Impacts of Outdoor Air Pollution on Human Semen Quality: A Meta-Analysis and Systematic Review.

Jianzhong Zhang,Hongjun Li,Zhonglin Cai,Jian Xiong,Chengquan Ma

doi:10.1155/2020/7528901

Abstract

Introduction Several studies have explored the association between outdoor air pollution and semen quality. However, the results were inconsistent. We performed the current meta-analysis to evaluate the role of outdoor air pollution in semen quality. Material and Methods. Databases including PubMed, Web of Science, and Embase were searched to identify relevant studies. Relative data in participants under higher exposure and lower exposure to air pollution were extracted. Pooled weighted mean differences (WMDs) with corresponding 95% confidence intervals (CIs) were utilized to assess the effects of outdoor air pollution on semen quality. In addition, trial sequential analyses (TSAs) were performed to obtain a more comprehensive assessment of analyses. Results A total of 11 studies with 4562 males were enrolled in the current meta-analysis. Higher air pollution levels were associated with significant decreases in semen volume (WMD: -0.16, 95% CI: -0.27 to -0.05), sperm concentration (WMD: -5.52, 95% CI: -9.88 to -1.16), progressive motility (WMD: -6.23, 95% CI: -11.64 to -0.81), total motility (WMD: -7.65, 95% CI: -14.09 to -1.20), and normal sperm morphology rate (WMD: -3.71, 95% CI: -5.59 to -1.82). In addition, the DNA fragmentation index significantly increased (WMD: 4.11, 95% CI: 1.94 to 6.29). Conclusions Air pollution is associated with decreased semen volume, sperm concentration, motility, and normal morphology rate.

Highlights

Several studies have explored the association between outdoor air pollution and semen quality
The results indicated that higher air pollution levels were associated with significant decreases in semen volume (WMD: -0.16, 95% confidence intervals (CIs): -0.27 to -0.05) (Figure 2(a)) and sperm concentration (WMD: -5.52, 95% CI: -9.88 to -1.16) (Figure 2(b))
The results indicated that air pollution was associated with significant decreases in progressive motility (WMD: -6.23, 95% CI: -11.64 to -0.81) (Figure 2(e)) and total motility (WMD: -7.65, 95% CI: -14.09 to -1.20) (Figure 2(f))

Summary

Introduction

Several studies have explored the association between outdoor air pollution and semen quality. Higher air pollution levels were associated with significant decreases in semen volume (WMD: -0.16, 95% CI: -0.27 to -0.05), sperm concentration (WMD: -5.52, 95% CI: -9.88 to -1.16), progressive motility (WMD: -6.23, 95% CI: -11.64 to -0.81), total motility (WMD: -7.65, 95% CI: -14.09 to -1.20), and normal sperm morphology rate (WMD: -3.71, 95% CI: -5.59 to -1.82). When the pollutants accumulate to enough concentration and sustained for enough time, air pollution will significantly impair the health of human beings It can result in various diseases including cardiovascular and lung diseases, neurologic disorders, and infertility [1,2,3,4,5].

Methods

Results

Conclusion