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Health Effects of Plastics, Microplastics, and Nanoplastics

By

Mark A. Mitchell MD, MPH

Co-chair,

National Medical Association

Council on Environmental Health and Climate Change

for

Connecticut Health Professionals for Climate Action

July 16, 2026

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Disclosures

I received no support from commercial interests for this presentation

I want to thank the Physician and Scientist Network Addressing Plastics and Health (P-SNAP) for support and images in this presentation.

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Overview

A History and Definition of Plastics
Use of Plastics
Environmental Injustice in the Lifecycle of Plastics
Properties of Health Concern with Plastics

Biological and Particulate Concerns
Chemical Concerns

Plastics in Healthcare
What are Microplastics and Nanoplastics?
Where are Microplastics Found?
Health Effects of Microplastics
Recommendations for Reducing Microplastic Exposure

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History of Plastics and Microplastics

Although plastics have been around since the 1940s, the evidence of the existence and health effects of microplastics has emerged only recently

Traditional environmental pollution is associated with the industrial revolution starting in late 18^th century

Chemicals mostly developed since World War II

Rubbertown, Louisville, KY

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What are Plastics?

Any material that can be heated and molded so that it retains the molded shape after it cools

Animal horn and amber are examples of natural plastics

Usually made of petroleum or natural gas

Unsustainable

Persistent in environment

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Additives

Plasticizers, flame retardants, stabilizers, antioxidants, UV stabilizers, slip agents, lubricants, anti-statics, curing agents, biocides, colorants, fillers, reinforcements

https://knowablemagazine.org/article/food-environment/2020/solving-growing-plastics-waste-puzzle. Accessed 28 April 2023

Hahladakis JN et al. 2018. An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling. J Hazard Mater.

How Are Plastics Usually Made?

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Image from Howard Homlar, MD

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Most production is for single use packaging

What are we doing with all this plastic. Packaging is the main plastic product. About 40 % of this is for food packaging. Packaging in general is a big reason why plastics has become so ubiquitous. Then there are chunks of styrofoam, reams of bubble wrap and a frequently thin layer of unnecessary film plastic has appeared everywhere and healthcare is no exception. So this is an area we need to look at to reduce.

I want to point out something here that is not perse related to medicine, but an important fact- Number 4 is textiles- 75% of our clothes contain synthetics and “fast fashion” is actually a massive part of the plastic crisis. Synthetics equal plastic and thousands of these microfilaments get into our wastewater everytime we do a load of laundry.

Plastic is also in most of our durable goods as well- from electronics, housing material, cars, furniture, but another place we can reduce is single use plastic- just used once and then thrown away.

Who has a guess as to what percentage of plastic is single use ?? One and done- like our laceration trays, chuxs pads and iced coffee cups.

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Why should we be concerned � about plastics like PVC?

Like many plastics, PVC requires the addition of numerous chemical additives, which can make the PVC product itself harmful to consumers.

These chemicals can leach out of PVC, posing risks to children and consumers. New car smell? New shower curtain smell? That’s the smell of toxic chemicals off-gassing from PVC.

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What is Bisphenol A?

Previously used as an artificial estrogen before Diethylstilbestrol (DES)
In polycarbonate (number “7”) and epoxies
Translucent hard plastic, often colored
Used in hard plastic

reusable food and beverage containers,
baby bottles and sippy cups,
water bottles and water coolers,
thermal cash register receipts
the lining of metal cans

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Health questions about BPA

Aneuploidy: Down’s Syndrome

Prostate cancer

Impaired brain development

Long-term memory formation

Obesity and diabetes

Low sperm count

Dementia

Hyperactivity

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PVC Lifecycle: Production

Activists block Terminals Pty Ltd,

major supplier of feedstock to the PVC industry.

Chlorinated chemicals used

and released during

manufacture

Vinyl chloride- angiosarcoma

of the liver

Pure PVC – 57% chlorine

Release dioxins

and mercury

Environmental racism

Worker impacts

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PVC Lifecycle: During Use

Include harmful additives which off-gas or leach during use.

Phthalates – may impair male reprod. system development, liver tumors, etc.
Lead, cadmium, organotins.

Children’s toys, IV bags, flooring, food wrap, new shower curtain smell.

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PVC Lifecycle: Disposal

As much as 7 billion pounds of PVC disposed of every year in U.S.

Difficult to recycle - one PVC bottle can contaminate 100,000 recyclable bottles.

Releases toxic chemicals (i.e. dioxins) when burned in incinerators or in landfill fires.

Photo from www.burnbarrel.org

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Environmental Justice Communities

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U.S. Plastics Disposal (8.7% recycled)�Source: US EPA

(https://www.epa.gov/facts-and-figures-about-materials-waste-and-recycling/plastics-material-specific-data)

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Healthcare’s Plastic Footprint

US healthcare facilities : 14,000 tons waste/ day

25% Plastic

7 million lbs of plastic waste a day

(Most of this is packaging)

Healthcare Plastics Recycling Council

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Plastics don’t biodegrade. They break into smaller and smaller fragments.

Microplastics occur during plastic production, use and eventually, over time, those that aren’t incinerated all become microplastics and nanoplastics

Slide from institute of Technology and the Environment– Penn State

In its absolute and final disposition, we suspect that the destination of most of the plastic in existence on earth is microplastics.

Plastic doesn’t break down in the environment. Instead, it breaks up into tinier and tinier pieces. A “microplastic” is anything smaller than a pencil eraser, but as it goes down it can become nanoplastic, which is smaller than a blood cell. And it goes smaller still. At this point, we have no evidence that plastic ever returns to its base elements – which is something that scientists like to talk about over drinks at big meetings.

It is worth thinking of plastic sort of like skin – wherever it is, it is constantly shedding micro and nano plastics.

The plastic that hasn’t yet broken into fragments is what is referred to as a “toxicity debt.”

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Source: https://saveourbays.org.uk/plastics

Microplastics and nanoplastics are very small…

Slide by Elizabeth Ryznar, MD

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What’s the difference between microplastics and nanoplastics?

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Where do microplastics come from?

Larger plastic items that break into smaller pieces over time:

Single-use plastic items:

Plastic bags
Plastic bottles
Plastic wrap
Plastic cutlery, etc.

Also, reusable items:

Clothing fibers
Tires
Plastic cutting boards, etc.

Intentionally created small particles:

Microbeads in cosmetics, face scrubs, toothpaste, etc.
Plastic pellets used in manufacturing

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Human Feces - Oct 2018

Placenta - Jan 2021

Lung - May 2021

Meconium - June 2021

Sputum - Jan 2022

Blood - May 2022

Breast Milk - June 2022

Liver - Aug 2022

Urine - Dec 2022

Where are the microplastics?

Veins - Feb 2023

Testes/Semen - March 2023

Heart Tissue - Aug 2023

Kidney - Feb 2024

Carotid plaque - March 2024

Brain - May 2024

Olfactory Bulb - Sept 2024

Bone - Nov 2024

Follicular Fluid - Feb 2025

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Types of Health Risk from Microplastics:

Particulates

PM 10
PM 2.5

Biologicals

Bacteria and viruses adhere to surfaces
Interference with immune response to biological agents

Chemicals

Trojan horse chemical delivery mechanism

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Researchers have identified 16,325 chemicals in plastics.

March 2024

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“...total plastics mass concentration in brains increased over 50% in the past 8 years.”

“Polyethylene was the predominant polymer”

“MNPs are selectively accumulated into the human brain.”

The brains of people with a history of alzheimer’s or dementia contained 5-10x more plastic

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Source: NYU Grossman School of Medicine (2026). 90% of Prostate Cancer Tumors Contained Microplastics. NYU Langone Health.

A groundbreaking study from NYU Langone reveals that microscopic plastic particles are infiltrating prostate tumors at 2.5 times the rate of non cancerous tissue.

Scientists at the NYU Grossman School of Medicine have identified a troubling presence of microplastics in 90% of prostate cancer tumors examined during a recent pilot study. On average, cancerous samples contained approximately 40 micrograms of plastic per gram, nearly triple the amount found in non-malignant tissue. This discovery marks the first major investigation in the West to directly compare plastic accumulation between cancerous and healthy prostate sites.

A new study has found tiny plastic particles in nine out of 10 men diagnosed with prostate cancer. Researchers also discovered that these microplastics were present at higher concentrations in cancerous tumors than in nearby non cancerous prostate tissue.

February 25, 2026

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Infertility

Dr Shanna Swan, “Countdown” Scribner 2021

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Changes in gene expression�� (two sets of mice with identical genes, food and exercise)

BPA in Mother’s diet altered gene expression

Mother’s exposure to stress altered gene expression

Jirtle et al. 2004

Newbold 2005

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Correlation vs Causation

Lee and Pak (2018) Persistent organic pollutants, mitochondrial dysfunction, and metabolic syndrome In Mitochondrial Dysfunction by Drug and Environmental Toxicants, Volume II

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How do we solve this?

Artwork by Javier Jean, 2023

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Tell patients to avoid plastics (and teflon) in food handling

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How to Reduce Chemical Exposure

De-plasticize your household

70% reduction in Bisphenol A in 48 hours through diet intervention
6 of 7 infertile couples achieved pregnancy

Eat fresh foods rather than canned (grow your own)

Avoid foods wrapped in plastics

Use glass and ceramic containers, especially for acidic and hot foods

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How to Reduce Bisphenol A Exposure

Refuse thermal receipts whenever practical

Cashiers wear gloves, especially if pregnant

Wash hands after handling receipts and money

Support legislation to ban BPA

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How to Reduce Phthalate Exposure

Don’t buy products in PVC (# 3) containers

Use natural cosmetics

Look up specific cosmetics in Skin Deep database http://www.ewg.org/skindeep

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Avoid plastics in infant care products

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And synthetic textiles in close proximity for long periods

(especially indoors)

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Recommend reverse osmosis water filters

Under Sink

$150 - $800

Whole House

$10,000 - $16,000

Countertop

$120 - $510

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Regulatory systems are the most efficient and the most just.

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Questions?��Let’s Keep our Families Healthy

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In vitro effects: Parkinson’s pathology

Calabrese et al Cell Death & Disease 2023; 176

Liu et al Sci Adv 2023; 9: eadi8716

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Anih et al., 2025; Sci. Int., 13 (1): 27-34

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Common toxicity mechanisms used by microplastic (MP) particles, plastic-associated chemicals, and adsorbed environmental pollutants to exert toxic effects

in human cells.

Different toxic outcomes also indicate suitable endpoint targets for the assessment of the MP-related toxicity.

NIAS – non-intentionally added substances.

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“...total plastics mass concentration in brains increased over 50% in the past 8 years.”

“MNPs are selectively accumulated into the human brain.”

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Image: Thompson, RC, et al, (2024).

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The plastic industry is cranking it out