The aim of this study was to investigate the association between coke oven emissions (COEs) exposure and total antioxidant capacity (T-AOC), and to explore whether genetic variations in metabolic enzyme genes GSTT1, GSTM1, GSTP1, and CYP2E1 can affect these associations in coke oven workers.

536 coke oven workers and 238 healthy controls were recruited. T-AOC of plasma was determined with kit. Five polymorphic loci of GSTT1 (+/-), GSTM1 (+/-), GSTP1 rs1695, CYP2E1 rs6413432 and CYP2E1 rs3813867 were detected by polymerase chain reaction and restriction fragment length polymorphism.

This study shows that the T-AOC in exposure group (12.02 ± 4.72) was significantly lower than that in control group (15.32 ± 7.19) (P < 0.01), and the COEs exposure could decrease the T-AOC of coke oven workers significantly [β(95% CI) = -2.663 (-4.538,-0.787), P < 0.001]. The T-AOC of female was lower than that of male in exposed and control groups (P < 0.001). The T-AOC was higher in GSTM1 (-) individuals than in GSTM1 (+) individuals in the control group (P = 0.037). The T-AOC with the AG genotype in GSTP1 rs1695 polymorphism was higher than that of the GG genotype in the control group (P = 0.043). The generalized linear model results showed that the risk factors for the decrease of T-AOC include GSTT1 (+) (b = -0.999, P = 0.009), female (b = -2.875, P < 0.01), COEs-exposed (b = -2.712, P = 0.004), GSTM1 (+) (b = -1.814, P = 0.008), and interactions of GSTM1 (+) and COEs-exposed (b = 1.872, P=0.024).

The risk factors for the decrease of T-AOC include GSTT1 (+), female, COEs-exposed, GSTM1 (+), and interactions of GSTM1 (+) and COEs-exposed.