Inverse Association between Ambient Sulfur Dioxide Exposure and Semen Quality in Wuhan, China

Abstract

Evidence concerning the association between ambient gaseous air pollutant exposures and semen quality is sparse, and findings in previous studies remain largely inconsistent. We enrolled 1759 men with 2184 semen examinations at a large reproductive medical center in Wuhan, China between 2013 and 2015. Inverse distance weighting interpolation was performed to estimate individual exposures to SO2, NO2, CO and O3 during the entire period (lag 0–90 days) and key periods (lag 0-9, 10-14, 70-90 days) of sperm development. Linear mixed models were used to analyze exposure-response relationships. SO2 exposure with 0-90 days lag was significantly associated with monotonically decreased sperm concentration (β for each interquartile range increase of exposure: −0.14; 95% CI: −0.23, −0.05), sperm count (−0.21; −0.30, −0.12) and total motile sperm count (−0.16; −0.25, −0.08). Significant associations were observed for total and progressive motility only when SO2 exposure was at the highest quintile (all Ptrend < 0.05). Similar trends were observed for SO2 exposure with 70-90 days lag. NO2, CO, or O3 exposure was not significantly associated with semen quality. Our results suggest that ambient SO2 exposure adversely affects semen quality, and highlight the potential to improve semen quality by reducing ambient SO2 exposure during early stage of sperm development.

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

“…Observational studies analyzing the effect of SO 2 and NO 2 on sperm quality have reported an unfavorable effect of these ambient particles on the sperm concentration and total count [9,10,15]. Our study suggested that NO 2 exposure was negatively associated with the sperm concentration and sperm motility, which is consistent with the finding of Broggia [9].…”

“…As air pollutants are known to be hazardous to humans, it is unethical to conduct an interventional study on humans. Most studies on the effects of ambient pollutants on humans have been retrospective or observational, and the majority of them focused solely on the effects of pollutants on semen quality [ 6 , 10 , 13 , 15 – 17 , 22 , 23 ].…”

“…The outcomes of other parameters of reproductive function, particularly testicular volume and the presence of varicocele, were not evaluated [ 3 , 13 , 14 ]. Furthermore, the effect of a particular gaseous molecule, for example, sulfur oxides or ozone (O 3 ), is still inconclusive, and the results of several studies have been conflicting each another [ 6 , 12 , 15 – 17 ]. This fueled our interest in conducting a study to evaluate the relationship between ambient pollutants and male reproductive functions based on semen parameters, sex hormone profile, and physical examination, namely examining testicular size and the presence of varicocele.…”

The Association between Ambient Temperature and Sperm Quality in Wuhan, China

“…Kim and colleagues examinated whether temperature and air pollution had an interactive effect on mortality in South Korea, and they found that temperature modified the effect of PM 10 and increased the risk of daily mortality [34]. An influence of air pollution on sperm quality has been reported in several studies [37,38], and it has been reported that air pollution is correlated with temperature [39]. Altogether, ambient temperature and air pollution may interact to affect sperm quality.…”

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

“…The testicular volume was negatively associated with the exposed mean concentration of SO 2 (p < 0.01). 17,18 In addition, Broggia et al reported that workers occupationally exposed to NO 2 had significantly lower total sperm motility than those not exposed to NO 2 . 19 However, Zhang et al found that SO 2, NO 2 , and PM2.5 were not associated with altered semen quality.…”