Modulation of the effect of prenatal PAH exposure on PAH-DNA adducts in cord blood by plasma antioxidants.

The fetus is more susceptible than the adult to the effects of certain carcinogens, such as polycyclic aromatic hydrocarbons (PAH). Nutritional factors, including antioxidants, have been shown to have a protective effect on carcinogen-DNA adducts and cancer risk in adults. We investigated whether the effect of prenatal airborne PAH exposure, measured by personal air monitoring during pregnancy, on the level of PAH-DNA adducts in a baby's cord blood is modified by the concentration of micronutrients in maternal and cord blood. The micronutrients examined were: retinol (vitamin A), alpha-tocopherol and gamma-tocopherol (vitamin E), and carotenoids. With the use of multiple linear regression, we found a significant interaction between prenatal PAH exposure and cord blood concentration of alpha-tocopherol and carotenoids in predicting the concentration of PAH adducts in cord blood. The association between PAH exposure and PAH adducts was much stronger among those with low alpha-tocopherol (beta = 0.15; P = 0.001) and among those with low carotenoids (beta = 0.16; P < 0.001) compared with babies with high levels of these micronutrients (among those with high alpha-tocopherol: beta = 0.05; P = 0.165; among those with high carotenoids: beta = 0.06; P = 0.111). These results suggest a protective effect of micronutrients on the DNA damage and potential cancer risk associated with prenatal PAH exposure.