Individual and joint associations of air pollutants exposure with semen quality: A retrospective longitudinal study in Wenzhou, China.

ABSTRACT

PURPOSE: The impact of air pollution on semen quality has been confirmed, yet the joint effect remains unclear. We evaluate the individual and joint associations of particulate (PM2.5 and PM10) and gaseous pollutants (NO2, SO2, O3 and CO) with semen quality. METHODS: We included 5,114 men in this study from 2014 to 2022. The individual and joint associations were measured by multiple linear regression models. RESULTS: Sperm motility and semen volume were inversely associated with pollutant concentrations during every stage of sperm development, especially at lag days 0-9 and 10-14 (all P < 0.05). Stratified analyses showed that the study pollutants (except CO) had a positive effect on semen concentration during the stage of sperm development, especially in spring and autumn, while a decreased total sperm number was associated with CO (all P < 0.05). However, joint associations of particulate and gaseous pollutants with semen quality parameters were not statistically significant (all P > 0.05). CONCLUSIONS: During all stages of sperm development, particulate and gaseous pollutants had individual negative impacts on sperm motility and semen volume, and these impacts were less pronounced in spring and autumn. Our findings highlight the importance and necessity of reducing the exposure to pollutants especially in the critical stage of sperm development to improve semen quality.