Ambient sulfur dioxide could have an impact on testicular volume from an observational study on a population of infertile male

Abstract

Background The present retrospective study investigates the effect of environmental pollutants on male reproductive health. Methods Male patients with primary infertility (n = 282) from a single center (National Taiwan University Hospital, Taipei, Taiwan), between January 2016 and December 2017, were identified. Patients were physically examined for the presence of varicocele, and the volume of both testicles. Semen quality was measured in terms of total sperm count (millions), sperm concentration (millions/ml), and the percentage of motile sperm cells and the sperm cells with normal morphology. Data on the concentration of SO 2 (ppb), O3 (ppb), NO and NO 2 (ppb), and PM2.5 concentrations (μg/m3), measured on daily and hourly basis, were acquired from the Environmental Protection Administration Executive Yuan, Taiwan. Individual exposure to pollutants was estimated based on the reported residential address of patients. Statistical analysis indicated the impact of each pollutant on the testicular volume and semen parameters. Results Mean ± SD of age was 36.7 ± 7.3 years. The average sperm count and concentration was 41.9 million/ml and 34.1 million/ml, respectively. Except for PM2.5, the mean concentration of all the particulate matters were within the reference value. NO2 and SO2 exposure were negatively associated with the sperm concentration and motility, and testicular volume, respectively. Conclusions NO2 and SO 2 exposure were negatively associated with the sperm concentration and motility, and testicular volume, respectively, in a population of infertile male. Nevertheless, studies are needed to ascertain the impact of different exposure levels of pollutants on the semen parameters.