Research by Wen Yang and others from First Affiliated Hospital of Anhui Medical University in China investigated the presence, distribution, and potential sources of microplastics (MPs) within the male reproductive system, examining both human and mouse samples. This “atlas” of the male reproductive system, published in Environmental Science and Pollution Research, involved direct measurement and characterization of MPs in biological samples, along with surveys of study participants, and descriptions of how the authors’ measurements compare to other research findings and sampling protocols within the relatively small but growing field of microplastics and reproduction research.
Yang et al. are not the first to investigate MPs in semen, but they went a step further in also measuring particles in samples of human testes, and epididymis, as well as using mice to study additional samples of testes and epididymis as well as seminal vesicles and prostates. “[T]he epididymis, seminal vesicles, and prostate all play key roles in the development, maturation, storage, and ejection of sperm.”
Mass spectrometry analyses (specifically Py-GC/MS) revealed three polymers in all 18 human testis samples: polyethylene (PE), polyvinyl chloride (PVC), and Polyamide-66 (PA66). Four types of MP polymers (polystyrene (PS), PVC, PA66, and PMMA) were detected in 12 of 15 semen samples.
Lifestyle and dietary surveys of the study participants found that “significantly higher PVC abundance was detected in those participants who often ate home-cooked meals (973.3 mg/kg) relative to those who ate takeaway food (475.2 mg/kg).” Other contributing factors were urbanization and using body scrub cleansers.
Interestingly, the study found that the median abundance of total MPs in testis samples was 2207 mg/kg, significantly higher than that in semen 25.98 μg/ml (P < 0.0001). “The present study shows that plastic particles < 10 μm in size can cross the blood-testis barrier into the seminiferous tubules. These particles may enter the epididymis with the transport of sperm and eventually enter the semen during ejaculation. However, plastic particles of larger particle sizes may be deposited in the testis, accounting for this concentration difference.”
Yang et al. did not investigate the potential health effects of the particles within the structures of the male reproductive system. Other studies have found exposure to various MP polymers affect testis development and fertility in mice as well as testicular aging and sperm quality. Microplastics may affect female fertility more than males (at least in mice). The ongoing AURORA project is investigating the effects of micro- and nanoplastics on maternal and early life health.
Reference
Yang, Wen, et al. (2024). “Atlas and source of the microplastics of male reproductive system in human and mice.” Environmental Science and Pollution Research. DOI: 10.1007/s11356-024-32832-x
Other recent studies on MNPs related to reproduction
Garcia, Marcus A., et al. (2024). “Quantitation and identification of microplastics accumulation in human placental specimens using pyrolysis gas chromatography mass spectrometry.” Toxicological Sciences. DOI: 10.1093/toxsci/kfae021
Paul, Indrani, et al. (2024). “Beyond the cradle – Amidst microplastics and the ongoing peril during pregnancy and neonatal stages: A holistic review.” Journal of Hazardous Materials. DOI: 10.1016/j.jhazmat.2024.133963
Hasanah, Uswatun, et al. (2024). “Plasticizing Pregnancy: Microplastics Identified in Expectant Mothers’ Feces.” Environmental Health Insights. DOI: 10.1177/11786302241235810
Wang, Hang, et al. (2024). “The adverse effects of developmental exposure to polystyrene nanoparticles on cognitive function in weaning rats and the protective role of trihydroxy phenolacetone.” Environmental Pollution. DOI: 10.1016/j.envpol.2024.123632
This article was originally published by Lindsey Parkinson at the Food Packaging Forum.
