重庆市主城区室内氡浓度调查与评价

根据重庆市城市组团式建设特点,采用径迹法对重庆市主城建成区开展室内氡浓度调查。结果表明,各区县室内氡浓度整体水平较低,重庆市主城区室内氡浓度平均值为64.5 Bq/m3,168个采样点均小于国家标准200 Bq/m3;吸入氡及子体对人员产生的年均有效剂量均低于《住房内氡浓度控制标准》和《地下建筑氡及其子体控制标准规定》中规定的室内氡浓度行动水平。     

贵阳室内氡时空分布特征研究

为了全面分析室内氡的时空分布特征、来源和影响因素,选择了贵阳市不同地理位置的居民住宅、办公场所和公共场所,进行了为期一年的室内氡监测。贵阳市室内氡的平均浓度为(72.7±1.6)Bq/m3,低于室内空气污染国家标准,达标率98.5%。其中居民住宅、办公场所和公共场所的室内氡浓度分别为(93.46±86.93)、(74.68±40.74)、(61±26.93)Bq/m3。研究表明,室内涂料、装修程度和通风效果、小区环境等对室内氡浓度高低有显著影响,室内氡也随季节变化而发生波动。对于居民住宅和公共场所氡的室内外来源相对重要性不同。居民住宅内新楼和旧楼不同楼层室内氡的来源、影响因素和分布特征有显著差异。     

Indoor radon measurement and effective dose assessment of 150 apartments in Mashhad,Iran

Environmental monitoring and indoor radon measurement are important for public health, to estimate the cancer risk of respiratory system and, if necessary, to suggest proper methods that reduce indoor radon level. In this research, indoor radon concentration in the air has been measured in 150 apartments in Mashhad city. The result demonstrates about 94.7% of apartments have radon concentration less than 100 Bq/m³, taken by WHO as the action level, and 5.3% have the concentration higher than this level. As well as, annual radon dose has been assessed using the equation for annual effective dose calculation introduced by United Nations Scientific Committee on the Effects of Atomic Radiation.     

Personal, indoor, and outdoor exposure to VOCs in the immediate vicinity of a local airport

This study measures the effect of emissions from an airport on the air quality of surrounding neighborhoods. The ambient concentrations of benzene, toluene, ethylbenzene, and o-, m-, and p-xylene (BTEX) were measured using passive samplers at 15 households located close to the airport (indoor, outdoor, and personal), at the end of airport runways and an out-of-neighborhood location. Measurements occurred over a 48-h period during summer 2006 and winter 2006?C2007. The average concentrations were 0.84, 3.21, 0.30, 0.99, and 0.34 ??g/m³ at the airport runways and 0.84, 3.76, 0.39, 1.22, and 0.39 ??g/m³ in the neighborhood for benzene, toluene, ethylbenzene, m-, p-, and o-xylene. The average neighborhood concentrations were not significantly different to those measured at the airport runways and were higher than the out-of-neighborhood location (0.48, 1.09, 0.15, 0.78, and 0.43 ??g/m³, each BTEX). B/T ratios were used as a tracer for emission sources and the average B/T ratio at the airport and outdoors were 0.20 and 0.23 for the summer and 0.40 and 0.42 for the winter, suggesting that both areas are affected by the same emission source. Personal exposure was closely related to levels in the indoor environment where subjects spent most of their time. Indoor/outdoor (I/O) ratios for BTEX ranged from 1.13 to 2.60 and 1.41 to 3.02 for summer and winter. The seasonal differences in I/O ratios reflected residential ventilation patterns, resulting in increased indoor concentrations of volatile organic compounds during winter.     

Levels, sources, and health risks of carbonyls in residential indoor air in Hangzhou, China

Concentrations of formaldehyde, acetaldehyde, acetone, propionaldehyde, i-pentanal, and butyraldehyde in residential indoor air in Hangzhou were determined. The mean concentration of the total carbonyl compounds in summer was 222.6 μg/m³, higher than that in winter (68.5 μg/m³). The concentration of a specific carbonyl in indoor air was higher than the outdoor air measurement, indicating the release of carbonyls from the indoor sources. Formaldehyde and acetone were the most abundant carbonyls detected in summer and winter, respectively. Multiple regression analysis indicated that carbonyl concentrations in residential indoor air depended on the age of decoration and furniture, as well as their concentrations in outdoor air. In addition, a primary estimation showed that the health risks of carbonyls in summer were higher than those in winter.     

Nitrous acid concentrations in homes and offices in residential areas in Greater Cairo

Indoor and outdoor measurements of nitrous acid and nitrogen dioxide were conducted at four homes and two offices in residential areas in Greater Cairo during winter (2000-2001) and summer (2001) seasons. Indoor nitrogen dioxide concentrations were higher than outdoor levels at the four homes, whereas indoor concentrations of nitrogen dioxide were lower than outdoor levels at the two offices, during both seasons. Indoor nitrous acid concentrations were higher than outdoor levels at all homes and offices during the period of study. The mean indoor nitrous acid concentrations were 6.8 ppb and 3.67 ppb in the four homes, whereas they were 1.42 ppb and 1.24 ppb in the two offices, during the winter and summer seasons, respectively. Indoor/outdoor ratios of nitrous acid concentration were 6.94 in the winter and 5.03 in the summer for all of the homes. However, the ratios were 1.31 and 1.61 during the winter and summer seasons, respectively, for the two offices. Insignificant positive correlation coefficients were found between indoor and outdoor concentrations of nitrous acid at homes and offices. The maximum outdoor nitrous acid concentrations were recorded during the winter season. Significant positive correlation coefficients were found between nitrous acid and nitrogen dioxide and relative humidity in homes and offices. The ratios of nitrous acid to nitrogen dioxide concentrations ranged from 0.045 to 0.16, with a mean of 0.1, in the four homes, whereas the ratios ranged from 0.026 to 0.09, with a mean of 0.059, in the two offices.     

PM10 Particulates in Relation to Other Atmospheric Pollutants

Concentrations of PM10 particulates have been compared to the concentrations of oxides of nitrogen and sulphur dioxide at the fourteen Automatic Urban Monitoring Network (AUN) sites operating during 1993, 1994 and 1995 using fully ratified data.Factors which are considered include diurnal variations in concentrations of the various substances, ratios between concentrations of PM10 and the other substances and differences between relationships in summer and winter and between weekdays and weekends. In addition temporal patterns of concentrations are considered. Variations between different cities is demonstrated. Differences in the seasonal size distribution are identified. It is shown that there is a good degree of consistency in concentrations of PM10 across urban areas at background locations and that there is evidence for long range transport of PM10.     

不同天气形势下杭州市空气污染特征个例分析

利用杭州市气象局观测资料、NCEP再分析资料和中尺度天气预报模式WRF的数值模拟结果,对杭州市2011—2012年春、夏、秋、冬4个季节各一天的污染天气进行分析;同时选取2012年夏季有利于污染物扩散的天气个例进行对比分析。结果表明,杭州市容易发生轻度污染的天气类型主要有4类:高压前部、高压底部、高压控制和高压后部;500 h Pa高空系统稳定,受西南气流影响,850 h Pa有暖平流,1 000 h Pa风速较小时,容易造成污染物的积累,发生空气污染现象。WRF模拟结果显示,当杭州市为偏北风且风速较小时,容易发生空气污染事件,当为偏南风且风速较大时,空气质量一般较好。温度层结分析发现,当近地层以及高空出现较为深厚的逆温层且低层温度层结呈现中性或者稳定时,不利于污染物的扩散,污染物容易在底层积累,出现近地层空气污染现象。     

Indoor radon/thoron levels and inhalation doses to some populations in Himachal Pradesh, India

It is well established that some areas of Himachal Pradesh (H.P.) state of India situated in the environs of the Himalayan mountains are relatively rich in uranium-bearing minerals. Some earlier studies by our group have indicated high levels of radon (>200 Bq m(-3)) in the dwellings. It is in this context that an indoor radon/thoron survey has been carried out in selected villages of four districts in the state of H.P. This survey has been conducted as a part of a national, coordinated project using twin chamber dosemeter cups designed by the Environmental Assessment Division (EAD), Department of Atomic Energy, Govt. of India. The track-etch technique is used for calibration of plastic detector LR-115 type-II which are employed for recording alpha tracks due to radon/thoron and their daughters. Year long radon/thoron data have been collected for seasonal correlations of indoor radon/thoron in the dwellings. The indoor radon levels have been found to vary from a minimum value of 17.4 Bq m(-3) to a maximum value of 140.3 Bq m(-3). The indoor thoron levels vary from a minimum value of 5.2 Bq m(-3) to a maximum value of 131.9 Bq m(-3). The year average dose rate for the local population varies from 0.03 microSv h(-1) to 0.83 microSv h(-1). The annual exposure dose to inhabitants in all the dwellings lies below the upper limit of 10 mSv given in ICRP-65.     

Outdoor-indoor air quality in Riyadh: SO2, NH3, and HCHO

A funded research project was conducted during the period July1992 through November 1994. The project was designed to evaluateindoor and ambient air quality in and around buildings of different types and uses in Riyadh, the capital of Saudi Arabia.Thirty intercity buildings and two outercity (background) siteswere carefully selected and monitored for air quality. Ten airpollutants, together with relevant meteorological parameters, were monitored indoor and outdoor at each site continuously andsimultaneously for a period of two weeks covering summer and winter seasons.This article discusses the results obtained for sulfur dioxide (SO₂), ammonia (NH₃) and formaldehyde (HCHO). Results of this investigation revealed that most sites had on the averageexceeded the recommended standards for SO₂ and NH₃ bothindoor and outdoor, with indoor levels being worse than outdoorduring winter time. Several sites also showed high levels of HCHO, with outdoor levels being consistently higher than indoor.Statistical and frequency analyses were performed on the collected data, showing seasonal and sector by sector variability, and outdoor-indoor correlations.     

Assessing radon concentrations in areas with few measurements

The New York State Department of Health has estimated and mappedradon concentrations for every town and city in the State. Sincefor many towns there are few indoor radon measurements, the radonestimates for these towns were determined using correlations to surficial geology. A project was conducted to target towns for additional measurements that currently have few data but, based on the surficial geology of the town, are estimated to have elevated levels of indoor radon. The objective of the project wasto obtain at least 30 additional measurements for the targeted towns and to compare the measurement results with the estimates based on geology. The study completed 1606 radon measurements from 9080 detector applications mailed to home owners in 94 underserved towns spread throughout the State. Of the 1115 basement measurements, 43% exceeded 148 Bq m^-3, with a maximum of 6900 Bq m^-3. Three homes measured in one town hadradon concentrations above 2900 Bq m^-3. Of the 491 living-area measurements, 19% exceeded 148 Bq m^-3, with a maximum of 2700 Bq m^-3. About 60% and 86% of measurementresults were within one standard deviation and a factor of two,respectively, of estimated concentrations. Results indicate thatregardless of the magnitude of radon potential, the estimates arein good agreement with measured concentrations.     

郑州市大气环境中半挥发性有机污染物分布规律研究

在郑州市交通密集区、工业区、居民文化区等不同功能区设置监测点位,分春、夏、秋、冬4季对大气环境中半挥发性有机污染物的污染状况进行初步研究。结果表明:不同季节半挥发性有机物检出数量的变化趋势为:冬季秋季春季夏季;不同功能区SVOC检出数量变化趋势为:交通密集区工业区混合区文化区对照区。     

Study of personal exposure to airborne respirable particles and carbon monoxide

Simultaneous measurements of CO and respirable particles (RP) at outdoor network stations and of personal exposure in a sample of twelve volunteers were carried out during the winter and summer season of 1980/81 in order to evaluate how well personal exposure can be assessed from outdoor network station data.The results have shown that personal exposure of our subjects to both CO and RP is in best correlation with exposure at home where subjects spend in the average nearly 70% of their time. While personal exposure to CO can hardly be related to outdoor CO levels, personal exposure to RP is in fair agreement with simultaneously measured outdoor concentrations in winter (but not in summer). A large intercept on WAE axis of the WAE/RP relationship indicates that a considerable part of personal exposure to RP should be attributed to particles which are not of indoor origin. This part does not follow the seasonal and day-to-day changes in outdoor RP concentration and causes a negative, but highly significant correlation between WAE/RP ratio and RP.     

Analysis of the air pollution climate at a background site in the Po valley

The Po valley in northern Italy is renowned for its high air pollutant concentrations. Measurements of air pollutants from a background site in Modena, a town of 200 thousand inhabitants within the Po valley, are analysed. These comprise hourly data for CO, NO, NO(2), NO(x), and O(3), and daily gravimetric equivalent data for PM(10) from 1998-2010. The data are analysed in terms of long-term trends, annual, weekly and diurnal cycles, and auto-correlation and cross-correlation functions. CO, NO and NO(2) exhibit a strongly traffic-related pattern, with daily peaks at morning and evening rush hour and lower concentrations over the weekend. Ozone shows an annual cycle with a peak in July due to local production; notwithstanding the diurnal cycle dominated by titration by nitrogen oxide, the decreasing long term trend in NO concentration did not affect the long term trend in O(3), whose mean concentration remained steady over the sampling period. PM(10) shows a strong seasonality with higher concentration in winter and lower concentration in summer and spring. Both PM(10) and ozone show a marked weekly cycle in summer and winter respectively. Regressions of PM(10) upon NO(x) show a consistently greater intercept in winter, representing higher secondary PM(10) in the cooler months of the year. There is a seasonal pattern in primary PM(10) to NO(x) ratios, with lower values in winter and higher values in summer, but the reasons are unclear.     

Radon risk assessment: The effect of voluntary sampling distributions and bias

This paper examines the problem of estimating indoor radon concentrations for radon-induced lung cancer risk assessment. Previous authors have identified various problems and possible corrections for the use of generally available radon screening measurements. Bias evident in data collected from volunteers is described; regional databases developed from voluntary data generally exhibit higher mean values than those obtained from random samples. Tools are developed to better characterize the differences in voluntary and random concentration distributions. Application is demonstrated using voluntary and random radon survey data for the state of North Dakota.     

Indoor concentrations of carbon monoxide in selected urban microenvironments

CO concentrations were measured in five kindergartens, one children's hospital and two homes for aged, practically without indoor sources, all situated in the city centre, for ten random days in winter and ten in summer. The indoor CO concentrations were the result of the distance from and the traffic density in the nearest street, of general pollution level, seasonal differences, day-to-day variations and daily cycle of air pollution, the vicinity of traffic having a dominant influence. Therefore location of institutions for sensitive population groups in old city centres within a block of houses seems to be a suitable solution as far as exposure to CO is concerned.Revised version of a paper presented as poster at the VIth World Congress on Air Quality, Paris 1983.     

垃圾填埋场不同区域挥发性有机污染物季节变化特点

通过对北京某垃圾填埋场大气中不同区域挥发性有机污染物(VOCs)的定性和定量分析,研究了其中部分VOCs的季节性特点和浓度分布规律。结果表明,夏、冬2季分别检测出98种和86种化合物,有12种美国环保署(USEPA)优先控制污染物在夏、冬季样品中均有检出。夏季样品中VOCs的浓度大多比冬季高,有的甚至高1个数量级以上。采用不同卫生填埋技术的各代表性区域的臭气浓度也呈现出规律性变化。为加强科学管理,减少扩散,降低风险提供参考。     

Indoor air quality assessment in child care and medical facilities in Korea

In order to characterize the status of indoor air pollution in some important facilities, a list of key criteria pollutants [particulate matter (PM(10)), carbon dioxide (CO(2)), carbon monoxide (CO), formaldehyde (HCHO), and bioaerosol] was measured from a total of 91 randomly selected sites in 18 different cities, Korea (February 2006 to December 2009). The target facilities include 43 child care facilities, 38 medical facilities, 6 elementary schools, and 4 postnatal care centers. The results showed that some air pollutants (e.g., CO and HCHO) did not exceed the recommended guideline [e.g., the Korean indoor air standard (KIAS) values of 10 ppm and 100 ppb, respectively]. However, concentration of PM(10), CO(2), and bioaerosol occasionally exceeded their respective guidelines (e.g., seven, three, and two cases). Discrete seasonalities were observed from indoor pollutants because of varying ventilation practice (e.g., summer time dominance of PM(10), HCHO, and bioaerosol or winter dominance of CO(2) and CO). However, as the concentrations of the indoor pollutants were scarcely above the recommended guideline level, more diversified approaches are desirable to diagnose the status of indoor pollution and to provide a realistic strategy for the improvement of IAQ.     

基于后向轨迹模式的区域大气污染及传输特征分析

选取南京市2017年PM2.5逐时观测数据,分析其颗粒物污染特征,并利用聚类分析、潜在源贡献因子法和GDAS气象数据,分析不同高度、季节下南京市主要气流输送路径及PM2.5污染的主要潜在源区。结果表明：南京市PM2.5污染冬季最严重,夏季最轻,逐时PM2.5浓度变化范围夏季小于冬季;夏季气流轨迹主要来自东南方向,秋冬春等季节以偏西和西北路径为主,且随着高度的增加,气流输送速度逐渐加快;冬季对南京市PM2.5污染的贡献最为显著,低层PM2.5污染贡献源区主要集中在近地区域,且贡献率较高,随着高度的增加,贡献源区由研究区域向四周辐散,贡献范围广,贡献率降低。     

A Quantile Regression Approach to Evaluate Factors Influencing Residential Indoor Radon Concentration

Indoor radon concentrations depend on building characteristics such as building materials, ventilation and water supply. In this paper, a quantile regression approach is proposed to evaluate the effect of some buildings factors potentially influencing indoor radon concentration. Many of the considered factors, such as soil connection, age of construction and being a single family building, are found to have a statistically significant effect; however, this is far from being constant across the entire support of indoor radon concentration. A potential impact due to geological and geo-physical reasons is also found using the altitude of building locations as a surrogate variable. In addition, a clear local spatial effect is detected by a spatial autoregression approach.