What Are Endocrine-Disrupting Chemicals?

From plastic food packaging to drinking water, children’s toys to medical equipment, Americans are regularly exposed to thousands of synthetic chemicals. Many offer convenience, but some can also be hazardous to people’s health—and the limits of current policies and regulations for these chemicals leave hundreds of millions of Americans at risk.

One category of compounds has been found to interfere with the human endocrine system—a complex network of glands and organs that make hormones, which are essential to many functions of the human body. These endocrine-disrupting chemicals (EDCs) have been linked to an array of health effects, including reproductive disorders, cancer, diabetes, and heart disease. EDCs are used in a wide range of products—such as baby bottles and toys, upholstery, construction materials, cleaning supplies, and cosmetics—that millions of people use daily without a second thought.

Studies show that virtually every American—more than 97% of the population, according to one survey—has at least one EDC in their body. These chemicals also have begun to leach into the environment and have been detected in virtually every corner of the world, from the peak of Mount Everest to some of the most remote parts of the ocean.

EDCs can be ingested, inhaled, or absorbed through the skin and affect human health in various ways. Some can look and act like hormones and can alter normal hormone actions, such as by turning biological processes on or off at the wrong time, which in turn leaves people more susceptible to a variety of serious health conditions. And because the human hormone system is so sensitive, even a microscopic amount of an EDC can have negative health effects.

Among the types of EDCs known to be harmful to human health are:

• Per- and polyfluoroalkyl substances (PFAS). Scientists have determined that certain PFAS—a widely used, long-lasting class of chemicals that have become known as “forever chemicals”—are endocrine disruptors, associated with decreased birth weight, obesity, pneumonia, gestational diabetes, kidney cancer, breast cancer, infertility, endometriosis, and more. People can be exposed to PFAS via consumer products, such as cookware, cosmetics, and food packaging, as well as from drinking water, wastewater, and farmland. The U.S. Geological Survey estimates that 45% of U.S. drinking water could be contaminated by one or more PFAS.
• Phthalates. Used to make plastics flexible, these chemicals have been detected in almost all people. They are linked to miscarriage, insulin resistance, reduced sperm quality, decreased birth weight, early puberty in girls, adverse cognitive development and IQ loss, Type 2 diabetes in adults, endometriosis, high blood pressure, and asthma.
• Bisphenols. This class of chemicals is often used in the production of plastics and epoxy resins used to make items such as eyewear, water bottles, baby bottles, and food storage containers. After scientific evidence raised health concerns about bisphenol A (BPA), many companies subsequently removed it from their products in 2008. However, they replaced it with two similar chemicals, bisphenol S and bisphenol F, which growing evidence links to many of the same health problems associated with BPA, such as cardiovascular disease, diabetes, and obesity.

Although anyone could be harmed by EDCs, some people are at greater risk. Endocrine disruptors can cause more serious harm at certain stages of human development when people are more susceptible to hormonal effects, such as during pregnancy, early childhood, and puberty. Therefore, pregnant women, developing fetuses, infants, and adolescents are disproportionally affected by exposure to these chemicals. Further, other populations are at heightened risk because of their professions, including firefighters, who have been regularly exposed to EDCs in firefighting foam and gear, and farmers, who have been unknowingly using PFAS-laden waste to fertilize their crops. People can also be at elevated risk if they live near military bases, airports, industrial manufacturing facilities, or other sources of harmful pollution.

EDCs are everywhere. And although lawmakers nationwide have taken some action to regulate the use of some endocrine-disrupting chemicals, continued and combined efforts of state and federal agencies, corporations, and health leaders are needed to promote safer alternatives and reduce Americans’ exposure to harmful EDCs.

Winnie Roberts directs The Pew Charitable Trusts’ conservation science and conservation support teams and Kathy Talkington directs Pew’s health programs.