A new study by scientists at the Lahey Hospital & Medical Center reveals that living near heavily microplastic-polluted waters along the US 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. “Marine Microplastic Levels and the Prevalence of Cardiometabolic Diseases in US Coastline Counties” was published in the June 18, 2025 issue of AHA/ASA Journal of the American Heart Association.
“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.
“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 added.
Compared with people who lived near waters with low levels of pollution—defined as seeing roughly “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. According to the study:
“The coastal counties with a higher concentration of marine microplastics in adjacent ocean water showed a higher prevalence of T2D, CAD, and stroke compared with those with lower concentrations. This association remained significant after adjusting for age, sex, physician access, and baseline community vulnerabilities of the counties. Together with other bodies of evidence studying the health concerns of microplastics to humans and the environment, our study supports the need for policies to protect against microplastic exposure and reduce marine water pollution.”
Read the full study.