Daily exposure to certain chemicals used to make plastic household items could be linked to the more than 356,000 global deaths from heart disease that occurred in 2018 alone, a new analysis of population surveys shows.
Although the chemicals, called phthalates, are in widespread use globally, the Middle East, South Asia, East Asia, and the Pacific bore a much larger share of the death toll than others—about three-fourths of the total.
For decades, experts have connected health problems to exposure to certain phthalates found in cosmetics, detergents, solvents, plastic pipes, bug repellants, and other products. These chemicals break down into microscopic particles and are ingested, and studies have linked such exposure to an increased risk of conditions ranging from obesity and diabetes to fertility issues and cancer.
Led by researchers at NYU Langone Health, the current study focused on a kind of phthalate called di-2-ethylhexyl phthalate (DEHP), which is used to make food containers, medical equipment, and other plastic items softer and more flexible. Exposure has been shown in other studies to prompt an overactive immune response (inflammation) in the heart's arteries, which over time is associated with increased risk of heart attack or stroke. In their new analysis, the authors estimated that DEHP exposure contributed to 356,238 deaths, or more than 13 percent of all global mortality from heart disease in 2018 among men and women ages 55 through 64.
By highlighting the connection between phthalates and a leading cause of death across the world, our findings add to the vast body of evidence that these chemicals present a tremendous danger to human health."
Sara Hyman, BS, study lead author, associate research scientist, NYU Grossman School of Medicine
In a past study from 2021, the research team tied phthalates to more than 50,000 premature deaths each year, mostly from heart disease, among older Americans. Their latest investigation is believed to be the first global estimate to date of cardiovascular mortality—or indeed any health outcome—resulting from exposure to the chemicals, said Hyman, who is also a graduate student at NYU School of Global Public Health.
A report on the findings was published online April 29 in the journal Lancet eBioMedicine.
For the research, the team used health and environmental data from dozens of population surveys to estimate DEHP exposure across 200 countries and territories. The information included urine samples containing chemical breakdown products left by the plastic additive. Mortality data was obtained from the Institute for Health Metrics and Evaluation, a research group in the United States that collects medical information worldwide to identify trends in public health.
Among the key findings, the study showed that losses in the combined region of East Asia and the Middle East and the combined region of East Asia and the Pacific accounted, respectively, for about 42 percent and 32 percent of the mortality from heart disease linked to DEHP. Specifically, India had the highest death count, at 103,587 deaths, followed by China and Indonesia. The larger heart death risks in these populations held true even after the researchers adjusted their statistical analysis to take into account population size within the studied age group.
A possible explanation, the authors say, is that these countries face higher rates of exposure to the chemicals, possibly because they are undergoing a boom in plastic production but with fewer manufacturing restrictions than other regions.
"There is a clear disparity in which parts of the world bear the brunt of heightened heart risks from phthalates," said study senior author Leonardo Trasande, MD, MPP. "Our results underscore the urgent need for global regulations to reduce exposure to these toxins, especially in areas most affected by rapid industrialization and plastic consumption," added Dr. Trasande, the Jim G. Hendrick, MD, Professor of Pediatrics at NYU Grossman School of Medicine.
Dr. Trasande, who is also a professor in the Department of Population Health, cautions that the analysis was not designed to establish that DEHP directly or alone caused heart disease and that higher death risks did not take into account other types of phthalates. Nor did it include mortality among those in other age groups. As a result, the overall death toll from heart disease connected to these chemicals is likely much higher, he says.
Dr. Trasande says that the researchers next plan to track how reductions in phthalate exposure may, over time, affect global mortality rates, as well as to expand the study to other health concerns posed by the chemicals, such as preterm birth. Dr. Trasande also serves as director of NYU Grossman School of Medicine's Division of Environmental Pediatrics and the Center for the Investigation of Environmental Hazards.
Funding for the study was provided by National Institutes of Health grant P2CES033423. Further study funding was provided by Beyond Petrochemicals.
Dr. Trasande has received support for travel or meetings from the Endocrine Society, the World Health Organization, the United Nations Environment Programme, Japan's Environment and Health Ministries, and the American Academy of Pediatrics. He has also received royalties and licenses from Houghton Mifflin Harcourt, Audible, Paidós, and Kobunsha, and has served in leadership or fiduciary roles at Beautycounter, Ahimsa, Grassroots Environmental Education, and Footprint. None of these activities were related to the current study. The terms and conditions of all of these relationships are being managed by NYU Langone Health.
In addition to Hyman and Dr. Trasande, other NYU Langone researchers involved in the study are Jonathan Acevedo, MPH and Chiara Giannarelli, MD, PhD.
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