Adult Organophosphate and Carbamate Insecticide Exposure and Sperm Concentration: A Systematic Review and Meta-Analysis of the Epidemiological Evidence.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of observational epidemiological studies
PubMed 37966213 · doi:10.1289/EHP12678
What was done
Authors conducted a systematic review and meta-analysis across three scientific databases (PubMed, Scopus, Web of Science), two U.S. government databases, and five NGO websites for studies published through August 11, 2022. They assessed the epidemiological evidence linking adult exposure to organophosphates (OPs) and N-methyl carbamates (NMCs) with sperm concentration. Risk of bias and evidence strength were evaluated via the Navigation Guide framework. Bias-adjusted standardized mean differences (SMD) were pooled using a three-level multivariate random-effects model with cluster-robust variance estimation.
What was found
Across 20 studies, 21 study populations, 42 effect sizes, and 1,774 adult men, higher exposure to OP and NMC insecticides was associated with lower sperm concentration (bias-adjusted SMD = -0.30; 95% CI: -0.49 to -0.10; P < 0.01). The pooled effect estimate varied across subgroups by risk of bias, insecticide class, exposure setting, and recruitment setting, but remained consistently negative across all analyses.
Why it matters
This review provides quantitative synthesis confirming that adult exposure to common organophosphate and carbamate insecticides is linked to reduced sperm concentration, strengthening the case for regulatory intervention to safeguard male reproductive health.
Limits
All included studies were observational, which limits causal inference and carries risk of residual confounding and exposure misclassification. The total sample size was relatively modest (1,774 men across 20 studies), and the pooled effect estimate showed heterogeneity across exposure and recruitment settings.
Cited by
- supports BPA, phthalates, PFAS, and pesticides/herbicides have published human outcome data linking exposure to adverse fertility outcomes including eggs retrieved, time to conception, and sperm quality.