM exposures during the synthesis of nanoparticles, packing of agglomerated TiO{sub 2} nanoparticles, and handling of nanodiamonds. Background particles were distinguished from the ENM concentrations by using different measurement techniques and indoor aerosol modelings. Risk characterization was performed by using a source specific exposure and calculated dose levels in units of particle number and mass. The exposure risk was estimated by using non-health based occupational exposure limits for ENMs. For the nanosized TiO{sub 2}, the risk was also assessed from dose

Indoor climate and the performance of ventilation in Finnish residences

International Nuclear Information System (INIS)

Ruotsalainen, R.; Roennberg, R.; Saeteri, J.; Majanen, A.; Seppaenen, O.; Jaakkola, J.J.K.

1992-01-01

The purpose of the study was to gather information about the actual ventilation and indoor air quality and to evaluate the differences between houses and apartments with different ventilation systems. A sample of 242 dwellings in the Helsinki metropolitan area was studied over periods of two weeks during the 1988-1989 heating season. The mean air-exchange rates had a high variation (average 0.52 l/h, range 0.07-1.55 l/h). The ASHRAE minimum value of 0.35 l/h was not achieved in 28% of the dwellings. The air-exchange rates were significantly lower in the houses than in the apartments (averages 0.45/0.64 l/h, p 3 (range 5-866 Bq/m 3 ); the Finnish target value of 200 Bq/m 3 was exceeded in 17% of the houses but in none of the apartments. The measurements indicate that the indoor air quality in Finnish dwellings is not always satisfactory with reference to human health and comfort. (au)

Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings.

Science.gov (United States)

Challoner, Avril; Pilla, Francesco; Gill, Laurence

2015-12-01

NO₂ and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person's well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM), to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO₂ indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO₂ exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts.

Towards Mobile Information Systems for Indoor Space

Directory of Open Access Journals (Sweden)

Xiaoxiang Zhang

2016-01-01

Full Text Available With the rapid development of Internet of things (IOT and indoor positioning technologies such as Wi-Fi and RFID, indoor mobile information systems have become a new research hotspot. Based on the unique features of indoor space and urgent needs on indoor mobile applications, in this paper we analyze some key issues in indoor mobile information systems, including positioning technologies in indoor environments, representation models for indoor spaces, query processing techniques for indoor moving objects, and index structures for indoor mobile applications. Then, we present an indoor mobile information management system named IndoorDB. Finally, we give some future research topics about indoor mobile information systems.

Measurement of indoor radon Concentrations in Osaka, Nara, Wakayama and Hyogo with passive dosemeters

International Nuclear Information System (INIS)

Mori, Toshiaki; Hori, Yasuharu; Takeda, Atsuhiko; Iwasaki, Tamiko; Uchiyama, Masahumi; Fujimoto, Kenzo; Kankura, Takako; Kobayashi, Sadayosi.

1989-01-01

Indoor radon concentrations of 792 houses in Osaka, Nara, Wakayama and Hyogo were measured by the passive dosemeter which was developed in Karlsruhe Nuclear Research Center in West Germany. Each house was measured at two places for successive two periods of six months to obtain annual average exposure due to radon daughters. The arithmetic mean concentration of all houses was 45.2 Bq/m 3 with a standard deviation of 27.2; the geometric mean, 40.7 Bq/m 3 and the median, 39 Bq/m 3 . The distribution of the radon levels was approximately log-normal with 80% of houses having radon concentrations less than 60 Bq/m 3 . The seasonal variation of the mean radon concentration was evident between the former period including winter value of 45 Bq/m 3 and the latter including summer value of 32 Bq/m 3 . The indoor radon concentrations of wooden houses were found to have the widest distribution with the highest value of 371 Bq/m 3 . The highest value obtained in the ferro-concrete house was 118 Bq/m 3 . Twelve houses having indoor radon concentrations higher than 120 Bq/m 3 were all Japanese traditional wooden houses with walls made of soil. (author)

Vitality of plants to live in the indoor environment

Science.gov (United States)

Shamsuri, Mohd Mahathir Suhaimi; Leman, A. M.; Hariri, Azian; Idris, Ahmad Fu'ad; Afandi, Azizi

2017-09-01

Indoor air quality (IAQ) is generally a public concern because 90% of people spend their time indoor. IAQ must be preserved wisely to guarantee the health of the building occupants. One of the ways to maintain the quality of air is by placing plants in the building. However, all plants come from the outdoor, and the environment is different compared to indoor. Environmental factors such as temperature and light will absolutely affect the growth of the plant. Light and temperature that are too bright or too deem can wither the plants. Nevertheless, certain plant is capable of adapting with different situation after assimilation process has been conducted. This study intends to analyze the capacity of seven selected plants (Anthurium, Dumb Cane, Golden Pothos, Kadaka Fern, Prayer Plant, Spider Plant, and Syngonium) to live in an indoor environment. The vitality of plants is based on photosynthetic level that is measured using leaf - chamber (LI-COR 6400). Two groups of plants were located in indoor and outdoor (indigenous location) setting, and were allowed to assimilate for two months before measurement were carried out. The results for the plant located indoor shows that only Spider Plant cannot perform photosynthesis under 300 lux, where the photosynthetic value remains negative. Meanwhile, other plants such as Anthurium, Dumb Cane, Golden Pothos, Kadaka Fern, Prayer Plant, and Syngonium that were left indoor showed similar 300 lux in which conform the ability of the plants to perform photosynthesis with the value of 0.3, 0.15, 0.35, 0.1, 0.15, and 0.1. In comparison, all of the plants that were stationed indoor and outdoor (except Spider Plant), the light compensation point (LCP) for indoor shows smaller value than the outdoor. This is because all the indoor plants had down - regulated their photosynthesis process by becoming more sensitive to light after their assimilation. From this study, it can be concluded that all plants except Spider Plant is able to live

Assessment of indoor air quality at an electronic cigarette (Vaping) convention.

Science.gov (United States)

Chen, Rui; Aherrera, Angela; Isichei, Chineye; Olmedo, Pablo; Jarmul, Stephanie; Cohen, Joanna E; Navas-Acien, Ana; Rule, Ana M

2017-12-29

E-cigarette (vaping) conventions are public events promoting electronic cigarettes, in which indoor use of e-cigarettes is allowed. The large concentration of people using e-cigarettes and poor air ventilation can result in indoor air pollution. In order to estimate this worst-case exposure to e-cigarettes, we evaluated indoor air quality in a vaping convention in Maryland (MD), USA. Real-time concentrations of particulate matter (PM 10 ) and real-time total volatile organic compounds (TVOCs), CO 2 and NO 2 concentrations were measured. Integrated samples of air nicotine and PM 10 concentrations were also collected. The number of attendees was estimated to range from 75 to 600 at any single observation time. The estimated 24-h time-weighted average (TWA) PM 10 was 1800 μg/m 3 , 12-fold higher than the EPA 24-h regulation (150 μg/m 3 ). Median (range) indoor TVOCs concentration was 0.13 (0.04-0.3) ppm. PM 10 and TVOC concentrations were highly correlated with CO 2 concentrations, indicating the high number of people using e-cigarettes and poor indoor air quality. Air nicotine concentration was 125 μg/m 3 , equivalent to concentrations measured in bars and nightclubs. E-cigarette aerosol in a vaping convention that congregates many e-cigarette users is a major source of PM 10 , air nicotine and VOCs, impairing indoor air quality. These findings also raise occupational concerns for e-cigarette vendors and other venue staff workers.

Evolution of the indoor biome.

Science.gov (United States)

Martin, Laura J; Adams, Rachel I; Bateman, Ashley; Bik, Holly M; Hawks, John; Hird, Sarah M; Hughes, David; Kembel, Steven W; Kinney, Kerry; Kolokotronis, Sergios-Orestis; Levy, Gabriel; McClain, Craig; Meadow, James F; Medina, Raul F; Mhuireach, Gwynne; Moreau, Corrie S; Munshi-South, Jason; Nichols, Lauren M; Palmer, Clare; Popova, Laura; Schal, Coby; Täubel, Martin; Trautwein, Michelle; Ugalde, Juan A; Dunn, Robert R

2015-04-01

Few biologists have studied the evolutionary processes at work in indoor environments. Yet indoor environments comprise approximately 0.5% of ice-free land area--an area as large as the subtropical coniferous forest biome. Here we review the emerging subfield of 'indoor biome' studies. After defining the indoor biome and tracing its deep history, we discuss some of its evolutionary dimensions. We restrict our examples to the species found in human houses--a subset of the environments constituting the indoor biome--and offer preliminary hypotheses to advance the study of indoor evolution. Studies of the indoor biome are situated at the intersection of evolutionary ecology, anthropology, architecture, and human ecology and are well suited for citizen science projects, public outreach, and large-scale international collaborations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

Directory of Open Access Journals (Sweden)

James D Johnston

Full Text Available Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr and summer (July-Sept, 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.

Indoor air: Reference bibliography

International Nuclear Information System (INIS)

Campbell, D.; Staves, D.; McDonald, S.

1989-07-01

The U. S. Environmental Protection Agency initially established the indoor air Reference Bibliography in 1987 as an appendix to the Indoor Air Quality Implementation Plan. The document was submitted to Congress as required under Title IV--Radon Gas and Indoor Air Quality Research of the Superfund Amendments and Reauthorization Act of 1986. The Reference Bibliography is an extensive bibliography of reference materials on indoor air pollution. The Bibliography contains over 4500 citations and continues to increase as new articles appear

Relationships of outdoor and indoor ultrafine particles at residences downwind of a major international border crossing in Buffalo, NY.

Science.gov (United States)

McAuley, T R; Fisher, R; Zhou, X; Jaques, P A; Ferro, A R

2010-08-01

During winter 2006, indoor and outdoor ultrafine particle (UFP) size distribution measurements for particles with diameters from 5.6 to 165 nm were taken at five homes in a neighborhood directly adjacent to the Peace Bridge Complex (PBC), a major international border crossing connecting Buffalo, New York to Fort Erie, Ontario. Monitoring with 1-s time resolution was conducted for several hours at each home. Participants were instructed to keep all external windows and doors closed and to refrain from cooking, smoking, or other activity that may result in elevating the indoor UFP number concentration. Although the construction and age for the homes were similar, indoor-to-outdoor comparisons indicate that particle infiltration rates varied substantially. Overall, particle concentrations indoors were lower and less variable than particle concentrations outdoors, with average indoor-outdoor ratios ranging from 0.1 to 0.5 (mean 0.34) for particles between 5.6 and 165 nm in diameter. With no indoor sources, the average indoor-outdoor ratios were lowest (0.2) for 20-nm particles, higher (0.3) for particles <10 nm, and highest (0.5) for particles 70-165 nm. This study provides insight into the penetration of UFP into homes and the resulting change in particle size distributions as particles move indoors near a major diesel traffic source. Although people spend most of their time in their homes, exposure estimates for epidemiological studies are generally determined using ambient concentrations. The findings of this study will contribute to improved size-resolved UFP exposure estimates for near roadway exposure assessments and epidemiological studies.

Methodology developed to make the Quebec indoor radon potential map

International Nuclear Information System (INIS)

Drolet, Jean-Philippe; Martel, Richard; Poulin, Patrick; Dessau, Jean-Claude

2014-01-01

This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal–Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal–Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m 3 in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists. - Highlights: • 5 radiogeochemical datasets were used to map the geogenic indoor radon potential. • An indoor radon potential was determined for each

Correlations of soil-gas and indoor radon with geology in glacially derived soils of the northern Great Plains

International Nuclear Information System (INIS)

Schumann, R.R.; Owen, D.E.; Peake, R.T.; Schmidt, K.M.

1990-01-01

This paper reports that a higher percentage of homes in parts of the northern Great Plains underlain by soils derived from continental glacial deposits have elevated indoor radon levels (greater than 4 pCi/L) than any other area in the country. Soil-gas radon concentrations, surface radioactivity, indoor radon levels, and soil characteristics were studied in areas underlain by glacially-derived soils in North Dakota and Minnesota to examine the factors responsible for these elevated levels. Clay-rich till soils in North Dakota have generally higher soil-gas radon levels, and correspondingly higher indoor radon levels, than the sandy till soils common to west-central Minnesota. Although the proportions of homes with indoor radon levels greater than 4 pCi/L are similar in both areas, relatively few homes underlain by sandy tills have screening indoor radon levels greater than 20 pCi/L, whereas a relatively large proportion of homes underlain by clayey tills have screening indoor radon levels exceeding 20 pCi/L. The higher radon levels in North Dakota are likely due to enhanced emanation from the smaller grains and to relatively higher soil radium concentrations in the clay-rich soils, whereas the generally higher permeability of the sandy till soils in Minnesota allows soil gas to be drawn into structures from a larger source volume, increasing indoor radon levels in these areas

Investigation of infiltration and indoor air quality

International Nuclear Information System (INIS)

1990-03-01

A multitask study was performed in the State of New York to provide information for guiding home energy conservation programs while maintaining acceptable indoor air quality. During the study, the statistical distribution of radon concentrations inside 2,400 homes was determined. The relationships among radon levels, house characteristics, and sources were also investigated. The direct impact that two specific air infiltration reduction measures--caulking and weatherstripping of windows and doors, and installation of storm windows and storm doors--have on house air leakage was investigated in 60 homes. The effect of house age on the impact of weatherization was also evaluated. Indoor and outdoor measurements of NO 2 , CO, SO 2 , and respirable suspended particulates (RSP) were made for 400 homes to determine the effect of combustion sources on indoor air quality and to characterize the statistical distribution of the concentrations. Finally, the combustion source data were combined with the information on air infiltration reduction measures to estimate the potential impact of these measures on indoor air quality

Control methods of radon and its progeny concentration in indoor atmosphere

International Nuclear Information System (INIS)

Ramachandran, T.V.; Subba Ramu, M.C.

1990-01-01

Exposure to radon-222 and its progeny in indoor atmosphere can result in significant inhalation risk to the population particularly to those living in houses with much higher levels of Rn. There are three methods generally used for the control of Rn and its progeny concentration in the indoor environment: (1) restricting the radon entry, (2) reduction of indoor radon concentration by ventilation or by aircleaning and (3) removal of airborne radon progeny by aerosol reduction. Prominent process of radon entry in most of the residence appears to be the pressure driven flow of soil gas through cracks or through other openings in the basements slab or subfloor. Sealing off these openings or ventilation of the slab or subfloor spaces are the methods of reducing the radon entry rate. Indoor radon progeny levels can also be reduced by decreasing the aerosol load in the dwellings. The results of a few experiments carried out to study the reduction in the working level concentration of radon, by decreasing the aerosol load are discussed in this paper. (author). 9 tabs., 8 figs., 37 refs

Multiple-level defect species evaluation from average carrier decay

Science.gov (United States)

Debuf, Didier

2003-10-01

An expression for the average decay is determined by solving the the carrier continuity equations, which include terms for multiple defect recombination. This expression is the decay measured by techniques such as the contactless photoconductance decay method, which determines the average or volume integrated decay. Implicit in the above is the requirement for good surface passivation such that only bulk properties are observed. A proposed experimental configuration is given to achieve the intended goal of an assessment of the type of defect in an n-type Czochralski-grown silicon semiconductor with an unusually high relative lifetime. The high lifetime is explained in terms of a ground excited state multiple-level defect system. Also, minority carrier trapping is investigated.

Indoor Air Quality of Residential Building Before and After Renovation

Science.gov (United States)

Sánka, Imrich; Földváry, Veronika

2017-06-01

This study investigates the impact of energy renovation on the indoor air quality of an apartment building during the heating season. The study was performed in one residential building before and after its renovation. An evaluation of the indoor air quality was performed using objective measurements and a subjective survey. The concentration of CO2 was measured in the bedrooms, and a sampling of the total volatile compounds (TVOC) was performed in the living rooms of the selected apartments. Higher concentrations of CO2 and TVOC were observed in the residential building after its renovation. The concentrations of CO2, and TVOC in some of the cases exceeded the recommended maximum limits, especially after implementing energy-saving measures on the building. The average air exchange rate was visibly higher before the renovation of the building. The current study indicates that large-scale renovations may reduce the quality of an indoor environment in many apartments, especially in the winter season.

Indoor and outdoor SO{sub 2} in a community near oil sand extraction and production facilities in northern Alberta

Energy Technology Data Exchange (ETDEWEB)

Kindzierski, W.B.; Ranganathan, H.K.S. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

2006-07-01

In order to examine whether the proximity to several oil sand operations in the Athabasca region has affected the air quality in nearby communities, a baseline study measuring indoor and outdoor sulphur dioxide (SO{sub 2}) levels was conducted in Fort McKay, a small native community located in northern Alberta. The study involved deploying a passive sampling device for 96 hours at 30 randomly chosen homes over a 6 week period such that 75 per cent of homes were sampled during weekdays and 25 per cent during weekends. The common living area of each home (kitchen or family room) was sampled indoors. Outdoor passive samplers were attached to a sampling stand under a shelter in the yard. This article presented an introduction to oil sands development in the region and discussed the link between SO{sub 2} emissions and outdoor air pollution. The passive sampling monitors and study methods were described. Last, the article discussed the results of the study and provided a discussion of quality assurance and quality control; indoor and outdoor SO{sub 2} levels; and air exchange measurements. It was concluded that the results of the testing to determine accuracy and precision of the monitors were both within 35 per cent based on a 96 hour average measurement, which are considered very low and consistent with levels observed elsewhere in Alberta. 43 refs., 5 tabs., 4 figs.

Low air exchange rate causes high indoor radon concentration in energy-efficient buildings

International Nuclear Information System (INIS)

Vasilyev, A.V.; Yarmoshenko, I.V.; Zhukovsky, M.V.

2015-01-01

Since 1995, requirements on energy-efficient building construction were established in Russian Building Codes. In the course of time, utilisation of such technologies became prevailing, especially in multi-storey building construction. According to the results of radon survey in buildings constructed meeting new requirements on energy efficiency, radon concentration exceeds the average level in early-constructed buildings. Preponderance of the diffusion mechanism of radon entry in modern multi-storey buildings has been experimentally established. The experimental technique of the assessment of ventilation rate in dwellings under real conditions was developed. Based on estimates of average ventilation rate, it was approved that measures to increase energy efficiency lead to reduction in ventilation rate and accumulation of higher radon concentrations indoors. Obtained ventilation rate values have to be considered as extremely low. (authors)

Indoor climate design for a monumental building with incidental high indoor moisture loads

NARCIS (Netherlands)

Schijndel, van A.W.M.

2005-01-01

The paper presents a study of the indoor climate of a monumental building with periodic high indoor moisture loads. Several scenarios of the past performance and new control classes are simulated and evaluated. The results include the influence of hygric inertia on the indoor climate and

Undisturbed dust as a metric of long-term indoor insecticide exposure: Residential DDT contamination from indoor residual spraying and its association with serum levels in the VHEMBE cohort.

Science.gov (United States)

Gaspar, Fraser W; Chevrier, Jonathan; Bornman, Riana; Crause, Madelein; Obida, Muvhulawa; Barr, Dana Boyd; Bradman, Asa; Bouwman, Henk; Eskenazi, Brenda

2015-12-01

Although approximately 123 million people may be exposed to high levels of insecticides through the use of indoor residual spraying (IRS) for malaria control, few studies exist on indoor insecticide contamination due to IRS and its relationship with human exposure. In the present study, we developed a sampling method to collect undisturbed dust from 50 homes in Limpopo, South Africa, a region where dichlorodiphenyltrichloroethane (DDT) has been used in IRS programs to prevent malaria for ~70years. We quantified DDT and its degradation products, dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) in dust samples to determine dust loading levels and compared these levels to paired serum concentrations of p,p'-DDT and p,p'-DDE in women residents. p,p'-DDT and p,p'-DDE had the highest detection frequencies in both dust (58% and 34% detection, respectively) and serum samples (98% and 100% detection, respectively). Significantly higher detection frequencies for o,p'-DDT, p,p'-DDE, and p,p'-DDD were observed in dust samples collected in buildings that had been previously sprayed for malaria control. We also observed a significant, positive association between dust loading and serum concentrations of p,p'-DDT and p,p'-DDE (Spearman's rho=0.68 and 0.54, respectively). Despite the low detection frequency in dust, our results indicate that undisturbed dust may be a good metric to quantify long-term home exposure to DDT-related compounds and that contamination of the home environment may be an important determinant/source of DDT and DDE exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of ventilation strategies on indoor radon concentrations based on a semiempirical model for Florida-style houses

International Nuclear Information System (INIS)

Hintenlang, D.E.; Al-Ahmady, K.K.

1994-01-01

Measurements in a full-scale experimental facility are used to benchmark a semiempirical model for predicting indoor radon concentrations for Florida-style houses built using slab-on-grade construction. The model is developed to provide time-averaged indoor radon concentrations from quantitative relationships between the time-dependent radon entry and elimination mechanisms that have been demonstrated to be important for this style of residential construction. The model successfully predicts indoor radon concentrations in the research structure for several pressure and ventilation conditions. Parametric studies using the model illustrate how different ventilation strategies affect indoor radon concentrations. It is demonstrated that increasing house ventilation rates by increasing the effective leakage area of the house shell does not reduce indoor radon concentrations as effectively as increasing house ventilation rates by controlled duct ventilation associated with the heating, ventilating, and air conditioning system. The latter strategy provides the potential to minimize indoor radon concentrations while providing positive control over the quality of infiltration air. 9 refs., 5 figs

Real-time door detection for indoor autonomous vehicle

Science.gov (United States)

He, Zhihao; Zhu, Ming

2017-07-01

Indoor Autonomous Vehicle(IAV) is used in many indoor scenes. Such as hotels and hospitals. Door detection is a key issue to guide the IAV into rooms. In this paper, we consider door detection in the use of indoor navigation of IAV. Since real-time properties are important for real-world IAV, the detection algorithm must be fast enough. Most monocular-camera based door detection model need a perfect detection of the four line segments of the door or the four corners. But in many situations, line segments could be extended or cut off. And there could be many false detected corners. And few of them can distinguish doors from door-like objects with door-like shape effectively. We proposed a 2-D vision model of the door that is made up of line segments. The number of parts detected is used to determine the possibility of a door. Our algorithm is tested on a database of doors.1 The robustness and real-time are verified. The precision is 89.4%. Average time consumed for processing a 640x320 figure is 44.73ms.

Predicted and actual indoor environmental quality: Verification of occupants' behaviour models in residential buildings

DEFF Research Database (Denmark)

Andersen, Rune Korsholm; Fabi, Valentina; Corgnati, Stefano P.

2016-01-01

with the building controls (windows, thermostats, solar shading etc.). During the last decade, studies about stochastic models of occupants' behaviour in relation to control of the indoor environment have been published. Often the overall aim of these models is to enable more reliable predictions of building...... performance using building energy performance simulations (BEPS). However, the validity of these models has only been sparsely tested. In this paper, stochastic models of occupants' behaviour from literature were tested against measurements in five apartments. In a monitoring campaign, measurements of indoor....... However, comparisons of the average stochastic predictions with the measured temperatures, relative humidity and CO2 concentrations revealed that the models did not predict the actual indoor environmental conditions well....

Long term indoor radon measurements in the pelletron laboratory at the UNAM physics institute

International Nuclear Information System (INIS)

Espinosa, G.; Golzarri, J. I.; Lopez, K.; Rickards, J.

2011-01-01

The results of six months of continuous measurement of the indoor radon concentration levels in the building where the Physics Institute 3 MV Pelletron particle accelerator is located are presented. This study has three major objectives: a) to know the actual values of the levels of indoor radon in this installation, where personnel spend many hours and sometimes days; b) assess the radiological risk from radon inhalation for personnel working permanently in the laboratory, as well as incidental users; and c) establish, if necessary, time limits for continuous permanence on the location for indoor radon exposure. Passive nuclear track detectors and dynamic systems were employed, covering six months (August, 2009 to January, 2010). For the calculation of internal dose the Radon Individual Dose Calculator was used. The results indicate that the indoor radon levels are below the US EPA recommended levels (400 Bq/m 3 ) in workplaces. The measurements help to establish levels for workplaces in Mexico. (Author)

Evaluation of Indoor Radio Deployment Options in High-Rise Building

DEFF Research Database (Denmark)

Nguyen, Huan Cong; Wigard, Jeroen; Kovacs, Istvan

2017-01-01

to the increase of inter-cell interference (ICI). Increasing transmit power brings largest gain when the density of indoor cell is low, and the noise and/or outdoor interference is the dominant source of performance degradation. When analyzing performance gain of an ideal receiver-side Interference Cancellation......In this paper we set out to analyze the indoor capacity under a realistic high-rise building scenario. The study takes into consideration the number of indoor cells deployed per floor, different inter-site distances (ISDs), transmit power settings and outdoor macro interference levels. The outcome...

Measurement of indoor radon-thoron and their progeny levels in dwellings and radon concentrations in ground water of Hassan city, Karnataka, India

International Nuclear Information System (INIS)

Srinivasa, E.; Rangaswamy, D.R.; Sannappa, J.

2014-01-01

The indoor radon and thoron concentrations in dwellings of Hassan city have been measured by using LR-115 type-Il Solid State Nuclear Tracks Detectors (SSNTDs). Measurements were carried in summer season from March to May-2013. The radon and thoron activity concentration in the corresponding dwellings has been found to vary from 7.4 to 45.7 Bqm -3 and 5.4 to 34.9 Bqm -3 with a median of 23.59±11 Bqm -3 and 14.47±8 Bqm -3 respectively. The overall average radon concentrations are found to be less than the lower reference level of 200 Bq m -3 of the International Commission on Radiological Protection. The annual effective dose received due to radon and its progeny by the inhabitants in the dwellings under study has also been calculated which found to vary from 0.320 ±0.4 to 1.86 ±1.1 mSv y -1 with an average value of 0.957±0.8 mSv -1 . The obtained results are much lower than the upper reference level of 10 mSv y -1 (ICRP 2007). Radon in bore well water at different locations of Hassan city was determined using the emanometry technique and exposure dose from ingestion of drinking water was estimated. The radon concentration in ground water was found to vary from 19.49 to 60.74 Bq l -1 with an average value of 47.16±14Bq l -1 . From this study it is evident that, the recorded ground water radon concentration values are higher than MCL of 11 Bq l -1 proposed by USEPA. The total dose due to inhalation and ingestion of 222 Rn in ground water ranges from 0.053 mSv y -1 to 0.165mSv y -1 with an average value of 0.127±0.038mSv y -1 . (author)

Individual and environmental risk factors for high blood lead concentrations in Danish indoor shooters

DEFF Research Database (Denmark)

Grandahl, Kasper; Suadicani, Poul; Jacobsen, Peter

2012-01-01

International studies have shown blood lead at levels causing health concern in recreational indoor shooters. We hypothesized that Danish recreational indoor shooters would also have a high level of blood lead, and that this could be explained by shooting characteristics and the physical...

Indoor NO/sub 2/ sampling in a large university campus in Benin city, southern Nigeria, using flames diffusion tubes

International Nuclear Information System (INIS)

Ukpebor, E.E.; Sadiku, Y.T.; Ahonkhai, S.I.

2005-01-01

Monitoring of NO/sub 2/ in different indoor environments (without cooking and with cooking using different fuels) was done. Flames diffusion tubes were used for the monitoring. The sampling duration was two weeks. The highest NO/sub 2/ concentration of 38.61 ppb (73.74 mug/m3) was monitored in the room where the cooking was done with a gas burner. This was followed by the room with firewood cooking, where the concentration was 36.75 ppb (70.19 mug/m3) and the least concentration of 24.05 ppb (46.80 mug/m3) was noted in the room, where kerosene stove was used for cooking. It is of significance to observe that the WHO annual average guideline value of 40 mug/m3 was exceeded in al the rooms where cooking was done. Levels obtained in this study, therefore, suggest a need for precautionary mitigation. However, the outdoor concentration of NO/sub 2/ was almost the same as that obtained indoors in the rooms without cooking. This suggests high penetration indoors of outdoor NO/sub 2/. A background level of 3.40 ppb (6.49 mug/m3) was established for the environment in Ugbowo, Benin City, Nigeria. (author)

Risk of Lung Cancer and Indoor Radon Exposure in France

International Nuclear Information System (INIS)

Baysson, H.; Tirmarche, M.; Tymen, G.; Ducloy, F.; Laurier, D.

2004-01-01

It is well established that radon exposure increases risks of lung cancer among underground miners. to estimate the lung cancer risk linked to indoor radon exposure, a hospital based case-control study was carried out in France, With a focus on precise reconstruction of past indoor radon exposure over the 30 years preceding the lung cancer diagnosis. The investigation rook place from 1992 to 1998 in four regions of France: Auvergne, Brittany, Languedoc and Limousin. During face-to-face interviews a standardized questionnaire was used to ascertain demographic characteristics, information on active and passive smoking, occupational exposure, medical history as well as extensive details on residential history. Radon concentrations were measured in the dwellings where subjects had lived at least one year during the 5-30 year period before interview. Measurements of radon concentrations were performed during a 6-month period, using two Kodalpha LR 115 detectors, one in the living room and one in the bedroom. The time-weighted average (TWA) radon concentration for a subject during the 5-30 year period before interview was based on radon concentrations over all addresses occupied by the subject weighted by the number of years spent at each address. For the time intervals without available measurements, we imputed the region-specific arithmetic average of radon concentrations for measured addresses of control subjects. Lung cancer risk was examined in relation to indoor radon exposure after adjustment for age, sex, region, cigarette smoking and occupational exposure. The estimated relative a risk per 100 Bq/m''3 was 1.04, at the borderline of statistical significance (95 percent Confidence Interval: 0.99, 1..1). These results are in agreement with results from other indoor radon case-control studies and with extrapolations from underground miners studies. (Author) 31 refs

Investigating Indoor Radon Levels and Influencing Factors in Primary Schools of Zulfi City, Saudi Arabia

International Nuclear Information System (INIS)

Al-Ghamdi, S. S.; Al-Garawi, M. S.; Al-Mosa, Tahani M.; Baig, M. R.

2011-01-01

Measurement of indoor Concentrations were performed in Zulfi city of Saudi Arabia, using CR-39 track etch detectors. This investigation focused on the influence of different parameters, namely different locations, school categories, school building types, and room type as well as on the existence of differences in radon concentration at floor levels. We divided the Zulfi city into five regions, keeping in mind their geographical locations between Tuwaiq Mountains and Al-Thuwayrat sands. The measured average radon concentrations for regions 1-5 respectively are: 87.0±14.2 Bq/m 3 , 83.4±6.0 Bq/m 3 , 61.6±6.4 Bq/m 3 , 63.7±5.4 Bq/m 3 and 87.5±6.Bq/m 3 and the minimum concentrations are 28.0 Bq/m 3 , 5.5 Bq/m 3 , 1.1 Bq/m 3 , 1.0 Bq/m 3 and 24 Bq/m 3 respectively. These results are still within normal limits and below the action level of 148 Bqm -3 set by the U.S. Environmental Protection Agency (EPA). A test of significance using Minitab program was applied to investigate if radon levels in regions are significantly different from each other. We tried all combinations, and found the following results. The ''within regions''(different location) test yielded, region 2 is not significant versus region ''1''(p = 0.783) and versus region ''5''(P = 0.646), whereas it is significant versus region ''3''(P = 0.0160) and also versus region ''4''(p = 0.018). We investigated government and rented school's building also and none was found significantly different (p = 0.052). Floors of the same building were tested in order to examine the radon concentration as a function of storey level. No significant difference was observed at floor levels (p = 0.009). When girl's schools versus Boys and kindergartens schools were tested they were found significantly different. It is believed that this significant difference is due to geographical nature of the area, since most of the girl's schools were selected from regions 2 and 3, these regions are relatively close to the Tuwaiq

Assessment of the impact of oxidation processes on indoor air pollution using the new time-resolved INCA-Indoor model

Science.gov (United States)

Mendez, Maxence; Blond, Nadège; Blondeau, Patrice; Schoemaecker, Coralie; Hauglustaine, Didier A.

2015-12-01

INCA-Indoor, a new indoor air quality (IAQ) model, has been developed to simulate the concentrations of volatile organic compounds (VOC) and oxidants considering indoor air specific processes such as: emission, ventilation, surface interactions (sorption, deposition, uptake). Based on the detailed version of SAPRC-07 chemical mechanism, INCA-Indoor is able to analyze the contribution of the production and loss pathways of key chemical species (VOCs, oxidants, radical species). The potential of this model has been tested through three complementary analyses: a comparison with the most detailed IAQ model found in the literature, focusing on oxidant species; realistic scenarios covering a large range of conditions, involving variable OH sources like HONO; and the investigation of alkenes ozonolysis under a large range of indoor conditions that can increase OH and HO2 concentrations. Simulations have been run changing nitrous acid (HONO) concentrations, NOx levels, photolysis rates and ventilation rates, showing that HONO can be the main source of indoor OH. Cleaning events using products containing D-limonene have been simulated at different periods of the day. These scenarios show that HOX concentrations can significantly increase in specific conditions. An assessment of the impact of indoor chemistry on the potential formation of secondary species such as formaldehyde (HCHO) and acetaldehyde (CH3CHO) has been carried out under various room configuration scenarios and a study of the HOx budget for different realistic scenarios has been performed. It has been shown that, under the simulation conditions, formaldehyde can be affected by oxidant concentrations via chemical production which can account for more than 10% of the total production, representing 6.5 ppb/h. On the other hand, acetaldehyde production is affected more by oxidation processes. When the photolysis rates are high, chemical processes are responsible for about 50% of the total production of

Investigation of indoor radon concentration in block houses in Omderman

International Nuclear Information System (INIS)

Ahmed, H. A. M.

2010-12-01

Radon is one of the naturally occurring radioactive elements in the environment as a member of the natural uranium decay. Exposure to radon in the home and workplace is one of the main risks of ionizing radiation thought to cause tens of thousands of deaths from lung cancer each year. In order to reduce this burden it is important that national authorities have methods and tools bases on solid scientific evidence and sound public health policy. The public needs to be aware of radon risks and the means to reduce and prevent these. This study presents of the studies dealing with the investigation of exposure from ionizing radiation. The radon levels in some selected type of building styles (Bricks Albulk) were investigated in Omderman city (public housing). The radon level in most of the houses found to range between 87.63 and 206 Bq/m 3 with average value of 127±23 Bq/m 3 . This is well lay within the allowable limit with average. The study indicates that building materials used does not add significant concentration of radon to indoor. It can be considered as safe type of building style from radiation protection point of view. (Author)

Indoor concentrations of radon 222 and its daughters: sources, range, and environmental influences

International Nuclear Information System (INIS)

Nero, A.V. Jr.

1985-04-01

The author here reviews what is presently known about factors affecting indoor concentrations of radon 222 and its daughters. In US single-family homes, radon concentrations are found to average about 1.5 pCi/1, but substantially higher concentrations occur frequently: perhaps a million US homes have concentrations exceeding 8 pCi/1 (from which occupants receive radiation doses comparable to those now experienced by uranium miners). The major contributor to indoor radon is ordinary soil underlying homes, with this radon being transported indoors primarily by the slight depressurization that occurs toward the bottom of a house interior (due to indoor-outdoor temperature differences and winds). Water from underground sources contributes significantly in a minority of cases, primarily residences with private wells, with public water supplies contributing only a few percent of indoor radon, even when drawn from wells. The strong variability in indoor concentrations is associated primarily with variability in the amount of radon entering homes from these various sources, and secondarily with differences in ventilation rates. However, for a given entry rate, the ventilation rate is the key determinant of indoor concentrations. Human doses are also influenced strongly by the chemical behavior of the daughters (i.e., decay products of radon), and considerable progress has been made recently in investigating a major aspect of this behavior, i.e., the manner in which daughters attach to airborne particles, to walls, and - indeed - to the lining of the lung itself, where the key radiation dose occurs

Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings

Directory of Open Access Journals (Sweden)

Avril Challoner

2015-12-01

Full Text Available NO2 and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person’s well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM, to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO2 indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO2 exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts.

Current implications of past DDT indoor spraying in Oman.

Science.gov (United States)

Booij, Petra; Holoubek, Ivan; Klánová, Jana; Kohoutek, Jiří; Dvorská, Alice; Magulová, Katarína; Al-Zadjali, Said; Čupr, Pavel

2016-04-15

In Oman, DDT was sprayed indoors during an intensive malaria eradication program between 1976 and 1992. DDT can remain for years after spraying and is associated with potential health risk. This raises the concern for human exposure in areas where DDT was used for indoor spraying. Twelve houses in three regions with a different history of DDT indoor spraying were chosen for a sampling campaign in 2005 to determine p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and p,p'-dichlorodiphenyldichloroethane (p,p'-DDD) levels in indoor air, dust, and outdoor soil. Although DDT was only sprayed indoor, p,p'-DDT, p,p'-DDE and p,p'-DDD were also found in outdoor soil. The results indicate that release and exposure continue for years after cessation of spraying. The predicted cancer risk based on concentrations determined in 2005, indicate that there was still a significant cancer risk up to 13 to 16years after indoor DDT spraying. A novel approach, based on region-specific half-lives, was used to predict concentrations in 2015 and showed that more than 21years after spraying, cancer risk for exposure to indoor air, dust, and outdoor soil are acceptable in Oman for adults and young children. The model can be used for other locations and countries to predict prospective exposure of contaminants based on indoor experimental measurements and knowledge about the spraying time-schedule to extrapolate region-specific half-lives and predict effects on the human population years after spraying. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of indoor radon, thoron concentrations, and their relationship with seasonal variation and geology of Udhampur district, Jammu & Kashmir, India.

Science.gov (United States)

Kumar, Ajay; Sharma, Sumit; Mehra, Rohit; Narang, Saurabh; Mishra, Rosaline

2017-07-01

Background The inhalation doses resulting from the exposure to radon, thoron, and their progeny are important quantities in estimating the radiation risk for epidemiological studies as the average global annual effective dose due to radon and its progeny is 1.3 mSv as compared to that of 2.4 mSv due to all other natural sources of ionizing radiation. Objectives The annual inhalation dose has been assessed with an aim of investigating the health risk to the inhabitants of the studied region. Methods Time integrated deposition based 222 Rn/ 220 Rn sensors have been used to measure concentrations in 146 dwellings of Udhampur district, Jammu and Kashmir. An active smart RnDuo monitor has also been used for comparison purposes. Results The range of indoor radon/thoron concentrations is found to vary from 11 to 58 Bqm -3 with an average value of 29 ± 9 Bqm -3 and from 25 to 185 Bqm -3 with an average value of 83 ± 32 Bqm -3 , respectively. About 10.7% dwellings have higher values than world average of 40 Bqm -3 prescribed by UNSCEAR. The relationship of indoor radon and thoron levels with different seasons, ventilation conditions, and different geological formations have been discussed. Conclusions The observed values of concentrations and average annual effective dose due to radon, thoron, and its progeny in the study area have been found to be below the recommended level of ICRP. The observed concentrations of 222 Rn and 220 Rn measured with active and passive techniques are found to be in good agreement.

Personal exposures to NO2 in the EXPOLIS-study: relation to residential indoor, outdoor and workplace concentrations in Basel, Helsinki and Prague

International Nuclear Information System (INIS)

Kousa, A.; Rotko, T.; Alm, S.; Monn, C.

2001-01-01

Personal exposures, residential indoor, outdoor and workplace levels of nitrogen dioxide (NO 2 ) were measured for 262 urban adult (25-55 years) participants in three EXPOLIS centres (Basel, Switzerland; Helsinki, Finland; and Prague, Czech Republic) using passive samplers for 48-h sampling periods during 1996-1997. The average residential outdoor and indoor NO 2 levels were lowest in Helsinki (24 ± 12 and 18 ± 11 μgm -3 , respectively), highest in Prague (61 ± 20 and 43 ± 23μgm -3 ), with Basel in between (36 ± 13 and 27± 13μgm -3 ). Average workplace NO 2 levels, however, were highest in Basel (36 ± 24μgm -3 ), lowest in Helsinki (27 ± 15μgm -3 ), with Prague in between (30 ± 18μgm -3 ). A time-weighted microenvironmental exposure model explained 74% of the personal exposure variation in all centre and in average 88% of the exposures. Log-linear regression models, using residential outdoor measurements (fixed site monitoring) combined with residential and work characteristics (i.e. work location, using gas appliances and keeping windows open), explained 48% (37%) of the personal NO 2 exposure variation. Regression models based on ambient fixed site concentrations alone explained only 11-19% of personal NO 2 exposure variation. Thus, ambient fixed site monitoring alone was a poor predictor for personal NO 2 exposure variation, but adding personal questionnaire information can significantly improve the predicting power. (Author)

A Pedestrian Approach to Indoor Temperature Distribution Prediction of a Passive Solar Energy Efficient House

Directory of Open Access Journals (Sweden)

Golden Makaka

2015-01-01

Full Text Available With the increase in energy consumption by buildings in keeping the indoor environment within the comfort levels and the ever increase of energy price there is need to design buildings that require minimal energy to keep the indoor environment within the comfort levels. There is need to predict the indoor temperature during the design stage. In this paper a statistical indoor temperature prediction model was developed. A passive solar house was constructed; thermal behaviour was simulated using ECOTECT and DOE computer software. The thermal behaviour of the house was monitored for a year. The indoor temperature was observed to be in the comfort level for 85% of the total time monitored. The simulation results were compared with the measured results and those from the prediction model. The statistical prediction model was found to agree (95% with the measured results. Simulation results were observed to agree (96% with the statistical prediction model. Modeled indoor temperature was most sensitive to the outdoor temperatures variations. The daily mean peak ones were found to be more pronounced in summer (5% than in winter (4%. The developed model can be used to predict the instantaneous indoor temperature for a specific house design.

Exposure caused by wireless technologies used for short-range indoor communication in homes and offices

International Nuclear Information System (INIS)

Schmid, G.; Lager, D.; Preiner, P.; Ueberbacher, R.; Cecil, S.

2007-01-01

In order to estimate typical radio frequency exposures from indoor used wireless communication technologies applied in homes and offices, WLAN, Bluetooth and Digital Enhanced Cordless Telecommunications systems, as well as baby surveillance devices and wireless headphones for indoor usage, have been investigated by measurements and numerical computations. Based on optimised measurement methods, field distributions and resulting exposure were assessed on selected products and real exposure scenarios. Additionally, generic scenarios have been investigated on the basis of numerical computations. The obtained results demonstrate that under usual conditions the resulting spatially (over body dimensions) averaged and 6-min time-averaged exposure for persons in the radio frequency fields of the considered applications is below ∼0.1% of the reference level for power density according to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines published in 1998. Spatial and temporal peak values can be considerably higher by 2-3 orders of magnitude. In case of some transmitting devices operated in close proximity to the body (e.g. WLAN transmitters), local exposure can reach the same order of magnitude as the basic restriction; however, none of the devices considered in this study exceeded the limits according to the ICNIRP guidelines. (authors)

Indoor particulate matter in developing countries: a case study in Pakistan and potential intervention strategies

Science.gov (United States)

Nasir, Zaheer Ahmad; Colbeck, Ian; Ali, Zulfiqar; Ahmad, Shakil

2013-06-01

Around three billion people, largely in low and middle income countries, rely on biomass fuels for their household energy needs. The combustion of these fuels generates a range of hazardous indoor air pollutants and is an important cause of morbidity and mortality in developing countries. Worldwide, it is responsible for four million deaths. A reduction in indoor smoke can have a significant impact on lives and can help achieve many of the Millennium Developments Goals. This letter presents details of a seasonal variation in particulate matter (PM) concentrations in kitchens using biomass fuels as a result of relocating the cooking space. During the summer, kitchens were moved outdoors and as a result the 24 h average PM10, PM2.5 and PM1 fell by 35%, 22% and 24% respectively. However, background concentrations of PM10 within the village increased by 62%. In locations where natural gas was the dominant fuel, the PM concentrations within the kitchen as well as outdoors were considerably lower than those in locations using biomass. These results highlights the importance of ventilation and fuel type for PM levels and suggest that an improved design of cooking spaces would result in enhanced indoor air quality.

Indoor particulate matter in developing countries: a case study in Pakistan and potential intervention strategies

International Nuclear Information System (INIS)

Nasir, Zaheer Ahmad; Colbeck, Ian; Ali, Zulfiqar; Ahmad, Shakil

2013-01-01

Around three billion people, largely in low and middle income countries, rely on biomass fuels for their household energy needs. The combustion of these fuels generates a range of hazardous indoor air pollutants and is an important cause of morbidity and mortality in developing countries. Worldwide, it is responsible for four million deaths. A reduction in indoor smoke can have a significant impact on lives and can help achieve many of the Millennium Developments Goals. This letter presents details of a seasonal variation in particulate matter (PM) concentrations in kitchens using biomass fuels as a result of relocating the cooking space. During the summer, kitchens were moved outdoors and as a result the 24 h average PM 10 , PM 2.5 and PM 1 fell by 35%, 22% and 24% respectively. However, background concentrations of PM 10 within the village increased by 62%. In locations where natural gas was the dominant fuel, the PM concentrations within the kitchen as well as outdoors were considerably lower than those in locations using biomass. These results highlights the importance of ventilation and fuel type for PM levels and suggest that an improved design of cooking spaces would result in enhanced indoor air quality. (letter)

Association of indoor air pollution with rhinitis symptoms, atopy and nitric oxide levels in exhaled air

DEFF Research Database (Denmark)

Hersoug, Lars-Georg; Husemoen, Lise Lotte N; Thomsen, Simon Francis

2010-01-01

Exposure to particulate matter (PM) outdoors can induce airway inflammation and exacerbation of asthma in adults. However, there is limited knowledge about the effects of exposure to indoor PM. The aim of this study was to investigate the association of exposure to indoor sources of PM...... with rhinitis symptoms, atopy and nitric oxide in exhaled air (FeNO) as a measure of airway inflammation....

Evaluation of annual effective dose from indoor radon concentration in Eastern Province, Dammam, Saudi Arabia

Science.gov (United States)

Abuelhia, E.

2017-11-01

The aim of this study is to determine the indoor radon concentration and to evaluate the annual effective dose received by the inhabitants in Dammam, Al-Khobar, and compare it with new premises built at university of dammam. The research has been carried out by using active detection method; Electronic Radon Detector (RAD-7) a solid state α-detector with its special accessories. The indoor radon concentration measured varies from 10.2 Bqm-3 to 25.8 Bqm-3 with an average value of 18.8 Bqm-3 and 19.7 Bqm-3 to 23.5 Bqm-3 with an average value of 21.7 Bqm-3, in Dammam and Al-khobar dwellings, respectively. In university of dammam the radon concentration varies from 7.4 Bqm-3 to 15.8 Bqm-3 with an average value of 9.02 Bqm-3. The values of annual effective doses were found to be 0.47mSv/y, 0.55mSv/y, and 0.23mSv/y, in Dammam, Al-khobar and university new premises, respectively. The average radon concentration in the old dwellings was two times compared to that in the new premises and it was 25.4 Bqm-3 lower than the world average value of 40 Bqm-3 reported by the UNSCEAR. The annual effective doses in the old dwellings was found to be (0.55mSv/y) two times the doses received at the new premises, and below the world wide average of 1.15mSv/y reported by ICRP (2010). The indoor radon concentration in the study region is safe as far as health hazard is concerned.

Indoor Radon and Its Decay Products: Concentrations, Causes, and Control Strategies

Energy Technology Data Exchange (ETDEWEB)

Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.

1990-01-01

This report is an introduction to the behavior of radon 222 and its decay products in indoor air. This includes review of basic characteristics of radon and its decay products and of features of the indoor environment itself, all of which factors affect behavior in indoor air. The experimental and theoretical evidence on behavior of radon and its decay products is examined, providing a basis for understanding the influence of geological, structural, and meteorological factors on indoor concentrations, as well as the effectiveness of control techniques. We go on to examine three important issues concerning indoor radon. We thus include (1) an appraisal of the concentration distribution in homes, (2) an examination of the utility and limitations of popular monitoring techniques and protocols, and (3) an assessment of the key elements of strategies for controlling radon levels in homes.

Relationships between socioeconomic and lifestyle factors and indoor air quality in French dwellings.

Science.gov (United States)

Brown, Terry; Dassonville, Claire; Derbez, Mickael; Ramalho, Olivier; Kirchner, Severine; Crump, Derrick; Mandin, Corinne

2015-07-01

To date, few studies have analyzed the relationships between socioeconomic status (SES) and indoor air quality (IAQ). The aim of this study was to examine the relationships between socioeconomic and other factors and indoor air pollutant levels in French homes. The indoor air concentrations of thirty chemical, biological and physical parameters were measured over one week in a sample of 567 dwellings representative of the French housing stock between September 2003 and December 2005. Information on SES (household structure, educational attainment, income, and occupation), building characteristics, and occupants' habits and activities (smoking, cooking, cleaning, etc.) were collected through administered questionnaires. Separate stepwise linear regression models were fitted to log-transformed concentrations on SES and other factors. Logistic regression was performed on fungal contamination data. Households with lower income were more likely to have higher indoor concentrations of formaldehyde, but lower perchloroethylene indoor concentrations. Formaldehyde indoor concentrations were also associated with newly built buildings. Smoking was associated with increasing acetaldehyde and PM2.5 levels and the risk of a positive fungal contamination index. BTEX levels were also associated with occupant density and having an attached garage. The major predictors for fungal contamination were dampness and absolute humidity. These results, obtained from a large sample of dwellings, show for the first time in France the relationships between SES factors and indoor air pollutants, and believe they should be considered alongside occupant activities and building characteristics when study IAQ in homes. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

New insight into the levels, distribution and health risk diagnosis of indoor and outdoor dust-bound FRs in colder, rural and industrial zones of Pakistan.

Science.gov (United States)

Khan, Muhammad Usman; Li, Jun; Zhang, Gan; Malik, Riffat Naseem

2016-09-01

This is the first robust study designed to probe selected flame retardants (FRs) in the indoor and outdoor dust of industrial, rural and background zones of Pakistan with special emphasis upon their occurrence, distribution and associated health risk. For this purpose, we analyzed FRs such as polybrominated diphenylethers (PBDEs), dechlorane plus (DP), novel brominated flame retardants (NBFRs) and organophosphate flame retardants (OPFRs) in the total of 82 dust samples (indoor and outdoor) collected three from each zone: industrial, rural and background. We found higher concentrations of FRs (PBDEs, DP, NBFRs and OPFRs) in industrial zones as compared to the rural and background zones. Our results reveal that the concentrations of studied FRs are relatively higher in the indoor dust samples being compared with the outdoor dust and they are ranked as: ∑OPFRs > ∑NBFRs > ∑PBDEs > ∑DP. A significant correlation in the FRs levels between the indoor and outdoor dust suggest the potential intermixing of these compounds between them. The principal component analysis/multiple linear regression predicts the percent contribution of FRs from different consumer products in the indoor and outdoor dust of industrial, rural and background zones to trace their source origin. The FRs detected in the background zones reveal the dust-bound FRs suspended in the air might be shifted from different warmer zones or consumers products available/used in the same zones. Hazard quotient (HQ) for FRs via indoor and outdoor dust intake at mean and high dust scenarios to the exposed populations (adults and toddlers) are found free of risk (HQ < 1) in the target zones. Furthermore, our nascent results will provide a baseline record of FRs (PBDEs, DP, NBFRs and OPFRs) concentrations in the indoor and outdoor dust of Pakistan. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radon measurements in indoor workplaces

International Nuclear Information System (INIS)

Tokonami, S.; Matsumoto, M.; Furukawa, M.; Fujimoto, K.; Fujitaka, K.; Pan, J.; Kurosawa, R.

1996-01-01

Radon measurements in several office buildings located in Tokyo were carried out with two types of device to study the time-dependent radon concentration in indoor workplaces. Both types of device use the electrostatic field for the collection of 218 Po onto the electrode of the detector. One provides an average radon concentration throughout the day. The other, in which a weekly timer is installed in the circuit of the electrode of the device, provides an average radon concentration during working hours (9:00-17:00, Monday-Friday). Although radon concentrations in Japanese dwellings have been found to be generally low, relatively high concentrations were observed in the office buildings. No consistent seasonal variation was recognised in this study. Little difference of average radon concentrations between working hours and the whole day was found throughout the year in two offices. On the other hand, a significant difference was observed in other offices. The operation of an air conditioner might change the radon concentration during working hours. From the results of radon measurements the average effective dose in the workplace was estimated to be 0.23 mSv for 2000 working hours in a year. (Author)

Detection of fluorotelomer alcohols in indoor environments and their relevance for human exposure.

Science.gov (United States)

Schlummer, Martin; Gruber, Ludwig; Fiedler, Dominik; Kizlauskas, Markus; Müller, Josef

2013-07-01

Fluorotelomer alcohols (FTOH) are important precursors of perfluorinated carboxylic acids (PFCA). These neutral and volatile compounds are frequently found in indoor air and may contribute to the overall human exposure to per- and polyfluorinated alkyl substances (PFAS). In this study air samples of ten workplace environments and a car interior were analysed. In addition, extracts and emissions from selected outdoor textiles were analysed in order to establish their potential contribution to the indoor levels of the above-mentioned compounds. Concentrations of FTOHs measured in air ranged from 0.15 to 46.8, 0.25 to 286, and 0.11 to 57.5ng/m(3) for 6:2, 8:2 and 10:2 FTOHs, respectively. The highest concentrations in air were identified in shops selling outdoor clothing, indicating outdoor textiles to be a relevant source of FTOH in indoor workplace environments. Total amounts of FTOH in materials of outdoor textiles accounted for selling outdoor textiles contains the highest levels of FTOH. Exposure of humans to perfluorooctanoic acid (PFOA) through absorption of FTOH and subsequent degradation is discussed on the basis of indoor air levels. Calculation of indoor air-related exposure using the median of the measured air levels revealed that exposure is on the same order of magnitude as the recently reported dietary intakes for a background-exposed population. On the basis of the 95th percentile, indoor air exposure to PFOA was estimated to exceed dietary exposure. However, indoor air-related intakes of FTOH are far below the tolerable daily intake (TDI) of PFOA, indicating that there is no risk to health, even when assuming an unrealistic complete degradation of FTOH into PFOA. Copyright © 2013 Elsevier Ltd. All rights reserved.

A comparative study of indoor radon concentrations between dwellings and schools

International Nuclear Information System (INIS)

Kapdan, E.; Altinsoy, N.

2012-01-01

The aim of this study is to determine the relationship of radon concentrations between dwellings and the schools located in the same regions and to obtain related indoor average radon concentration dwelling–school correction factor for similar locations. The research has been carried out by determining indoor radon concentrations at schools and dwellings located at the same districts in the selected two separate research fields called The Former Adapazari region and The New Adapazari region in the city of Adapazari using a total of 81 Cr-39 passive radon detectors for 75 days. The average radon concentrations have been determined for the dwellings and the schools in 15 districts of the Former Adapazari region as 59.9 Bq m −3 and 57.1 Bq m −3 , respectively. The results in 4 districts of the New Adapazari region were 63.5 Bq m −3 for the dwellings and 61.0 Bq m −3 for the schools. Moreover, the annual effective doses were calculated as 1.33 mSv/y and 1.41 mSv/y for the dwellings of Former Adapazari and New Adapazari, respectively. It was seen that the doses received in the dwellings are about four times the doses received in the schools. The indoor radon concentration dwelling–school correction factor was found to be 1.04±0.01 for the research area.

Indoor radon problem in energy efficient multi-storey buildings.

Science.gov (United States)

Yarmoshenko, I V; Vasilyev, A V; Onishchenko, A D; Kiselev, S M; Zhukovsky, M V

2014-07-01

Modern energy-efficient architectural solutions and building construction technologies such as monolithic concrete structures in combination with effective insulation reduce air permeability of building envelope. As a result, air exchange rate is significantly reduced and conditions for increased radon accumulation in indoor air are created. Based on radon survey in Ekaterinburg, Russia, remarkable increase in indoor radon concentration level in energy-efficient multi-storey buildings was found in comparison with similar buildings constructed before the-energy-saving era. To investigate the problem of indoor radon in energy-efficient multi-storey buildings, the measurements of radon concentration have been performed in seven modern buildings using radon monitoring method. Values of air exchange rate and other parameters of indoor climate in energy-efficient buildings have been estimated. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Methodology developed to make the Quebec indoor radon potential map

Energy Technology Data Exchange (ETDEWEB)

Drolet, Jean-Philippe, E-mail: jean-philippe.drolet@ete.inrs.ca [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Martel, Richard [Institut national de la recherche scientifique, Eau Terre Environnement Research Centre (ETE-INRS), 490 de la Couronne, G1K 9A9 Quebec (Canada); Poulin, Patrick [Institut national de santé publique du Québec (INSPQ), 945 avenue Wolfe, G1V 5B3 Quebec (Canada); Dessau, Jean-Claude [Agence de la santé et des services sociaux des Laurentides, 1000 rue Labelle, J7Z 5 N6 Saint-Jérome (Canada)

2014-03-01

This paper presents a relevant approach to predict the indoor radon potential based on the combination of the radiogeochemical data and the indoor radon measurements in the Quebec province territory (Canada). The Quebec ministry of health asked for such a map to identify the radon-prone areas to manage the risk for the population related to indoor radon exposure. Three radiogeochemical criteria including (1) equivalent uranium (eU) concentration from airborne surface gamma-ray surveys, (2) uranium concentration measurements in sediments, (3) bedrock and surficial geology were combined with 3082 basement radon concentration measurements to identify the radon-prone areas. It was shown that it is possible to determine thresholds for the three criteria that implied statistically significant different levels of radon potential using Kruskal–Wallis one way analyses of variance by ranks. The three discretized radiogeochemical datasets were combined into a total predicted radon potential that sampled 98% of the studied area. The combination process was also based on Kruskal–Wallis one way ANOVA. Four statistically significant different predicted radon potential levels were created: low, medium, high and very high. Respectively 10 and 13% of the dwellings exceed the Canadian radon guideline of 200 Bq/m{sup 3} in low and medium predicted radon potentials. These proportions rise up to 22 and 45% respectively for high and very high predicted radon potentials. This predictive map of indoor radon potential based on the radiogeochemical data was validated using a map of confirmed radon exposure in homes based on the basement radon measurements. It was shown that the map of predicted radon potential based on the radiogeochemical data was reliable to identify radon-prone areas even in zones where no indoor radon measurement exists. - Highlights: • 5 radiogeochemical datasets were used to map the geogenic indoor radon potential. • An indoor radon potential was determined for

Effectiveness of air purifier on health outcomes and indoor particles in homes of children with allergic diseases in Fresno, California: A pilot study.

Science.gov (United States)

Park, Hye-Kyung; Cheng, Kai-Chung; Tetteh, Afua O; Hildemann, Lynn M; Nadeau, Kari C

2017-05-01

Epidemiologic studies indicate that indoor air pollution is correlated with morbidity caused by allergic diseases. We evaluated the effectiveness of reducing the levels of indoor fine particulate matter <2.5 micrometer diameter (PM 2.5 ) in Fresno, California using air purifiers on health outcomes in children with asthma and/or allergic rhinitis. The active group (with air purifiers) and the control group consisted of eight houses each. Air purifiers were installed in the living rooms and bedrooms of the subjects in the active group during the entire 12-week study duration. Childhood asthma control test, peak flow rate monitoring, and nasal symptom scores were evaluated at weeks 0, 6, and 12. At 12 weeks, the active group showed a trend toward an improvement of childhood asthma control test scores and mean evening peak flow rates, whereas the control group showed deterioration in the same measures. Total and daytime nasal symptoms scores significantly reduced in the active group (p = 0.001 and p = 0.011, respectively). The average indoor PM 2.5 concentrations reduced by 43% (7.42 to 4.28 μg/m 3 ) in the active group (p = 0.001). Intervention with air purifiers reduces indoor PM 2.5 levels with significant improvements in nasal symptoms in children with allergic rhinitis in Fresno.

Indoor air quality: The hidden side of the indoor environment

NARCIS (Netherlands)

Oliveira Fernandes, E. de; Bluyssen, P.M.; Clausen, G.H.

1996-01-01

The physical environment can be defined and understood in manv different ways, both from its nature, e.g., thermal, accoustic, etc., or its dimension, e.g., global, local, urban, indoors. The indoor environment is much more than the space or the light effects; it is the result of a complex

Indoor radon measurement in some adobe houses in the Kassena Nankana area of the Upper East Region

International Nuclear Information System (INIS)

Quashie, F. K.

2010-06-01

Inhalation of radon and its daughter products is the major contributor to the total exposure of the population to natural radiation. The present study has measured radon gas concentration in some Adobe houses and the soil radon gas around these houses in the Kassena Nankana Area of the Upper East Region by using passive radon indoor dosimeter containing solid-state nuclear track detector (SSNTD) commercially known as LR - 115 (type II, pelliculable). Fifty (50) indoor radon dosimeters were placed in the various Adobe houses in the study area. Additionally, thirty (30) dosimeters were placed in the soil around some of the houses at a depth of 75 cm. Soil radon dosimeters were retrieved after two (2) weeks while the indoor radon dosimeters were retrieved after 78 to 82 days. The detectors were then chemically etched. The digital laser optic system and the spark counter coupled with microfiche reader were used in counting both the indoor and soil detectors respectively. Indoor radon concentration in the study area range from 35.28 Bq/m 3 to 244.22 Bq/m 3 . An active dosimeter known as the radon scout plus which gives instantaneous readings between 1 to 3 hours was also used in nineteen of the adobe houses in the study area and a total average radon concentration of 56.90 Bq/m3 was obtained. The soil radon concentration was also found to range from 2.12 kBq/m 3 to 15.03 kBq/m 3 . A good correlation was found to exist between the soil radon concentration and that of the indoor radon concentration with a correlation coefficient of about 0.61. The mean radon emanation coefficient of some fifteen (15) soil samples monitored was 0.46. The average annual effective dose was estimated to be about 1.66 mSv/y and that of the average annual effective dose using the equilibrium equivalent factor (F) was 1.00 mSv/y

Long term and equilibrium factor indoor radon measurements

International Nuclear Information System (INIS)

Martinez, T.; Lartigue, J.; Navarrete, M.; Cabrera, L.; Ramirez, A.; Elizarraras, V.

1998-01-01

This paper presents the annual radon gas concentrations obtained during the 1994-1995 monitoring campaign using passive electret system (type E-PERM). Radon levels were measured in 154 single family dwellings, in normal occupancy conditions (open house condition) in the metropolitan zone of Mexico City. At the same time radon monitoring was performed outdoors. The results show the general log-normal distribution of integrated indoor radon concentration with an annual indoor mean of 3.8 pCi x l -1 . The seasonal variations show the minimum mean values in the summer season which are 39% lower than that in autumn. Equilibrium factors (F) were measured in 12 typical houses both in autumn and winter using a continuous working level monitor for short-lived radon decay products and H-chamber loaded with a short term electret (HST, E-PERM) for radon gas. The obtained total mean equilibrium factors are: F=0.41±0.17 and F=0.29±0.04 for indoor and outdoor, respectively. A quality program was also improved. (author)

Indoor Environmental Quality Benefits of Apartment Energy Retrofits

Energy Technology Data Exchange (ETDEWEB)

Noris, Federico [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Adamkiewicz, Gary [Harvard School of Public Health, Boston MA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Russell, Marion [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spears, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Vermeer, Kimberly [Urban Habitate Initiatives Inc., Boston, MA (United States); Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2013-06-01

Sixteen apartments serving low-income populations in three buildings were retrofit with the goal of simultaneously reducing energy consumption and improving indoor environmental quality (IEQ). Retrofit measures varied among apartments and included, among others, envelope sealing, installation of continuous mechanical ventilation systems, upgrading bathroom fans and range hoods, attic insulation, replacement of heating and cooling systems, and adding wall-mounted particle air cleaners. IEQ parameters were measured, generally for two one-week periods before and after the retrofits. The measurements indicate an overall improvement in IEQ conditions after the retrofits. Comfort conditions, bathroom humidity, and concentrations of carbon dioxide, acetaldehyde, volatile organic compounds, and particles generally improved. Formaldehyde and nitrogen dioxide levels decreased in the building with the highest concentrations, were unchanged in a second building, and increased in a third building. IEQ parameters other than particles improved more in apartments with continuous mechanical ventilation systems installed. In general, but not consistently, larger percent increases in air exchange rates were associated with larger percent decreases in indoor levels of the pollutants that primarily come from indoor sources.

Predicted indoor radon concentrations from a Monte Carlo simulation of 1 000 000 granite countertop purchases

International Nuclear Information System (INIS)

Allen, J G; Zwack, L M; MacIntosh, D L; Minegishi, T; Stewart, J H; McCarthy, J F

2013-01-01

Previous research examining radon exposure from granite countertops relied on using a limited number of exposure scenarios. We expanded upon this analysis and determined the probability that installing a granite countertop in a residential home would lead to a meaningful radon exposure by performing a Monte Carlo simulation to obtain a distribution of potential indoor radon concentrations attributable to granite. The Monte Carlo analysis included estimates of the probability that a particular type of granite would be purchased, the radon flux associated with that type, the size of the countertop purchased, the volume of the home where it would be installed and the air exchange rate of that home. One million countertop purchases were simulated and 99.99% of the resulting radon concentrations were lower than the average outdoor radon concentrations in the US (14.8 Bq m −3 ; 0.4 pCi l −1 ). The median predicted indoor concentration from granite countertops was 0.06 Bq m −3 (1.59 × 10 −3 pCi l −1 ), which is over 2000 times lower than the US Environmental Protection Agency’s action level for indoor radon (148 Bq m −3 ; 4 pCi l −1 ). The results show that there is a low probability of a granite countertop causing elevated levels of radon in a home. (paper)

Rethinking Indoor Localization Solutions Towards the Future of Mobile Location-Based Services

Science.gov (United States)

Guney, C.

2017-11-01

Satellite navigation systems with GNSS-enabled devices, such as smartphones, car navigation systems, have changed the way users travel in outdoor environment. GNSS is generally not well suited for indoor location and navigation because of two reasons: First, GNSS does not provide a high level of accuracy although indoor applications need higher accuracies. Secondly, poor coverage of satellite signals for indoor environments decreases its accuracy. So rather than using GNSS satellites within closed environments, existing indoor navigation solutions rely heavily on installed sensor networks. There is a high demand for accurate positioning in wireless networks in GNSS-denied environments. However, current wireless indoor positioning systems cannot satisfy the challenging needs of indoor location-aware applications. Nevertheless, access to a user's location indoors is increasingly important in the development of context-aware applications that increases business efficiency. In this study, how can the current wireless location sensing systems be tailored and integrated for specific applications, like smart cities/grids/buildings/cars and IoT applications, in GNSS-deprived areas.

RETHINKING INDOOR LOCALIZATION SOLUTIONS TOWARDS THE FUTURE OF MOBILE LOCATION-BASED SERVICES

Directory of Open Access Journals (Sweden)

C. Guney

2017-11-01

Full Text Available Satellite navigation systems with GNSS-enabled devices, such as smartphones, car navigation systems, have changed the way users travel in outdoor environment. GNSS is generally not well suited for indoor location and navigation because of two reasons: First, GNSS does not provide a high level of accuracy although indoor applications need higher accuracies. Secondly, poor coverage of satellite signals for indoor environments decreases its accuracy. So rather than using GNSS satellites within closed environments, existing indoor navigation solutions rely heavily on installed sensor networks. There is a high demand for accurate positioning in wireless networks in GNSS-denied environments. However, current wireless indoor positioning systems cannot satisfy the challenging needs of indoor location-aware applications. Nevertheless, access to a user’s location indoors is increasingly important in the development of context-aware applications that increases business efficiency. In this study, how can the current wireless location sensing systems be tailored and integrated for specific applications, like smart cities/grids/buildings/cars and IoT applications, in GNSS-deprived areas.

Diversity and taxonomy of Chaetomium and chaetomium-like fungi from indoor environments

Directory of Open Access Journals (Sweden)

X.W. Wang

2016-06-01

Full Text Available During a study of indoor fungi, 145 isolates belonging to Chaetomiaceae were cultured from air, swab and dust samples from 19 countries. Based on the phylogenetic analyses of DNA-directed RNA polymerase II second largest subunit (rpb2, β-tubulin (tub2, ITS and 28S large subunit (LSU nrDNA sequences, together with morphological comparisons with related genera and species, 30 indoor taxa are recognised, of which 22 represent known species, seven are described as new, and one remains to be identified to species level. In our collection, 69 % of the indoor isolates with six species cluster with members of the Chaetomium globosum species complex, representing Chaetomium sensu stricto. The other indoor species fall into nine lineages that are separated from each other with several known chaetomiaceous genera occurring among them. No generic names are available for five of those lineages, and the following new genera are introduced here: Amesia with three indoor species, Arcopilus with one indoor species, Collariella with four indoor species, Dichotomopilus with seven indoor species and Ovatospora with two indoor species. The generic concept of Botryotrichum is expanded to include Emilmuelleria and the chaetomium-like species B. muromum (= Ch. murorum in which two indoor species are included. The generic concept of Subramaniula is expanded to include several chaetomium-like taxa as well as one indoor species. Humicola is recognised as a distinct genus including two indoor taxa. According to this study, Ch. globosum is the most abundant Chaetomiaceae indoor species (74/145, followed by Ch. cochliodes (17/145, Ch. elatum (6/145 and B. piluliferum (5/145. The morphological diversity of indoor Chaetomiaceae as well as the morphological characteristics of the new genera are described and illustrated. This taxonomic study redefines the generic concept of Chaetomium and provides new insight into the phylogenetic relationships among different genera within

Contribution from indoor sources to particle number and mass concentrations in residential houses

Science.gov (United States)

He, Congrong; Morawska, Lidia; Hitchins, Jane; Gilbert, Dale

As part of a large study investigating indoor air in residential houses in Brisbane, Australia, the purpose of this work was to quantify emission characteristics of indoor particle sources in 15 houses. Submicrometer particle number and approximation of PM 2.5 concentrations were measured simultaneously for more than 48 h in the kitchen of all the houses by using a condensation particle counter (CPC) and a photometer (DustTrak), respectively. In addition, characterizations of particles resulting from cooking conducted in an identical way in all the houses were measured by using a scanning mobility particle sizer (SMPS), an aerodynamic particle sizer (APS) and a DustTrak. All the events of elevated particle concentrations were linked to indoor activities using house occupants diary entries, and catalogued into 21 different types of indoor activities. This enabled quantification of the effect of indoor sources on indoor particle concentrations as well as quantification of emission rates from the sources. For example, the study found that frying, grilling, stove use, toasting, cooking pizza, cooking, candle vaporizing eucalyptus oil and fan heater use, could elevate the indoor submicrometer particle number concentration levels by more than five times, while PM 2.5 concentrations could be up to 3, 30 and 90 times higher than the background levels during smoking, frying and grilling, respectively.

Indoor radon measurements and methodologies in Latin American countries

International Nuclear Information System (INIS)

Canoba, A.; Lopez, F.O.; Arnaud, M.I.; Oliveira, A.A.; Neman, R.S.; Hadler, J.C.; Iunes, P.J.; Paulo, S.R.; Osorio, A.M.; Aparecido, R.; Rodriguez, C.; Moreno, V.; Vasquez, R.; Espinosa, G.; Golzarri, J.I.; Martinez, T.; Navarrete, M.; Cabrera, I.; Segovia, N.; Pena, P.; Tamez, E.; Pereyra, P.; Lopez-Herrera, M.E.; Sajo-Bohus, L.

2001-01-01

According to the current international guidelines concerning environmental problems, it is necessary to evaluate and to know the indoor radon levels, specially since most of the natural radiation dose to man comes from radon gas and its progeny. Several countries have established National Institutions and National Programs for the study of radon and its connection with lung cancer risk and public health. The aim of this work is to present the indoor radon measurements and the detection methods used for different regions of Latin America (LA) in countries such as Argentina, Brazil, Ecuador, Mexico, Peru and Venezuela. This study shows that the passive radon devices based on alpha particle nuclear track methodology (NTM) is one of the more generalized methods in LA for long term indoor radon measurements, CR-39, LR-115 and Makrofol being the more commonly used detector materials. The participating institutions and the radon level measurements in the different countries are presented in this contribution

Changes in indoor pollutants since the 1950s

DEFF Research Database (Denmark)

Weschler, Charles J.

2009-01-01

Over the past half-century there have been major changes in building materials and consumer products used indoors. Composite-wood, synthetic carpets. polymeric flooring, foam Cushioning, plastic items and scented cleaning agents have become ubiquitous. The same is true for mechanical and electrical...... appliances such as washer/dryers, TVs and Computers. These materials and products emit an array of chemicals including solvents. unreacted monomers, and additives. The consequent changes in emission profiles for indoor pollutants have been accompanied by modifications in building operations. Residences...... changed. Taken together, these changes have altered the kind and concentrations of chemicals that occupants are exposed to in their homes, workplaces and schools. Since the 1950s, levels of certain indoor Pollutants (e.g., formaldehyde, aromatic and chlorinated solvents, chlorinated pesticides, PCBs) have...

Indoor navigation by image recognition

Science.gov (United States)

Choi, Io Teng; Leong, Chi Chong; Hong, Ka Wo; Pun, Chi-Man

2017-07-01

With the progress of smartphones hardware, it is simple on smartphone using image recognition technique such as face detection. In addition, indoor navigation system development is much slower than outdoor navigation system. Hence, this research proves a usage of image recognition technique for navigation in indoor environment. In this paper, we introduced an indoor navigation application that uses the indoor environment features to locate user's location and a route calculating algorithm to generate an appropriate path for user. The application is implemented on Android smartphone rather than iPhone. Yet, the application design can also be applied on iOS because the design is implemented without using special features only for Android. We found that digital navigation system provides better and clearer location information than paper map. Also, the indoor environment is ideal for Image recognition processing. Hence, the results motivate us to design an indoor navigation system using image recognition.

External gamma exposure to radon progeny in indoor air

International Nuclear Information System (INIS)

Fujimoto, Kenzo

1985-01-01

The external γ-exposure from radon progeny uniformly distributed in indoor air was estimated by a computer program that was developed. This program can calculate the fluence rate, exposure rate and average energy for any given point in a room of any given size. As numerical example, the exposure rate normalized to unit airborne activity is presented, together with the fluence-weighted and exposure-weighted average photon energies, for a room of representative geometry containing radon progeny in equilibrium. To cover other conditions encountered in practice, quantitative evaluations are additionally presented of the effect on the exposure brought by changes in certain parameters, such as equilibrium factor, wall thickness, room size and receptor position. The study has quantitatively substantiated the prevailing postulate that the effective dose equivalent due to external exposure resulting from normal indoor concentrations of airborne radon progeny in the room of representative geometry should only amount to 0.04 % of that from the internal exposure from the same sources, and that it should be of similarly negligible order compared with internal exposure also in the case of other room geometries. (author)

Effect of ventilation rate on concentrations of indoor radon and its progenies

International Nuclear Information System (INIS)

Wang Chunhong; Liu Yanyang; Liu Fudong; Liu Senlin; Chen Ling

2012-01-01

To study concentrations of indoor radon and its progenies, ventilation rates and their corresponding concentrations of indoor radon and its progenies were measured using tracer-gas dilution method. Results show that both ventilation rates and concentrations of indoor radon varied insignificantly and radon concentration were higher than the outdoor environment while doors and windows were all closed with air-conditioner on and off respectively; the concentrations declined and close to the outdoor level when doors and windows were all open with ventilators in operation. Accordingly, in modern life, especially in summer, people's preference for air-conditioners but natural ventilation would result in an increase of indoor radon concentration. (authors)

Indoor Temperatures in Low Cost Housing in Johannesburg, South Africa.

Science.gov (United States)

Naicker, Nisha; Teare, June; Balakrishna, Yusentha; Wright, Caradee Yael; Mathee, Angela

2017-11-18

Ambient and indoor temperature affects thermal comfort and human health. In a changing climate with a predicted change in temperature extremes, understanding indoor temperatures, both hot and cold, of different housing types is important. This study aimed to assess the hourly, daily and monthly variation in indoor temperatures in different housing types, namely formal houses, informal houses, flats, government-built low-cost houses and old, apartheid era low-cost housing, in five impoverished urban communities in Johannesburg, South Africa. During the cross-sectional survey of the Health, Environment and Development study data loggers were installed in 100 homes (20 per suburb) from February to May 2014. Indoor temperature and relative humidity were recorded on an hourly basis. Ambient outdoor temperatures were obtained from the nearest weather station. Indoor and outdoor temperature and relative humidity levels were compared; and an inter-comparison between the different housing types were also made. Apparent temperature was calculated to assess indoor thermal comfort. Data from 59 retrieved loggers showed a significant difference in monthly mean indoor temperature between the five different housing types ( p informal settlement houses had the greatest variation in temperature and experienced temperatures between 4 and 5 °C warmer than outdoor temperatures. Housing types occupied by poor communities experienced indoor temperature fluctuations often greater than that observed for ambient temperatures. Families living in government-built low-cost and informally-constructed homes are the most at risk for indoor temperature extremes. These types of housing should be prioritised for interventions aimed at assisting families to cope with extreme temperatures, gaining optimal thermal comfort and preventing temperature-related health effects.

Indoor Temperatures in Low Cost Housing in Johannesburg, South Africa

Directory of Open Access Journals (Sweden)

Nisha Naicker

2017-11-01

Full Text Available Ambient and indoor temperature affects thermal comfort and human health. In a changing climate with a predicted change in temperature extremes, understanding indoor temperatures, both hot and cold, of different housing types is important. This study aimed to assess the hourly, daily and monthly variation in indoor temperatures in different housing types, namely formal houses, informal houses, flats, government-built low-cost houses and old, apartheid era low-cost housing, in five impoverished urban communities in Johannesburg, South Africa. During the cross-sectional survey of the Health, Environment and Development study data loggers were installed in 100 homes (20 per suburb from February to May 2014. Indoor temperature and relative humidity were recorded on an hourly basis. Ambient outdoor temperatures were obtained from the nearest weather station. Indoor and outdoor temperature and relative humidity levels were compared; and an inter-comparison between the different housing types were also made. Apparent temperature was calculated to assess indoor thermal comfort. Data from 59 retrieved loggers showed a significant difference in monthly mean indoor temperature between the five different housing types (p < 0.0001. Low cost government-built houses and informal settlement houses had the greatest variation in temperature and experienced temperatures between 4 and 5 °C warmer than outdoor temperatures. Housing types occupied by poor communities experienced indoor temperature fluctuations often greater than that observed for ambient temperatures. Families living in government-built low-cost and informally-constructed homes are the most at risk for indoor temperature extremes. These types of housing should be prioritised for interventions aimed at assisting families to cope with extreme temperatures, gaining optimal thermal comfort and preventing temperature-related health effects.

Indoor air quality

International Nuclear Information System (INIS)

Hollowell, C.D.

1981-06-01

Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced ventilation in buildings may significantly increase exposure to indoor air pollution and perhaps have adverse effects on occupant health and comfort. Preliminary findings suggest that reduced ventilation may adversely affect indoor air quality unless appropriate control strategies are undertaken. The strategies used to control indoor air pollution depend on the specific pollutant or class of pollutants encountered, and differ somewhat depending on whether the application is to an existing building or a new building under design and construction. Whenever possible, the first course of action is prevention or reduction of pollutant emissions at the source. In most buildings, control measures involve a combination of prevention, removal, and suppression. Common sources of indoor air pollution in buildings, the specific pollutants emitted by each source, the potential health effects, and possible control techniques are discussed

Exposure to ultrafine particles in relation to indoor events and dwelling characteristics

DEFF Research Database (Denmark)

Spilak, Michal; Frederiksen, Marie; Kolarik, Barbara

2014-01-01

Exposure to ultrafine particles (UFP) in homes is associated with health risks such as cardiovascular disease and/or respiratory problems. These risks are heightened by the long time that people spend indoors. Therefore reducing the particle concentration in homes leads to improved health among its....... Furthermore, the winter season was associated significantly with high UFP levels indoors. Results of our study also indicated that owning a pet, wood-type floors and floor levels close to the ground are associated with increased UFP levels....

Impacts of Mixing on Acceptable Indoor Air Quality in Homes

Energy Technology Data Exchange (ETDEWEB)

Sherman, Max H.; Walker, Iain I.

2010-01-01

Ventilation reduces occupant exposure to indoor contaminants by diluting or removing them. In a multi-zone environment such as a house, every zone will have different dilution rates and contaminant source strengths. The total ventilation rate is the most important factor in determining occupant exposure to given contaminant sources, but the zone-specific distribution of exhaust and supply air and the mixing of ventilation air can play significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage, air distribution system, and contaminant source and occupant locations. Most U.S. and Canadian homes have central heating, ventilation, and air conditioning systems, which tend to mix the air; thus, the indoor air in different zones tends to be well mixed for significant fractions of the year. This article reports recent results of investigations to determine the impact of air mixing on exposures of residential occupants to prototypical contaminants of concern. We summarize existing literature and extend past analyses to determine the parameters than affect air mixing as well as the impacts of mixing on occupant exposure, and to draw conclusions that are relevant for standards development and for practitioners designing and installing home ventilation systems. The primary conclusion is that mixing will not substantially affect the mean indoor air quality across a broad population of occupants, homes, and ventilation systems, but it can reduce the number of occupants who are exposed to extreme pollutant levels. If the policy objective is to minimize the number of people exposed above a given pollutant threshold, some amount of mixing will be of net benefit even though it does not benefit average exposure. If the policy is to minimize exposure on average, then mixing air in homes is detrimental and should not be encouraged. We also conclude that most homes in the US have adequate mixing

Tetrabromobisphenol A in Indoor Dust from Houses and Internet Cafes

Directory of Open Access Journals (Sweden)

Ma. Pythias B. Espino

2011-12-01

Full Text Available Tetrabromobisphenol A or TBBPA is a widely used brominated flame retardant in modern materials such as electronic products, plastics and building materials. TBBPA can leach out of flame retardant-treated products during production, use, reuse, and final disposal of these consumer products. It has thus become a contemporary environmental contaminant. This study reports the levels of TBBPA in indoor dust from houses (n=4 and internet cafes (n=5 in Angono and Quezon City, in the Philippines. TBBPA in indoor dust was analyzed by ultrasonication-assisted hexane extraction and HPLC-UV determination. The instrument and method detection limits were 0.004 ng uL-1 and 1275 ng g-1, respectively. The standard calibration solutions ranged from 0.03 to 0.30 ng uL-1 (r2=0.9956. The extraction recovery was 78% (n=3. TBBPA was found in six of the nine indoor dust samples studied where the concentrations ranged from not detected to 4916 ng g-1. The occurrence and levels of TBBPA in indoor dusts are significant and suggest the need for further investigations especially in other microenvironments where people may be exposed to this contaminant.

A New Indoor Positioning System Architecture Using GPS Signals.

Science.gov (United States)

Xu, Rui; Chen, Wu; Xu, Ying; Ji, Shengyue

2015-04-29

The pseudolite system is a good alternative for indoor positioning systems due to its large coverage area and accurate positioning solution. However, for common Global Positioning System (GPS) receivers, the pseudolite system requires some modifications of the user terminals. To solve the problem, this paper proposes a new pseudolite-based indoor positioning system architecture. The main idea is to receive real-world GPS signals, repeat each satellite signal and transmit those using indoor transmitting antennas. The transmitted GPS-like signal can be processed (signal acquisition and tracking, navigation data decoding) by the general receiver and thus no hardware-level modification on the receiver is required. In addition, all Tx can be synchronized with each other since one single clock is used in Rx/Tx. The proposed system is simulated using a software GPS receiver. The simulation results show the indoor positioning system is able to provide high accurate horizontal positioning in both static and dynamic situations.

Indoor radon variations in central Iran and its geostatistical map

Science.gov (United States)

Hadad, Kamal; Mokhtari, Javad

2015-02-01

We present the results of 2 year indoor radon survey in 10 cities of Yazd province in Central Iran (covering an area of 80,000 km2). We used passive diffusive samplers with LATEX polycarbonate films as Solid State Nuclear Track Detector (SSNTD). This study carried out in central Iran where there are major minerals and uranium mines. Our results indicate that despite few extraordinary high concentrations, average annual concentrations of indoor radon are within ICRP guidelines. When geostatistical spatial distribution of radon mapped onto geographical features of the province it was observed that risk of high radon concentration increases near the Saqand, Bafq, Harat and Abarkooh cities, this depended on the elevation and vicinity of the ores and mines.

Accurate measurement of indoor radon concentration using a low-effective volume radon monitor

International Nuclear Information System (INIS)

Tanaka, Aya; Minami, Nodoka; Mukai, Takahiro; Yasuoka, Yumi; Iimoto, Takeshi; Omori, Yasutaka; Nagahama, Hiroyuki; Muto, Jun

2017-01-01

AlphaGUARD is a low-effective volume detector and one of the most popular portable radon monitors which is currently available. This study investigated whether AlphaGUARD can accurately measure the variable indoor radon levels. The consistency of the radon-concentration data obtained by AlphaGUARD is evaluated against simultaneous measurements by two other monitors (each ∼10 times more sensitive than AlphaGUARD). When accurately measuring radon concentration with AlphaGUARD, we found that the net counts of the AlphaGUARD were required of at least 500 counts, <25% of the relative percent difference. AlphaGUARD can provide accurate measurements of radon concentration for the world average level (∼50 Bq m -3 ) and the reference level of workplace (1000 Bq m -3 ), using integrated data over at least 3 h and 10 min, respectively. (authors)

Radon gas exposure levels in some selected areas in Egypt

International Nuclear Information System (INIS)

Ali, E.M.; Taha, T.M.; Gomaa, M.A.; El-Hussein, A.M.; Ahmed, A.A.

2005-01-01

During a summer season of 2003, the atmospheric concentrations of radon gas were measured indoor every one-hour for twenty-four hour measurements in some selected areas, using Pylon-AB4. Two hundreds and forty samples were monitored to determine the concentration of radon gas at each location using high-efficiency Lucas type continuous passive cell. The average values of radon gas concentration were taken in three time intervals 6.00:18.00, 18.00:6.00 and whole day. The average values of indoor radon gas of two locations using three time intervals were 4.82±0.63, 9±0.71 and 6.9±0.33 and 9.6±0.23, 11.82±0.42 and 9.37±0.7 Bq/m /h. respectively. The exposure levels were within the ICRP and EPA recommendations

An indoor radon survey of the X-ray rooms of Mexico City hospitals

Energy Technology Data Exchange (ETDEWEB)

Juarez, Faustino [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100. Estado de Mexico, 50000, Mexico. Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Circuito (Mexico); Reyes, Pedro G. [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario No. 100. Estado de Mexico, 50000 (Mexico); Espinosa, Guillermo [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria, Mexico D.F. Cp.04510 (Mexico)

2013-07-03

This paper presents the results of measurements of indoor radon concentrations in the X-ray rooms of a selection of hospitals in the metropolitan area of Mexico City. The metropolitan area of Mexico City is Mexico's largest metropolitan area by population; the number of patients requiring the use of X-rays is also the highest. An understanding of indoor radon concentrations in X-ray rooms is necessary for the estimation of the radiological risk to which patients, radiologists and medical technicians are exposed. The indoor radon concentrations were monitored for a period of six months using nuclear track detectors (NTD) consisting of a closed-end cup system with CR-39 (Lantrack Registered-Sign ) polycarbonate as detector material. The indoor radon concentrations were found to be between 75 and 170 Bq m{sup -3}, below the USEPA-recommended indoor radon action level for working places of 400 Bq m{sup -3}. It is hoped that the results of this study will contribute to the establishment of recommended action levels by the Mexican regulatory authorities responsible for nuclear safety.

Determining the ventilation and aerosol deposition rates from routine indoor-air measurements.

Science.gov (United States)

Halios, Christos H; Helmis, Costas G; Deligianni, Katerina; Vratolis, Sterios; Eleftheriadis, Konstantinos

2014-01-01

Measurement of air exchange rate provides critical information in energy and indoor-air quality studies. Continuous measurement of ventilation rates is a rather costly exercise and requires specific instrumentation. In this work, an alternative methodology is proposed and tested, where the air exchange rate is calculated by utilizing indoor and outdoor routine measurements of a common pollutant such as SO2, whereas the uncertainties induced in the calculations are analytically determined. The application of this methodology is demonstrated, for three residential microenvironments in Athens, Greece, and the results are also compared against ventilation rates calculated from differential pressure measurements. The calculated time resolved ventilation rates were applied to the mass balance equation to estimate the particle loss rate which was found to agree with literature values at an average of 0.50 h(-1). The proposed method was further evaluated by applying a mass balance numerical model for the calculation of the indoor aerosol number concentrations, using the previously calculated ventilation rate, the outdoor measured number concentrations and the particle loss rates as input values. The model results for the indoors' concentrations were found to be compared well with the experimentally measured values.

Spatial subdivision of complex indoor environments for 3D indoor navigation

NARCIS (Netherlands)

Diakite, A.A.; Zlatanova, S.

2018-01-01

As we realize that we spend most of our time in increasingly complex indoor environments, applications to assist indoor activities (e.g. guidance) have gained a lot of attention in the recent years. The advances in ubiquitous computing made possible the development of several spatial models

Exoskeletons and economics: indoor arthropod diversity increases in affluent neighbourhoods.

Science.gov (United States)

Leong, Misha; Bertone, Matthew A; Bayless, Keith M; Dunn, Robert R; Trautwein, Michelle D

2016-08-01

In urban ecosystems, socioeconomics contribute to patterns of biodiversity. The 'luxury effect', in which wealthier neighbourhoods are more biologically diverse, has been observed for plants, birds, bats and lizards. Here, we used data from a survey of indoor arthropod diversity (defined throughout as family-level richness) from 50 urban houses and found that house size, surrounding vegetation, as well as mean neighbourhood income best predict the number of kinds of arthropods found indoors. Our finding, that homes in wealthier neighbourhoods host higher indoor arthropod diversity (consisting of primarily non-pest species), shows that the luxury effect can extend to the indoor environment. The effect of mean neighbourhood income on indoor arthropod diversity was particularly strong for individual houses that lacked high surrounding vegetation ground cover, suggesting that neighbourhood dynamics can compensate for local choices of homeowners. Our work suggests that the management of neighbourhoods and cities can have effects on biodiversity that can extend from trees and birds all the way to the arthropod life in bedrooms and basements. © 2016 The Authors.

Graph Model Based Indoor Tracking

DEFF Research Database (Denmark)

Jensen, Christian Søndergaard; Lu, Hua; Yang, Bin

2009-01-01

The tracking of the locations of moving objects in large indoor spaces is important, as it enables a range of applications related to, e.g., security and indoor navigation and guidance. This paper presents a graph model based approach to indoor tracking that offers a uniform data management...

Ventilation, indoor air quality, and health in homes undergoing weatherization.

Science.gov (United States)

Francisco, P W; Jacobs, D E; Targos, L; Dixon, S L; Breysse, J; Rose, W; Cali, S