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Joachim Heinrich - One of the best experts on this subject based on the ideXlab platform.
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Traffic-related atmospheric pollutants levels during pregnancy and offspring's Term Birth weight: a study relying on a land-use regression exposure model.
Environmental Health Perspectives, 2007Co-Authors: Rémy Slama, Verena Morgenstern, Josef Cyrys, Anne Zutavern, Olf Herbarth, Heinz-erich Wichmann, Joachim Heinrich, Lisa Study GroupAbstract:BACKGROUND: Some studies have suggested that particulate matter (PM) levels during pregnancy may be associated with Birth weight. Road traffic is a major source of fine PM (PM with aero-dynamic diameter < 2.5 microm; PM(2.5)). OBJECTIVE: We deTermined to characterize the influence of maternal exposure to atmospheric pollutants due to road traffic and urban activities on offspring Term Birth weight. METHODS: Women from a Birth cohort [the LISA (Influences of Lifestyle Related Factors on the Human Immune System and Development of Allergies in Children) cohort] who delivered a non-premature baby with a Birth weight > 2,500 g in Munich metropolitan area were included. We assessed PM(2.5), PM(2.5) absorbance (which depends on the blackness of PM(2.5), a marker of traffic-related air pollution), and nitrogen dioxide levels using a land-use regression model, taking into account the type and length of roads, population density, land coverage around the home address, and temporal variations in pollution during pregnancy. Using Poisson regression, we estimated prevalence ratios (PR) of Birth weight < 3,000 g, adjusted for gestational duration, sex, maternal smoking, height, weight, and education. RESULTS: Exposure was defined for 1,016 Births. Taking the lowest quartile of exposure during pregnancy as a reference, the PR of Birth weight < 3,000 g associated with the highest quartile was 1.7 for PM(2.5) [95% confidence interval (CI), 1.2-2.7], 1.8 for PM(2.5) absorbance (95% CI, 1.1-2.7), and 1.2 for NO(2) (95% CI, 0.7-1.7). The PR associated with an increase of 1 microg/m(3) in PM(2.5) levels was 1.13 (95% CI, 1.00-1.29). CONCLUSION: Increases in PM(2.5) levels and PM(2.5) absorbance were associated with decreases in Term Birth weight. Traffic-related air pollutants may have adverse effects on Birth weight.
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traffic related atmospheric pollutants levels during pregnancy and offspring s Term Birth weight a study relying on a land use regression exposure model
Environmental Health Perspectives, 2007Co-Authors: Rémy Slama, Verena Morgenstern, Josef Cyrys, Anne Zutavern, Olf Herbarth, Heinz-erich Wichmann, Joachim HeinrichAbstract:Particulate matter (PM) is a major family of atmospheric pollutants (National Center for Environmental Assessment 2004). Fine PM (PM with an aerodynamic diameter < 2.5 μm; PM2.5) and, perhaps to a greater extent, ultra-fine particles (PM < 0.1 μm) can penetrate the innermost region of the lungs, and a fraction of them can cross the lung epithelium and enter the blood circulation (Kreyling et al. 2002). Several epidemiologic studies have reported associations between PM levels—most often total suspended particles (TSP) and PM < 10 μm in aerodynamic diameter (PM10)—around the maternal home address during pregnancy with offspring Birth weight (reviewed by Glinianaia et al. 2004; Sram et al. 2005). Few studies assessed exposure to PM2.5 (Basu et al. 2004; Bell et al. 2007; Dejmek et al. 2000; Jedrychowski et al. 2004; Parker et al. 2005). Four of these studies reported a decrease in Term Birth weight in relation to maternal exposure to PM2.5 during pregnancy; exposure was assessed using individual dosimeters carried 48 hr during pregnancy (Jedrychowski et al. 2004), from the pregnancy-average of the measurements of the air quality monitoring stations within an 8-km radius from the home address (Basu et al. 2004; Parker et al. 2005), or of all the measurement stations located in the county of residence of the woman (Bell et al. 2007). Fine particles are composed of nonorganic compounds (sulfate, nitrate, ammonium and hydrogen ions, certain transition metals), elemental carbon, organic species including poly-cyclic aromatic hydrocarbons (PAHs) and many other families (National Center for Environmental Assessment 2004; Schauer et al. 1999, 2002). Vehicular traffic is one of the major sources of fine particles. Nitrogen dioxide, PM2.5 mass concentration, and also PM2.5 absorbance are possible markers of traffic-related pollution (Janssen et al. 2001). More specifically, PM2.5 absorbance is a measure of the blackness of PM2.5, which strongly depends on the presence of elemental carbon in PM2.5 (Janssen et al. 2001; Kinney et al. 2000). Because elemental carbon represents a major fraction of diesel motor exhausts (Lloyd and Cackette 2001; Schauer et al. 1999), PM2.5 absorbance is considered a sensitive marker of air pollution due to diesel engines and truck traffic (Janssen et al. 2001; Kinney et al. 2000) and is probably a more sensitive marker of traffic-related pollution than PM2.5 (Cyrys et al. 2003; Kinney et al. 2000; Roemer and van Wijnen 2001). Diesel exhaust (Lloyd and Cackette 2001) has been shown in experimental animal studies to be a possible mutagenic agent, to cause allergic and nonallergic respiratory diseases (Krzyzanowski et al. 2005; Pope and Dockery 2006), to be a possible reprotoxicant, and to act as an endocrine disruptor (Takeda et al. 2004; Tsukue et al. 2002; Yoshida et al. 2006). No epidemiologic study has described the association between PM absorbance and Birth weight. With a few exceptions (Choi et al. 2006; Jedrychowski et al. 2004; Wilhelm and Ritz 2003), most epidemiologic studies on the influence of PM or traffic-related pollutants on intrauterine growth restriction relied on Birth weight certificates for the collection of Birth weight and adjustment factors, whereas exposure was assessed from the background monitoring stations closest to the home address of the mother at the time of delivery. This design has several limitations: Factors known to strongly influence Birth weight—such as maternal smoking, weight, or height, not always or accurately available in Birth certificates—could not always be controlled for, not allowing researchers to discard confounding (Glinianaia et al. 2004). Exposure misclassification is also a concern: First, pregnancy is often a time to change address, so the exposure levels around the home address at the time of Birth might not match exposure levels around the home address during pregnancy for a number of women. Second, all women living within a distance of up to several kilometers around a monitoring station are assumed to be exposed to the pollutants’ levels measured by the station. To limit exposure misclassification, one may prefer to exclude women living far away from monitoring stations (Wilhelm and Ritz 2005); however, monitoring stations are often located at places where population density is higher, and hence air pollution levels are higher. Therefore, if unmeasured environmental or social factors influencing Birth weight also varied with distance from monitoring stations, selection bias might occur in studies restricted to subjects living close to monitoring stations. This dilemma between exposure mis-classification and possible selection bias could be avoided by using alternative approaches to model exposure, such as land-use regression or dispersion modeling, which allow modeling of fine spatial contrasts in pollution levels in an area considered as a whole, using information on sources of pollution (Nieuwenhuijsen et al. 2006). Within a cohort conducted in the Munich metropolitan area (Bavaria), we aimed to characterize the influence of maternal exposure to PM2.5, PM2.5 absorbance, and NO2 during pregnancy on the Birth weight of offspring at Term, using a land-use regression exposure model and taking into account factors known to influence intrauterine growth.
Rémy Slama - One of the best experts on this subject based on the ideXlab platform.
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Traffic-related atmospheric pollutants levels during pregnancy and offspring's Term Birth weight: a study relying on a land-use regression exposure model.
Environmental Health Perspectives, 2007Co-Authors: Rémy Slama, Verena Morgenstern, Josef Cyrys, Anne Zutavern, Olf Herbarth, Heinz-erich Wichmann, Joachim Heinrich, Lisa Study GroupAbstract:BACKGROUND: Some studies have suggested that particulate matter (PM) levels during pregnancy may be associated with Birth weight. Road traffic is a major source of fine PM (PM with aero-dynamic diameter < 2.5 microm; PM(2.5)). OBJECTIVE: We deTermined to characterize the influence of maternal exposure to atmospheric pollutants due to road traffic and urban activities on offspring Term Birth weight. METHODS: Women from a Birth cohort [the LISA (Influences of Lifestyle Related Factors on the Human Immune System and Development of Allergies in Children) cohort] who delivered a non-premature baby with a Birth weight > 2,500 g in Munich metropolitan area were included. We assessed PM(2.5), PM(2.5) absorbance (which depends on the blackness of PM(2.5), a marker of traffic-related air pollution), and nitrogen dioxide levels using a land-use regression model, taking into account the type and length of roads, population density, land coverage around the home address, and temporal variations in pollution during pregnancy. Using Poisson regression, we estimated prevalence ratios (PR) of Birth weight < 3,000 g, adjusted for gestational duration, sex, maternal smoking, height, weight, and education. RESULTS: Exposure was defined for 1,016 Births. Taking the lowest quartile of exposure during pregnancy as a reference, the PR of Birth weight < 3,000 g associated with the highest quartile was 1.7 for PM(2.5) [95% confidence interval (CI), 1.2-2.7], 1.8 for PM(2.5) absorbance (95% CI, 1.1-2.7), and 1.2 for NO(2) (95% CI, 0.7-1.7). The PR associated with an increase of 1 microg/m(3) in PM(2.5) levels was 1.13 (95% CI, 1.00-1.29). CONCLUSION: Increases in PM(2.5) levels and PM(2.5) absorbance were associated with decreases in Term Birth weight. Traffic-related air pollutants may have adverse effects on Birth weight.
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traffic related atmospheric pollutants levels during pregnancy and offspring s Term Birth weight a study relying on a land use regression exposure model
Environmental Health Perspectives, 2007Co-Authors: Rémy Slama, Verena Morgenstern, Josef Cyrys, Anne Zutavern, Olf Herbarth, Heinz-erich Wichmann, Joachim HeinrichAbstract:Particulate matter (PM) is a major family of atmospheric pollutants (National Center for Environmental Assessment 2004). Fine PM (PM with an aerodynamic diameter < 2.5 μm; PM2.5) and, perhaps to a greater extent, ultra-fine particles (PM < 0.1 μm) can penetrate the innermost region of the lungs, and a fraction of them can cross the lung epithelium and enter the blood circulation (Kreyling et al. 2002). Several epidemiologic studies have reported associations between PM levels—most often total suspended particles (TSP) and PM < 10 μm in aerodynamic diameter (PM10)—around the maternal home address during pregnancy with offspring Birth weight (reviewed by Glinianaia et al. 2004; Sram et al. 2005). Few studies assessed exposure to PM2.5 (Basu et al. 2004; Bell et al. 2007; Dejmek et al. 2000; Jedrychowski et al. 2004; Parker et al. 2005). Four of these studies reported a decrease in Term Birth weight in relation to maternal exposure to PM2.5 during pregnancy; exposure was assessed using individual dosimeters carried 48 hr during pregnancy (Jedrychowski et al. 2004), from the pregnancy-average of the measurements of the air quality monitoring stations within an 8-km radius from the home address (Basu et al. 2004; Parker et al. 2005), or of all the measurement stations located in the county of residence of the woman (Bell et al. 2007). Fine particles are composed of nonorganic compounds (sulfate, nitrate, ammonium and hydrogen ions, certain transition metals), elemental carbon, organic species including poly-cyclic aromatic hydrocarbons (PAHs) and many other families (National Center for Environmental Assessment 2004; Schauer et al. 1999, 2002). Vehicular traffic is one of the major sources of fine particles. Nitrogen dioxide, PM2.5 mass concentration, and also PM2.5 absorbance are possible markers of traffic-related pollution (Janssen et al. 2001). More specifically, PM2.5 absorbance is a measure of the blackness of PM2.5, which strongly depends on the presence of elemental carbon in PM2.5 (Janssen et al. 2001; Kinney et al. 2000). Because elemental carbon represents a major fraction of diesel motor exhausts (Lloyd and Cackette 2001; Schauer et al. 1999), PM2.5 absorbance is considered a sensitive marker of air pollution due to diesel engines and truck traffic (Janssen et al. 2001; Kinney et al. 2000) and is probably a more sensitive marker of traffic-related pollution than PM2.5 (Cyrys et al. 2003; Kinney et al. 2000; Roemer and van Wijnen 2001). Diesel exhaust (Lloyd and Cackette 2001) has been shown in experimental animal studies to be a possible mutagenic agent, to cause allergic and nonallergic respiratory diseases (Krzyzanowski et al. 2005; Pope and Dockery 2006), to be a possible reprotoxicant, and to act as an endocrine disruptor (Takeda et al. 2004; Tsukue et al. 2002; Yoshida et al. 2006). No epidemiologic study has described the association between PM absorbance and Birth weight. With a few exceptions (Choi et al. 2006; Jedrychowski et al. 2004; Wilhelm and Ritz 2003), most epidemiologic studies on the influence of PM or traffic-related pollutants on intrauterine growth restriction relied on Birth weight certificates for the collection of Birth weight and adjustment factors, whereas exposure was assessed from the background monitoring stations closest to the home address of the mother at the time of delivery. This design has several limitations: Factors known to strongly influence Birth weight—such as maternal smoking, weight, or height, not always or accurately available in Birth certificates—could not always be controlled for, not allowing researchers to discard confounding (Glinianaia et al. 2004). Exposure misclassification is also a concern: First, pregnancy is often a time to change address, so the exposure levels around the home address at the time of Birth might not match exposure levels around the home address during pregnancy for a number of women. Second, all women living within a distance of up to several kilometers around a monitoring station are assumed to be exposed to the pollutants’ levels measured by the station. To limit exposure misclassification, one may prefer to exclude women living far away from monitoring stations (Wilhelm and Ritz 2005); however, monitoring stations are often located at places where population density is higher, and hence air pollution levels are higher. Therefore, if unmeasured environmental or social factors influencing Birth weight also varied with distance from monitoring stations, selection bias might occur in studies restricted to subjects living close to monitoring stations. This dilemma between exposure mis-classification and possible selection bias could be avoided by using alternative approaches to model exposure, such as land-use regression or dispersion modeling, which allow modeling of fine spatial contrasts in pollution levels in an area considered as a whole, using information on sources of pollution (Nieuwenhuijsen et al. 2006). Within a cohort conducted in the Munich metropolitan area (Bavaria), we aimed to characterize the influence of maternal exposure to PM2.5, PM2.5 absorbance, and NO2 during pregnancy on the Birth weight of offspring at Term, using a land-use regression exposure model and taking into account factors known to influence intrauterine growth.
Bert Brunekreef - One of the best experts on this subject based on the ideXlab platform.
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Traffic-related air pollution, preTerm Birth and Term Birth weight in the PIAMA Birth cohort study.
Environmental research, 2010Co-Authors: Ulrike Gehring, Alet H. Wijga, Paul Fischer, Johan C. De Jongste, Marjan Kerkhof, Gerard H. Koppelman, Henriette A. Smit, Bert BrunekreefAbstract: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 (PM2.5) 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. (C) 2010 Elsevier Inc. All rights reserved.
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Ambient air pollution exposure, residential mobility and Term Birth weight in Oslo, Norway.
Environmental research, 2010Co-Authors: Christian Madsen, Ulrike Gehring, Bert Brunekreef, Sam-erik Walker, Hein Stigum, Øyvind Næss, Per NafstadAbstract: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.
Ulrike Gehring - One of the best experts on this subject based on the ideXlab platform.
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maternal exposure to particulate air pollution and Term Birth weight a multi country evaluation of effect and heterogeneity
Environmental Health Perspectives, 2013Co-Authors: Payam Dadvand, Ulrike Gehring, Jennifer D Parker, Michelle L Bell, Matteo Bonzini, Michael Brauer, Lyndsey A Darrow, Svetlana V Glinianaia, Nelson Gouveia, Jong Han LeemAbstract:Background: A growing body of evidence has associated maternal exposure to air pollution with adverse effects on fetal growth; however, the existing literature is inconsistent. Objectives: We aimed to quantify the association between maternal exposure to particulate air pollution and Term Birth weight and low Birth weight (LBW) across 14 centers from 9 countries, and to explore the influence of site characteristics and exposure assessment methods on between-center heterogeneity in this association. Methods: Using a common analytical protocol, International Collaboration on Air Pollution and Pregnancy Outcomes (ICAPPO) centers generated effect estimates for Term LBW and continuous Birth weight associated with PM10 and PM2.5 (particulate matter ≤ 10 and 2.5 μm). We used meta-analysis to combine the estimates of effect across centers (~ 3 million Births) and used meta-regression to evaluate the influence of center characteristics and exposure assessment methods on between-center heterogeneity in reported effect estimates. Results: In random-effects meta-analyses, Term LBW was positively associated with a 10-μg/m3 increase in PM10 [odds ratio (OR) = 1.03; 95% CI: 1.01, 1.05] and PM2.5 (OR = 1.10; 95% CI: 1.03, 1.18) exposure during the entire pregnancy, adjusted for maternal socioeconomic status. A 10-μg/m3 increase in PM10 exposure was also negatively associated with Term Birth weight as a continuous outcome in the fully adjusted random-effects meta-analyses (-8.9 g; 95% CI: -13.2, -4.6 g). Meta-regressions revealed that centers with higher median PM2.5 levels and PM2.5:PM10 ratios, and centers that used a temporal exposure assessment (compared with spatiotemporal), tended to report stronger associations. Conclusion: Maternal exposure to particulate pollution was associated with LBW at Term across study populations. We detected three site characteristics and aspects of exposure assessment methodology that appeared to contribute to the variation in associations reported by centers.
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Traffic-related air pollution, preTerm Birth and Term Birth weight in the PIAMA Birth cohort study.
Environmental research, 2010Co-Authors: Ulrike Gehring, Alet H. Wijga, Paul Fischer, Johan C. De Jongste, Marjan Kerkhof, Gerard H. Koppelman, Henriette A. Smit, Bert BrunekreefAbstract: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 (PM2.5) 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. (C) 2010 Elsevier Inc. All rights reserved.
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Ambient air pollution exposure, residential mobility and Term Birth weight in Oslo, Norway.
Environmental research, 2010Co-Authors: Christian Madsen, Ulrike Gehring, Bert Brunekreef, Sam-erik Walker, Hein Stigum, Øyvind Næss, Per NafstadAbstract: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.
Lisa Study Group - One of the best experts on this subject based on the ideXlab platform.
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Traffic-related atmospheric pollutants levels during pregnancy and offspring's Term Birth weight: a study relying on a land-use regression exposure model.
Environmental Health Perspectives, 2007Co-Authors: Rémy Slama, Verena Morgenstern, Josef Cyrys, Anne Zutavern, Olf Herbarth, Heinz-erich Wichmann, Joachim Heinrich, Lisa Study GroupAbstract:BACKGROUND: Some studies have suggested that particulate matter (PM) levels during pregnancy may be associated with Birth weight. Road traffic is a major source of fine PM (PM with aero-dynamic diameter < 2.5 microm; PM(2.5)). OBJECTIVE: We deTermined to characterize the influence of maternal exposure to atmospheric pollutants due to road traffic and urban activities on offspring Term Birth weight. METHODS: Women from a Birth cohort [the LISA (Influences of Lifestyle Related Factors on the Human Immune System and Development of Allergies in Children) cohort] who delivered a non-premature baby with a Birth weight > 2,500 g in Munich metropolitan area were included. We assessed PM(2.5), PM(2.5) absorbance (which depends on the blackness of PM(2.5), a marker of traffic-related air pollution), and nitrogen dioxide levels using a land-use regression model, taking into account the type and length of roads, population density, land coverage around the home address, and temporal variations in pollution during pregnancy. Using Poisson regression, we estimated prevalence ratios (PR) of Birth weight < 3,000 g, adjusted for gestational duration, sex, maternal smoking, height, weight, and education. RESULTS: Exposure was defined for 1,016 Births. Taking the lowest quartile of exposure during pregnancy as a reference, the PR of Birth weight < 3,000 g associated with the highest quartile was 1.7 for PM(2.5) [95% confidence interval (CI), 1.2-2.7], 1.8 for PM(2.5) absorbance (95% CI, 1.1-2.7), and 1.2 for NO(2) (95% CI, 0.7-1.7). The PR associated with an increase of 1 microg/m(3) in PM(2.5) levels was 1.13 (95% CI, 1.00-1.29). CONCLUSION: Increases in PM(2.5) levels and PM(2.5) absorbance were associated with decreases in Term Birth weight. Traffic-related air pollutants may have adverse effects on Birth weight.
