Influence of genetic polymorphism on t,t-MA/S-PMA ratio in 301 benzene exposed subjects.

This study investigated the effect of polymorphic genes GSTT1, GSTM1, GSTA1, EHPX1, NQO1, CYP2E1, CYP1A and MPO on the urinary concentrations and ratio (R) of the benzene metabolites trans,trans-muconic acid (t,t-MA) and S-phenyl mercapturic acid (S-PMA) in 301 oil refinery workers. The metabolites' concentrations are lower and R is higher (100.66) in non-smokers (n=184) than in smokers (n=117, R=36.