Plastics Are Harmful to Human Health

Acknowledgements: I quote substantially from the excellent article published by Neha Patek for the Yale Climate Connections site, among other sources. I also draw on several sources of information provided by the wonderful instructor Kathleen Sellers through her Toxins in Consumer Products course at Harvard Extension School.

There Has Been An Explosion in Plastic Use Across the Globe Since the 1970’s – and in Plastics in Our Bodies

There is mainstream recognition that plastics are a significant environmental problem. Awareness of the risks of plastics to human health is growing, but perhaps not creating the widespread alarm that is needed right now.

According to the Minderoo-Monaco Commission on Plastics and Human Health, plastic production has increased 230-fold since the 1950s and is projected to triple by 2060. The following chart illustrates this explosive growth (UNEP, 2021).

(United Nations Environment Programme (2021). Drowning in Plastics – Marine Litter and Plastic Waste Vital Graphics, created by GRID-Arendal/Levi Westerveld/Studio Atlantis)

Over 98% of plastics are produced from fossil carbon – coal, oil and gas, and growth in plastics is largely being driven by fossil fuel companies.

“Explosive recent growth in plastics production reflects a deliberate pivot by the integrated multinational fossil-carbon corporations that produce coal, oil and gas and that also manufacture plastics. These corporations are reducing their production of fossil fuels and increasing plastics manufacture.” says Philip Landrigan, pediatrician and director of the Program on Global Public Health and the Common Good and the Boston College Observatory.” (Patek, 2025)

“Every company who is currently engaged in producing plastic, if you look at their capital budgets for the next two to three years, they’re all talking about expansion plans,” said Ramesh Ramachandran, CEO of No Plastic Waste.” (CNBC)

As a result of this plastics boom, plastics and the harmful chemicals comprising them are now everywhere in our environment, which we then eat, drink, breathe, and sometimes absorb through the skin.

“Over time, tiny pieces from the plastic that litters our environment – toys, bottles, bags, food packaging, polyester clothing – break off. These fragments continue to break down into smaller and smaller particles. When plastic is heated – in the sun, microwave, or dishwasher, for example – it sheds even more.” (Patek, 2025)

Microplastics are defined as plastic fragments less than five millimeters in size, and nanoplastics are smaller than one micrometer.

As Nepa Patek describes in her article: “These particles are pervasive in our homes – in indoor air, household dust, bottled water, tap water, meat, salt, fruits, vegetables, seafood, baby formula, and breast milk.

”Microscopic plastic particles have been found in every corner of the environment, from the peaks of Mount Everest to the depths of the Mariana Trench.” (Patek, 2025). They have also been found in remote lakes in the Teton mountains in Wyoming. How do they get there? Wind and rain. Pollution often travels easily around the world.

“The human body is no exception. Scientists have detected plastic particles in nearly every part of the human body – essentially, anywhere they have looked. They’ve been found in our lungs, liver, kidneys, blood, breast milk, placenta, colon, spleen, brain, and even reproductive organs like the testicles and ovaries. Emerging evidence of their impacts – ranging from inflammation to oxidative stress – suggests that plastic exposures may be fueling the growing wave of chronic disease.” (Patek, 2025)

Plastics Contain A Large Number of Hazardous Chemicals That We Are Regularly Exposed To Every Day

Plastics in our everyday lives exposes us to a mix of harmful chemicals that are known, as well as newer ones that have not yet been studied sufficiently. Plastics contain a “brew of chemicals added to give the plastic different properties like flexibility, stability, or color. Over 16,000 different types of chemical additives are used to design the broad array of plastic products. These additives can leach out into the environment over time. Some of these chemicals are toxic, and most are very poorly regulated.” “Fewer than 20% have ever been tested for toxicity.” (Patek, 2025)

Another study in 2018 looked at chemicals found in plastic packaging and identified 148 that are known to be hazardous, out of a total of at least 906 chemicals associated with the plastic packaging (and as much as 3,377).

“The chemical additives used in plastics can also leach into our food and water, pass through our skin, and migrate out of shedding microplastics. The most well-known of the toxic plastic additives are bisphenol A (BPA), added to make plastics harder; phthalates, used to make them flexible; and PFAS (per- and polyfluoroalkyl substances), also known as “forever chemicals,” added to make plastics resistant to heat, oil, and stains.” (Patek, 2025)

The following graphics describe the various categories of intentional additives and other unintentional substances found in plastics (UNEP, 2021).

How We Are Exposed to Plastics On a Regular Basis and How They Affect Our Bodies

The following graphics illustrate examples of the amount of microplastics each person consumes regularly through food, water, and air (UNEP, 2021).

Neha Patek’s article explains the following:

“What happens to micro- and nanoplastics once they enter our bodies is not completely understood. A lot depends on the particle’s size, shape, and chemical makeup – for now, their long-term fate and the long-term risk to our health is an area of active scientific study.

“Plastic particles that enter through our mouths generally move through our digestive system and are eliminated in stool. But the smallest pieces can collect in the lining of our gut or even migrate into our bloodstream. From there, these microscopic pieces can travel to organs like the liver, kidneys, and brain. Some of these plastic particles are eventually flushed out through urine or bile, but some collect in our organs.

“When we inhale plastic fibers, larger pieces are caught in the lining of our nose or throat and can be cleared out when we exhale. But smaller pieces can reach deep into our lungs, where some can cross into the bloodstream.

“Studies suggest these particles, along with toxic materials added or stuck to them, trigger inflammation, cell death, and tissue damage. In lab and animal model findings, microplastics and the dangerous chemicals they carry have disrupted gut and lung barriers, interfered with hormone regulation, and harmed sperm and egg cells.

A “landmark study published in the New England Journal of Medicine that suggests real-world human health consequences. Researchers found microplastics in the clogged neck arteries of close to 60% of studied patients. After three years, people with microplastics had 4.5 times the rate of heart attack, stroke, and death compared to people without microplastics in their clogged arteries.” (Patek, 2025)

There is Enough Evidence of Harm to Take Action

“The report by Minderoo-Monoco Commission on Plastics and Human Health outlines converging lines of evidence showing that plastics cause disease, disability, and premature death across every stage of their life cycle – from fossil fuel extraction to manufacturing, use, and disposal.

“Some of the strongest evidence of plastic-related diseases is linked to specific chemical additives.

“BPA is one of the most well-known plastic chemicals and is part of a larger group of additives known as endocrine-disrupting chemicals, substances that can mimic or interfere with the body’s hormone signals. This group also includes phthalates, PFAS, and certain flame retardants, all commonly found in everyday products.

“There is a lot of data linking specific plastic-related chemicals like certain phthalates, flame retardants, and PFAS with neurodevelopmental harm, including IQ loss and ADHD symptoms,” says Elizabeth Ryznar, a psychiatrist who focuses on the neuropsychiatric risks of plastic. (Patek, 2025)

A new study presents further evidence that “plastic polymers and their chemical additives, particularly di-2-ethylhexylphthalate (DEHP), contribute to cardiovascular disease (CVD). Phthalates are commonly used in the production of plastic materials and have been linked to increased oxidative stress, metabolic dysfunction, and cardiovascular disease.” (Hyman et al, 2025). Previous research has linked DEHP exposure to more inflammation in blood vessels, a response that can elevate the risk of heart attacks and strokes over time.

The health harms of micro- and nanoplastic particles needs to be better understood, but early evidence is alarming.

“In a recent analysis of human and animal studies, researchers reviewed the evidence for health risks in three major body systems: digestive, reproductive, and respiratory. The strongest evidence linked microplastics to impaired sperm quality and weakened gut immunity. There was moderate evidence to suspect harm to female reproductive hormones, gut inflammation, and lung function. The research findings also supported a link to colon and lung cancer that needs further study.” (Patek, 2025)

(Patek, 2025)

The Precautionary Principle and Plastics

“Given the growing evidence of harm, experts emphasize the importance of the precautionary principle: Although more research will always be needed to understand exactly how every organ system is affected, enough data exists to recognize that plastics are hazardous to our health. 

“This is especially true for pregnant women, infants, and young children who may be among the most vulnerable. When dangerous exposures to any substance happen during critical windows of development, the damage can have lifelong repercussions. 

“Microplastics have been identified in placentas and the first bowel movement that a baby has after birth, suggesting that plastics have made their way into the circulation and digestive tract of babies even before they are born. Early life exposures to microplastics and toxic chemical additives like BPA and phthalates may increase long-term risk for obesity, autism, and ADHD, changing the lifelong trajectory of a child and their family.

“The microplastics research is really early, but I’m a firm believer in the precautionary principle,” Ryznar says. “Our exposure is growing exponentially. We don’t want to wait 30 years for definitive proof – by then it’ll be too late and too many people will be harmed.” (Patek, 2025)