Plastics

What plastics are and the types that matter

Plastic is a synthetic material made mostly from fossil fuels, shaped into everything from water bottles to food wrap to the fibers in clothing and carpet. The health concern is not the plastic alone. It is the chemicals mixed into it and the particles it breaks into over time. Four categories account for most of the worry.

BPA, or bisphenol A, is a chemical used to harden plastic and line food and drink cans. The FDA reports BPA can migrate from packaging into food, and it turns up in the urine of the vast majority of Americans tested. Phthalates are a group of chemicals added to make plastic soft and flexible, common in vinyl flooring, shower curtains, food packaging, and personal care products. Microplastics are tiny fragments, smaller than 5 millimeters, that form as larger plastic breaks apart. PFAS, sometimes called forever chemicals, are a class of thousands of compounds used to make products resist grease, water, and stains, and the CDC reports they are found in the blood of nearly all Americans. Each one behaves differently, and each one reaches the body in its own way.

Plastic sits in nearly every room, and the exposure comes from ordinary use, not misuse. The kitchen is the largest source. Food containers, plastic wrap, bottled water, canned food linings, and nonstick cookware all put plastic and its chemicals in direct contact with what you eat and drink.

Heat makes it worse. The FDA and researchers note that heating food in plastic containers increases the amount of chemicals that migrate into the food, which is why microwaving in plastic raises exposure. Beyond the kitchen, vinyl flooring, carpet, upholstery, and shower curtains shed phthalates and particles into household dust. Personal care products like lotions, shampoos, and cosmetics carry phthalates. Synthetic clothing sheds plastic fibers into the air with every wear and wash. PFAS coat stain-resistant furniture, waterproof jackets, and grease-resistant food wrappers. The plastic in a home is not a single product. It is a background layer that constantly sheds into the air, dust, water, and food around it.

Plastic reaches the body through 3 main paths. Ingestion is the largest. A 2019 study commissioned by the World Wildlife Fund estimated that people may consume about 5 grams of microplastic a week, roughly the weight of a credit card, through food and water. Plastic chemicals leach into food from packaging and cookware, and microplastics turn up in tap water, bottled water, seafood, and salt.

Inhalation is the second path. Microplastic fibers shed from carpet, upholstery, and synthetic clothing float in household dust and indoor air, and people breathe them in throughout the day. A 2022 study in the journal Science of the Total Environment found microplastics deep in living human lung tissue, confirming that inhaled particles reach the lungs and stay there. Skin contact is the third path. Phthalates and other chemicals in lotions, cosmetics, and personal care products absorb through the skin directly into the body. Together, the three paths mean exposure is nearly constant, running through the food, the air, and the products a household uses every day.

What plastics do to the body

The central concern is hormone disruption. BPA and phthalates are endocrine disruptors, meaning they interfere with the body's hormone system, and the National Institute of Environmental Health Sciences reports they can mimic or block hormones like estrogen and testosterone that control growth, metabolism, and reproduction. Because hormones operate at tiny doses, even small exposures can matter.

The research links these chemicals to a range of effects. The NIEHS connects BPA and phthalate exposure to reproductive problems, and studies associate phthalates with reduced fertility and altered hormone levels in adults. PFAS carry their own documented risks. The CDC's Agency for Toxic Substances and Disease Registry links PFAS exposure to increased cholesterol, changes in liver enzymes, reduced vaccine response in children, and increased risk of kidney and testicular cancer. Broader research ties plastic chemical exposure to higher rates of obesity, type 2 diabetes, and heart disease, though the strength of each link varies. Microplastics themselves are still under study, but researchers are examining whether the particles cause inflammation and carry other chemicals into the tissues where they lodge.

Who is most at risk

Children carry the greatest risk. They eat, drink, and breathe more relative to their body size than adults, and they spend more time on the floor where plastic dust and fibers collect, so they take in more. Their bodies and hormone systems are still developing, which makes them especially sensitive to endocrine disruptors. The American Academy of Pediatrics issued a 2018 policy statement urging families to reduce children's exposure to BPA and phthalates, citing effects on brain development, behavior, and the timing of puberty.

Pregnant women are the other high-risk group. Phthalates, BPA, and PFAS can cross the placenta and reach the developing fetus, and research links prenatal exposure to these chemicals with effects on fetal development and birth outcomes. The concern is timing. Exposure during pregnancy and early childhood hits the body during the windows when hormones guide development, so the same dose that an adult clears without visible effect can alter how a child grows. Infants add another route entirely, since microplastics and plastic chemicals have been detected in both infant formula prepared in plastic bottles and in human breast milk.

Plastic inside the human body

The evidence that plastic reaches the body has moved fast. In 2022, the Environment International study found microplastics in the blood of most adults tested, showing the particles can travel through the bloodstream. The same year, the lung tissue study found microplastics lodged deep in the lungs of living people. Also in 2022, a study in the journal Polymers detected microplastics in human breast milk for the first time, in 26 of 34 samples tested.

The particles have since turned up in other tissues. Researchers have reported microplastics in the placenta, the liver, and human stool, and a 2024 study in the New England Journal of Medicine found microplastics and nanoplastics in the plaque removed from patients' arteries, noting those patients had a higher rate of heart attack, stroke, and death over the following months. Scientists caution that finding particles in tissue is not the same as proving they cause a specific disease. What the research establishes is that plastic no longer stays outside the body. It circulates within it, and the work of measuring the consequences is ongoing.

What a household can do

Cut kitchen exposure first, because food and drink are the largest source. Store and reheat food in glass or stainless steel instead of plastic, and never microwave food in a plastic container, since heat drives chemicals into the food. Filter tap water with a system rated for the contaminant you are targeting, and choose fresh or frozen food over canned when you can, since can linings often contain BPA.

Reduce what sheds into your air and dust next. Vacuum with a HEPA filter and dust with a damp cloth to capture plastic fibers before you breathe them, and open windows when outdoor air is clean to clear indoor dust. Choose natural fibers like cotton and wool over synthetic fabrics where practical. Check personal care products, since phthalates often hide under the word "fragrance" on a label, and pick products labeled phthalate-free and paraben-free. For PFAS, skip nonstick cookware when it is scratched, avoid stain-resistant and waterproof treatments where you can, and check whether your water utility tests for PFAS, since the EPA finalized the first national drinking water limits for these chemicals in 2024. Protect children and pregnant women directly: use glass baby bottles, avoid plastic toys that go in the mouth when possible, and wash hands before eating to clear plastic dust picked up from floors and surfaces.