Associations between urinary monohydroxylated polycyclic aromatic hydrocarbons and unexplained recurrent spontaneous abortion and health risk assessment in a large case-control study in China

Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental endocrine disruptors with known carcinogenic, reproductive, and developmental toxicity. Important knowledge gaps remain regarding the rela-tionship between PAH exposure and unexplained recurrent spontaneous abortion (URSA). In the present study, twelve monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were measured in the urine of 413 URSA cases and 434 controls. The main OH-PAHs measured in this study were monohydroxy metabolites of naphthalene, followed by fluorene and phenanthrene. After the creatinine correction, the median concentration of urinary OH-PAHs in the control group (17.4 mu g/g Creatinine) was higher than that in the case group (14.2 mu g/g Creatinine). There was no positive relationship between PAH exposure and URSA using binary logistic regression analysis. Among 847 Chinese women of childbearing age, residential environment, type of drinking water, and education level were the influencing factors of PAH exposure. The health risk assessment showed that over 98% of women had a carcinogenic risk with carcinogenic risk values above the acceptable level (10-6). Although this large-scale case-control study did not observe an association between PAH exposure and URSA, more attention should be paid to the high carcinogenic risk due to PAH exposure in women of reproductive age.