Microplastics have been discovered in penises for the first time, raising questions about a potential role in erectile dysfunction.

The revelation comes after the pollutants were recently detected in testes and semen. Male fertility has fallen in recent decades and more research on potential harm of microplastics to reproduction is imperative, say experts.

The researchers said the penis could be particularly vulnerable to contamination with microplastics due to high blood flow during erections. People ingest microplastics through eating, drinking and breathing and the tiny particles have been detected in blood.

The study assessed tissue taken from five men who were undergoing surgery related to erectile dysfunction. Microplastics were found in four cases, with PET and polypropylene being the most prevalent. Both are used in food and drink packaging and other everyday items.

There appears to be widespread contamination of people’s bodies with microplastics, with scientists finding them wherever they look. The impact on health is as yet unknown but microplastics have been shown to cause damage to human cells in the laboratory.

The particles can cause inflammation in tissue, as air pollution particles do, and chemicals in the plastics could also cause harm. Doctors found a substantially raised risk of stroke and heart attack death in people whose arteries were contaminated with microplastics.

Millions of tonnes of plastic waste are dumped in the environment every year and much is broken down into microplastics. These have polluted the entire planet, from the summit of Mount Everest to the deepest oceans.

Dr Ranjith Ramasamy, who led the new research while at the University of Miami in the US, said: “The penis is a vascular, spongy organ so is definitely vulnerable. We know erectile dysfunction is multifactorial. You need good hormones, nerves, blood supply, and good smooth muscle tissue for an erection to happen.

“We found that microplastics were present in the smooth muscle of the penis. All we know is that they are not supposed to be there, and we suspect that it could lead to smooth muscle dysfunction.”

Ramasamy said more research was urgently needed to determine the potential role of microplastics in erectile dysfunction and male infertility. Sperm counts in men have been falling for decades and 40% of low counts remain unexplained, although chemical pollution has been implicated by many studies. Recent studies in mice have reported that microplastics reduced sperm count and caused abnormalities and hormone disruption.

Ramasamy said: “We’ve moved past whether we have microplastics in us, to whether there is a level of microplastics beyond which things become pathologic.”

The new research, published in IJIR: Your Sexual Medicine Journal, analysed tissue samples taken from five men who were undergoing surgery for an inflatable penile prosthesis, which is a treatment option for men with severe erectile dysfunction. The microplastics detected ranged in size from 0.5mm down to 0.002mm.

The researchers said the pervasive spread of microplastics was alarming andit was imperative to understand the potential implications for human health.

Ramasamy said: “As a society, we need to be cognisant that drinking water from plastic water bottles, getting takeout food in plastic containers and, even worse, microwaving food in plastic containers, are contributing to having things in our body that should not be there. And the penis is the one organ that everybody will pay attention to.”

• This article was amended on 19 June 2024 to remove an assertion related to the volume of blood that flows to the penis during an erection.