title: Multi-pollutant exposure profiles associated with term low birth weight in Los Angeles County.
abstract: Research indicates that multiple outdoor air pollutants and adverse neighborhood conditions are spatially correlated. Yet health risks associated with concurrent exposure to air pollution mixtures and clustered neighborhood factors remain underexplored. Statistical models to assess the health effects from pollutant mixtures remain limited, due to problems of collinearity between pollutants and area-level covariates, and increases in covariate dimensionality. Here we identify pollutant exposure profiles and neighborhood contextual profiles within Los Angeles (LA) County. We then relate these profiles with term low birth weight (TLBW). We used land use regression to estimate NO2, NO, and PM2.5 concentrations averaged over census block groups to generate pollutant exposure profile clusters and census block group-level contextual profile clusters, using a Bayesian profile regression method. Pollutant profile cluster risk estimation was implemented using a multilevel hierarchical model, adjusting for individual-level covariates, contextual profile cluster random effects, and modeling of spatially structured and unstructured residual error. Our analysis found 13 clusters of pollutant exposure profiles. Correlations between study pollutants varied widely across the 13 pollutant clusters. Pollutant clusters with elevated NO2, NO, and PM2.5 concentrations exhibited increased log odds of TLBW, and those with low PM2.5, NO2, and NO concentrations showed lower log odds of TLBW. The spatial patterning of pollutant cluster effects on TLBW, combined with between-pollutant correlations within pollutant clusters, imply that traffic-related primary pollutants influence pollutant cluster TLBW risks. Furthermore, contextual clusters with the greatest log odds of TLBW had more adverse neighborhood socioeconomic, demographic, and housing conditions. Our data indicate that, while the spatial patterning of high-risk multiple pollutant clusters largely overlaps with adverse contextual neighborhood cluster, both contribute to TLBW while controlling for the other.
authors.affiliation: College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, United States.
authors.forename: Eric
authors.initials: E
authors.lastname: Coker
authors.affiliation: Department of Mathematics, Brunel University, London, UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Liverani
authors.affiliation: School of Public Health, University of California, Los Angeles, Los Angeles, CA, United States.
authors.forename: Jo Kay
authors.initials: JK
authors.lastname: Ghosh
authors.affiliation: School of Public Health, University of California, Berkeley, Berkeley, CA, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Jerrett
authors.affiliation: School of Public Health, University of California, Berkeley, Berkeley, CA, United States.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Beckerman
authors.affiliation: Department of Information Science, City of Hope National Cancer Center, Duarte, CA, United States.
authors.forename: Arthur
authors.initials: A
authors.lastname: Li
authors.affiliation: School of Public Health, University of California, Los Angeles, Los Angeles, CA, United States.
authors.forename: Beate
authors.initials: B
authors.lastname: Ritz
authors.affiliation: College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, United States.
authors.forename: John
authors.initials: J
authors.lastname: Molitor
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis*; D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis*; D001499:Bayes Theorem; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D006798:Housing; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D015141:Los Angeles / Q000453:epidemiology; D015233:Models, Statistical; D009569:Nitric Oxide / Q000009:adverse effects / Q000032:analysis; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D012111:Residence Characteristics
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D009569:Nitric Oxide; D009585:Nitrogen Dioxide
keywords: Air pollution; Bayesian; Clustering; Low birth weight; Pollutant profile; Profile regression