OBJECTIVETo investigate the relationship between the level of di-2-ethylhexyl phthalate (DEHP) and idiopathic oligoasthenospermia by measuring the content of DEHP in the semen samples of different subjects.

METHODSWe obtained semen samples from 100 infertile men with idiopathic oligoasthenospermia, 50 working all the year round in the plastic greenhouse (group A) and the other 50 constantly dining from plastic meal boxes (group B). We also enrolled 50 normal male volunteers as controls (group C). We conducted semen analyses using a computer-assisted sperm analyzer, measured the DEHP concentration by reversed-phase high-pressure liquid chromatography, and subjected the data to statistic processing by t-test and correlation analysis.

RESULTSThe mean concentrations of DEHP in the seminal plasma were (0.72 +/- 0.48), (0.71 +/- 0.49) and (0.21 +/- 0.18) mg/L in groups A, B and C, respectively, significantly higher in A and B than in C (both P < 0.05). The DEHP concentration was negatively correlated with sperm motility (P < 0.05).

CONCLUSIONThe DEHP level in the seminal plasma is higher in infertile men frequently exposed to plastic products than in normal males and excessive DEHP may be one of the important factors of idiopathic male infertility.