Evaluation of benzene exposure in children living in Campania (Italy) by urinary trans,trans-muconic acid assay

The urinary benzene metabolite trans,trans-muconic acid (MA) was determined in 144 children living in Campania (Italy): 92 from Naples (1,300,000 inha bitants), designated as an urban source, and compared to 52 from Pollica (3 00 inhabitants), considered a rural. background exposure for benzene. The c hildren participating in the study were tested by an anonymous questionnair e about the possible sources of exposure to benzene. Quantifiable levels of MA were found in 63% of the urine samples analyzed. Setting the value of n ondetectable urinary samples at 7 mug/L MA, a value that is one-half of the instrument detection limit of 14 mug/L, the mean urinary concentration lev els were 98.7 +/- 81.0 mug/L and 48.4 +/- 71.7 mug/L in Naples and Pollica, respectively; adjustment of these values to creatinine clearance resulted in MA levels of 141.2 +/- 145.4 mug/L in Naples and 109.8 +/- 133.2 mug/L i n Pollica. Passive smoke exposure did not significantly affect urinary MA l evels, but proximity of the home to traffic increased urine MA content. Dat a show that MA can be utilized as a biomarker for exposure; however, a clea r-cut association to benzene requires personal monitoring and control of di etary sorbic acid.