The discomforting presence of microplastics in everything around us including the fish we fish we devour and the vegetables we cook is known to all. A new study has now revealed that these minute particles have now even managed to enter the testicles of men making their sperms less and less potent.
A study published last week in the Toxicological Sciences, a monthly peer-reviewed scientific journal published by the Oxford University press, has revealed that researchers who tested 23 human testicles and 47 dog testicles have found microplastics in every sample. They also found that dog testes with higher concentrations of certain microplastics tended to have lower sperm counts.
Using advanced sensitive pyrolysis-gas chromatography/mass spectrometry, the team of researchers quantified 12 types of microplastics within 47 canine and 23 human testes. Data on reproductive organ weights, and sperm count in dogs were collected. Statistical analyses, including descriptive analysis, correlational analysis, and multivariate linear regression analyses were applied to investigate the association of microplastics with reproductive functions.
The study revealed the presence of microplastics in all canine and human testes, with significant inter-individual variability and the mean total microplastic levels in dogs were 122.63 µg/g and 328.44 µg/g in humans.
The study revealed the presence of microplastics in all canine and human testes, with significant inter-individual variability and the mean total microplastic levels in dogs were 122.63 µg/g and 328.44 µg/g in humans. Both humans and canines exhibited relatively similar proportions of the major polymer types, with Polyethylene (PE) being dominant. Furthermore, a negative correlation between specific polymers such as PVC and PET and the normalized weight of the testis was observed which highlight the pervasive presence of microplastics in the male reproductive system in both canine and human testes with potential consequences on male fertility.
A comparative analysis of microplastics in canine and human testes revealed that total microplastics were nearly three times greater in human testes than in canine tissues. Also, significantly higher levels of PE, PVC, ABS, N66, N6, PP, SBR, PET, PMMA, and PC were observed in human testes compared with canine tissues. PE was the most common polymer in both species, accounting for 36.4 per cent in dogs and 35.2 per cent in humans. Interestingly, human testes contained a higher proportion of Acrylonitrile butadiene styrene (ABS) and a lower percentage of PVC compared with canine testes. These differences in composition and concentration between species offer insights into potential species-specific variations in environmental exposure and accumulation.
Both humans and canines exhibited relatively similar proportions of the major polymer types, predominated with PE. The study also highlights the need to determine the dose-response effects of these microplastics and to conduct mechanistic studies on the reproductive system.
In India, the threat posed by microplastics is huge as the country ranks infamously among the top four in the world for releasing microplastics in the world’s waterways. According to the 2024 Plastic Overshoot Day (POD) report, China, India, USA and JAPAN account for 51 per cent of the total 3,153,813 tonnes of microplastics that will be dumped into the oceans worldwide this year.
Some of the limitations of this study include the small sample size and that the human subjects in the study were unique and typically did not experience a natural death. Therefore, the data should be considered indicative of what might be found in adult human testes but not necessarily representative of a broader population, the researchers had claimed.