An Exposure Assessment of DI-(2-Ethylhexyl) Phthalate (DEHP) and DI- n -Butyl Phthalate (DBP) in Human Semen

Levels of the phthalates such as di(2-ethylhexyl) phthalate (DEHP), mono(2-ethylhexyl) phthalate (MEHP, a major metabolite of DEHP), di-n-butyl phthalate (DBP), mono-n-butyl phthalate (MBP, a major metabolite of DBP), and phthalic acid (P, (a common metabolite of phthalates, including DEHP and DBP) were determined in the semen samples of 99 healthy volunteers without known prior medicosurgical history. Samples were obtained from young men (age 20-25 yr) who visited a clinic, and the semen concentrations of phthalates were measured using ultra-performance liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS). UPLC/MS/MS showed that mean concentrations in semen samples were 1.07 microg/ml for MEHP, 0.61 microg/ml for DEHP, 0.39 microg/ml for PA, 0.06 microg/ml for MBP, and 0.003 microg/ml for DBP. The concentration of MEHP (the metabolite of DEHP) was highest, and the concentrations of the metabolites including MEHP, MBP, and PA were higher than actual concentrations of parent DEHP and DBP. These findings suggest the detection of phthalates in healthy human semen might require further investigation for effects on human fertility.