It’s been known for decades that phthalates—a group of chemicals that make plastics more durable—are endocrine disruptors, chemicals that block, mimic, or interfere with the body’s hormones. But a new study from researchers at NYU Grossman School of Medicine in New York City, published in The Lancet Planetary Health, found that exposure to such chemicals is also linked to an increased risk of lower birth weight and gestational age—and death—among newborns, in addition to lower academic performance, diabetes, and heart disease in childhood and beyond.

Phthalates can be found in “a broad swath” of consumer products, from personal care to food packaging, Dr. Leonardo Trasande, a professor of pediatrics and population health at NYU Langone Health, tells Fortune.

“We’ve gotten accustomed to phthalates being added in food packaging and the proverbial cucumber wrapped in plastic wrap, which I don’t understand,” he says.

Trasande and his team analyzed data from 5,000 pregnant women participating in the Environmental Influences on Childhood Health Outcomes (ECHO) program, led by the National Institutes of Health. They measured levels of 20 different metabolites—chemicals produced during digestion and other bodily processes—in urine samples three times during each woman’s pregnancy, and later looked for associations with preterm birth and other outcomes in the offspring.

Aside from concluding that at least 56,600 preterm births in the U.S. in 2018 were likely linked, at least in part, to phthalate exposure, they also calculated the economic cost of such births: $1.6 million for all babies born preterm potentially due to phthalates in 2018, and $8.1 billion over those children’s lifetimes combined.

While a number of studies have shown a link between phthalates and preterm birth, such studies only examined urine samples from women once during their pregnancies. Trasande says his team is the first to use a diverse, representative study population and measure metabolites multiple times during each pregnancy.

How to reduce your family’s phthalate exposure

“Our findings uncover the tremendous medical and financial burden of preterm births we believe are connected to phthalates, adding to the vast body of evidence that these chemicals present a serious danger to human health,” Trasande says. “There is a clear opportunity here to lessen these risks by either using safer plastic materials or by reducing the use of plastic altogether whenever possible.”

There’s a general sense that reducing one’s plastic footprint is a “crunchy, granola thing to do,” he says. But it’s not: It’s a matter of health and safety.

Pregnant women and anyone else concerned about their daily exposure to phthalates can do a few things to reduce their risk, according to Trasande, including:

• Using stainless steel and glass for food storage
• Not microwaving or dishwashing plastic
• Avoiding plastics marked with the recycling numbers 3, 6, and 7

“We’re all living on a planet predicated on the notion that plastics are the future,” he said. “Frankly, plastics are the past.”