Does pyrethroid exposure lower human semen quality? a systematic review and meta-analysis

Area of Science:

• Environmental Health
• Toxicology
• Reproductive Medicine

Background:

• Pyrethroids, widely used insecticides, pose potential toxicity risks, including spermotoxicity.
• Existing research on pyrethroids' impact on semen quality is conflicting, necessitating further investigation.

Purpose of the Study:

• To systematically review and meta-analyze the effects of pyrethroid exposure on human sperm quality.
• To evaluate the global impact of pyrethroids on male reproductive health indicators.

Main Methods:

• Systematic review and meta-analysis conducted following PRISMA guidelines.
• Eligibility criteria based on PECO framework; risk of bias assessed using OHAT and GRADE tools.
• Quantitative meta-analysis performed using Review Manager (RevMan) on 12 eligible studies involving 2,050 male subjects.

Main Results:

• Pyrethroid exposure was significantly associated with reduced sperm motility.
• Region-specific effects observed: reduced sperm motility in Poland and the US, decreased sperm count in Japan.
• Inconsistent effects on sperm concentration noted between Poland and the US.

Conclusions:

• Pyrethroids demonstrate potential adverse effects on sperm motility, count, and concentration.
• Inconsistent evidence highlights the need for further research, particularly prospective cohort or controlled cross-sectional studies.
• Future studies should focus on varying exposure levels to better assess pyrethroid-induced spermotoxicity.