Early-life exposure to a mixture of phenols and respiratory health in preschool children.

INTRODUCTION

Exposure to synthetic phenols is suspected to affect child respiratory health, but epidemiological findings are not consistent and studies on exposure during infancy are lacking. We aimed to investigate the association between exposure to a mixture of phenols in pregnancy and infancy and children's respiratory health.

METHODS

Among 363 mother-child pairs from the Suivi de l'Exposition à la Pollution Atmosphérique durant la Grossesse et Effets sur la Santé cohort, 12 phenols were measured in weekly-pooled urine samples collected twice during pregnancy (second and third trimesters) and in infancy (2 months and 1 year). Children's lung function was assessed through tidal breathing flow-volume loops and nitrogen multiple-breath washout at 2 months, and standard and intra-breath oscillometry at 3 years. Time-specific phenol exposure profiles were identified through cluster analysis and then studied in association with respiratory health using adjusted regression models.

RESULTS

Two exposure profiles were identified at each point in time, characterised by low versus high levels of several phenol compounds. Overall, high exposure profiles were associated with altered oscillometry parameters at 3 years, particularly a high profile in the second trimester with higher frequency dependence of resistance and lower volume dependence of reactance, between a high profile at 2 months and lower reactance at 7 Hz, and between a high profile at 1 year and higher area of the reactance curve, resistance at 7 Hz and volume dependence of resistance.

CONCLUSION

Using repeated and accurate assessments of phenol exposure, this study provides evidence of the deleterious effects of early-life exposure to a mixture of phenols on lung function in preschool children.