Urinary mutagens in municipal refuse incinerator workers and water treatment workers

Municipal refuse incineration workers may be exposed to mutagenic compounds from gaseous and particulate emissions and during ash removal operations. The frequency of urinary mutagens was measured by the Ames test among a sample of 104 refuse incinerator workers in seven incinerator plants during March-May 1988. The frequency was compared to that observed in 61 water treatment employees in 11 municipal water treatment facilities during the same period. Incinerator workers had a significantly higher risk for urinary mutagens and promutagens as compared to water plant workers after controlling for age. Among incinerator workers, increased risk of having urinary mutagens was associated with workers who wore protective clothing (defined as clothing other than masks or gloves) or whose job classification was equipment repair. It also showed a weak positive association with increasing age. There was an increased risk of urinary promutagens associated with not wearing gloves. The presence or absence of mutagenicity in workers' urine varied with plant location. Incinerator operating conditions affecting the production of toxicants and mutagens are discussed and the results of other studies involving toxicant exposure of humans near incinerators are cited.