Analysis of Urinary Metabolites of Polycyclic Aromatic Hydrocarbons in IncinerationWorkers: Masayoshi ICHIBA, et al. Department of Social and Environmental Medicine, Saga Medical School-Incineration workers are exposed to various pyrolysis products of organic materials, heavy metals and polycyclic aromatic hydrocarbons (PAHs). In this study, the exposure of incineration workers to PAHs was evaluated by measuring urinary metabolites of pyrene and naphthalene. The concentrations of urinary 1-hydroxypyrene (1OHP), a metabolite of pyrene, and 2-naphthol (2NP), a metabolite of naphthalene, were measured among 100 workers in 4 different types of incinerators, both before and after their work shifts. These incinerators were two old types, one modern type and one outdoors. The medians of urinary 1OHP of before and after the work shifts obtained from all workers were 0.067 and 0.044 µg/gCr, respectively; and the medians of urinary 2NP were 7.5 and 10.0 µg/ gCr, respectively. A significant increase of 2NP after the work shift was found at one old incinerator. A significant decrease of metabolites was found at the other old incinerator. Significant correlations were found between urinary metabolites and cigarettes smoked per day. The effect of smoking on urinary metabolite levels was also important. Significant correlations were found between urinary 1OHP and 2NP levels in all workers. In multiple regression analysis smoking habit and incinerator type were found as significant factors. The improvement of the work environment, through decreasing exposure to both tobacco smoke and hazardous work shift-related substances, should be an occupational health aim. Field StudyKey words: Polycyclic aromatic hydrocarbon, Incineration workers, 1-hydroxypyrene, 2-naphthol Incineration workers are exposed to various pyrolysis products of organic materials, including dioxin, heavy metals and polycyclic aromatic hydrocarbons (PAHs). There have been some studies on biomonitoring of pyrolysis products, heavy metals and PAHs in incineration workers [1][2][3][4][5][6][7] . In these studies, urinary metabolites of PAHs were measured as the occupational exposure markers. The most common metabolites of PAHs are urinary 1-hydroxypyrene (1OHP), a metabolite of pyrene, or 2-naphthol (2NP), a metabolite of naphthalene 8,9) . Pyrene and naphthalene were not thought of as carcinogens. The reasons for measuring them are that their urinary concentrations are relatively high and their measurements are easier compared to those of carcinogenic PAHs, such as benzo[a]pyrene. Recently naphthalene was reclassified as being possibly carcinogenic to humans by IARC in 2002 10) . Consequently, the importance of measuring naphthalene metabolite levels has increased. There have been few reports concerning the measurement of both urinary 1OHP and 2NP at the same time in incineration workers, and the data in previous studies has usually been taken at a single incinerator site. Few studies have compared metabolite measurements at different incinerator site.I...