A tobacco-related carcinogen: assessing the impact of smoking behaviours of cohabitants on benzene exposure in children

BACKGROUND: Secondhand smoke (SHS) represents a major preventable cause of morbidity for communities, especially for children, who are more susceptible than adults to the adverse effects of passive smoking. SHS contains several carcinogens, including benzene. OBJECTIVE: To investigate the role of household characteristics and the smoking behaviours of cohabitants in predicting SHS-derived benzene exposure levels. Methods In this cross-sectional study, 122 children (aged 5-11 years old) were selected from a school in rural Italy. Characteristics of their home environment and the smoking habits of the children's cohabitants were obtained via questionnaire, and urinary unmodified benzene (u-UB) and cotinine (a specific nicotine metabolite) levels were determined from spot urine samples. RESULTS: Significant differences between SHS-exposed and SHS-unexposed children were found with respect to u-UB levels (median values 359.50 and 92.50 ng/litre, respectively; p<0.001). The excretion of u-UB increased significantly in parallel to increased SHS exposure as follows: unexposed to SHS (median value 92.50 ng/litre)<cohabitant(s) smoker(s) not smoking inside the home (282.00 ng/litre)<cohabitant(s) smoking inside the home only when children are out (314.50 ng/litre)