Urinary metabolites of di(2-ethylhexyl) phthalate relation to sperm motility, reactive oxygen species generation, and apoptosis in polyvinyl chloride workers
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To measure the concentrations of urinary di(2-ethylhexyl) phthalate (DEHP) metabolites in polyvinyl chloride (PVC) workers and a control group for determining the relationship of DEHP exposure to semen quality, sperm reactive oxygen species (ROS) generation, and sperm apoptosis.
We assessed the metabolites of DEHP, namely urinary mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and semen quality, such as sperm concentration, motility, morphology, ROS generation, and DNA damage by using terminal deoxynucleotidyl transferase-mediated nick end labeling assay obtained from 47 workers employed within two PVC pellet plants and 15 graduate students in Taiwan.
Sperm concentration and motility were significantly affected in the high-exposure group. The percentage and intensity of sperm ROS generation were higher in the high-exposure group than those in the control group. After adjustment for age, smoking status, and coffee consumption, the decrease in sperm motility was inversely associated with the concentration of MEHP (β = −0.549, p = 0.0085), MEHHP (β = −0.155, p = 0.0074), and MEOHP (β = −0.201, p = 0.0041). Moreover, sperm apoptosis and ROS generation were positively associated with MEHHP and MEOHP concentration, respectively.
This was the first study to explore the associations between levels of DEHP exposure, sperm motility, ROS generation, and apoptosis. The results suggested that urinary MEHHP and MEOHP were sensitive biomarkers for reflecting the relationship between DEHP exposure and semen quality.
KeywordsDi(2-ethylhexyl) phthalate Urinary metabolites Semen quality Apoptosis TUNEL assay
Body mass index
Geometric standard deviation
Nicotinamide adenine dinucleotide phosphate
Reactive oxygen species
Sperm chromatin DNA structure assay
Terminal deoxynucleotidyl transferase-mediated nick end labeling
The authors acknowledge the financial support provided by the Institute of Occupational Safety and Health (IOSH98-M306) and the National Science Council (NSC 100-2314-B-327-001) of Taiwan.
Conflict of interest
The authors declare that they have no conflict interest.
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