• In "Plastic Detox", six couples reduced their plastic exposure and saw promising results.
• Traces of polymers have been found in seminal fluid.
• Some everyday actions to replace microplastics in daily life (or at least in part)

A new documentary, "The Plastic Detox", recently released on Netflix, has brought the topic of microplastics and their potential link to infertility back into focus. It did so through an experiment: six couples with unexplained fertility problems were given alternatives to plastic, in order to gradually reduce their exposure (since eliminating it entirely is virtually impossible).

The experiment was led by an 89-year-old American epidemiologist and professor of environmental medicine: Shanna Swan. The idea was to catalogue all the plastic sources that were part of the couples' lives and ban them from everyday use. The first measures concerned food and water. The epidemiologist suggested buying fresh food whenever possible to reduce exposure to phthalates found in food packaging, heating food in glass or ceramic containers rather than plastic ones, drinking tap water instead of bottled water, and avoiding personal care and household products labelled with the words "fragrance" or "perfume".

During the experiment, which lasted approximately three months — the time needed for sperm to regenerate — Dr. Swan measured the concentrations of chemical substances in urine and seminal fluid. The results showed that five out of six men improved sperm quality across multiple parameters, one third of participants saw their body mass index decrease, 60 per cent reported increased energy levels and better sleep quality, and four couples managed to conceive.

What science says about microplastics and fertility

Many experimental studies on animal models show that exposure to micro- and nanoplastics can damage reproductive health in both sexes. In particular, in male mice it has been observed that polystyrene, like other polymers, reduces testosterone levels and worsens sperm count, motility and morphology. In females, a significant reduction in ovarian size and hormonal alterations are likely to develop.

"Most of the evidence in the scientific literature is based first on animal models rather than human ones, but in truth traces of polypropylene and polyethylene have also been found in human seminal fluid," explains Dr. Stefania Piloni, a specialist in obstetrics and gynaecology and an expert in fertility, to LifeGate. "It is not easy to establish whether microplastics can actually cause sterility, but it has been confirmed that polymers infiltrate amniotic fluid — the environment in which foetuses develop — potentially affecting up to three generations (if the foetus is female)."

In Plastic Detox, phthalates are discussed at length, but there are other equally widespread and dangerous microplastics, Dr. Piloni points out, such as PVC (polyvinyl chloride) and nylon. The problem for ejaculated sperm will persist for at least three months until a new spermatogenesis occurs (i.e., the biological process by which male gametes are formed in the seminiferous tubules of the testes), which takes place roughly every ninety days. "But what matters is that this documentary has shed light on a truth: subfertility is reversible. And it does not matter that the sample was too small — a case report is valid even if carried out on just one person or couple," the doctor concludes.

A future without microplastics

Current studies are clear: the complete removal of microplastics from the daily lives of individuals is not currently possible. Microplastics — plastic particles smaller than 5 millimetres — have been detected in drinking water, air, soil, food, and even in human biological samples such as blood, saliva, placenta and faeces.

Interventions such as bans on single-use plastics and taxes on plastic bags have reduced consumption by between 8 and 85 per cent in various countries. However, as long as global plastic production — now exceeding 359 million tonnes per year — is not drastically reduced, and as long as microplastics already dispersed in the environment continue to degrade into ever smaller particles, the possibility of escaping them entirely remains remote.

At a personal level, it becomes essential to adopt certain daily actions that can reduce — though not eliminate — exposure. In addition to those already mentioned, these include not wearing glitter in make-up, avoiding chewing gum, choosing detergents and clothing made from plant-based raw materials, buying loose-leaf tea rather than tea bags, stopping the use of plastic baby bottles for newborns, and using sunscreens with natural UV filters.