Preliminary data suggest an association between infant mortality rates and several measures of ambient air pollution, including dustfall and polycyclic aromatic hydrocarbons (PAH). The effects of airborne PAH components on fetal growth and early childhood development are of primary interest since we have previously demonstrated that these pollutants were associated with significant decrements in birthweight, length and head circumference in Polish newborn babies. The undertaken research combines a state-of-the-art environmental monitoring and molecular approaches with comprehensive neurodevelopment assessments. A further innovation is the incorporation of biomarkers (lead and antioxidants in cord blood) to control for potential confounding of exposure-effect. The mean overall concentrations of specific PAH compounds in Kraków were highest for benzo(b)fluoranthene (23 ng/m3), benzo(a)anthracene (16 ng/m3), indeno(l,2,3-cd)pyrene (14 ng/m3), chyresene (13 ng/m3) and benzo(a)pyrene (12 ng/m3). In general, concentrations of the PAH compounds measured by personal monitoring were considerably higher among the residents of the higher polluted area of the city. The comparison between the Kraków and New York City monitoring ambient data demonstrates that the concentrations and proportions of specific compounds in the total PAH mixture differ widely across these cities. Thus, one may expect that the PAH-related health risks would differ between the two areas not only because exposures are different, but also because the PAH profile differs. Presumably, this different profile is a consequence, at least in part, of variations in the sources of fossil and solid fuels used in production of energy. In Poland, solid fuels such as coal is used to a much greater extent than in New York City, where fossil fuels are the universal source of energy production. Auto emissions for example, are low in benzo(a)pyrene, whereas such emissions from refuse burning are high.