Exposure levels and influencing factors of di(2-ethylhexyl) phthalate in urine of adults in a hospital of Jilin Province, China

Objective To assess the urinary di(2-ethylhexyl) phthalate (DEHP) metabolite level and its determinants in adults.

Methods A total of 210 adults from a hospital in Jilin Province were included in the study in March 2022, urina sanguinis specimens were collected and urine levels of five metabolites of DEHP, including mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-carboxymethylhexyl) phthalate (MCMHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), were determined by high performance liquid chromatography tandem mass spectrometry. The relationships between the concentrations of DEHP metabolites in the urine were examined using Spearman's correlation analysis. The difference in DEHP metabolites level between items of each variable was examined using independent samples t-test. The relationships between the selected factors and the DEHP metabolite levels in urine were analyzed using a multiple linear regression model.

Results The detection rates of MEHP and MEOHP were 98.6% and 99.5%, and those of MEHHP, MCMHP, and MECPP were 100.0%, respectively. MCMHP showed the highest median metabolite concentration of 14.54 μg/L (14.10 μg/g creatinine). After adjusting for covariates, active smoking was significantly associated with urinary MEOHP (β=-0.151, 95%CI: -0.299, -0.004). Passive smoking was significantly associated with MCMHP (β=-0.184, 95% CI: -0.323, -0.045), MECPP (β=-0.192, 95%CI: -0.332, -0.051), and ΣDEHP (β=-0.146, 95%CI: -0.291, -0.001). The use of plastic water cups was significantly related to MEHHP (β=-0.147, 95% CI: -0.284, -0.009). The frequency of skin care cosmetics use was significantly associated with MEOHP (β=-0.115, 95% CI: -0.297, -0.012) and MEHHP (β=-0.194, 95% CI: -0.337, -0.051).

Conclusion Most adults in this study were exposed to DEHP. No smoking, avoiding exposure to second-hand smoke, reducing the use of plastic water cups and skin care cosmetics in daily life may decrease DEHP exposure levels.