Ambient air pollution and low birth weight in Connecticut and Massachusetts

BACKGROUND: Several studies have examined whether air pollution affects birth weight; however results vary and many studies were focused on Southern California or were conducted outside of the United States. OBJECTIVES: We investigated maternal exposure to particulate matter with aerodynamic diameter < 10, < 2.5 microm (PM(10), PM(2.5)), sulfur dioxide, nitrogen dioxide, and carbon monoxide and birth weight for 358,504 births in Massachusetts and Connecticut from 1999 to 2002. METHODS: Analysis included logistic models for low birth weight (< 2,500 g) and linear models with birth weight as a continuous variable. Exposure was assigned as the average county-level concentration over gestation and each trimester based on mother's residence. We adjusted for gestational length, prenatal care, type of delivery, child's sex, birth order, weather, year, and mother's race, education, marital status, age, and tobacco use. RESULTS: An interquartile increase in gestational exposure to NO(2), CO, PM(10), and PM(2.5) lowered birth weight by 8.9 g [95% confidence interval (CI), 7.0-10.8], 16.2 g (95% CI, 12.6-19.7), 8.2 g (95% CI, 5.3-11.1), and 14.7 g (95% CI, 12.3-17.1), respectively. Lower birth weight was associated with exposure in the third trimester for PM(10), the first and third trimesters for CO, the first trimester for NO(2) and SO(2), and the second and third trimesters for PM(2.5). Effect estimates for PM(2.5) were higher for infants of black mothers than those of white mothers. CONCLUSIONS: Results indicate that exposure to air pollution, even at low levels, may increase risk of low birth weight, particularly for some segments of the population.     

空气污染物对出生体重影响的研究

目的研究空气污染物可吸入颗粒物（PM10）、二氧化硫（SO2）、二氧化氮（NO2）对新生儿出生体重的影响。方法收集了广东某地2003—2005年分娩时孕满37周的围产数据。调查的因素包括产妇的年龄、职业、文化、出生地、是否有准生证、孕周、是否有高危因素、末次月经时间、分娩日期、孕次、产次；产妇丈夫的职业、文化；新生儿的性别、出生身高、体重。用2002—2005年的空气污染数据估计暴露水平。结果性别、母亲年龄、母亲职业、母亲原地址、孕期高危情况、孕次、是否有准生证分组，出生体重组间差异有统计学意义；不同孕期PM10、SO2、NO2暴露分组之间出生体重差异有统计学意义。多元线性回归分析显示可吸入颗粒物PM10、SO2、NO2浓度每增加10μg/m^3，出生体重分别减少1．90～3．94g、1．65～2．73g、2．70～3．76g。结论空气污染物与低出生体重有关，空气污染对妊娠结局的影响值得关注。     

Association between maternal exposure to ambient air pollutants during pregnancy and fetal growth restriction

Previous research demonstrated consistent associations between ambient air pollution and emergency room visits, hospitalizations, and mortality. Effect of air pollution on perinatal outcomes has recently drawn more attention. We examined the association between intrauterine growth restriction (IUGR) among singleton term live births and sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), and fine particles (PM2.5) present in ambient air in the Canadian cities of Calgary, Edmonton, and Montreal for the period 1985-2000. Multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for IUGR, based on average daily levels of individual pollutants over each month and trimester of pregnancy after adjustment for maternal age, parity, infant gender, season, and city of residence. A 1 ppm increase in CO was associated with an increased risk of IUGR in the first (OR=1.18; 95% CI 1.14-1.23), second (OR=1.15; 95% CI 1.10-1.19) and third (OR=1.19; 95% CI 1.14-1.24) trimesters of pregnancy, respectively. A 20 ppb increase in NO2 (OR=1.16; 95% CI 1.09-1.24; OR=1.14; 95% CI 1.06--1.21; and OR=1.16; 95% CI 1.09-1.24 in the first, second, and third trimesters) and a 10 mug/m3 increase in PM2.5 (OR=1.07; 95% CI 1.03-1.10; OR=1.06; 95% CI 1.03-1.10; and OR=1.06; 95% CI 1.03-1.10) were also associated with an increased risk of IUGR. Consistent results were found when ORs were calculated by month rather than trimester of pregnancy. Our findings add to the emerging body of evidence that exposure to relatively low levels of ambient air pollutants in urban areas during pregnancy is associated with adverse effects on fetal growth.     

Air pollution and low birth weight in the city of Rio de Janeiro, Brazil, 2002

The objective of this study was to evaluate the effect of air pollution on low birth weight in full term singleton newborns in the city of Rio de Janeiro, Brazil. The study adopted a cross-sectional design based on the year 2002. Data on live births were obtained from the Live Birth Information System of the Brazilian Ministry of Health. Low birth weight was defined as less than 2,500 g. Maternal exposure to air pollution was defined as the mean for a given pollutant over each trimester of pregnancy and was assessed taking birth date into account. Adjusted odds ratios (OR) were estimated for each potential risk factor. For PM(10), CO, and NO(2), no significant increases were detected. For SO(2), the OR of the fourth interquartile range of exposure in the third trimester of pregnancy was 1.149 (95%CI: 1.016-1.301). For O(3), the estimated OR was 0.830 (95%CI: 0.750-0.987). When exposure variable was regarded as a continuous measure, the OR for PM(10), CO, and SO2 in the third trimester were not statistically significant and were 1.089, 2.223, and 1.259, respectively.     

A cohort study of traffic-related air pollution impacts on birth outcomes

BACKGROUND: Evidence suggests that air pollution exposure adversely affects pregnancy outcomes. Few studies have examined individual-level intraurban exposure contrasts. OBJECTIVES: We evaluated the impacts of air pollution on small for gestational age (SGA) birth weight, low full-term birth weight (LBW), and preterm birth using spatiotemporal exposure metrics. METHODS: With linked administrative data, we identified 70,249 singleton births (1999-2002) with complete covariate data (sex, ethnicity, parity, birth month and year, income, education) and maternal residential history in Vancouver, British Columbia, Canada. We estimated residential exposures by month of pregnancy using nearest and inverse-distance weighting (IDW) of study area monitors [carbon monoxide, nitrogen dioxide, nitric oxide, ozone, sulfur dioxide, and particulate matter < 2.5 (PM2.5) or < 10 (PM10) microm in aerodynamic diameter], temporally adjusted land use regression (LUR) models (NO, NO2, PM2.5, black carbon), and proximity to major roads. Using logistic regression, we estimated the risk of mean (entire pregnancy, first and last month of pregnancy, first and last 3 months) air pollution concentrations on SGA (< 10th percentile), term LBW (< 2,500 g), and preterm birth. RESULTS: Residence within 50 m of highways was associated with a 26% increase in SGA [95% confidence interval (CI), 1.07-1.49] and an 11% (95% CI, 1.01-1.23) increase in LBW. Exposure to all air pollutants except O3 was associated with SGA, with similar odds ratios (ORs) for LUR and monitoring estimates (e.g., LUR: OR = 1.02; 95% CI, 1.00-1.04; IDW: OR = 1.05; 95% CI, 1.03-1.08 per 10-microg/m3 increase in NO). For preterm births, associations were observed with PM2.5 for births < 37 weeks gestation (and for other pollutants at < 30 weeks). No consistent patterns suggested exposure windows of greater relevance. CONCLUSION: Associations between traffic-related air pollution and birth outcomes were observed in a population-based cohort with relatively low ambient air pollution exposure.     

Long-term exposure to urban air pollution and myocardial infarction

BACKGROUND: Cohort studies have reported increased risks of cardiopulmonary mortality from long-term air pollution exposure, but the evidence is limited and inconclusive. We studied the association between long-term exposure to source-specific air pollution and myocardial infarction (MI) in a case-control study of first-time MI cases and population controls age 45 to 70 years in Stockholm county in 1992 to 1994. METHODS: Home addresses during several decades were combined with historical emission databases and dispersion models to obtain annual mean levels of pollutants from traffic and heating during 30 years for 1397 cases and 1870 controls. Nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter with an aerodynamic diameter less than 10 microm (PM10) were used as indicators of traffic emissions and sulfur dioxide (SO2) as an indicator of emissions from residential heating. RESULTS: There was no association between long-term average air pollution exposure and overall MI, but an increased risk of fatal MI was suggested, especially for out-of-hospital death. After adjustment for cardiovascular risk factors, the odds ratio for fatal MI associated with a 5th to 95th percentile difference in 30-year average exposure was 1.51 (95% confidence interval = 0.96-2.16) for NO2, 1.22 (0.98-1.52) for CO, 1.39 (0.94-2.07) for PM10, and 1.24 (0.77-2.02) for SO2. For out-of-hospital death, the odds ratio related to NO2 exposure was 2.17 (1.05-4.51). CONCLUSIONS: This study provides some support for an association between long-term air pollution exposure and fatal cardiovascular disease.     

Association between ambient air pollution and birth weight in São Paulo, Brazil

Objectives: Previous studies have implicated air pollution in increased mortality and morbidity, especially in the elderly population and children. More recently, associations with mortality in infants and with some reproductive outcomes have also been reported. The aim of this study is to explore the association between exposure to outdoor air pollution during pregnancy and birth weight. Design: Cross sectional study using data on all singleton full term live births during a one year period. For each individual birth, information on gestational age, type of delivery, birth weight, sex, maternal education, maternal age, place of residence, and parity was available. Daily mean levels of PM₁₀, sulphur dioxide, nitrogen dioxide, carbon monoxide, and ozone were also gathered. The association between birth weight and air pollution was assessed in regression models with exposure averaged over each trimester of pregnancy. Setting: São Paulo city, Brazil. Results: Birth weight was shown to be associated with length of gestation, maternal age and instruction, infant gender, number of antenatal care visits, parity, and type of delivery. On adjusting for these variables negative effects of exposure to PM₁₀ and carbon monoxide during the first trimester were observed. This effect seemed to be more robust for carbon monoxide. For a 1 ppm increase in mean exposure to carbon monoxide during the first trimester a reduction of 23 g in birth weight was estimated. Conclusions: The results are consistent in revealing that exposure to air pollution during pregnancy may interfere with weight gain in the fetus. Given the poorer outlook for low birthweight babies on a number of health outcomes, this finding is important from the public health perspective.     

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.     

Environmental health surveillance of low birth weight in Seoul using air monitoring and birth data]

OBJECTIVES: The principal objective of this study was to determine the relationship between maternal exposure to air pollution and low birth weight and to propose a possible environmental health surveillance system for low birth weight. METHODS: We acquired air monitoring data for Seoul from the Ministry of Environment, the meteorological data from the Korean Meteorological Administration, the exposure assessments from the National Institute of Environmental Research, and the birth data from the Korean National Statistical Office between January 1, 2002 and December 31, 2003. The final birth data were limited to singletons within 37-44 weeks of gestational age. We defined the Low Birth Weight (LBW) group as infants with birth weights of less than 2500g and calculated the annual LBW rate by district. The air monitoring data were measured for CO, SO(2), NO(2), and PM(10) concentrations at 27 monitoring stations in Seoul. We utilized two models to evaluate the effects of air pollution on low birth weight: the first was the relationship between the annual concentration of air pollution and low birth weight (LBW) by individual and district, and the second involved a GIS exposure model constructed by Arc View 3.1. RESULTS: LBW risk (by Gu, or district) was significantly increased to 1.113(95% CI=1.111-1.116) for CO, 1.004 (95% CI=1.003-1.005) for NO(2), 1.202(95% CI=1.199-1.206) for SO(2), and 1.077(95% CI=1.075-1.078) for PM(10) with each interquartile range change. Personal LBW risk was significantly increased to 1.081(95% CI=1.002-1.166) for CO, 1.145(95% CI=1.036-1.267) for SO(2), and 1.053(95% CI=1.002-1.108) for PM(10) with each interquartile range change. Personal LBW risk was increased to 1.003(95% CI=0.954-1.055) for NO(2), but this was not statistically significant. The air pollution concentrations predicted by GIS positively correlated with the numbers of low birth weights, particularly in highly polluted regions. CONCLUSIONS: Environmental health surveillance is a systemic, ongoing collection effort including the analysis of data correlated with environmentally-associated diseases and exposures. In addition, environmental health surveillance allows for a timely dissemination of information to those who require that information in order to take effective action. GIS modeling is crucially important for this purpose, and thus we attempted to develop a GIS-based environmental surveillance system for low birth weight.     

围孕期空气污染暴露与子代先天性甲状腺功能减退的关系:基于中国30个省份的研究

目的探讨围孕期母体空气污染暴露水平对子代先天性甲状腺功能减退症(CH)发病风险的影响。方法回顾性收集中国2014年10月1日至2015年9月31日30个省份CH的发病率。遵循空气污染对妊娠期效应的滞后性和累积性原则,回顾性收集中国30个省份2014年1月1日至2015年9月31日PM2.5、PM10、NO2、SO2、CO和O3的平均暴露水平。构建二项Logistic回归模型,并纳入各省份人均国民生产总值、废水中铅、汞和砷的暴露量作为混杂因素,分析围孕期空气污染暴露对子代CH发病风险的影响。结果我国2015年CH的年发病率约为4.31/万人,其中浙江省(7.42/万人)和福建省(7.34/万人)的发病率最高,发病率最低的省份为新疆(1.88/万人)。围孕期母体PM2.5高暴露会显著增加CH的发病风险,围孕期PM2.5的暴露水平每上升1μg/m3,该地区CH高发的风险将会增加0.102倍(OR=1.102, 95%CI:1.001~1.213,P <0.05)。此外,围孕期NO2平均暴露水平的升高也会显著增加CH的发病风险(OR=1.211, 95%CI:1.033~1.419, P <0.05)。在双污染物模型中,围孕期母体PM2.5和NO2的高暴露仍会显著增加CH的发病风险,当对PM10的暴露水平进行调整后,PM2.5和NO2暴露对CH发病率的影响均最为显著(OR=1.585、1.580,均P <0.05)。但PM10、SO2、CO和O3对CH的发病风险没有显著的影响(OR=1.007、0.987、0.925、0.061,均P>0.05)。结论本研究通过大数据分析发现,围孕期母体PM2.5和NO2高暴露会显著增加子代CH的发病风险。围孕期空气污染暴露可能影响子代腺体功能的发育。     

妊娠期大气二氧化氮暴露与孕妇维生素D缺乏症的关联

目的 孕妇维生素D缺乏症与妊娠期糖尿病、妊娠期高血压、孕妇贫血以及胎儿生长受限和早产等不良妊娠结局密切相关。本研究旨在探讨妊娠期大气二氧化氮（nitrogen dioxide,NO2）暴露与孕妇维生素D缺乏症的关联。方法 选取2013年5月-至2014年５月,在某市妇幼保健院建卡的孕妇作为初始研究对象。按照入选和排除标准最终纳入3244名孕妇进入本研究。通过问卷调查收集孕妇的一般人口学信息;利用环境监测站点的数据模拟孕妇在妊娠期间大气NO2的暴露水平;采用酶联免疫吸附法检测孕晚期孕妇血清中25（OH）D的浓度。结果 孕妇在孕早期、中期、晚期以及整个孕期NO2暴露水平的中位数分别为:39.52、36.84、28.09以及31.90μg/m3。孕晚期血清中25(OH)D浓度的平均值为42.09nmol/L。多元线性回归分析的结果显示,孕中期、孕晚期以及整个孕期NO2的暴露水平每增加10μg / m3,孕妇血清中25（OH）D的水平分别降低2.224nmol/L（95%CI:-2.777,-1.671）,2.240nmol/L（95%CI:-2.665,-1.816）以及5.299 nmol/L（95%CI:-6.481,-4.177）。多元logistic回归分析的结果显示,随着孕中期、孕晚期以及整个孕期NO2的暴露水平的增加,孕妇VD缺乏症发生的风险增加,其OR值分别为1.338（95%CI:1.225,1.461）,1.347（95%CI:1.259,1.442）以及2.049（95%CI:1.709～2.456）。结论 孕期NO2暴露是孕妇维生素D缺乏症发生的一个危险因素。在制订维生素D缺乏症的防控措施时需要考虑孕期NO2的暴露。     

Associations between air pollution and mortality in Phoenix, 1995-1997

We evaluated the association between mortality outcomes in elderly individuals and particulate matter (PM) of varying aerodynamic diameters (in micrometers) [PM(10), PM(2.5), and PM(CF )(PM(10) minus PM(2.5))], and selected particulate and gaseous phase pollutants in Phoenix, Arizona, using 3 years of daily data (1995-1997). Although source apportionment and epidemiologic methods have been previously combined to investigate the effects of air pollution on mortality, this is the first study to use detailed PM composition data in a time-series analysis of mortality. Phoenix is in the arid Southwest and has approximately 1 million residents (9. 7% of the residents are > 65 years of age). PM data were obtained from the U.S. Environmental Protection Agency (EPA) National Exposure Research Laboratory Platform in central Phoenix. We obtained gaseous pollutant data, specifically carbon monoxide, nitrogen dioxide, ozone, and sulfur dioxide data, from the EPA Aerometric Information Retrieval System Database. We used Poisson regression analysis to evaluate the associations between air pollution and nonaccidental mortality and cardiovascular mortality. Total mortality was significantly associated with CO and NO(2) (p < 0.05) and weakly associated with SO(2), PM(10), and PM(CF) (p < 0. 10). Cardiovascular mortality was significantly associated with CO, NO(2), SO(2), PM(2.5), PM(10), PM(CF) (p < 0.05), and elemental carbon. Factor analysis revealed that both combustion-related pollutants and secondary aerosols (sulfates) were associated with cardiovascular mortality.     

Air pollution and hospitalization due to angina pectoris in Tehran, Iran: a time-series study

BACKGROUND: Health effects of air pollution have been studied in many different parts of the world. Although a fairly large number of studies have explored the cardiovascular impacts of air pollution, because of its unique location we studied the association between air pollutants and hospital admissions due to angina pectoris in Tehran for the first time. METHODS: This is a retrospective time-series study. The variables of the study include the levels of five air pollutants-nitrogen dioxide (NO(2)), carbon monoxide (CO), ozone (O(3)), sulfur dioxide (SO(2)), and particulate matter <10 microm in aerodynamic diameter (PM(10))-as independent variables; daily hospitalizations due to angina pectoris in 25 academic hospitals in Tehran as the dependent variable; and mean daily temperature and humidity, seasonality, time trend, and day of the week as potential confounders. All variables were measured during a 5-year period from 21 March 1996 to 20 March 2001. The data of mean daily levels of NO(2), CO, O(3), SO(2), and PM(10) were collected from one of the stations of Tehran's Air Quality Control Corp. Data were analyzed using Poisson regression models. Relative risks of angina pectoris admissions were calculated for an increase in 1mg/m(3) for CO and 10 microg/m(3) for the other pollutants. RESULTS: Daily admissions due to angina pectoris were significantly related to the CO level, after controlling for confounder effects. Each unit increase in the CO level caused a 1.00934 increase in the number of admissions (95% CI, 1.00359--1.01512). This association was verified with a lag of 1 day. There was no significant association between the other air pollutants and the number of daily admission due to angina pectoris. CONCLUSIONS: We found that with increasing levels of the pollutant CO, the number of admissions due to cardiac angina rose. Ischemic heart disease is the leading cause of death in Iran. Air pollution control will reduce the number of this preventable disease and resulting deaths.     

空气污染和低出生体重

空气污染与低出生体重之间的关系的研究在国外已有较多报道,通过回顾文献发现,孕期接触空气中的一氧化碳、可吸入颗粒、二氧化硫、二氧化氮、多环有机物、总悬浮颗粒等物质的污染可能与低出生体重的发生有关,但目前发生机制还不明确.     

Air pollution and emergency admissions in Boston, MA

STUDY OBJECTIVE: Many studies have shown that ambient particulate air pollution (PM) is associated with increased risk of hospital admissions and deaths for cardiovascular or respiratory causes around the world. In general these have been analysed in association with PM(10) and ozone, whereas PM(2.5) is now the particle measure of greatest health and regulatory concern. And little has been published on associations of hospital admissions and PM components. DESIGN: This study analysed hospital admissions for myocardial infarction (15 578 patients), and pneumonia (24 857 patients) in associations with fine particulate air pollution, black carbon (BC), ozone, nitrogen dioxide (NO(2)), PM not from traffic, and carbon monoxide (CO) in the greater Boston area for the years 1995-1999 using a case-crossover analysis, with control days matched on temperature. MAIN RESULTS: A significant association was found between NO(2) (12.7% change (95% CI: 5.8, 18)), PM(2.5) (8.6% increase (95% CI: 1.2, 15.4)), and BC (8.3% increase (95% CI: 0.2, 15.8)) and the risk of emergency myocardial infarction hospitalisation; and between BC (11.7% increase (95% CI: 4.8, 17.4)), PM(2.5) (6.5% increase (95% CI: 1.1, 11.4)), and CO (5.5% increase (95% CI: 1.1, 9.5)) and the risk of pneumonia hospitalisation. CONCLUSIONS: The pattern of associations seen for myocardial infarction and pneumonia (strongest associations with NO(2), CO, and BC) suggests that traffic exposure is primarily responsible for the association with heart attacks.     

Long-term exposure to ambient air pollution and cardiopulmonary mortality in women

BACKGROUND: Living close to major roads or highways has been suggested to almost double the risk of dying from cardiopulmonary causes. We assessed whether long-term exposure to air pollution originating from motorized traffic and industrial sources is associated with total and cause-specific mortality in a cohort of women living in North Rhine-Westphalia, Germany. METHODS: The study was a follow-up of a series of cross-sectional studies carried out during the 1980s and 1990s on the health of women (age 50-59 years). Approximately 4800 women were followed up for vital status and migration. Exposure to air pollution was defined by distance to major roads calculated from Geographic Information System data and by 1- and 5-year average nitrogen dioxide (NO2) and particle (PM10) concentrations calculated from air monitoring station data. We analyzed associations between exposure and mortality using Cox's proportional hazards models adjusting for confounders. Relative risks (RRs) refer to an interquartile range increase in exposure (16 microg/m for NO2; 7 microg/m for PM10). RESULTS: During the follow-up period, 8% of the women died, 3% from cardiopulmonary causes. Cardiopulmonary mortality was associated with living within a 50-meter radius of a major road (adjusted RR = 1.70; 95% confidence interval = 1.02-2.81), with NO2 (1.57; 1.23-2.00 for 1-year average), and with PM10 (1.34; 1.06-1.71 for 1-year average). Exposure to NO2 was also associated with all-cause mortality (1.17; 1.02-1.34). No association was seen with noncardiopulmonary nonlung cancer mortality. CONCLUSIONS: Living close to major roads and chronic exposure to NO2 and PM10 may be associated with an increased mortality due to cardiopulmonary causes.     

Residential outdoor air pollution and lung function in schoolchildren

BACKGROUND: Long-term exposure to outdoor air pollution has typically been estimated on the aggregate level, and more individual measures of exposure are needed. We investigated the associations with lung function of residential outdoor air pollution in early life, total lifetime, and days before lung function test. METHODS: In 2001-2002, spirometry was performed in 2307 9- and 10-year-old children who had lived in Oslo, Norway, since birth. Outdoor air pollution exposure for each child was assessed by the EPISODE dispersion model, calculating hourly concentrations of nitrogen dioxide (NO2), particulate matter (PM) with aerodynamic diameter less than 10 microm (PM10) and 2.5 microm (PM2.5). We applied linear regression analysis stratified by sex. RESULTS: Early and lifetime exposures to outdoor air pollution were associated with reduced peak expiratory flow and reduced forced expiratory flow at 25% and 50% of forced vital capacity, especially in girls. One interquartile increase of lifetime exposure to NO2, PM10, and PM2.5 was associated with change in adjusted peak respiratory flow of, respectively, -79 mL/s (95% confidence interval = -128 to -31), -66 mL/s (-110 to -23), and -58 mL/s (-94 to -21). We also found short-term effects of NO2 that became stronger with increasing time lags, but no short-term effects of PM. When we included short- and long-term NO2 exposures simultaneously, only the long-term effect remained. We found no effect on forced volumes. Adjusting for a contextual socioeconomic factor diminished the associations. CONCLUSIONS: Short- and long-term residential exposures to traffic-related pollutants in Oslo were associated with reduced peak expiratory flow and forced expiratory flow at 25% and 50% in 9- to 10-year-old children, especially in girls, with weaker associations after adjusting for a contextual socioeconomic factor.     

太原市孕期空气污染暴露对早产的影响

目的探讨太原市空气污染物暴露对早产的影响。方法选择太原市城区2005年11月1日至2007年8月1日出生的围生儿为研究对象。出生数据来源于太原市出生监测系统,数据清洗后符合研究质量要求的为31145例,早产组1092例,对照组30053例。研究协变量共计15项,包括母亲年龄、民族、文化程度、家庭住址、家庭收入、职业、职业暴露、吸烟、饮酒、父亲吸烟、采暖方式、叶酸增补、产前检查、怀孕季节、围生儿性别。空气污染数据来源于太原市环境保护监测站,包括SO2、NO2、PM10的逐日平均浓度。应用Logistic回归模型,控制混杂因素,基本模型建立后,分别以其中一种大气污染物为目标变量,建立怀孕初期和怀孕末期3个月单污染物、双污染物、三污染物影响的Logistic回归模型。结果怀孕初期3个月,控制了混杂因素和其他污染物的影响后,NO2最高污染物水平(≥25.43μg/m3)与最低污染物水平(<22.12μg/m3)相比,早产的危险度(OR值)升高22.7%。关于PM10的影响,未发现有统计学意义(P>0.10)。本研究未发现怀孕初期SO2空气污染对早产的有害影响。临产前3个月,单污染物模型中,NO2每升高一个四分位数,早产的危险度(OR值)升高19.1%。与怀孕初期相比,SO2空气污染对早产的影响明显增加,三污染物模型中OR值由0.615～0.771上升到0.823～1.045,PM10的影响减小,三污染物模型中OR值由1.136～1.231降为0.885～1.014。但SO2和PM10对早产的影响无统计学意义(P>0.10)。结论本研究进一步证实了孕期NO2暴露对早产的影响,未来研究需要进一步探讨适宜的研究设计和孕期暴露敏感时段。     

Ambient air pollution and respiratory emergency department visits

BACKGROUND: A number of emergency department studies have corroborated findings from mortality and hospital admission studies regarding an association of ambient air pollution and respiratory outcomes. More refined assessment has been limited by study size and available air quality data. METHODS: Measurements of 5 pollutants (particulate matter [PM10], ozone, nitrogen dioxide [NO2], carbon monoxide [CO], and sulfur dioxide [SO2]) were available for the entire study period (1 January 1993 to 31 August 2000); detailed measurements of particulate matter were available for 25 months. We obtained data on 4 million emergency department visits from 31 hospitals in Atlanta. Visits for asthma, chronic obstructive pulmonary disease, upper respiratory infection, and pneumonia were assessed in relation to air pollutants using Poisson generalized estimating equations. RESULTS: In single-pollutant models examining 3-day moving averages of pollutants (lags 0, 1, and 2): standard deviation increases of ozone, NO2, CO, and PM10 were associated with 1-3% increases in URI visits; a 2 microg/m increase of PM2.5 organic carbon was associated with a 3% increase in pneumonia visits; and standard deviation increases of NO2 and CO were associated with 2-3% increases in chronic obstructive pulmonary disease visits. Positive associations persisted beyond 3 days for several of the outcomes, and over a week for asthma. CONCLUSIONS: The results of this study contribute to the evidence of an association of several correlated gaseous and particulate pollutants, including ozone, NO2, CO, PM, and organic carbon, with specific respiratory conditions.     

Exposures to air pollutants during pregnancy and preterm delivery

The association between preterm delivery (PTD) and exposure to air pollutants has recently become a major concern. We investigated this relationship in Incheon, Republic of Korea, using spatial and temporal modeling to better infer individual exposures. The birth cohort consisted of 52,113 singleton births in 2001-2002, and data included residential address, gestational age, sex, birth date and order, and parental age and education. We used a geographic information system and kriging methods to construct spatial and temporal exposure models. Associations between exposure and PTD were evaluated using univariate and multivariate log-binomial regressions. Given the gestational age, birth date, and the mother's residential address, we estimated each mother's potential exposure to air pollutants during critical periods of the pregnancy. The adjusted risk ratios for PTD in the highest quartiles of the first trimester exposure were 1.26 [95% confidence interval (CI), 1.11-1.44] for carbon monoxide, 1.27 (95% CI, 1.04-1.56) for particulate matter with aerodynamic diameter < or = 10 microm, 1.24 (95% CI, 1.09-1.41) for nitrogen dioxide, and 1.21 (95% CI, 1.04-1.42) for sulfur dioxide. The relationships between PTD and exposures to CO, NO2, and SO2 were dose dependent (p < 0.001, p < 0.02, p < 0.02, respectively) . In addition, the results of our study indicated a significant association between air pollution and PTD during the third trimester of pregnancy. In conclusion, our study showed that relatively low concentrations of air pollution under current air quality standards during pregnancy may contribute to an increased risk of PTD. A biologic mechanism through increased prostaglandin levels that are triggered by inflammatory mediators during exposure periods is discussed.