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ObjectivesPossible relationship between semen quality (semen volume, sperm concentration and sperm motility) and parabens exposure was investigated in male partners of couples who visited a gynecology clinic in Tokyo for infertility consultation (n = 42, 36.8 ± 5.4 years).MethodsSemen parameters were measured according to WHO guideline at the clinic, and urinary methyl- (MP), ethyl- (EP), propyl- (PP) and butyl (BP) paraben concentrations were measured with liquid chromatography-tandem mass spectrometry.ResultsGeometric mean urinary concentrations (geometric standard deviation) of the subjects were 48.2 (4.52), 1.88 (4.72), 1.13 (6.75) and 0.184 (11.1) ng/mL for MP, EP, PP and BP, respectively. No significant association was found between semen parameters and urinary paraben concentrations in multiple regression analyses and logistic regression analyses.ConclusionsTwo reasons of the absence of adverse effects on semen quality might be suggested: lower paraben exposure level of the subjects and small sample size. Further investigation of effect of paraben exposure among general male population at environmental levels is warranted.

During a cross-validation practice of urinary analysis of pyrethroid insecticide metabolite (3-phenoxybenzoic acid, 3-PBA) by two laboratories (Lab A and Lab B), difference in 3-PBA concentration was noticed. The analytical methods used in the exercise were enzymatic deconjugation (glucuronidase/sulfatase) followed by solid phase extraction and isotope dilution LC-MS-MS determination (Lab A) and acidic deconjugation followed by liquid-liquid extraction and gas chromatography-mass spectrometry determination (Lab B). A significant difference was found for one of the five samples: lower value was obtained in Lab A. Use of acidic deconjugation in Lab A resulted in comparable value with the analytical result for this sample originally obtained in Lab B. The comparison was extended to 42 urine samples taken from Japanese males in Lab A by using the two different deconjugation methods and LC-MS-MS determination. Significantly lower value was obtained for enzymatic deconjugation in some of the 42 urine samples. The results suggested the presence of other conjugated species of 3-PBA than glucuronide and sulfate in human urine. Although the overall agreement between the values obtained by the deconjugation methods was fair, it appears that urine samples should be pretreated by acidic deconjugation for the analysis in biological monitoring of pyrethroid exposure.

Inorganic arsenic (iAs) has been known as a testicular toxicant in experimental rodents. Possible association between iAs exposure and semen quality (semen volume, sperm concentration, and sperm motility) was explored in male partners of couples (n = 42) who visited a gynecology clinic in Tokyo for infertility consultation. Semen parameters were measured according to WHO guideline at the clinic, and urinary iAs and methylarsonic acid (MMA), and dimethylarsinic acid concentrations were determined by liquid chromatography-hydride generation-ICP mass spectrometry. Biological attributes, dietary habits, and exposure levels to other chemicals with known effects on semen parameters were taken into consideration as covariates. Multiple regression analyses and logistic regression analyses did not find iAs exposure as significant contributor to semen parameters. Lower exposure level of subjects (estimated to be 0.5 μg kg(-1) day(-1)) was considered a reason of the absence of adverse effects on semen parameters, which were seen in rodents dosed with 4-7.5 mg kg(-1).