Urinary Levels of Free 2,5-Hexanedione in Italian Subjects Non-Occupationally Exposed to n-Hexane

The purpose of the study is to evaluate the urinary levels of free 2,5-hexanedione (2,5-HD) in Italian subjects non-occupationally exposed to n-hexane, in order to define background values in non-occupational settings. The study was carried out on 99 subjects of the general population. The analysis of free 2,5-HD was performed by gas chromatography-mass spectrometry. Personal information about the subjects was ascertained by means of a self-administered questionnaire. The urinary levels of free 2,5-HD were in the range of <12.0-77.9 mu g/L (5th-95th percentiles). The urinary excretion of the metabolite did not seem to be influenced by gender, age, smoking habit or area of residence. Statistically significant differences (p = 0.03) were found between the free 2,5-HD urinary levels according to the vehicular traffic intensity within the area of residence and to body mass index of subjects. The background levels of free 2,5-HD found in this study could contribute to the definition of reference values of general population non-occupationally exposed and could be useful to the toxicologists and industrial hygienists to determine whether workers have been exposed to higher levels of n-hexane than the general population.