Forever chemicals accumulate up the food web, with recent research indicating that apex predators have higher concentrations because they're eating prey that also have accumulated the substances.

See this interactive global map that highlights which forever chemicals have been detected in specific wildlife species, providing data on hundreds of species exposed to these hard-to-breakdown substances.

Forever chemicals are so common that experts concluded in 2022 that it's uncertain whether limiting consumer exposure would truly reduce one's exposure to these substances, and noted it would still take years for the body to clear them.

Used since the 1940s, 'forever chemicals' include thousands of different types of substances routinely integrated into industry and consumer products, yet research suggests they can accumulate in the body over time.

Watch 'Last Week Tonight' explore the risks of 'forever chemicals,' a group of human-made chemicals used in everyday products to make them resistant to water, stains, grease, and heat. (Warning: language.)

Most of the 86,000 consumer chemicals registered with the US EPA have never received rigorous toxicity testing, though not all those are still in current use.

A remote Scottish island is awash in forever chemicals even though there are no obvious industrial sources nearby, and scientists suspect the toxic substances are accumulating via sea spray.

Although PFAS, or forever chemicals, are intentionally designed to be extremely stable and long-lasting because of their strong carbon-fluorine bonds, these bonds can be broken by heat, plasma, and supercritical water.

Teflon was an accidental discovery by a DuPont scientist in the 1930s resulting from efforts to create a safe refrigerant.

Explore this interactive EPA map, which shows 'forever chemical' testing results for public water systems—with brown spots indicating testing results above national limits.

Why bacterial bioremediation may help counter the negative effects of past chemical solutions

Molecules such as DDT, a synthetic insecticide, and PFAS—"forever" chemicals used to make products resistant to heat, water, and grease—have historically been used across various industries but are now known to be harmful. Microbes that can convert some of these substances into nontoxic products, such as water and carbon dioxide, have already been identified, with ongoing research to find others.

Listen to a reporter discuss his story spotlighting a decadeslong corporate cover-up about forever chemicals, substances, which can persist in the environment for hundreds of years—though not forever.

Microplastics are entering human food chains through carrots, wheat, and other foodstuffs grown in farmlands fertilized by sewage sludge.

Microplastics have been found across all of Earth's depths and altitudes, from plastic debris in the Mariana Trench to fragments found in snow samples near the summit of Mount Everest.

The five most common chemicals found in modern food

Most modern processed foods rely on a number of preservatives to stay fresh from production to our plates. The most common include citric acid (preservative and flavor), sodium benzoate (preservative), xanthan gum (thickening and stabilizing), carrageenan (thickening), and red dyes 3 and 4 (for color).

View the estimated decomposition times for various everyday plastic products, which often fragment into smaller microplastics as molecular bonds are weakened by sunlight.

The amount of plastic chemicals in 300 everyday Bay Area foods

Food production is more complicated than it appears, and manufacturing, packaging, and shipping processes can add significant substances to your food. This massive project compiled data on 300 samples of foods delivered to the San Francisco area, testing for the presence of 18 different kind of plastic. Learn how to read the data here with its helpful guides and then explore the table yourself.

Microplastics have been found everywhere there is liquid or vapor water, from the oceans and tropical waters to polar ice and the air we breathe, posing growing risks to wildlife and ecosystems.

BPA-free plastics may still pose health risks because they often contain other structurally similar chemicals.

Many chemicals used in fracking fluid have been classified as toxic

Although the fluid has been known to leach into drinking water supplies, raising health concerns, fracking is exempt from federal clean water regulations due to a loophole in the Energy Policy Act of 2005 championed by former US Vice President Dick Cheney.

Scientists have found that sewage sludge used as fertilizer introduces various microplastics into soil, which persist in farmland for decades.

The prevalence of microplastics came from plastic’s affordability and versatility

Microplastics' durability and overuse have led to massive pollution that overwhelms the planet's ecosystems. Avian, terrestrial, and marine life have been observed to contain microplastics in their bodies, but reverting to paper, cotton, and other materials in manufacturing also brings environmental challenges.

Stainless steel and cast-iron pans should be used over older nonstick cookware

Although modern nonstick pans avoid forever chemicals like PFOA, they were previously used in the manufacturing of Teflon coatings and have been linked with certain types of cancer, infertility, and other adverse health outcomes. Vintage plastic utensils should also be avoided due to the leeching of contaminants in early formulations of plastic.

Research shows that over 1,000 metric tons of microplastics fall on national parks every year—equivalent to 120 million bottles of water.

As of 2025, the FDA states that microplastics have not yet been shown to pose a risk to human health, though it acknowledges that evidence suggests microplastics and nanoplastics have entered the food supply.

Some invasive species can provide benefits to ecosystems over time

In the 1990s, round gobies were introduced into the Great Lakes, rapidly spreading and competing with local sculpin and logperch. However, Lake Erie watersnakes, which were on the endangered species list, shifted their diet to be almost entirely made up of the plentiful round gobies, contributing to their loss of endangered status in 2011.

Fish in polar waters contain proteins in their blood that act as antifreeze, and some manufacturers have used lab-grown versions of these proteins to help keep ice cream smooth.

Synthetic pheromones may protect coral reefs by attracting their predators

Researchers in Australia and Japan have developed these nontoxic chemicals to attract crown-of-thorns starfish, which consume corals that make up the Great Barrier Reef. As of 2026, synthetic pheromones have been shown to be effective in lab trials, and future field trials will attempt to lure starfish into areas for mass removal.

Supplements often have issues with impurities, toxins, and inaccurate labels

Consumer Reports' tests of more than 20 supplement powders and shakes in 2025 found that more than two-thirds of them contain unsafe levels of lead. Some contained 10 times the amount of lead that's considered acceptable to ingest in a day. The levels they found, in some cases, were even higher than when they tested the products 15 years earlier.

Microplastics have been identified across human body systems, with research finding they are most commonly ingested through inhalation, drinking water, and diet before crossing barriers into organs.

Fluorinated molecules are the most impactful, longest-lasting greenhouse gases

Developed as replacements for ozone-depleting substances in refrigeration and air conditioning systems, these compounds are released through leaks in and ongoing use of these appliances, as well as from various industrial processes. They can remain in the atmosphere for thousands of years and have warming potentials that are a thousand to tens of thousands of times greater than those of carbon dioxide.

Ultraprocessed foods are linked with a 58% elevated risk of developing dementia.

The cleanup of oil and other chemical spills involves a combination of methods tailored to different settings, including vacuuming, dispersing absorbent materials, chemicals, or biological agents, and localized burning.

The ocean's ability to store carbon long-term is being hindered by marine heatwaves

More than 4,000 robotic floats with biogeochemical data sensors, including oxygen, pH, nitrate, suspended particles, chlorophyll, temperature, and conductivity, have been deployed as part of the Global Ocean Biogeochemical Array. They have identified changes to ecosystem structure affecting the ocean's ability to transport carbon from surface waters into the deep.

Explore how close you live to some of the most contaminated places in the US

Known as Superfund sites, these toxic locations undergo long-term cleanup to remove hazardous waste, protect health, and restore land for safe reuse. As of 2025, the EPA lists around 1,300 active Superfund sites on its National Priorities List, with more than 450 cleaned and removed since 1980.

Mermaid tears are a long-lasting and hazardous form of ocean microplastic pollution, whose chemical composition enables them to contain higher concentrations of certain toxins than the surrounding environment.

Microplastics are infiltrating the human body with unclear but concerning effects

Scientists have linked microplastics to immune system damage, hormone disruption, inflammatory diseases, and even cancer—yet most of their health impacts remain unknown due to limited research. Studies suggest we ingest about a credit card's worth of plastic weekly.

While major oil spills result from accidental pipeline ruptures or damage to transportation vessels or rigs, as much as half the oil that reaches coastlines has naturally leaked from the seafloor.

Research shows that microplastics and nanoplastics can accumulate in major arteries, and patients with these deposits are significantly more likely to suffer heart attacks, strokes, or death.

Nanoplastics can bypass the blood-brain barrier and may harm the nervous system

Nanoplastics are formed from the breakdown of microplastics and can breach cells. Their large surface area relative to size allows them to carry higher concentrations of forever chemicals than the surrounding environment into sensitive organs.

How a polluted New York City waterway created extremophiles hungry for 'black mayonnaise'

In the 19th century, coal processing plants, oil refineries, a tannery, and other industries lining the Gowanus Canal contaminated its waters with coal tar, sewage, and other pollutants, forming the toxic sludge. Samples taken from the site before clean-up efforts revealed over 450 species of microbes with metabolisms adapted to break down these contaminants.

Microplastics 101: What we know about the contaminants invading our bodies

Fifty-one trillion particles of microplastics float in our oceans. Yet there is very little science of how this affects our health. This quick 2-minute video explains the dangers of microplastics.

Some marine life can survive the extreme pressure of the deep ocean because of specialized molecules that strengthen proteins, enzymes, and cellular membranes.

Volatile chemical contamination can last in burn areas long after urban wildfires

Lead, arsenic, asbestos, and other chemicals have been found trapped in smoke-exposed rugs, couches, pillows, and other furniture that appeared otherwise undamaged from the 2025 LA wildfires. The gradual release of these substances has produced dangerous indoor air concentrations and contributed to increased emergency room visits and abnormal blood tests.

The Love Canal disaster exposed the dangers of buried toxic waste

In the late 1970s, residents of Niagara Falls, New York, discovered their neighborhood was built atop 20,000 tons of chemical waste. Leaking toxins caused illness and birth defects, sparking nationwide outrage and leading to the creation of the EPA's Superfund cleanup program in 1980.

Find fracking wells where you live and what chemicals operators are using

Fracturing fluid recipes are largely proprietary, but FracFocus has maintained a database of chemical disclosures since 2011. Today, the Department of Energy-affiliated nonprofit has more than 240,000 disclosures, along with a searchable database of fracking wells by state, county, and city.

Why it's so hard to end the use of toxic lead

Lead was one of the earliest metals mined on Earth, desired for its soft malleability and used in cosmetics, pipework, gasoline, and more. But even though researchers demonstrated its toxicity in the 20th century, much of the world still uses it.

The risks of bioremediation, from intermediate products to ecological disruption

A step in the series of complex biochemical reactions involved in the implemented bioremediation process may produce dangerous molecules—sometimes more toxic than the initial pollutants—that require ongoing monitoring to ensure optimal conditions for processing these intermediates toward the eventual, safe outputs. Introducing non-native nutrients or species, including GMOs, may alter existing food webs and gene pools.

Why a Montreal Protocol amendment cut back on the replacements for CFCs

Hydrofluorocarbons were introduced in the 1990s as ozone-safe substitutes for chlorofluorocarbons and hydrochlorofluorocarbons. However, scientists later found that they trap thousands of times more thermal energy in the atmosphere than carbon dioxide does, prompting a 2016 amendment to the Protocol to phase them out.

The Office of Chemical Safety and Pollution Prevention regulates toxic substances

This office evaluates and manages risks from industrial chemicals and pesticides. It reviews new chemicals before they enter the market, restricts hazardous substances, and promotes safer alternatives to protect human health and the environment.

Butterfly populations have declined by 22% from 2000 to 2020

Research suggests that one in every five butterflies is lost due to pesticide use, habitat loss, and climate change. Playing a vital role in pollination, their declining populations threaten plant reproduction and the health of ecosystems.