Prenatal, Early-Life and Lifetime Exposure to Air Pollution and Childhood Lung Function and Asthma: The Avon Longitudinal Study of Parents and Children (ALSPAC) Cohort Study

Abstract

Background: Only a few studies have investigated early-life air pollution exposures on childhood lung function and asthma, with inconsistent results. We examined associations of exposure to air pollution during pregnancy, infancy and lifetime periods with lung function and current asthma in the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort.Methods: Forced expiratory volume in 1 second (FEV1) and Forced vital capacity (FVC) were measured at age 8 years and converted into age-height-gender adjusted z-scores. Current asthma was derived from answers to relevant questionnaire items. Exposures to source-specific particulate matter with a diameter≤10µm (PM10) during each trimester, 0-6 months, 7-12 months (1990-1993) through childhood up to age 8 years (1991-2001) were estimated using a dispersion model, accounting for residential mobility. Linear and logistic regression models were fitted to explore the associations, adjusting for gestational age, damp and mould at home, passive smoking exposure, home ownership, maternal education and smoking during pregnancy.Results: 13,963 study children were included in this analysis. At age 8 years, exposure to interquartile (IQR) higher PM10 (0.72µg/m3) from road traffic during the first trimester was associated with lower FEV1 (-0.05, 95%CI:-0.08 to -0.02) and FVC (-0.05, 95%CI:-0.08 to -0.02) z-scores. Similar significant associations were also seen with PM10 in the second and third trimester, 0-6months, 7-12 months and 0-7 years. Associations were stronger among children whose mother had a lower education level or smoked during pregnancy. PM10 from all sources during the third trimester was significantly associated with lower FVC z-scores. Current asthma was not associated with PM10 at any time periods.Conclusion: Preliminary results suggested that exposure to road-traffic PM10 from as early as in the first trimester may result in small but significant reductions in lung function at age 8 years.