Exposure to air pollution during the first 1000 days of life and subsequent health service and medication usage in children

Background: Evidence of health effects following early life exposure to short-to-medium duration of high pollution levels is extremely limited.

Objectives: We aimed to evaluate the associations between: 1. intrauterine exposure to fine particulate matter (PM_2.5) from coal mine fire emissions and the frequencies of general practitioner attendances and dispensations of prescribed asthma inhalers, steroid skin creams, and antibiotics during the first year of life; 2. infant exposure and those outcomes during the year following the fire.

Methods: All participants were recruited from the Latrobe Valley of Victoria, Australia. Participants’ 24-h average and hourly peak mine fire-specific PM_2.5 exposures from 09/02/2014 to 31/03/2014 were estimated using chemical transport modelling. Outcome data were obtained from the Australian Medicare Benefits Schedule and Pharmaceutical Benefits Scheme from each child’s birth to 31/12/2016. We used negative binomial and logistic regression models to independently assess risks of the outcomes associated with every 10 and 100 μg m⁻³ increase in average or peak PM_2.5 exposure, respectively, while adjusting for potential confounders.

Results: We included 286 of 311 children whose parents consented to be linked, comprising 77 with no exposure, 88 with intrauterine exposure and 121 with exposure in infancy. 10- and 100- μg m⁻³ increases in average and peak PM_2.5 exposure during infancy were associated with greater incidence of antibiotics being dispensed during the year following the fire: the adjusted incidence rate ratios were 1.24 (95% CI 1.02, 1.50, p = 0.036) and 1.14 (1.00, 1.31, p = 0.048) respectively. No other significant associations were observed.

Conclusion: Exposure to coal mine fire emissions during infancy was associated with increased dispensing of antibiotics. This could reflect increased childhood infections or increased prescriptions of antibiotics in the year following the fire.