WWe breathe, eat, and drink tiny particles of plastic. But are these tiny specks in the body harmless, dangerous, or somewhere in between?

A small study published Wednesday New England Medical Journal How these debris (microplastics and smaller nanoplastics) affect the heart raises more questions than answers. Although the Italian study has some weaknesses, it is likely to draw attention to the debate surrounding plastic pollution. Most of the plastic waste is not recycled, but instead breaks down into these particles. “This study is interesting, but it has quite a few practical limitations,” said Dr. Steve Nissen, a heart expert at the Cleveland Clinic. “Maybe this is a wake-up call that we need to take the issue of microplastics more seriously. As a cause of heart disease? Not proven. As a potential cause? Yeah, maybe.”

What did the research find?

The study involved 257 people who had surgery to unclog blood vessels in their necks. Italian researchers analyzed fat deposits that surgeons removed from the carotid arteries, which supply blood and oxygen to the brain.

Using two methods, they found evidence of plastic (mostly invisible nanoplastics) in arterial plaques in 150 patients, but no evidence of plastic in 107 patients. .

They followed these people for three years. During that time, 30 to 20 percent of people who used plastic suffered a heart attack, stroke, or died from some other cause, compared to about 8 percent of people who had no trace of plastic.

Researchers also found more evidence of inflammation in people who had plastic debris inside their blood vessels. Inflammation is the body’s response to injury and is thought to increase the risk of heart attack and stroke.

“We hope that the alarming messages from our research will raise awareness among citizens, especially governments, to finally recognize the importance of the health of our planet.” said Dr. Raffaele Malfera of the University of Campania in Italy. Email your research results.

What problems are there in research?

The study was very small and only looked at people who had narrowed arteries that already put them at risk of heart attack or stroke. Patients wearing plastic had more heart disease, diabetes, and high cholesterol than those without plastic. They were more likely to be male and more likely to be smokers.

Although the researchers attempted to adjust for these risk factors during statistical analysis, they may have overlooked important differences between the groups that could explain the results. This type of study cannot prove that plastic is the cause of the problem.

Researchers did not have information about what people were ingesting or breathing that could be contributing to the plastic.

The specimen may have been contaminated in the laboratory. The researchers acknowledged as much in their paper, suggesting that future studies be conducted in clean rooms, where the air is filtered to remove contaminants.

Researchers suggest that people who wore plastic had a four times higher risk of heart attack, stroke and death. That seems high, Nissen said.

“That means these microplastics are the most important cause of coronary heart disease ever discovered. And I don’t think that’s true,” he said.

What’s next?

Dr. Philip Landrigan of Boston University said more research is needed. Landrigan, who contributed an accompanying editorial to the magazine, said this is the first report suggesting a link between microplastics and nanoplastics and human disease. Other scientists have found plastic debris in lungs, liver, blood, placenta, and breast milk.

“This does not prove cause and effect, but it does suggest cause and effect. And we hope this study can be quickly replicated by other researchers in other populations. We need to disprove it,” he said.