Objective: To explore the effects of interaction between environmental exposure factors and genetic polymorphism in toxicant metabolizing enzymes on risk of occupational chronic benzene poisoning.
Methods: One hundred and fifty-two cases of chronic benzene poisoning were analyzed for the risk by case-only study.
Results: The frequency of non-null GSTT1 gene in benzene poisoning workers with moderate benzene exposure level was higher than that in cases with lower benzene exposure (68.63% vs 38.00%, OR(adj) = 4.32, 95% CI 1.75 - 10.66, P = 0.002). The frequency of NQO1 C.609T/T gene in alcohol drinking group was higher than that in non-drinking group (61.11% vs 20.00%, OR(adj) = 8.03, 95% CI 2.28 - 28.25, P = 0.001), moreover, it was higher in workers with smoking and drinking than that in the rest group, and in drinking x exposure level workers than that in non-drinking x exposure level workers (85.71% vs 22.76%, OR(adj) = 18.62, 95% CI 2.01 - 172.72, P = 0.01 and 61.11% vs 20.00%, OR(adj) = 3.18, 95% CI 1.55 - 6.52, P = 0.002 respectively). The frequency of non-null GSTM1 gene was also higher in drinking x exposure level workers than that in non-drinking x exposure level workers (66.67% vs 47.06%, OR(adj) = 1.99, 95% CI 1.05 - 3.76, P = 0.036).
Conclusion: There is interaction between the polymorphism of GSTT1 gene and moderate benzene exposure level; non-null GSTM1 gene and drinking x exposure level increase the risk of occupational chronic benzene poisoning; polymorphism of NQO1 gene C.609 also interacts with drinking, while polymorphism of NQO1 gene and drinking x smoking may further increase the risk of occupational chronic benzene poisoning.