The United Nations reports that a staggering amount of plastic – over 430 million metric tons – is produced annually.

A research article published in the scientific journal, Science Advances in 2017, provided one of the first comprehensive overviews of the cumulative problem of plastic pollution. Since the advent of large-scale production of synthetic materials in the early 1950s, we have created a staggering 8.3 billion metric tons of plastics.

By 2015, about 6,300 million metric tons of plastic waste had been generated. Despite massive campaigns, only 9% of plastic was recycled. Of the rest, 12% were incinerated, with a vast majority (79%) ending up in landfills or scattered in the natural environment.

The study sounded the dire warning that we're on track to have 12,000 million metric tons of plastic waste cluttering our environment by 2050. The primary driver behind the surge in plastics is the packaging industry, which switched en masse from reusable to disposable containers in the modern era.

Plastics have been found in every corner of the globe, from the deepest ocean trenches to remote mountain tops, signalling a profound and pervasive environmental issue.

But, plastics don’t end up just in the environment, they’re inside our bodies and they may be killing us.

The troubling new study

In January this year, a study by scientists from Columbia University and Rutgers University was published in the scientific journal, Proceedings of the National Academy of Sciences. Testing three undisclosed brands of bottled water in the US, they found that a litre of such water contains, on average, around 240,000 detectable fragments of tiny plastic, which result from the breakdown of plastic. This figure exceeds earlier estimates by a staggering 10 to 100 times.

The researchers employed stimulated Raman scattering microscopy, a technique that uses two lasers to detect particles. They also integrated machine learning to help identify these particles, focusing on seven common types of plastic. This resulted in a more precise way to detect these tiny plastic particles.

Specifically, the researchers detected both microplastics, tiny plastic pieces ranging from 5 millimeters down to 1 micrometre; and nanoplastics, even smaller particles less than 1 micrometre in size.

How a study found microplastics and nanoplastics in the human body

Microplastics are not new, and you may have heard of them before. They have been identified in human lungs, blood, excrement, and even in placentas. Microplastics have been directly linked to lung inflammation, asthma, cancer, cognitive disorders, and premature birth. They’re also thought to disturb the way certain natural hormones work in the body.

Nanoplastics may pose an even greater risk due to their smaller size since they can be more easily mistaken by cells as natural components.

Last week, a landmark study led by doctors and scientists at the University of Campania in Naples and other medical centres in Italy was published in the leading medical journal, The New England Journal of Medicine. The research provided more startling evidence that microplastics and nanoplastics have infiltrated the human body.

This investigation focused on 257 individuals undergoing surgery who were undergoing carotid endarterectomy for asymptomatic carotid artery disease. The team found that 58% of these patients harboured microplastics and nanoplastics within their arterial plaque. The presence of these minute plastics was linked to a 4.5 times greater risk of experiencing adverse health outcomes, including heart attacks, strokes, and even death.

Over a follow-up period of nearly three years, the researchers substantiated the existence of plastics in a significant fraction of the participants. They also provided clear images of microplastics and nanoplastics lodged within arterial plaque. The team showed detrimental effects in the presence of these tiny plastics at a molecular level, which implicates them in worsening cardiovascular disease.

Even though the researchers looked at a small group of patients and they admit that there might be other factors they haven't considered, the evidence for a link between plastics and heart disease is compelling.

Taken together, these two new studies should be a wake-up call. The problem of plastic pollution has direct effects on our health. We need to take immediate steps to stop this ever-present danger.

Anirban Mahapatra is a scientist and the author of COVID-19: Separating Fact From Fiction. His second popular science book, When The Drugs Don’t Work: The Hidden Pandemic That Could End Medicine, will be published this year. The views expressed are personal.