Long term effects of prenatal and postnatal airborne PAH exposures on ventilatory lung function of non-asthmatic preadolescent children. Prospective birth cohort study in Krakow

Abstract

The main goal of the study was to test the hypothesis that prenatal and postnatal exposures to polycyclic aromatic hydrocarbons (PAH) are associated with depressed lung function in non-asthmatic children. The study sample comprises 195 non-asthmatic children of non-smoking mothers, among whom the prenatal PAH exposure was assessed by personal air monitoring in pregnancy. At the age of 3, residential air monitoring was carried out to evaluate the residential PAH exposure indoors and outdoors. At the age of 5 to 8, children were given allergic skin tests for indoor allergens; and between 5 and 9 years lung function testing (FVC, FEV05, FEV1 and FEF25-75) was performed. The effects of prenatal PAH exposure on lung function tests repeated over the follow-up were adjusted in the General Estimated Equation (GEE) model for the relevant covariates. No association between FVC with prenatal PAH exposure was found; however for the FEV1 deficit associated with higher prenatal PAH exposure (above 37 ng/m(3)) amounted to 53 mL (p=0.050) and the deficit of FEF25-75 reached 164 mL (p=0.013). The corresponding deficits related to postnatal residential indoor PAH level (above 42 ng/m(3)) were 59 mL of FEV1 (p=0.028) and 140 mL of FEF25-75 (p=0.031). At the higher residential outdoor PAH level (above 90 ng/m(3)) slightly greater deficit of FEV1 (71 mL, p=0.009) was observed. The results of the study suggest that transplacental exposure to PAH compromises the normal developmental process of respiratory airways and that this effect is compounded by postnatal PAH exposure.

Keywords: Air pollution; Birth cohort; Lung function; Prenatal exposure; Preschool children.

Figure 1

The flow chart illustrating the availabity of parcipants and data collection at the various ages

Figure 2

Prenatal (2000–2003) and postnatal (2003–2007) residential PAH levels (gmean with 95% CI) measured in non-heating and heating seasons.

Figure 3

Height of children measured at various ages during the follow-up

Figure 4

Predicted average values of FEV₁ (based on GEE model) by the prenatal PAH concentrations (ln-transformed) at various levels of residential outdoor PAH concentrations (local polynomial smoothing)