We already know that microplastics are everywhere — in our soil, water, air, and even in our bodies. But now, a large-scale study from the United States is drawing a troubling connection between where you live and how your heart fares, especially if your postcode is close to heavily polluted ocean waters.
Living in a U.S. coastal county bordered by ocean waters with very high concentrations of microplastics may increase the risk of heart and metabolic diseases, such as Type 2 diabetes, coronary artery disease and stroke, according to new research.
“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,” says lead author Sarju Ganatra, a cardiology expert. “Plastic pollution is not just an environmental issue – it may also be a public health issue.”
Microplastics — defined as plastic particles smaller than 5 millimetres — are created when larger plastic waste breaks down over time. They come from familiar sources like food packaging, synthetic clothes, cosmetics, and paint. Once these particles enter marine ecosystems, they don’t stay neatly in the water column. They seep into the ground through seawater intrusion, a process where seawater mixes with groundwater resources and can contaminate groundwater aquifers in coastal areas.
In this new study, researchers divided U.S. coastal counties into four groups based on the level of microplastic pollution within 200 nautical miles of the shoreline. They then compared rates of three major cardiometabolic conditions: Type 2 diabetes, coronary artery disease, and stroke.
The results were striking. People living in counties with very high marine microplastic pollution had:
- 18% higher adjusted prevalence of Type 2 diabetes
- 7% higher for coronary artery disease
- 9% more strokes.
The association between high microplastic pollution levels and more people with cardiometabolic diseases was consistent even after adjusting for age, gender, access to doctors, socioeconomic status and environmental considerations.
Importantly, the researchers emphasise that microplastic exposure doesn’t stop at the coastline.
“While this study measured pollution in ocean water, pollution isn’t limited to the sea,” says Ganatra. “Microplastics are everywhere: in drinking water, in the food we eat, especially seafood, and even in the air we breathe. So, while we examined data from microplastics collected from ocean water and the health status of people living in communities nearby, microplastic pollution affects all of us, regardless of where we live.”
The research team is currently designing follow-up studies to evaluate how microplastic exposure influences biological markers of inflammation and cardiovascular stress.
“This study adds to a growing body of evidence that the garbage we discard into the environment often finds its way back to us. It’s time to shift from awareness to action,” says Ganatra. “We urge policymakers to view plastic pollution as an environmental crisis as well as a potential health crisis.”
This research was published in the American Heart Association.