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Microplastics: What You Don't See That May Be Harmful

Microplastics are found everywhere. What are the dangers?

Key points

  • Nearly all evidence points in the direction that microplastics accumulate in the body and can be carcinogenic.
  • Microplastics are found everywhere, from clothing to toothpaste to babies' teethers.
  • The microplastics industry may leverage arguments that cigarette companies used, such as the products are helpful.

Going to a shoe store was an adventure in my boyhood, not to buy a pair of shoes but to stand on the fluoroscope, a machine that emitted a green glow. It was great fun to see the bones of my feet as they were exposed to X-rays. While my mother believed that an X-ray of my feet would mean better-fitting shoes, I thought it was great seeing my skeletal feet.

My mother wasn’t aware of the hazards involved in x-raying my feet every few months in a shoe store, but certainly, those profiting from the practice knew better. Despite the mounting evidence that the haphazard use of fluoroscopes was potentially dangerous, the machines weren’t removed from the stores until many years later.

While fluoroscopes finally disappeared from stores in the early 1960s, cigarette sales continued. Like fluoroscopes, those profiting from the sale of the product denied that they were dangerous to one’s health. The tobacco industry doubled down with dubious claims, deceptions, and outright lies. Cigarette companies admitted that many who smoked did die early, but, they said, correlation doesn’t prove causation.

Smoking may be associated with other bad habits that cause increased mortality. Since it is unethical to deliberately subject humans to potentially hazardous procedures, research was done on mice or was epidemiological. Despite these limitations, the evidence was overwhelming: Smoking was a serious health hazard.

The final argument against banning smoking had nothing to do with health but appeal to personal freedom. It is a person's right to determine what they do with their health. When studies showed that second-hand smoke was as dangerous as smoking itself, the tide finally turned. No longer was smoking a personal issue; it was a social concern.

It is a long-standing ethical and legal position that personal liberty ends when it harms another. As it is sometimes expressed, my right to swing my arm ends where your nose begins. It is the same argument used in regulating car emissions, factories dumping pollutants into the water, or requiring licensed electricians on job sites.

Microplastics are today’s fluoroscopes and cigarettes. Unlike plastics that we can see, microplastics are invisible to the naked eye. For this reason, less attention has been paid to it than plastics in general. These tiny pieces of plastic are found in synthetic clothing, wet wipes, tea bags, laundry and dishwasher pods, paper takeaway cups, glitter, facial cleansers, cosmetics, in some medicines, and many industrial paints. The list also includes ordinary dust, bottled water, and various foods.

Microplastics are a danger to marine life and turtles and birds, but little is known about their effect on human health. However, evidence is sufficient for Kurunthachalam Kannan, professor of pediatrics at NYU School of Medicine, to say, “Human exposure to microplastics is a health concern.”

A recent study by Dr. Kannan and colleagues showed that infants have 10-20 times higher microplastics concentrations in their feces than adults. Kannan explained,

Why? Infants mouthing behavior, such as crawling on carpets and chewing on textiles, as well as various products used for children including teethers, plastics toys, feeding bottles, utensils such as spoons can all contribute to such exposure.

Understanding the impact of microplastics on health is complex (as with cigarettes, you can’t ethically design a study that subjects people to potential harm), but nearly all evidence points in the direction that microplastics accumulate in the body and are carcinogenic.

Below is a chart from a review study of the potential effects of microplastics on human health, published in the International Journal of Environmental Research and Public Health, 2020.

Journal of Environmental Research and Public Health
Source: Journal of Environmental Research and Public Health

We can anticipate that the plastic industry responses will follow the same arc as that of the shoe manufacturers and tobacco companies:

  1. Microplastics are helpful (the X-rays will lead to better-fitting shoes).
  2. Because fish are dying from microplastics doesn’t prove they are harmful to humans (mice aren’t people).
  3. Microplastics found in people’s bodies do not mean that they caused the illness (smokers may be living an unhealthy lifestyle in general).
  4. Even if microplastic is hazardous to health, consumers should be free to buy what they want (you don’t have to smoke if you don’t want to).

Government regulation of microplastics is beginning, especially as it relates to aquatic life. But now that we know that infants are subject to these harmful and perhaps even deadly substances, this may move society to take bolder and quicker action. It was done with fluoroscopes in shoe stores, and it happened with the tobacco industry.

Change is hard, especially when the danger is invisible. The naked eye can’t see viruses, but we know that they can make us sick. So, too, we can change habits and preferences if we acknowledge just how harmful microplastics are for us.