Levels of urinary metabolites of four PAHs and cotinine determined in 1016 volunteers living in Central Italy.

Polycyclic aromatic hydrocarbons (PAH) are products of the incomplete combustion of organic materials, and exposure of the general population to PAH is ubiquitous. They are also present in tobacco smoke. Some PAH are classified as carcinogens. Urine samples from 747 non-smoking and 269 smoking subjects living in the same area of Central Italy were analyzed in order to determine reference values for PAHs exposure of a general population. The concentration of cotinine, urinary metabolite of nicotine was also measured in these samples in order to classify the subjects as smokers or not. The median concentration and 50th percentile in females was higher than in males for all metabolites; 1- and 2-hydroxynaphtalene (1-OHNAP and 2-OHNAP) and 1-hydroxypyrene (1-OHPy), are significantly higher in smokers; on the other side 3-hydroxybenzo[a]pyrene (3-OHBaPy) and 6-hydroxynitropyrene (6-OHNPy) do not correlate with the cotinine concentration.