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.     

Association between air pollution and low birth weight: a community-based study.

The relationship between maternal exposure to air pollution during periods of pregnancy (entire and specific periods) and birth weight was investigated in a well-defined cohort. Between 1988 and 1991, all pregnant women living in four residential areas of Beijing were registered and followed from early pregnancy until delivery. Information on individual mothers and infants was collected. Daily air pollution data were obtained independently. The sample for analysis included 74,671 first-parity live births were gestational age 37-44 weeks. Multiple linear regression and logistic regression were used to estimate the effects of air pollution on birth weight and low birth weight (< 2,500 g), adjusting for gestational age, residence, year of birth, maternal age, and infant gender. There was a significant exposure-response relationship between maternal exposures to sulfur dioxide (SO2) and total suspended particles (TSP) during the third trimester of pregnancy and infant birth weight. The adjusted odds ratio for low birth weight was 1.11 (95% CI, 1.06-1.16) for each 100 micrograms/m3 increase in SO2 and 1.10 (95% CI, 1.05-1.14) for each 100 micrograms/m3 increase in TSP. The estimated reduction in birth weight was 7.3 g and 6.9 g for each 100 micrograms/m3 increase in SO2 and in TSP, respectively. The birth weight distribution of the high-exposure group was more skewed toward the left tail (i.e., with higher proportion of births < 2,500 g) than that of the low-exposure group. Although the effects of other unmeasured risk factors cannot be excluded with certainty, our data suggests that TSP and SO2, or a more complex pollution mixture associated with these pollutants, contribute to an excess risk of low birth weight in the Beijing population.     

Traffic-related air pollution, preterm birth and term birth weight in the PIAMA birth cohort study

Background

Maternal exposure to air pollution has been associated with adverse pregnancy outcomes. Few studies took into account the spatial and temporal variation of air pollution levels.

Objectives

To evaluate the impact of maternal exposure to traffic-related air pollution during pregnancy on preterm birth and term birth weight using a spatio-temporal exposure model.

Methods

We estimated maternal residential exposure to nitrogen dioxide (NO₂), particulate matter (PM_2.5) and soot during pregnancy (entire pregnancy, 1st trimester, and last month) for 3853 singleton births within the Dutch PIAMA prospective birth cohort study by means of temporally adjusted land-use regression models. Associations between air pollution concentrations and preterm birth and term birth weight were analyzed by means of logistic and linear regression models with and without adjustment for maternal physical, lifestyle, and socio-demographic characteristics.

Results

We found positive, statistically non-significant associations between exposure to soot during entire pregnancy and during the last month of pregnancy and preterm birth [adj. OR (95% CI) per interquartile range increase in exposure 1.08 (0.88–1.34) and 1.09 (0.93–1.27), respectively]. There was no indication of an adverse effect of air pollution exposure on term birth weight.

Conclusions

In this study, maternal exposure to traffic-related air pollution during pregnancy was not associated with term birth weight. There was a tendency towards an increased risk of preterm birth with increasing air pollution exposure, but statistical power was low.     

Ambient air pollution exposure and full-term birth weight in California

Background  

Studies have identified relationships between air pollution and birth weight, but have been inconsistent in identifying individual pollutants inversely associated with birth weight or elucidating susceptibility of the fetus by trimester of exposure. We examined effects of prenatal ambient pollution exposure on average birth weight and risk of low birth weight in full-term births.     

Anxiety during pregnancy, prematurity, and low birth weight: a systematic literature review

The purpose of this systematic literature review was to examine publications that had investigated the effect of anxiety on prematurity and/or low birth weight. The PubMed, BVS, CINAHL, and HEALTHSTAR databases, published from 1966 to 2006, were tracked using the following key words: "anxiety", "pregnancy", "low birth weight", and "prematurity". Thirteen studies were found: 11 cohorts, 1 cross-sectional, and 1 case-control. Most studies (7/13) were conducted in the United States. The most reliable results came from four studies, whose strengths were: exclusion of adolescents and/or women older than 34 years, studies that analyzed anxiety during the second and/or third trimester of pregnancy, used validated scales to measure anxiety, kept loss-to-follow-up rates below 30%, and applied adequate control of confounders. Anxiety during pregnancy was associated with prematurity and/or low birth weight in eight studies. Odds ratios and relative risks varied from 1.08 to 2.31. Carefully designed and well-conducted studies are still needed to clarify the relationship between anxiety during pregnancy, prematurity, and low birth weight considering that the accumulated evidence remains controversial.     

Impact of ambient air pollution on birth weight in Sydney, Australia

Background: Studies in Asia, Europe, and the Americas have provided evidence that ambient air pollution may have an adverse effect on birth weight, although results are not consistent. Methods: Average exposure during pregnancy to five common air pollutants was estimated for births in metropolitan Sydney between 1998 and 2000. The effects of pollutant exposure in the first, second, and third trimesters of pregnancy on risk of "small for gestational age" (SGA), and of pollutant exposure during pregnancy on birth weight were examined. Results: There were 138 056 singleton births in Sydney between 1998 and 2000; 9.7% of babies (13 402) were classified as SGA. Air pollution levels in Sydney were found to be quite low. In linear regression models carbon monoxide and nitrogen dioxide concentrations in the second and third trimesters had a statistically significant adverse effect on birth weight. For a 1 part per million increase in mean carbon monoxide levels a reduction of 7 (95% CI –5 to 19) to 29 (95% CI 7 to 51) grams in birth weight was estimated. For a 1 part per billion increase in mean nitrogen dioxide levels a reduction of 1 (95% CI 0 to 2) to 34 (95% CI 24 to 43) grams in birth weight was estimated. Particulate matter (diameter less than ten microns) in the second trimester had a small statistically significant adverse effect on birth weight. For a 1 microgram per cubic metre increase in mean particulate matter levels a reduction of 4 grams (95% CI 3 to 6) in birth weight was estimated. Conclusion: These findings of an association between carbon monoxide, nitrogen dioxide, and particulate matter, and reduction in birth weight should be corroborated by further study.     

Outdoor air pollution and lung cancer

In the 1950s evidence of an ongoing epidemic of lung cancer in the United States and Western Europe led researchers to examine the role of outdoor air pollution, which was considered by some to be a likely cause. Although epidemiologic research quickly identified the central role of cigarette smoking in this epidemic, and despite progress in reducing outdoor air pollution in Western industrialized countries, concerns that ambient air pollution is causing lung cancer have persisted to the present day. This concern is based on the fact that known carcinogens continue to be released into outdoor air from industrial sources, power plants, and motor vehicles, and on a body of epidemiologic research that provides some evidence for an association between outdoor air pollution and lung cancer. This article reviews the epidemiologic evidence for this association and discusses the limitations of current studies for estimating the lung cancer risk in the general population. It also identifies research needs and suggests possible approaches to addressing outstanding questions.     

广东某市空气污染对低出生体重的影响分析

目的 定量化研究广东某市大气污染对新生儿低出生体重的影响.方法 利用2007年广东某市所有助产机构围产保健数据库,获得新生儿出生病例资料,从广东某市气象局获得气象资料,大气污染资料来源于广东某市环境监测站.采用广义可加模型进行广东某市大气污染与新生儿低出生体重发生间的关系分析,同时控制气象因素、时间趋势、工作日效应等混杂因素的影响.结果 2007年广东某市空气中二氧化氮、可吸入颗粒物和二氧化硫的日均浓度分别为61.04、82.51、51.67μg/m3;广东某市新生儿低出生体重数为19.19例/日.Pearson相关分析结果表明,二氧化氮、可吸入颗粒物、二氧化硫浓度与温度及相对湿度均呈负相关.滞后效应和累积效应的广义可加模型时序分析结果均显示,单污染物的健康效应显著.在滞后效应中3种污染物的健康效应均在滞后3天达到最大值,当大气中二氧化氮、可吸入颗粒物、二氧化硫浓度每上升100μg/m3,其RR值分别为1.0569(95%CI:1.0182～1.0955)、1.0677(95%CI:1.0217 ～1.1136)、1.1252(95%CI:1.0561 ～1.1944).在累积效应中二氧化氮、二氧化硫的健康效应均在滞后3天达到最大值,每上升100μg/m3,其RR值分别为1.0625(95%CI:1.0127 ～1.1122)、1.1618(95%CI:1.0741 ～1.2495);可吸入颗粒物的健康效应在滞后4天达到最大值,每上升100μg/m3,其RR值为1.0972(95%CI:1.0314～1.1629).结论 广东某市大气二氧化氮、可吸入颗粒物、二氧化硫污染对新生儿低出生体重发生率具有潜在的影响.     

Ambient air pollution exposure, residential mobility and term birth weight in Oslo, Norway

Environmental exposure during pregnancy may have lifelong health consequences for the offspring and some studies have association between maternal exposure to air pollution during pregnancy and offspring’s birth weight. However, many of these studies do not take into account small-scale variations in exposure, residential mobility, and work addresses during pregnancy.We used information from the National Birth Registry of Norway to examine associations between ambient environmental exposure such as air pollution and temperature, and offspring’s birth weight taking advantage of information on migration history and work address in a large population-based cohort. A dispersion model was used to estimate ambient air pollution levels at all residential addresses and work addresses for a total of 25,229 pregnancies between 1999 and 2002 in Oslo, Norway.Ambient exposure to traffic pollution for the entire pregnancy was associated with a reduction in term birth weight in crude analyzes when comparing children of the highest and lowest exposed mothers. No evidence for an association between exposure to traffic pollution at home and work addresses and term birth weight after adjustment for covariates known to influence birth weight during pregnancy. After stratification, small statistically non-significant reductions were present but only for multiparious mothers. This group also had less residential mobility and less employment during pregnancy.The overall findings suggest no clear association between term birth weight and traffic pollution exposure during pregnancy. However, mobility patterns could introduce possible confounding when examining small-scale variations in exposure by using addresses. This could be of importance in future studies.     

Hierarchical spatial modeling of uncertainty in air pollution and birth weight study

In environmental health studies air pollution measurements from the closest monitor are commonly used as a proxy for personal exposure. This technique assumes that air pollution concentrations are spatially homogeneous in the neighborhoods associated with the monitors and consequently introduces measurement error into a resultant model. To model the relationship between maternal exposure to air pollution and birth weight, we build a hierarchical model that accounts for the associated measurement error. We allow four possible scenarios, with increasing flexibility, for capturing this uncertainty. In the two simplest cases, we specify models with a constant variance term and a variance component that allows uncertainty in the exposure measurements to increase as the distance between maternal residence and the location of the closest monitor increases. In the remaining two models, we introduce spatial dependence using random effects. The models are illustrated using Bayesian hierarchical modeling techniques that relate pregnancy outcomes from the North Carolina Detailed Birth Records to air pollution data from the U.S. Environmental Protection Agency.     

Maternal psychological stress and distress as predictors of low birth weight,prematurity and intrauterine growth retardation

OBJECTIVES: To evaluate: (1) the associations between maternal psychological stress, distress and low birth weight (LBW), prematurity and intrauterine growth retardation (IUGR); (2) the interactions between maternal stress, distress and smoking, alcohol and coffee intake; (3) the prevalences of stress and distress in pregnancy. DESIGN: Longitudinal cohort study. SETTING: Jundiaí city, S?o Paulo state, Brazil. SUBJECTS: A total of 865 pregnant women who attended antenatal care between September 1997 and August 2000. METHODS: Measures of stress and distress were obtained, by interview, three times in pregnancy: at a gestational age (GA) lower than 16 weeks, from 20 to 26 weeks and from 30 to 36 weeks. Stress was investigated by the perceived stress scale, PSS, and distress by both the general health questionnaire, GHQ, and the State Trait Anxiety inventories, STAI. The outcomes were: LBW (birth weight <2500 g), prematurity (gestational age (GA) at birth <37 weeks) and IUGR (birth weight for GA 相似文献   

Ambient air pollution and birth weight in full-term infants in Atlanta, 1994-2004

Background

An emerging body of evidence suggests that ambient levels of air pollution during pregnancy are associated with fetal growth.

Objectives

We examined relationships between birth weight and temporal variation in ambient levels of carbon monoxide, nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone, particulate matter ≤ 10 μm in diameter (PM₁₀), ≤ 2.5 μm (PM_2.5), 2.5 to 10 μm (PM_2.5–10), and PM_2.5 chemical component measurements for 406,627 full-term births occurring between 1994 and 2004 in five central counties of metropolitan Atlanta.

Methods

We assessed relationships between birth weight and pollutant concentrations during each infant’s first month of gestation and third trimester, as well as in each month of pregnancy using distributed lag models. We also conducted capture-area analyses limited to mothers residing within 4 miles (6.4 km) of each air quality monitoring station.

Results

In the five-county analysis, ambient levels of NO₂, SO₂, PM_2.5 elemental carbon, and PM_2.5 water-soluble metals during the third trimester were significantly associated with small reductions in birth weight (−4 to −16 g per interquartile range increase in pollutant concentrations). Third-trimester estimates were generally higher in Hispanic and non-Hispanic black infants relative to non-Hispanic white infants. Distributed lag models were also suggestive of associations between air pollutant concentrations in late pregnancy and reduced birth weight. The capture-area analyses provided little support for the associations observed in the five-county analysis.

Conclusions

Results provide some support for an effect of ambient air pollution in late pregnancy on birth weight in full-term infants.     

Traffic-related air toxics and term low birth weight in Los Angeles County, California

Background: Numerous studies have linked criteria air pollutants with adverse birth outcomes, but there is less information on the importance of specific emission sources, such as traffic, and air toxics.Objectives: We used three exposure data sources to examine odds of term low birth weight (LBW) in Los Angeles, California, women when exposed to high levels of traffic-related air pollutants during pregnancy.Methods: We identified term births during 1 June 2004 to 30 March 2006 to women residing within 5 miles of a South Coast Air Quality Management District (SCAQMD) Multiple Air Toxics Exposure Study (MATES III) monitoring station. Pregnancy period average exposures were estimated for air toxics, including polycyclic aromatic hydrocarbons (PAHs), source-specific particulate matter < 2.5 μm in aerodynamic diameter (PM_2.5) based on a chemical mass balance model, criteria air pollutants from government monitoring data, and land use regression (LUR) model estimates of nitric oxide (NO), nitrogen dioxide (NO₂) and nitrogen oxides (NO_x). Associations between these metrics and odds of term LBW (< 2,500 g) were examined using logistic regression.Results: Odds of term LBW increased approximately 5% per interquartile range increase in entire pregnancy exposures to several correlated traffic pollutants: LUR measures of NO, NO₂, and NO_x, elemental carbon, and PM_2.5 from diesel and gasoline combustion and paved road dust (geological PM_2.5).Conclusions: These analyses provide additional evidence of the potential impact of traffic-related air pollution on fetal growth. Particles from traffic sources should be a focus of future studies.     

极低出生体重儿早产儿视网膜病的高危因素分析

目的探讨极低出生体重儿(VLBW)早产儿视网膜病(ROP)的患病率、高危因素.方法分别对1997～2000年期间233例VLBW和1999～2000年期间121例VLBW进行回顾性分析.结果233例VLBW中有56例ROP,患病率为24.0%,其中每年ROP患病率在22.6%～25.5%,1例致盲.通过对30余种高危因素与121例VLBW发生ROP关系进行综合分析及应用逐步Logistic回归分析法发现,低出生体重、输血、低氧血症、低碳酸血症是造成ROP的重要原因.结论预防ROP的发生应首先减少低出生体重儿的发生率,减少输血,预防和及时纠正低氧血症、低碳酸血症.     

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.     

Caffeine consumption during pregnancy and prevalence of low birth weight and prematurity: a systematic review

This article reports on a systematic review of studies on caffeine intake during pregnancy and prevalence of low birth weight and prematurity, focusing on methods to quantify intake and control for confounding. The review consisted of an article search from 1996 to 2006 in MEDLINE, LILACS, and PubMed, using the key words: "caffeine", "coffee", "low birth weight", "birth weight", "preterm", "premature", and "prematurity". Ten articles were selected. Methods used to quantify caffeine consumption were: semi-quantitative food frequency questionnaires for diet or only caffeinated products, including one self-applied questionnaire; food recall; questions on type and method of preparation; analysis of samples; and urine and plasma caffeine levels. In three studies, high caffeine consumption was associated with low birth weight and/or prematurity. Contradictions between studies may be due to difficulties in measuring caffeine consumption; assessment of different caffeine sources; variations in the mode of preparation and amount consumed; and sample size. Association between moderate caffeine consumption and fetal growth was not demonstrated, so a more precise measurement of caffeine intake is necessary.     

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.