A recent study has reportedly identified “an association between postnatal urinary bisphenol A (BPA) concentrations and asthma in children.” Kathleen Donohue, et al., “Prenatal and postnatal bisphenol A exposure and asthma development among inner-city children,” Journal of Allergy and Clinical Immunology, March 2013. Columbia University researchers apparently used urinary samples collected from pregnant women during their third trimesters and from their children at ages 3, 5 and 7 years to conclude that BPA concentrations (i) “at age 3 years were associated positively with wheeze at ages 5 years … and 6 years,” (ii) “at age 7 years were associated with wheeze at age 7,” and (iii) “at ages 3, 5, and 7 years were associated with asthma measured at ages 5 to 12 years.”

The authors also noted, however, that “prenatal BPA concentrations were associated inversely with odds of wheeze at age 5 years,” a finding that contradicted their initial hypothesis and led them to suggest, among other things, that “children’s greater food consumption in proportion to body weight” might account for their higher urinary BPA concentrations when compared to maternal prenatal samples. “The mechanism by which BPA exposure during early childhood might influence asthma risk in subsequent years remains an open question,” concludes the study, which ultimately cites previous research speculating that BPA might influence asthma risk “through upregulation of TH2 pathways and possibly reductions in regulatory T-cell counts.”