Urinary benzene and trans,trans-muconic acid excretion as biomakers of low level occupational exposure to benzene

Misurament of urinary trans,trans muconic acid excretion is considered a reliable biomarker of occupational exposure to benzene.However at low level occupational and environmental exposure, an increased dietary intake of sorbic acid, a common anti-oxidant,can greatly reduce its specificity.Direct monitoring of urinary benzene requires technical prcautions and numerous non occipational sources of exposure might make it difficult using it as an indicator of low level occupational exposure.Within the Italian multicentre project on the " Effect of genetic polymorphisms and non occupational exposures on the inter-individual variability of biomarkers of exposure to benzene and PAH" cordinated nation-wide by the Clinica Devoto" of the University of Milan, we measured pre-shift and end-shift urinary excretion of benzene and t,t-MA in 33 oil refinery workers and 35 military fuel attendants of the Italian Air Force