Polyethylene in human testicles, a possible cause of decreased sperm count

One of the reasons for the decrease in sperm count in men, that is, their concentration in sperm, could be hidden in the omnipresent microplastics. A study, published in the journal Toxicological Sciencestested 23 human testes and 47 pet dog testes, identifying a high presence of microplastics in each sample analyzed. In particular, the tests were conducted through the dissolution of the tissue samples and the analysis of the residual plastic, left over from the collected material. All this after a treatment with specific substances, a separation step in ultra-centrifuges and the spectrometric analysis of the precipitate.

The dog testicles – 47 samples versus 23 from humans – were obtained from veterinary practices and shelters that conducted neutering operations. Human ones from a series of bodies of men aged between 16 and 88 subjected to autopsies in 2016.

Due to the preservation methodologies of the human samples, the experts were unable to measure the sperm count. However, it was possible to do this with dog testicles: the count was lower in samples with increased PVC contamination. The study naturally demonstrates a correlation, as always – they recall Guardian and the scientists themselves – are further research is needed to demonstrate that microplastics actually cause a decrease in sperm count.

Sperm, the decline has been worrying for decades

The starting point of the investigation is known and worrying: the number of sperm in men is declining for decadesand many studies have highlighted thechemical pollution, such as that linked to pesticides, among the possible causes of this phenomenon as well as many others of an endocin nature and beyond. Recently, for example we talked about it here, microplastics were also discovered in human bloodin the placenta It is in the breast milkindicating without surprise but with growing concern for the possible consequences of widespread contamination of organisms.

The impact on health is in fact still to be evaluated, although it has been tested in the laboratory like microplastics cause damage to human cellular mechanisms. This is because the particles end up depositing in the tissues and trigger inflammation, like the polluting particles present in the air, and at the same time they could be the very numerous chemical substances present in plastic to cause tissue damage. The area is much explored by researchers and offers new features on the topic every month: last March, for example, doctors had warned of potentially dangerous effects after having found a substantial increase in the risk of stroke, heart attack and premature death in people whose blood vessels were contaminated with microscopic plastics.

«At first I doubted whether microplastics could penetrate the reproductive system – he explained Xiaozhong Yu, from the University of New Mexico – when I first received the results on dogs I was surprised. I was even more surprised when I received the results in humans. The impact on younger generations could be more worrying” as plastic pollution is more widespread in the environment than ever, Yu added. Traces of it can now be found everywhere, from the top of Everest to the most inaccessible depths of the oceans up to the ice of Antarctica, without forgetting the enormous island continents floating in the seas, largely composed of plastic of all kinds. Other smaller investigations of the same type, one last year in China and another on mice, had obtained comparable results.

In particular, human testicles showed a concentration of plastic almost three times higher than that found in dog testicles: 330 micrograms per gram of tissue versus 123 micrograms. The polyethylene, used for the production of plastic bags and bottleswas the most common microplastic foundfollowed precisely – but in canine samples – by PVC. Overall, there were a dozen types of plastic identified. PVC, in particular, “can release many chemicals that interfere with spermatogenesis and contains chemicals that cause endocrine disruption,” Yu said.

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