北京市三城区室内空气污染水平的初步研究

目的 探讨室内空气污染的影响因素。方法 在空气污染物监测和流行病学调查的基础上,于2001年1月～3月在北京市选取了东城、石景山、海淀3个城区,以整群抽样的方法每区随机选取各70户居民点,对每户卧室和厨房的PM10、PM2.5、SO2的室内平均浓度做了监测,并以统一调查问卷将监测结果和采样点环境条件做了记录。结果 颗粒物在三城区冬季室内总平均浓度PM10为0.555mg/m3、PM2.5为0.512mg/m3,SO2总平均浓度为0.052mg/m3,低于国家规定标准。颗粒物在各区卧室和厨房中的浓度分布均超过国家卫生标准且卧室和厨房差异无显著性。SO2平均浓度在东城和海淀区厨房和卧室中的平均浓度差异有显著性,厨房高于卧室（P <0.05）,并高于国家居室卫生标准的要求。结论北京冬季居民住宅室内PM10和PM2.5污染对居民健康构成一定威胁。     

2010年北京市归因于大气PM2.5污染的过早死亡研究

目的 评估大气PM2.5长期暴露导致的过早死亡,为科学制定政策保护人群健康提供科学依据.方法 收集卫星遥感反演的北京市2010年的PM2.5浓度数据、人口数据、基线死亡率等基础数据,利用GIS空间统计工具将网格化的PM2.5污染数据转换为区县尺度数据,基于WHO的经典全球疾病负担评估模型和PM25全暴露范围RR函数表,评估北京市各区县归因于大气PM2.5污染的过早死亡,并探讨其空间分布特征及分疾病种类的特点.结果 2010年北京市各区县的大气PM25年均浓度均超过GB 3095-2012《环境空气质量标准》二级浓度限值(35 μg/m3);北京市归因于大气PM:5污染的过早死亡数为16 527人,归因死亡率为0.843‰,中心城区和东南部郊区的过早死亡风险较高,过早死亡数最多的为朝阳区(5 648人,归因死亡率为1.542‰)和海淀区(4 21 1人,归因死亡率为1.284‰),过早死亡数最少的为西北部郊区.结论北京市2010年归因于大气PM2.5污染的过早死亡人数较多,应引起相关部门的重视;在制定政策减少归因于大气PM2.5污染的过早死亡时,应重点关注人口密集的中心城区和发展较快的东南部郊区,并基于各区县过早死亡的疾病分布特点开展针对性的宣教和防控.     

北京市大气污染与城区居民死亡率关系的时间序列分析

为定量评价北京市大气污染对居民每日疾病死亡率的影响 ,运用时间 -序列分析方法 ,控制了流感、季节等混杂因素的影响后 ,对北京市主要大气污染物CO、SO2 、NOX、TSP、PM10 与居民相应疾病死亡率的相关关系进行了定量评价。以呼吸系统疾病、循环系统疾病、冠心病、慢性阻塞性肺病和消化系统肿瘤疾病死亡人数分别为因变量 ,大气污染物浓度和平均温度、湿度为自变量 ,进行了泊松回归分析。单变量分析结果表明 ,除TSP对冠心病死亡率的影响无显著意义外 ,大气中CO、SO2 、NOX 、TSP浓度与呼吸系统、心脑血管疾病、慢性阻塞性肺病和冠心病死亡率之间的正相关关系均有显著意义 ,而多因素泊松回归得到的暴露 -反应关系模型显示 ,SO2 浓度每提高 10 0 μg m3,呼吸系统、循环系统、冠心病和慢性阻塞性肺病疾病死亡率分别增加 4 2 1%、3 97%、10 68%和 19 2 2 % ;总悬浮颗粒物每增加 10 0 μg m3 ,呼吸系统疾病死亡率增加 3 19% ,循环系统死亡率增加 0 62 %。提示大气污染物浓度的升高会引起相应疾病死亡率的增加     

2015-2019年兰州市两区大气细颗粒物及其化学成分变化趋势

目的 分析兰州市两区2015-2019年大气细颗粒物(fine particulate matter,PM2.5)浓度及其化学成分变化趋势.方法 于2015年1月至2019年12月在兰州市选择住宅区代表城关区和工业区代表西固区2个采样点,采集大气细颗粒物样品,检测其质量浓度、金属和类金属元素、水溶性离子及多环芳烃(po...     

Children's respiratory morbidity prevalence in relation to air pollution in four Chinese cities

We examined respiratory health effects of long-term exposure to ambient air pollution in 7,621 schoolchildren residing in eight districts of four Chinese cities. The four cities exhibited wide between-city and within-city gradients in ambient levels of four size fractions of particulate matter [less than or equal to 2.5 micro m in aerodynamic diameter (PM(2.5)), between 2.5 and 10 micro m (PM(10-2.5)), less than or equal to 10 micro m (PM(10)), and total suspended particulates (TSP)] and two gaseous pollutants (SO(2) and NO(x)). Informed consent and written responses to questionnaires about children's personal, residential, and family information, as well as their health histories and status, were obtained with the help of the parents and the school personnel. We used a two-stage regression approach in data analyses. In the first-stage logistic regressions, we obtained logits of district-specific prevalence of wheeze, asthma, bronchitis, hospitalization for respiratory diseases, persistent cough, and persistent phlegm, adjusted for covariates representing personal, household, and family parameters. Some of these covariates were found to be risk factors of children's respiratory health, including being younger in the study group, being male, having been breast-fed, sharing bedrooms, sharing beds, room being smoky during cooking, eye irritation during cooking, parental smoking, and a history of parental asthma. In several of the second-stage variance-weighted linear regressions, we examined associations between district-specific adjusted prevalence rates and district-specific ambient levels of each pollutant. We found positive associations between morbidity prevalence and outdoor levels of PM of all size fractions, but the association appeared to be stronger for coarse particles (PM(10-2.5)). The results also present some evidence that ambient levels of NO(x) and SO(2) were positively associated with children's respiratory symptoms, but the evidence for these two gaseous pollutants appeared to be weaker than that for the PM.     

Personal exposure to particles in Banská Bystrica, Slovakia

Epidemiological studies have associated adverse health impacts with ambient concentrations of particulate matter (PM), though these studies have been limited in their characterization of personal exposure to PM. An exposure study of healthy nonsmoking adults and children was conducted in Banska Bystrica, Slovakia, to characterize the range of personal exposures to air pollutants and to determine the influence of occupation, season, residence location, and outdoor and indoor concentrations on personal exposures. Twenty-four-hour personal, at-home indoor, and ambient measurements of PM10, PM2.5, sulfate (SO4(2-)) and nicotine were obtained for 18 office workers, 16 industrial workers, and 15 high school students in winter and summer. Results showed that outdoor levels of pollutants were modest, with clear seasonal differences: outdoor PM10 summer/winter mean = 35/45 microg/m3; PM2.5 summer/winter mean = 22/32 microg/m3. SO4(2-) levels were low (4-7 microg/m3) and relatively uniform across the different sample types (personal, indoor, outdoor), areas, and occupational groups. This suggests that SO4(2-) may be a useful marker for combustion mode particles of ambient origin, although the relationship between personal exposures and ambient SO4(2-) levels was more complex than observed in North American settings. During winter especially, the central city area showed higher concentrations than the suburban location for outdoor, personal, and indoor measures of PM10, PM2.5, and to a lesser extent for SO4(2-), suggesting the importance of local sources. For PM2.5 and PM10, ratios consistent with expectations were found among exposure indices for all three subject groups (personal>indoor>outdoor), and between work type (industrial>students>office workers). The ratio of PM2.5 personal to indoor exposures ranged from 1.0 to 3.9 and of personal to outdoor exposures from 1.6 to 4.2. The ratio of PM10 personal to indoor exposures ranged from 1.1 to 2.9 and the ratio of personal to outdoor exposures from 2.1 to 4.1. For a combined group of office workers and students, personal PM10/PM2.5 levels were predicted by statistically significant multivariate models incorporating indoor (for PM2.5) or outdoor (for PM10) PM levels, and nicotine exposure (for PM10). Small but significant fractions of the overall variability, 15% for PM2.5 and 17% for PM10, were explained by these models. The results indicate that central site monitors underpredict actual human exposures to PM2.5 and PM10. Personal exposure to SO4(2-) was found to be predicted by outdoor or indoor SO4(2-) levels with 23-71% of the overall variability explained by these predictors. We conclude that personal exposure measurements and additional demographic and daily activity data are crucial for accurate evaluation of exposure to particles in this setting.     

Particulate matter,sulfur dioxide,and daily mortality in Chongqing,China

In 1995, daily mortality in a district of Chongqing, China, was analyzed from January through December for associations with daily ambient sulfur dioxide and fine particles (airborne particles with diameters less than or equal to 2.5 microm; PM2.5. The mean concentration of PM2.5 was 147 microg/m3 (maximum, 666 microg/m3), and that of SO2 was 213 microg/m3 (maximum, 571 microg/m3). On average, 9.6 persons died each day. We used a generalized additive model using robust Poisson regression to estimate the associations of mean daily SO2 and PM2.5 with daily mortality (on the same day and at lags up to 5 days) adjusted for trend, season, temperature, humidity, and day of the week. The relative risk of mortality associated with a 100 microg/m3 increase in mean daily SO2 was highest on the second lag day [1.04; 95% confidence interval (CI), 1.00-1.09] and the third lag day (1.04; 95% CI, 0.99-1.08). The associations between daily mortality and mean daily PM2.5 were negative and statistically insignificant on all days. The relative risk of respiratory mortality on the second day after a 100 microg/m3 increase in mean daily SO2 was 1.11 (95% CI, 1.02-1.22), and that for cardiovascular mortality was 1.10 (95% CI, 1.02-1.20). The relative risk of cardiovascular mortality on the third day after a 100 microg/m3 increase in mean daily SO2 was 1.20 (95% CI, 1.11-1.30). The relative risks of mortality due to cancer and other causes were insignificant on both days. The estimated effects of mean daily SO2 on cardiovascular and respiratory mortality risk remained after controlling for PM2.5.     

2019年西安市两城区PM2.5中多环芳烃污染状况及来源分析

目的 调查西安市两城区大气PM2.5中多环芳烃（PAHs）的污染状况,探讨其污染特征及其主要污染来源。方法 2019年每月10—16日和遇到雾霾天气（AQI>200）连续在西安市雁塔区和莲湖区两个监测点采集大气PM2.5样品,按照HJ 647—2013（《环境空气和废气 气相和颗粒物中 多环芳烃的测定 高效液相色谱法》）检测样品中多环芳烃的含量,采用因子分析法对其主要污染来源进行分析。结果 西安市两个主城区PM2.5质量浓度的中位数为0.053mg/m³,低于国家环境空气质量二级标准,超标率为40.50%（81/200）,莲湖区、雁塔区PM2.5质量浓度中位数分别为0.054mg/m³、0.046mg/m³,超标率分别为42.16%（43/102）、38.78%（38/98）,两个地区间的差异无统计学意义（Z=-1.369,P=0.171）。冬季PM2.5质量浓度最高（0.091mg/m³）,夏季PM2.5质量浓度最低,（0.026mg/m³）,不同季节PM2.5质量浓度存在统计学差异（Z=113.949,P<0.001）。莲湖区PM2.5中多环芳烃含量最高的是苯并［g,h,i］苝,其次是茚并［1,2,3-cd］芘、苯并［b］荧蒽,雁塔区PM2.5中多环芳烃含量最高的是荧蒽、芘、茚并［1,2,3-cd］芘,两个地区多环芳烃各成分差异无统计学意义。因子分析法显示西安市PM2.5中多环芳烃的主要来源是汽车尾气（莲湖区、雁塔区贡献率分别为65.32%、61.38%）、燃煤（莲湖区、雁塔区贡献率分别为9.92%、9.34%）、工业来源（莲湖区、雁塔区贡献率分别为7.92%、8.20%）。结论 2019年西安市大气PM2.5超标较严重,主要污染来源于汽车尾气、燃煤和工业来源的混合型污染。     

广州市交通警察执勤期间大气污染物区域暴露特征初探

[目的]通过监测广州市内外勤交警执勤区域大气污染物浓度,初步研究内外勤交警执勤期间大气污染物的暴露特征和水平,为机动车尾气高暴露人群的生物效应评价技术研究提供现场调查数据。[方法]应用电子分析仪监测广州市内外勤交警执勤区域及内勤交警工作的岑村交警大楼的二氧化氮（NO2）、一氧化碳（CO）、可吸入颗粒物（PM10）、二氧化硫（SO2）等污染物的浓度,计算相关空气质量评价指数。[结果]外勤交警执勤期间暴露的NO2、CO、PM10、SO2的平均浓度分别为（0.34±0.17）、（1.93±2.97）、（0.10±0.05）、（0.49±1.54）mg/m3,大气质量为Ⅴ级,属重污染,NO2和SO2为主要污染物;内勤交警执勤期间暴露的NO2、CO、PM10、SO2的平均浓度分别为（0.08±0.05）、（0.22±0.26）、（0.05±0.05）、（0.02±0.02）mg/m3,大气污染物浓度低于外勤交警（P〈0.01）,大气质量为Ⅱ级,尚清洁,NO2和PM10为主要污染物。[结论]广州市外勤交警执勤期间暴露的主要气态污染物浓度超标,其中以NO2的超标情况最严重,属中重度污染,符合混合型污染的特征;内勤交警大气污染物的暴露浓度低于外勤交警。     

学龄儿童尿中8-羟基脱氧鸟苷水平与交通干道大气污染关系的研究

[目的]探讨健康学龄儿童尿8-羟基脱氧鸟苷（8-OH—dG）水平及其与交通干道大气污染之间的关系。[方法]选择距离交通干道约30m的某小学及符合入选标准的30名学龄儿童作为研究对象。分别于2008年5月份和11月份,在该小学操场的区域监测点各进行1次连续5d的区域氮氧化物（NOx）、SO2、O3、细颗粒物（PM2.5）污染水平检测;对学龄儿童活动点（课堂教学区、课外活动区、家校往返途中）的NO2、SO2、O3扎颗粒物（PM10）污染水平各进行1次连续3d的监测,并对学龄儿童尿液8-OH—dG含量各进行1次检测。[结果]5月份和11月份区域监测结果显示,所测各污染物污染负荷系数最大的为PM2.5和NOx,PM2.5的污染负荷系数分别为0．33和0．27,NOx分别为0．31和0．26。与5月份相比,11月份学龄儿童尿8-OH-dG水平明显升高（P〈0．001）。个体暴露各污染物水平与学龄儿童尿8-OH—dG水平呈正相关,均有统计学意义（P〈0．001）,其中个体暴露PM10与8-OH—dG的回9-3系数最大（βPM10=0．40、βNO2＝0．38、βO3=0．36、βSO2=0．36）。[结论]交通干道大气污染的暴露可能是学龄儿童尿8-OH、dG水平的影响因素。     

Urban background particulate matter and allergic sensitization in adults of ECRHS II

BACKGROUND: Epidemiological studies have shown weak or inconsistent associations between ambient air pollutants and allergic sensitization. The aim of this study was to evaluate whether regional urban air pollution may partly explain the large variation in the prevalence of allergic sensitization across cities of the European Community Respiratory Health Survey (ECRHS) II. METHODS: ECRHS is a cross-sectional survey initiated in 29 countries across Europe in the 1990s (ECRHS I) with a follow-up conducted 10 years later (ECRHS II). Subject characteristics were measured by questionnaires and blood tests conducted for the measurement of specific immunoglobulin E. Fine particle mass (PM(2.5), <2.5 microm) and sulphur on PM(2.5) were measured in 21 centres and annual averages of urban regional background air pollution were calculated. Results were scaled by an interquartile range increase in ambient PM(2.5) (6.03 microg/m(3)) and sulphur (1336 ng/m(3)). Generalized estimating equations were applied to compute population average effect estimates with adjustment for age, gender, smoking habit, education and number of siblings. RESULTS: A notable variation in pollution level and prevalence of allergic sensitization was observed. Moreover, exposure to urban regional background air pollution was not associated with allergic sensitization; adjusted odds ratios and 95% confidence interval were 1.02 (0.95-1.09) for PM(2.5) and 1.08 (0.86-1.31) for sulphur. These statistically non-significant associations were sensitive to model specification. CONCLUSIONS: The study suggests that regional air pollution measured at fixed sites is not associated with allergic sensitization among adults in ECRHS II.     

住宅室内空气颗粒物污染状况及其与大气浓度关系的初探

目的了解当前住宅室内空气PM2.5和PM10的污染水平及其与室外大气浓度的关系。方法选择10户市区常住家庭,采用单孔多段冲击式颗粒物采样仪进行室内外空气PM2.5、PM10浓度的同时监测。结果非采暖期室内空气PM2.5和PM10的浓度范围分别为27.0～272.9μgm3和42.9～309.6μgm3;采暖期分别为20.7～251.4μgm3和34.0～283.9μgm3。PM2.5与PM10浓度之间呈良好的直线相关关系。室内外颗粒物浓度的相关关系在非采暖期和采暖期有所不同。结论住宅室内空气颗粒物污染比较严重,今后应进一步研究室内颗粒物的污染规律,探讨颗粒物对人群健康的影响。     

室内燃煤与大气污染对儿童肺功能的交互影响

目的 研究室内燃煤与大气污染对儿童肺功能的交互作用影响。方法 1995—1996年间在中国4城市的城区和郊区的8所小学对6～12岁的儿童进行肺功能的队列测试,每年分冷、暖两季进行。通过3步回归过程进行统计分析。结果 室外空气颗粒物与儿童第1秒最大呼气量(FEV1)、用力肺活量(FVC)和FEV1／FVC都有显著的负相关关系。家庭燃煤与TSP对FEV1和FVC有较显著的交互作用。家庭燃煤与PM10对肺功能的交互作用较弱,但有加重颗粒物对肺功能产生不利影响的趋势。未发现室内燃煤与SO2和NOx对肺功能有显著的交互影响作用。结论 家庭燃煤这种室内污染因素加重了环境空气颗粒物污染,特别是TSP对儿童肺功能的不利影响。     

Long-term concentrations of ambient air pollutants and incident lung cancer in California adults: results from the AHSMOG study.Adventist Health Study on Smog.

The purpose of this study was to evaluate the relationship of long-term concentrations of ambient air pollutants and risk of incident lung cancer in nonsmoking California adults. A cohort study of 6,338 nonsmoking, non-Hispanic, white Californian adults, ages 27-95, was followed from 1977 to 1992 for newly diagnosed cancers. Monthly ambient air pollution data were interpolated to zip code centroids according to home and work location histories, cumulated, and then averaged over time. The increased relative risk (RR) of incident lung cancer in males associated with an interquartile range (IQR) increase in 100 ppb ozone (O3) was 3.56 [95% confidence interval (CI), 1.35-9.42]. Incident lung cancer in males was also positively associated with IQR increases for mean concentrations of particulate matter <10 microm (PM10; RR = 5.21; CI, 1.94-13.99) and SO2 (RR = 2.66; CI, 1.62-4.39). For females, incident lung cancer was positively associated with IQR increases for SO2 (RR = 2.14; CI, 1.36-3.37) and IQR increases for PM10 exceedance frequencies of 50 microg/m3 (RR = 1.21; CI, 0.55-2.66) and 60 microg/m3 (RR = 1.25; CI, 0.57-2.71). Increased risks of incident lung cancer were associated with elevated long-term ambient concentrations of PM10 and SO2 in both genders and with O3 in males. The gender differences for the O3 and PM10 results appeared to be partially due to gender differences in exposure.     

Ambient endotoxin concentrations in PM10 from Southern California

Concentrations of endotoxin in urban air pollution have not previously been extensively characterized. We measured 24-hr levels of PM10 (particulate matter < 10 microm in aerodynamic diameter) and the associated endotoxin component once every 6 weeks for 1 year in 13 communities in Southern California. All the samples collected had detectable PM10 and endotoxin levels. The geometric mean PM10 was 34.6 microg/m3 [geometric SD (GSD), 2.1; range, 3.0-135]. By volume, the endotoxin geometric mean was 0.44 endotoxin units (EU)/m3 (GSD, 3.1; range, 0.03-5.44). Per unit material collected, the geometric mean of endotoxin collected was 13.6 EU/mg (GSD, 3.2; range, 0.7-96.8). No correlation was found between endotoxin concentrations and other ambient pollutants concurrently measured [ozone, nitrogen dioxide, total acids, or PM2.5 (particulate matter < 2.5 micro m in aerodynamic diameter]. PM10 and endotoxin concentrations were significantly correlated, most strongly in summer. Samples collected in more rural and agricultural areas had lower PM10 and mid-range endotoxin levels. The high desert and mountain communities had lower PM10 levels but endotoxin levels comparable with or higher than the rural agricultural sites. By volume, endotoxin levels were highest at sites downwind of Los Angeles, California, which were also the locations of highest PM10. Endotoxin concentrations measured in this study were all < 5.5 EU/m3, which is lower than recognized thresholds for acute adverse health effects for occupational exposures but in the same range as indoor household concentrations. This study provides the first extensive characterization of endotoxin concentration across a large metropolitan area in relation to PM10 and other pollutant monitoring, and supports the need for studies of the role of endotoxin in childhood asthma in urban settings.     

Exposure of chronic obstructive pulmonary disease patients to particles: respiratory and cardiovascular health effects.

To examine hypotheses regarding air pollution health effects, we conducted an exploratory study to evaluate relationships between personal and ambient concentrations of particles with measures of cardiopulmonary health in a sample of patients with chronic obstructive pulmonary disease (COPD). Sixteen currently non-smoking COPD patients (mean age=74) residing in Vancouver were equipped with a particle (PM(2.5)) monitor for seven 24-h periods. Subjects underwent ambulatory heart monitoring, had their lung function and blood pressure (BP) measured, and recorded symptoms and medication use. Ambient PM(2.5), PM(10), sulfate, and gaseous pollutant concentrations were monitored at five sites within the study area. Although no associations between air pollution and lung function were statistically significant, an estimated effect of 3% and 1% declines in daily FEV(1) change (DeltaFEV(1)) for each 10 microg/m(3) increase in ambient PM(10) and PM(2.5), respectively, was observed. Increases of 1 microg/m(3) in personal or ambient sulfate were associated with 1.0% and 0.3% declines in DeltaFEV(1), respectively. Weak associations were observed between particle concentrations and increased supraventricular ectopic heartbeats and with decreased systolic BP. No consistent associations were observed between any particle metric and diastolic BP, heart rate, or heart rate variability (r-MSSD or SDNN), symptom severity, or bronchodilator use. Of the pollutants measured, ambient PM(10) was most consistently associated with health parameters; the use of personal exposures did not improve the strength of any associations or lead to increased effect estimates.     

Indoor air quality in ice skating rinks in Hong Kong

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 microm (PM(2.5)), particulate matter with diameter less than 10 microm (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 microg/m(3), 851 to 1329 ppm, and 550 to 765 microg/m(3), respectively. The average NO and NO(2) concentrations ranged from 69 to 1006 microg/m(3) and 58 to 242 microg/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.     

Dog ownership enhances symptomatic responses to air pollution in children with asthma

BACKGROUND: Experimental data suggest that asthma exacerbation by ambient air pollutants is enhanced by exposure to endotoxin and allergens; however, there is little supporting epidemiologic evidence. METHODS: We evaluated whether the association of exposure to air pollution with annual prevalence of chronic cough, phlegm production, or bronchitis was modified by dog and cat ownership (indicators of allergen and endotoxin exposure). The study population consisted of 475 Southern California children with asthma from a longitudinal cohort of participants in the Children's Health Study. We estimated average annual ambient exposure to nitrogen dioxide, ozone, particulate matter < 10, 2.5, and 10-2.5 microm in aerodynamic diameter (PM10, PM2.5, and PM10-2.5, respectively), elemental and organic carbon, and acid vapor from monitoring stations in each of the 12 study communities. Multivariate models were used to examine the effect of yearly variation of each pollutant. Effects were scaled to the variability that is common for each pollutant in representative communities in Southern California. RESULTS: Among children owning a dog, there were strong associations between bronchitic symptoms and all pollutants examined. Odds ratios ranged from 1.30 per 4.2 microg/m3 for PM10-2.5 [95% confidence interval (CI), 0.91-1.87) to 1.91 per 1.2 microg/m3 for organic carbon (95% CI, 1.34-2.71). Effects were somewhat larger among children who owned both a cat and dog. There were no effects or small effects with wide CIs among children without a dog and among children who owned only a cat. CONCLUSION: Our results suggest that dog ownership, a source of residential exposure to endotoxin, may worsen the relationship between air pollution and respiratory symptoms in asthmatic children.     

Ambient exposure and nasal inflammation in adults and children--a preliminary analysis

The epidemiological evidence that ambient exposure, including particulate matter (PM) is related to adverse health outcomes continues to mount. Inflammation and disease of the upper respiratory tract are commonly suggested as effects of ambient exposure. Therefore we studied both ambient exposure and nasal effects in a 4-months cross-sectional survey in Nordrhein-Westfalen (Germany). At 4 locations in 3 different cities ambient exposure to TSP (total suspended particles), O3, NOx and SO2 was derived from compliance measurements by governmental offices, and 884 subjects (501 mothers and 383 children, 6-7 years old) were screened using nasal lavage, with success rates of 90 and 75%, respectively. No differences in total cell counts or percentage of neutrophils were found between mothers or children from the 4 different locations, despite small but significant differences in ambient exposure to TSP, SO2, O3, and NOx during this period. A higher epithelial cell count in mothers and children from one city might be related to general higher ambient pollution in that location. Interestingly, total cells and interleukin-8 levels in children were higher than in mothers and possibly reflect their increased susceptibility to effects of air pollution. Future analysis will concentrate on temporal relations between inflammation and exposure, including individual risk factors such as allergy, smoking and the presence of disease.     

Air pollution and daily mortality in seven major cities of Korea, 1991-1997

The relationship between ambient air pollution and daily mortality in seven major cities of Korea for the period 1991-1997 was examined. These cities account for half of the Korean population (about 22 million). The observed concentrations of sulfur dioxide (SO(2), mean=23.3 ppb), ozone (O(3), mean=23.7 ppb), and total suspended particulates (TSP, mean=77.9 microg/m(3)) during the study period were at levels below Korea's current ambient air quality standards. Generalized additive models were applied to allow for the highly flexible fitting of seasonal and long-term time trends in air pollution as well as nonlinear associations with weather variables, such as air temperature and relative humidity. In city-specific analyses, an increase of 50 ppb of SO(2) corresponded to 1-12% more deaths, given constant weather conditions. The risk of all-cause mortality was estimated to increase by 0.5-4%, with an increase in the 2-day moving average of TSP levels equal to 100 microg/m(3). In multipollutant models with pooled data, we found that the estimated risk of death by SO(2) was notably unaffected by adding the other two pollutants (TSP and O(3)) to the model and was statistically significant in various regression models. The rate ratio (RR) for SO(2) remained elevated, indicating an excess mortality of 3% 50 ppb (RR=1.03; 95% CI, 1.01-1.05). TSP's effect on mortality maintained its significance with O(3), but not with SO(2). This implies that there may be collinearity problems where TSP and SO(2) are included in the same model or that TSP may function less than SO(2) as a surrogate for fine particles in the ambient air of Korea. In conclusion, increased mortality was associated with air pollution at SO(2) levels below the current recommendation for air quality. Further research is needed to clarify the relationship between SO(2) and fine particles in Korea.