Serum phthalate esters levels and their correlation with sex hormones in human.

[Objective] To evaluate the exposure level of di[2-ethylhexyl] phthalate(DEHP)and di-n-butyl phthalate(DBP) in human,and to study their correlation with the levels of sex hormones Estrogen(E2)and Testosterone(T).[Methods] Serum samples were collected intravenously from 420 university students who are residents of Shanghai,aged 18 to 19(male 216,female 204).For DEHP and DBP level determination,samples were separated using a temperature program and extracted using liquid phase extraction.Prepared samples were then run through GC-MS.Esters concentrations were calculated using a 5-point standard curve.To determine blood hormone levels,a fully automated ELISA and chemiluminescence detection was used.[Results] The minimum detectable level for both DEHP and DBP were 0.1 μg/L with the linear range of 1-10 000 μg/L.Recovery percentage of DEHP and DBP were 91.3%-94.0% and 91.2%-94.1%,respectively.Coefficients of variation of DEHP and DBP were 0.49%-2.79% and 0.61%-3.42%,respectively.Background contamination was not detected.Of the 420 samples examined,88(male 41,female 47)showed a DEHP level above the minimum detectable value with the mean concentration of 54.14 μg/L and QR of 40.22 μg/L.There was no significant gender difference in percentage and concentrations(P 0.05).DBP was detected only in 7(male 1,female 6)out of 420 samples with the mean value of 10.17 μg/L and QR of 9.30 μg/L.It was found in the 41 male with positive DEHP that their DEHP levels had a positive correlation with their testosterone levels(Rs=0.347,P=0.048).Compared with the 59 DEHP negative males,DEHP positive males had higher E2 leve(lP=0.035).Furthermore,data suggested that DEHP positive rate increased as the E2 level increased(β=-0.017,OR=0.983,P=0.021).[Conclusion] DEHP positive rate was much higher than that of DBP in objects studied,indicating a higher DEHP exposure level.There was a correlation between DEHP level and testosterone in males.DEHP positive group had higher E2 level than the negative group.