Within this research project, several biomarkers were evaluated for their use as internal dosimeters of benzene exposure. Urinary benzene and urinary trans, trans-muconic acid were shown to be suitable as sensitive, non-invasive biomarkers of exposure to low (<1 ppm) benzene concentrations, with potential applicability in human biomonitoring. The exposure profile of people handling petroleum fuels was analysed with respect to indirect exposure indexes (eg type and amount of fuel delivered). The benefit of the reduction of benzene content in gasoline was highlighted by a time trend analysis during the years 1992-1995.
The analysis of different markers of deoxyribonucleic acid (DNA) damage in human biomonitoring demonstrated the sensitivity of molecular cytogenetic techniques and new biomarkers of DNA damage (alkaline single cell gel electrophoresis, excretion of modified DNA bases) in the assessment of the biological effects of exposure to low benzene and petroleum fuels. Retrospective cohort epidemiological studies in fuel station attendants showed increased relative risks among workers with relatively greater benzene exposure. A cross sectional epidemiological study suggested increased risks for several pathological parameters, including lung function and allergic diseases, in children living in polluted areas. Environmental surveys confirmed the ubiquity of benzene pollution in urban and industrial areas, at levels not much lower than those which were shown to elicit a biological effect in occupationally exposed individuals, supporting the need for environmental reduction of benzene pollution.
