Microplastic presence in dog and human testis and its potential association with sperm count and weights of testis and epididymis.
Level 4 - case-series / case-control
Cross-sectional tissue quantification and correlational study.
PubMed 38745431 · doi:10.1093/toxsci/kfae060
What was done
Researchers quantified and characterized 12 microplastic polymer types in 47 canine and 23 human testes using pyrolysis-gas chromatography/mass spectrometry. Reproductive organ weights and canine sperm counts were measured, and associations between microplastic concentrations and reproductive metrics were assessed using correlational and multivariate linear regression analyses.
What was found
Microplastics were detected in all canine and human testicular samples. Mean total microplastic levels were 122.63 µg/g in dogs and 328.44 µg/g in humans, with polyethylene (PE) being the dominant polymer in both. Specific polymers, notably polyvinyl chloride (PVC) and polyethylene terephthalate (PET), were negatively correlated with normalized testis weight. Numerical effect sizes for canine sperm count were not provided in the abstract.
Why it matters
This study provides direct tissue evidence that microplastics accumulate in mammalian testicular tissue and identifies an association between specific polymers and reduced testicular weight.
Limits
The human sample was small (n = 23), and the observational, cross-sectional design cannot establish causality. Sperm count data were only collected in dogs, and the abstract omits quantitative associations for sperm outcomes as well as donor clinical histories and environmental exposure sources.
Cited by
- supports Higher levels of plastics like PVC in the reproductive system are linked to lower sperm counts.
- supports Microplastics have been identified in human testicular tissue, sperm, and the blood-testis barrier.