PRENATAL AMBIENT EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS IN AIR POLLUTION COMPOUNDS AND THE OCCURRENCE OF RESPIRATORY SYMPTOMS OVER THE FIRST YEAR OF LIFE

Abstract

ISEE-100 Aim: The purpose of the study was to test the hypothesis that infants with higher levels of prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) from fossil fuel combustion may be at greater risk of developing respiratory symptoms. Methods: The study was carried out in a cohort of 333 newborns in Krakow, Poland, followed over the first year of life, for whom the data from prenatal personal air monitoring of mothers in the second trimester of pregnancy were available. The relative risks of respiratory symptoms due to prenatal PAH exposure were adjusted for potential confounders (gender of child, birth weight, maternal atopy, maternal education as a proxy for the socio-economic status, exposure to postnatal environmental tobacco smoke, and moulds in households) in the Poisson regression models. Results: Increased risk related to prenatal PAH exposure was observed for the occurrence of various respiratory symptoms such as for barking cough (RR = 4.80; 95% CI = 2.73–8.44), wheezing without cold (RR = 3.83; 95% CI = 1.18–12.43), sore throat (RR = 2.56; 95% CI = 1.57–4.16), ear infection (RR = 1.82; 95% CI = 1.03–3.23), cough irrespective of respiratory infections (RR = 1.27; 95% CI = 1.07–1.52), and cough without cold (RR = 1.72; 95% CI = 1.02–2.92). PAH exposure had an impact on the duration of respiratory symptoms as well. Conclusion: Since barking cough and wheezing are basic features of allergic inflammation in bronchial airways, the results of the study suggest that prenatal PAH exposure may increase the risk of other factors that can enhance allergic reaction inflammation. PAH exposure may also increase respiratory symptoms in the postnatal period. The results indicate that reduction of prenatal exposure to these common urban pollutants can benefit respiratory health of infants. The study also calls attention to the fact that prenatal exposure to PAHs was not only related to higher occurrence of respiratory symptoms, but also inversely correlated with weight, length, and reduced head circumference at birth.