BENZENE EXPOSURE, ASSESSED BY URINARY TRANS,TRANS-MUCONIC ACID, IN URBAN CHILDREN WITH ELEVATED BLOOD LEAD LEVELS

A pilot study was performed to evaluate the feasibility of using trans ,trans-muconic acid (MA) as a biomarker of environmental benzene expos ure. A secondary aim was to provide data on the extent of exposure to selected toxicants in a unique population consisting of inner-city chi ldren who were already overexposed to one urban hazard, lead. Potentia l sources of benzene were assessed by a questionnaire. Exposure biomar kers including urinary MA and continine and blood lead. Mean MA was 17 6.6 +/- 341.7 ng/mg creatinine in the 79 children who participated. A wide range of values was found with as many as 10.1%, depending on the comparison study, above the highest levels reported in adults not exp osed by occupation. Mean MA was increased in children evaluated in the afternoon compared to morning, those at or above the median for time spent playing near the street, and those studied in the first half of the investigation. MA levels were not associated with blood lead or, c onsistently, with either questionnaire environmental tobacco smoke (ET S) data or cotinine. As expected, the mean blood lead level was elevat ed (23.6 mu g/dl). Mean continine was also increased at 79.2 ng/mg cre atinine. We conclude that the use of MA as a biomarker for environment al benzene exposure is feasible since it was detectable in 72% of subj ects with a wide range of values present. In future studies, correlati on of MA with personal air sampling in environmental exposure will be essential to fully interpret the significance of these findings. In ad dition, these inner-city children comprise a high risk group for expos ure to environmental toxicants including ETS, lead, and probably benze ne, based on questionnaire sources and its presence in ETS.