Phthalates exposure of Chinese reproductive age couples and its effect on male semen quality, a primary study

Phthalates are suspected of having adverse effects on androgen-regulated reproductive development in animals and may be toxic for human sperm. The purposes of our study were to investigate the general exposure of a Chinese reproductive age cohort to these ubiquitous pollutants and to assess their potential effect on semen quality.Six phthalate metabolites, monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), monobenzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), and mono-2-ethyl-5-oxohexyl phthalate (MEOHP) were measured in spot urines of 150 individuals recruited from a Chongqing, China, reproductive institute. The questionnaire and clinical data were evaluated, and the correlations of phthalate exposure and semen qualities like semen volume, sperm concentration, motility and sperm motion parameters, were determined by multiple logistic regression analysis.The creatinine adjusted average concentrations for MMP, MEP, MBP, MBzP, MEHP and MEOHP were 41.3, 300, 41.0, 0.78, 2.99 and 3.90 μg/g, respectively. After adjustment for age, body mass index (BMI), abstinence, smoking, drinking, and education, there was a borderline-significant dose–response relationship between MBP and sperm concentration, with odd ratios (ORs) 1.0, 6.8 and 12.0 for increasing exposure tertiles (p = 0.05). Although the dose–response relationships for MMP and MEP versus sperm concentration were not significant, a significant positive correlation between MEP and straight-line velocity of sperm motion was observed.The present data may imply some effects of phthalate exposure on semen. However, due to the small sample size, our finding needs to be confirmed on a larger population.

Research highlights
► In this report, we investigated 6 phthalate mono esters in urine of a reproductive age cohort from Chongqing, China.
► To our knowledge, this is the first study based on Chinese cohort to investigate the reproductive age phthalate exposure and the relationship between phthalate exposure and semen quality.
► The preliminary results suggest that the subjects are commonly exposure to phthalate, and the phthalate exposure (MBP, MEP, and MMP) may play a potential role in reproduction age males’ semen quality on these Chinese men.
► In view of human reproductive health and current widespread use of phthalate in China as well as our preliminary results, the report will be a valuable reference for the further environmental health studies.