Fine particulate matter exposure and incident atopic dermatitis: A birth cohort study

Understudied the association between exposure to fine particulate matter (PM2.5) from conception to one year after birth and later development of atopic dermatitis (AD) has not been completely elucidated. To investigate the effects of PM2.5 exposure during pregnancy and infancy on AD and explore sensitive time windows to identify biological pathways of the effects of PM2.5 on AD. A birth cohort study comprising 564,869 term births born between 2004-2013 and followed up until 5 years after birth. A satellite-based model was used to calculate PM2.5 exposure for each child. A Cox proportional hazard model combined with a distributed lag non-linear model was performed to examine the associations of AD with PM2.5, as well as the dose-response relationship. The birth cohort comprised of 76,944 cases diagnosed with AD. Increased cumulative exposure to PM2.5 from 34 weeks of gestation until birth, as well as from 33 weeks after birth during infancy, was significantly associated with a higher incidence of AD. In the dose-response relationship, exposure to PM2.5 more than 65 μg/m3 might sharply increase the risk of AD. Both prenatal and postnatal exposures to PM2.5 were related to later development of AD. The susceptible time windows may be late gestation and early life after birth.