In a groundbreaking study, researchers have discovered microplastics in human penises for the first time, prompting questions about their potential link to erectile dysfunction.

This discovery follows previous findings where microplastics were detected in testes and semen. Experts say that male fertility has been declining in recent decades, and further research into the potential reproductive harm caused by microplastics is urgently needed.

The new research, which was published in International Journal of Impotence Research: Your Sexual Medicine Journal, said some of the microplastics detected in penises were as large as .5mm.

“The penis is a vascular, spongy organ so is definitely vulnerable. We know erectile dysfunction is multifactorial,” the lead researcher, Dr. Ranjith Ramasamy of the University of Miami, said, according to the Guardian. “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,” the doctor said.

The researchers noted that the penis might be particularly susceptible to microplastic contamination due to increased blood flow during erections. People are exposed to microplastics through everyday activities like eating, drinking, and breathing, with the tiny particles already identified in human blood.

The study analyzed tissue samples from five men undergoing surgery for erectile dysfunction. Microplastics were found in four of these cases, with PET and polypropylene being the most common types. These materials are widely used in food and beverage packaging as well as other everyday items.

Microplastics can cause tissue inflammation, similar to air pollution particles, and the chemicals in plastics may also pose health risks. Previous studies have linked microplastic contamination in arteries to a significantly higher risk of stroke and heart attack death.