Highly microplastic-polluted US coastal waters linked to serious health risks, study finds

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Living near heavily microplastic-polluted waters along the United States coastline may significantly raise the risk of developing type 2 diabetes, stroke and coronary artery disease, a condition in which plaque blocks the blood vessels feeding the heart, a new study found.

“This is one of the first large-scale studies to suggest that living near waters heavily polluted with microplastics may be linked to chronic health conditions,” said senior author Dr. Sarju Ganatra, medical director of sustainability and vice chair of research in the department of medicine at Lahey Hospital & Medical Center in Burlington, Massachusetts.

“While this study measured pollution in ocean water, pollution isn’t limited to the sea. Microplastics are everywhere: in drinking water, in the food we eat, especially seafood, and even in the air we breathe,” Ganatra said in a statement.

What are microplastics?

Microplastics are polymer fragments that can range from less than 0.2 inch (5 millimeters) down to 1/25,000th of an inch (1 micrometer). Anything smaller is a nanoplastic that must be measured in billionths of a meter.

Such minuscule particles can invade individual cells and tissues in major organs, experts say, potentially interrupting cellular processes and depositing endocrine-disrupting chemicals such as bisphenols, phthalates, flame retardants, perfluoroalkyl and polyfluoroalkyl substances or PFAS, and heavy metals.

“The chemicals can be carried to your liver and your kidney and your brain and even make their way across the placental boundary and end up in an unborn child,” Sherri “Sam” Mason, director of sustainability at Penn State Behrend in Erie, Pennsylvania, told CNN in an earlier interview.

A flurry of recent studies have discovered microplastics and nanoplastics in human brain tissue, the testes and the penis, human blood, lung and liver tissues, urine and feces, mother’s milk, and the placenta.

In the first analysis to illustrate harm to human health, a March study found people with microplastics or nanoplastics in their carotid artery tissues were twice as likely to have a heart attack, stroke or die from any cause over the next three years than people who had none.

Ocean ‘bathtubs’ of polluted waters

Coastal waters were considered heavily polluted if every “bathtub” of ocean water contained 10 or more plastic particles, according to the study published Wednesday in the Journal of the American Heart Association.

Measurements of microplastic concentrations were taken by the National Centers for Environmental Information between 2015 and 2020 for the ocean waters within 200 nautical miles of 152 coastal counties along the Pacific Ocean, Atlantic Ocean and the Gulf of Mexico.

Researchers then compared disease prevalence in those counties with whether residents lived near low or very high concentrations of microplastics. That data was then adjusted for other contributing risk factors such as age, sex, race, ethnicity, access to physicians and socioeconomic status.

Compared with people who lived near waters with low levels of pollution — defined as seeing maybe “one tiny plastic speck in 200 bathtubs of ocean water” — people who lived near highly polluted waters had an 18% higher prevalence of type 2 diabetes, a 9% higher risk of stroke and a 7% higher risk of coronary artery disease, the study found.

However, the study cannot prove a cause-and-effect relationship between nearby ocean microplastic levels that were only measured in water and the development of cardiometabolic diseases, Ganatra said.

“We also didn’t measure plastic levels in residents of these counties, and we don’t yet know the exact ways these particles may harm the body. So, while the findings are compelling, they should be a call for more in-depth research, not for making definitive conclusions,” Ganatra added.

Chemicals in microplastics are linked to known health harms

The study has additional limitations, including lack of information on the chemicals microplastics contain, said Ria Devereux, an environmental research fellow for the Sustainability Research Institute of the University of East London via email.

Chemicals commonly used in plastic production have been found to pose health risks, including skin irritation, respiratory diseases, hormonal disruptions and certain cancers.

“The adverse effects of chemicals used in plastic production are particularly pronounced in the Gulf of Mexico, an area often referred to as ‘Cancer Alley,’” said Devereux, who was not involved in the new research. “This region experiences a higher-than-average incidence of cancer, diabetes, and respiratory diseases, which are concentrated in particular areas.

“The reason behind this is the concentration of petrochemical, petroleum and production plants involved in plastic production and an increase in the presence of chemicals used within the plastic production such as BPA and Phthalates,” she added.

Phthalates, which are found in consumer products such as food storage containers, shampoo, makeup, perfume and children’s toys, may have contributed to more than 13% of all global mortality from heart disease in 2018 among men and women ages 55 through 64, according to an April study.

“Phthalates contribute to inflammation and systemic inflammation in the coronary arteries, which can accelerate existing disease and lead to acute events including mortality,” Dr. Leonardo Trasande, Jim G. Hendrick, M.D. Professor of Pediatrics and professor of population health at NYU Grossman School of Medicine, told CNN in a prior interview.

The chemical compound bisphenol A, or BPA, is an endocrine disruptor, affecting the hormones in the body, and fetuses and babies are especially vulnerable. The chemical compound has been linked to fetal abnormalities, low birth weight, and brain and behavior disorders in infants and children, as well as diabetes, heart disease, cancer and obesity in adults. One study even found erectile dysfunction in workers exposed to BPA.

Limiting your exposure to plastic

While it’s not yet possible to clean microplastics from the ocean, there are steps one can take to reduce exposure to chemicals from plastics.

“One is to reduce our plastic footprint by using stainless steel and glass containers, when possible,” Trasande previously told CNN.

“Avoid microwaving food or beverages in plastic, including infant formula and pumped human milk, and don’t put plastic in the dishwasher, because the heat can cause chemicals to leach out,” he said.

In addition, check the recycling code on the bottom of packaging to find the plastic type, and avoid plastics with recycling code 3, which typically contain phthalates, Trasande said.

Cut down on the use of disposable plastics and bring reusable bags to the grocery store, suggests the Natural Resources Defense Council, an environmental advocacy group. Invest in a zippered fabric bag and ask the dry cleaner to return your clothes in that instead of those thin sheets of plastic. Bring a travel mug to the local coffee store for takeout and silverware to the office, cutting back on plastic cups and utensils.

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