What They Found in the Plaque
In Naples, Italy, cardiologists examined plaque scraped from patients’ carotid arteries during routine surgery. Microplastics turned up in just under 60% of the samples.
Of the 304 patients enrolled, 257 completed roughly three years of follow-up. Among the 150 whose plaque held plastic, 30 went on to have a heart attack, a stroke, or die, compared with 8 of the 107 whose plaque was clean, about 4.5 times the risk. This was a real study, published in the New England Journal of Medicine in 2024, not a simulation.
A Material With No Address
Climate change has carbon dioxide, tracked for years. Lead poisoning has blood-lead levels, tracked in people. Plastic never got a meter like that, even though it’s everywhere by design, in packaging, clothing, tires, paint. It sheds constantly and shows up differently in every organ, making it hard to study as one problem. Until recently, nobody had connected how much plastic gets made, how much piles up in the environment, and how much disease follows.
Enter the Countdown
A new project launched in The Lancet in August 2025 aims to close that gap. It’s led by Philip Landrigan, based at Boston College’s Global Observatory on Planetary Health, and modeled on the existing Lancet Countdown on health and climate change.
Plastic has one advantage climate doesn’t: almost all of it starts in one industry, petrochemicals, made from oil and gas. That makes it possible to trace a single line from extraction to production to pollution to disease, as one dataset instead of scattered studies.
The Scale Nobody Quite Grasps
Global plastic production grew from 2 million metric tons in 1950 to 475 million metric tons in 2022, roughly a 237-fold increase in 72 years. Less than 10% has ever been recycled; the rest was burned, buried, or left to drift. About 8.8 billion short tons of plastic waste now persist on the planet.
The health bill runs over $1.5 trillion a year. In 2015 alone, air pollution from plastic manufacturing was linked to about 158,000 premature deaths and $200 billion in losses. In the US, three plastic-related chemicals account for $675 billion a year.
What We Actually Don’t Know
The Naples findings come from one hospital and haven’t been repeated elsewhere. A 4.5-times risk is large, but it’s correlation, not proof of cause. Plastic might simply collect more easily in arteries already unhealthy rather than damage them, and since operating rooms are full of plastic equipment, some of what was found may reflect contamination during surgery rather than disease.
The bigger admission: according to Landrigan, roughly 75% of chemicals used in plastics have never been tested for toxicity. That’s not proof of danger, just proof nobody knows yet.
The Industry Is Betting the Other Way
Landrigan points to Shell’s roughly $6 billion petrochemical plant in Beaver County, Pennsylvania, built to turn fracked natural gas into plastic pellets, the raw material behind bottles and car parts. The same industry now facing questions about plastic’s cost to human health is investing billions to make more of it, not less.
We’ve Done This Before
In 2022, UN member states agreed to draft the first legally binding treaty covering plastic’s full life cycle. The latest round of talks ran in Geneva through August 14, 2025, with 175 countries at the table. A bloc including China, Russia, Iran, and Saudi Arabia pushed back on production caps, favoring recycling instead.
Whether the treaty ends up with real enforcement is still uncertain, and Landrigan has said he doubts the US would back a strict version. But the whole project rests on one bet: that measuring a problem consistently, the way climate scientists track carbon, makes it harder to ignore.
Why Measuring Changes Everything
Most people already carry a vague unease about plastic: the water bottle, the takeout container, the fibers shed from synthetic clothes. What’s missing is a number to attach that unease to.
That’s the point of this Countdown: not to declare plastic a proven killer overnight, since the science is still early, but to build the kind of running record that made carbon and lead impossible to dismiss once someone started counting. A gas well, a pellet plant in Pennsylvania, a plaque sample from a patient in Naples: three points on one line almost nobody had connected before.