Common plastic chemicals linked to 356,000 annual heart disease deaths worldwide

Chemicals used to make plastics more flexible are linked to more than 356,000 deaths annually across the globe, creating what researchers called a “substantial global health burden,” according to a new peer-reviewed study. 

The study, published Tuesday in the journal eBiomedicine, is the first to estimate heart disease deaths from exposure to di-2-ethylhexyl phthalate (DEHP), a class of phthalate chemicals that are used in raincoats, food packaging, shower curtains, PVC flooring and pipes, IV bags and other items. The chemicals make plastics softer and more pliable but are associated with multiple health problems, including hormone disruption, obesity, diabetes, infertility, cancer and heart problems.

The study does not prove DEHP causes heart-related deaths, however, it adds to evidence that exposure to the widespread chemicals — and the plastics that carry them — could raise people’s risk of heart disease. 

The new study comes as US regulators are undertaking a risk evaluation of DEHP to see if it requires further regulation and are accepting public comments on the review until May 6. The study also adds to a global debate over how to limit plastics and other chemicals linked to human and environmental health problems.   

The researchers used environmental and health data from 200 countries and territories to estimate DEHP exposure and compared this to 2018 mortality data from the Institute for Health Metrics and Evaluation, an independent population health research organization. The researchers estimated DEHP exposure contributed to 356,238 deaths, which represents 13% of all global deaths from heart disease in 2018 among people aged 55 to 64. The authors calculated these premature deaths caused a $510 billion economic burden. 

People from countries in the Middle East, South Asia, East Asia and the Pacific accounted for roughly half the estimated deaths. India had the highest estimated DEHP-linked heart disease death total, with more than 100,000. 

“This study uncovers a substantial global health burden attributable to DEHP exposure,” the authors wrote. “These data highlight critical global disparities in loss of life due to plastics pollution.” 

It’s not entirely clear why these countries had such a large proportion of the deaths, said study senior author Dr. Leonardo Trasande, a professor of pediatrics at the NYU Grossman School of Medicine.

Phthalate impacts to heart health

The findings build on a 2021 study from the authors that tied phthalates to roughly 50,000 premature deaths among older people in the US each year, mostly from heart disease. In addition, a 2023 review found that most recent studies examining the link between phthalates and heart problems found an association, including strokes, arrhythmias, hypertension and other problems. 

It’s not entirely clear how phthalates, including DEHP, could impact the heart. But researchers say they could potentially disrupt receptors that are crucial for metabolism and increase oxidative stress — both of which can lead to heart problems and disease.  

Laura Vandenberg, a researcher and professor of environmental health sciences at University of Massachusetts Amherst School of Public Health & Health Sciences, said it’s likely that the heart disease link is due to these “indirect” effects of phthalates, including DEHP. 

“Phthalates, in general, are known on a molecular level to increase levels of oxidative stress, and also to serve as obesogens and metabolic-disrupting chemicals,” Vandenberg said.  Obesogens refer to chemicals that cause our bodies to produce more fat.

Obesity is a risk factor for heart disease, and oxidative stress, which causes cell damage, can lead to heart problems as well. 

Microplastics and nonplastics “carry chemicals along for the ride,” Trasande said, but it’s possible the tiny bits of plastics themselves also might be causing tissue injury, leading to heart impacts. 

When asked about the new study, Kevin Ott, executive director of the Flexible Vinyl Alliance, which advocates for use of PVC plastics, pointed to a 2018 US Food and Drug Administration (FDA) study that stated there hadn’t been a human health study that connected phthalates and human health impacts.

“Phthalates, in general, are known on a molecular level to increase levels of oxidative stress, and also to serve as obesogens and metabolic-disrupting chemicals.” -Laura Vandenberg, University of Massachusetts Amherst

Academic studies, however, are consistently at odds with the FDA stance. A large 2022 study that reviewed phthalates human health research found links to multiple health problems and that “health risks can occur at exposure levels below the ‘safe dose’ levels set out by regulators.” 

The Flexible Vinyl Alliance petitioned the FDA in 2018 to remove 23 phthalates from use in any materials that contact food during processing, packaging storage or handling, saying that industry had already stopped using them. The FDA accepted the petition in 2022, revoking the authorizations. However, DEHP remains in use and the alliance has supported its continued use, along with three other remaining phthalates used in food materials, saying in a letter to the FDA the chemicals are “minimally used” and remain “safe for their intended use when deployed for food contact and food packaging.” 

Trasande said the safest way to minimize health risks from chemicals is to “regulate by class.” 

“We’ve had a bunch of problems with regrettable substitutions,” he said. “If we reduce DEHP I’m not convinced you’ll reduce this mortality. But if you reduced plastic use or phthalates as a class, you would.”

An “opportunity” to get DEHP out of products

Globally, about 3 million to 4 million tons of DEHP are produced each year, representing about 40% of chemicals used to make plastics softer. Under the Toxic Substances Control Act the US Environmental Protection Agency (EPA) considers DEHP a “high priority substance,” which triggered a risk evaluation – happening now –  to see if it requires further regulation. The agency, which already has a 6 parts per billion limit for DEHP in drinking water, is accepting public comments on the DEHP review until May 6. 

There’s an “opportunity to get DEHP out of as many products as possible,” said Judith Enck, president of Beyond Plastics, a nonprofit organization that fights plastic pollution. 

She added that DEHP has “not been studied enough” and pointed out that “millions of Americans get drinking water from PVC pipes,” which contain DEHP. 

“After 40 or 50 years many cities are getting around to replacing lead service lines and we don’t want to replace those with PVC,” she said, adding that Beyond Plastics is advocating for copper lines. 

Trasande said the best available data suggests our diets are the main route of exposure for DEHP, but it’s not clear that’s the case across the globe. He suggested some simple steps that won’t “break the bank” to limit exposure including using glass and stainless steel containers instead of plastic, not microwaving plastic and looking at recycling numbers, as #3 is for PVC plastics that could contain phthalates.

(Featured image by HI! ESTUDIO for Unsplash)