[Environmental and biological reference values of aromatic polycyclic hydrocarbons].

Minimum requirements for the production of reference values are listed, namely: data of a sufficient number of monitored subjects, individual dosimetric measurements for at least 24 h, answers to an appropriate questionnaire, repetition of measurements at different times of year, and use of an analytical method with known reproducibility and detection limits, the accuracy of which has been established using certified materials or at least interlaboratory calibrations. The few studies reporting individual dosimetric measurements for airborne polycyclic aromatic hydrocarbons are reviewed. Only one of these studies (Minoia et al. 1997), conducted in Pavia with 28 male and 28 female subjects, meets all the requirements for definition of environmental reference values. It found mean benzo(a)pyrene values of 0.37 ng/m3 in winter and 0.12 ng/m3 in summer. Various papers on urinary 1-hydroxypyrene are then discussed and it is found impossible to propose a single biological reference value for populations of different nations, due to differences in environmental conditions and diet. A review of the literature produced in Italy suggests adoption of the biological reference value suggested by Roggi et al. (1996), namely 0.172 microgram/g creat. for non smokers (125 subjects from three Italian towns). Perusal of the literature for other biological indicators of exposure to PAHs, such as 1-naphthol and hydroxyphenanthrenes, suggests that insufficient data is available to establish any reference values.