The findings, part of a £1.85m project funded by the Natural Environment Research Council looking at how plastics transport bacteria and viruses, concluded that microplastics enabled pathogen transfer in the environment. The paper is published in the journal Environmental Pollution. “Being infectious in the environment for three days, that’s long enough to get from the wastewater treatment works to the public beach,” Quilliam said.

Recent studies have shown that cutting methane could be one of the fastest ways of holding down global temperature rises, and that sharp cuts now could prevent a rise of about 0.25C by 2050.

Chemicals such as bisphenols and dioxins are thought to interfere with hormones and damage sperm quality, and the study found combinations of these compounds are present at “astonishing” levels, up to 100 times those considered safe.

Increased public understanding of chemical contaminants in blood “raises questions about the safety of the blood supply”, says Lanphear. “And of course, there’s going to be a lot of disbelief, a lot of dismissal of this because that’s pretty inconvenient.”

PFAS, or per- and polyfluoroalkyl substances, are a class of about 9,000 compounds used to make products heat-, water- or stain-resistant. Known as “forever chemicals” because they don’t naturally break down, they have been linked to cancer, thyroid disruption, liver problems, birth defects, immunosuppression and more.