Comparing exposure assessment methods for traffic-related air pollution in an adverse pregnancy outcome study.

BACKGROUND Previous studies reported adverse impacts of traffic-related air pollution exposure on pregnancy outcomes. Yet, little information exists on how effect estimates are impacted by the different exposure assessment methods employed in these studies. OBJECTIVES To compare effect estimates for traffic-related air pollution exposure and preeclampsia, preterm birth (gestational age less than 37 weeks), and very preterm birth (gestational age less than 30 weeks) based on four commonly used exposure assessment methods. METHODS We identified 81,186 singleton births during 1997-2006 at four hospitals in Los Angeles and Orange Counties, California. Exposures were assigned to individual subjects based on residential address at delivery using the nearest ambient monitoring station data [carbon monoxide (CO), nitrogen dioxide (NO(2)), nitric oxide (NO), nitrogen oxides (NO(x)), ozone (O(3)), and particulate matter less than 2.5 (PM(2.5)) or less than 10 (PM(10))μm in aerodynamic diameter], both unadjusted and temporally adjusted land-use regression (LUR) model estimates (NO, NO(2), and NO(x)), CALINE4 line-source air dispersion model estimates (NO(x) and PM(2.5)), and a simple traffic-density measure. We employed unconditional logistic regression to analyze preeclampsia in our birth cohort, while for gestational age-matched risk sets with preterm and very preterm birth we employed conditional logistic regression. RESULTS We observed elevated risks for preeclampsia, preterm birth, and very preterm birth from maternal exposures to traffic air pollutants measured at ambient stations (CO, NO, NO(2), and NO(x)) and modeled through CALINE4 (NO(x) and PM(2.5)) and LUR (NO(2) and NO(x)). Increased risk of preterm birth and very preterm birth were also positively associated with PM(10) and PM(2.5) air pollution measured at ambient stations. For LUR-modeled NO(2) and NO(x) exposures, elevated risks for all the outcomes were observed in Los Angeles only--the region for which the LUR models were initially developed. Unadjusted LUR models often produced odds ratios somewhat larger in size than temporally adjusted models. The size of effect estimates was smaller for exposures based on simpler traffic density measures than the other exposure assessment methods. CONCLUSION We generally confirmed that traffic-related air pollution was associated with adverse reproductive outcomes regardless of the exposure assessment method employed, yet the size of the estimated effect depended on how both temporal and spatial variations were incorporated into exposure assessment. The LUR model was not transferable even between two contiguous areas within the same large metropolitan area in Southern California.

[1]  H. Kan,et al.  Prospective Analysis of Traffic Exposure as a Risk Factor for Incident Coronary Heart Disease: The Atherosclerosis Risk in Communities (ARIC) Study , 2008, Environmental health perspectives.

[2]  A. Szpiro,et al.  Including Caline3 Dispersion Model Predictions into a Land Use Regression Model for NOx in Los Angeles, California and Seattle, Washington. , 2008 .

[3]  Lidia Morawska,et al.  Concentrations of submicrometre particles from vehicle emissions near a major road , 2000 .

[4]  Beate Ritz,et al.  Ambient air pollution and preterm birth in the environment and pregnancy outcomes study at the University of California, Los Angeles. , 2007, American journal of epidemiology.

[5]  F. Ballester,et al.  Air pollution exposure during pregnancy and reduced birth size: a prospective birth cohort study in Valencia, Spain , 2010, Environmental health : a global access science source.

[6]  B. Ritz,et al.  Effect of Air Pollution on Preterm Birth Among Children Born in Southern California Between 1989 and 1993 , 2000, Epidemiology.

[7]  M. Nieuwenhuijsen,et al.  Association between GIS-Based Exposure to Urban Air Pollution during Pregnancy and Birth Weight in the INMA Sabadell Cohort , 2009, Environmental health perspectives.

[8]  Thomas W. Kirchstetter,et al.  Impact of California Reformulated Gasoline On Motor Vehicle Emissions. 1. Mass Emission Rates , 1999 .

[9]  Beate Ritz,et al.  Association between Local Traffic-Generated Air Pollution and Preeclampsia and Preterm Delivery in the South Coast Air Basin of California , 2009, Environmental health perspectives.

[10]  Roberto Romero,et al.  Epidemiology and causes of preterm birth , 2008, The Lancet.

[11]  Steve L Mara,et al.  A Wide Area of Air Pollutant Impact Downwind of a Freeway during Pre-Sunrise Hours. , 2009, Atmospheric environment.

[12]  Peter J. Diggle,et al.  Modelling spatio‐temporal variation in exposure to particulate matter: a two‐stage approach , 2008 .

[13]  Donald R Mattison,et al.  Environmental Exposures and Adverse Pregnancy Outcomes: A Review of the Science , 2008, Reproductive Sciences.

[14]  J. Samet.  Traffic, Air Pollution, and Health , 2007, Inhalation toxicology.

[15]  David T. Allen,et al.  Daily, Seasonal, and Spatial Trends in PM2.5 Mass and Composition in Southeast Texas Special Issue of Aerosol Science and Technology on Findings from the Fine Particulate Matter Supersites Program , 2004 .

[16]  D. Niemeier,et al.  Near-roadway air quality: synthesizing the findings from real-world data. , 2010, Environmental science & technology.

[17]  R. Slama,et al.  Methodological issues in studies of air pollution and reproductive health. , 2009, Environmental research.

[18]  Michael Brauer,et al.  Within-urban variability in ambient air pollution: Comparison of estimation methods , 2008 .

[19]  B. Gomišček,et al.  Spatial and temporal variations of PM1, PM2.5, PM10 and particle number concentration during the AUPHEP—project , 2004 .

[20]  W. King,et al.  Residential mobility during pregnancy. , 2004, Paediatric and perinatal epidemiology.

[21]  T. Tjoa,et al.  Repeated respiratory hospital encounters among children with asthma and residential proximity to traffic , 2008, Occupational and Environmental Medicine.

[22]  Christian Seigneur,et al.  A comprehensive performance evaluation of MM5-CMAQ for the Summer 1999 Southern Oxidants Study episode—Part II: Gas and aerosol predictions , 2006 .

[23]  Martin Bobak,et al.  Ambient Air Pollution and Pregnancy Outcomes: A Review of the Literature , 2005, Environmental health perspectives.

[24]  S F Bottoms,et al.  The preterm prediction study: risk factors for indicated preterm births. Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development. , 1998, American journal of obstetrics and gynecology.

[25]  E. Fujita,et al.  Overview of the 1997 Southern California Ozone Study (SCOS97-NARSTO) , 2003 .

[26]  Donald Dabdub,et al.  Simulation and analysis of secondary organic aerosol dynamics in the South Coast Air Basin of California , 2006 .

[27]  L. Waller,et al.  Ambient Air Pollution and Preterm Birth: A Time-series Analysis , 2009, Epidemiology.

[28]  C. Gotway,et al.  Exposures to Air Pollutants during Pregnancy and Preterm Delivery , 2006, Environmental health perspectives.

[29]  Michael Brauer,et al.  Centre for Health Services and Policy Research, and , 2022 .

[30]  P. E. Benson.  CALINE4 - A DISPERSION MODEL FOR PREDICTING AIR POLLUTANT CONCENTRATIONS NEAR ROADWAYS. FINAL REPORT , 1984 .

[31]  Yifang Zhu,et al.  Study of ultrafine particles near a major highway with heavy-duty diesel traffic , 2002 .

[32]  Beate Ritz,et al.  Predicting traffic-related air pollution in Los Angeles using a distance decay regression selection strategy. , 2009, Environmental research.

[33]  Arthur M. Winer,et al.  Exposure of PM2.5 and EC from diesel and gasoline vehicles in communities near the Ports of Los Angeles and Long Beach, California , 2009 .

[34]  A. Cano,et al.  The effects on offspring of premature parturition. , 2001, Human reproduction update.

[35]  J. Gulliver,et al.  A review of land-use regression models to assess spatial variation of outdoor air pollution , 2008 .

[36]  Beate Ritz,et al.  Local Variations in CO and Particulate Air Pollution and Adverse Birth Outcomes in Los Angeles County, California, USA , 2005, Environmental health perspectives.

[37]  S. Lipshultz,et al.  Effects of environmental exposures on the cardiovascular system: prenatal period through adolescence. , 2004, Pediatrics.

[38]  N. Anthonisen,et al.  Risk of physician-diagnosed asthma in the first 6 years of life. , 2004, Chest.

[39]  Beate Ritz,et al.  Residential proximity to traffic and adverse birth outcomes in Los Angeles county, California, 1994-1996. , 2003, Environmental health perspectives.

[40]  A. Correa,et al.  A review of the literature on the effects of ambient air pollution on fetal growth. , 2004, Environmental research.

[41]  R. Slama,et al.  Traffic-Related Atmospheric Pollutants Levels during Pregnancy and Offspring’s Term Birth Weight: A Study Relying on a Land-Use Regression Exposure Model , 2007, Environmental health perspectives.

[42]  F. Ballester,et al.  Exposure to ambient air pollution and prenatal and early childhood health effects , 2004, European Journal of Epidemiology.

[43]  Richard P. Turco,et al.  Development of an individual exposure model for application to the Southern California children's health study , 2005 .

[44]  K. Pinkerton,et al.  INFLUENCE OF AIR POLLUTION ON RESPIRATORY HEALTH DURING PERINATAL DEVELOPMENT , 2006, Clinical and experimental pharmacology & physiology.