Exploring the Association between Arsenic Exposure and Sperm Quality: A Systematic Review and Meta-analysis.

Background: Human beings are routinely exposed to arsenic, a ubiquitous environmental toxicant present in food, water, air and soil. Both acute and chronic exposure to this metalloid poses significant health risks, including negative impact on the male reproductive system, as evident from studies in humans and animals. Objective: The current systematic review evaluated the impact of arsenic exposure on semen quality in human populations to determine any association between decline in semen quality and arsenic exposure. Materials and Methods: A total of 361 studies were retrieved from systematic literature search in electronic databases, namely Scopus, PubMed and Cochrane central databases. Two step screening process was performed by two reviewers independently, and finally four studies were included in the review. Results: Two cross-sectional studies were included for meta-analysis. In cross-sectional studies, pooled mean semen volume (3.18 ml; 95% confidence interval [CI]: 2.34-4.02; I² = 86.5%), sperm concentration (78.69 × 106/mL; 95% CI: 66.01-91.37; I² = 0.0%) and sperm motility (52.13%; 95% CI: 29.88-74.37; I² = 95.0%) were within or above the World Health Organization reference values, although with high heterogeneity. The findings from two case-control studies could not be pooled due to a lack of appropriate non-exposure controls and are therefore described narratively. Interpretation: The meta-analysis suggests that arsenic exposure may negatively influence semen volume, with inconsistent effects on concentration and motility. Despite biological plausibility involving oxidative stress and endocrine disruption, the limited number of studies and methodological variability restrict definitive conclusions. Further large scale, longitudinal studies with standardised exposure and outcome assessments are essential to validate these findings. Limitations: The small number of eligible studies and high heterogeneity across designs and exposure assessments limit the generalizability of findings. In addition, the lack of longitudinal data restricts causal inference regarding arsenic's effect on semen quality. PROSPERO Registration: CRD42024529010.