Prenatal, early-life and childhood exposure to air pollution and lung function in the UK Avon Longitudinal Study of Parents and Children (ALSPAC) cohort

Rationale: This study investigated asssociations of source-specific air pollution exposure during pregnancy trimesters, infancy and childhood in relation to lung function at ages eight and 15 years in ~14,000 children.

Methods: Individual exposure to primary road, local and long range particulate matter with diameter ≤10µm (PM10) were estimated using dispersion modelling for each pregnancy trimester, ages 0-6 months, 7-12 months (1990-1993) and annually to age 15 years (1991-2008). Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were measured at age eight and 15 years and converted into age-height-gender adjusted z-scores. Linear regression analyses were conducted, adjusting for potential confounders.

Results: 13,963 study children were included in the analysis. At age 8 years, exposure to interquartile range (IQR) higher primary PM10 (0.72µg/m3) from road traffic during the first trimester was associated with lower FEV1 (-0.049, 95%CI:-0.082 to -0.016) and FVC (-0.048, 95%CI:-0.081 to -0.015) z-scores. Similar associations were also seen for exposures during the second and third trimester, and during 0-6 months, 7-12 months, and 0-7 years. Associations were stronger among boys, children whose mother had a lower education level or smoked in pregnancy. PM10 from all sources during the third trimester was significantly associated with lower FVC z-scores. No significant negative associations were seen at age 15 years.

Conclusions: 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 eight years.