Microplastics: A silent threat to health

Today, microplastics are found almost everywhere. Scientists first found small pieces of plastic in the ocean, in organisms such as fish and shellfish, until it entered what we consume on a regular basis. Vegetables, fruits, even beer and salt. One study suggests that the average adult may consume up to 2,000 microplastics per year from salt consumption alone. 

What is Microplastics? 

Microplastics are plastic parts that are smaller than 5 millimeters, while nanoplastics are even smaller, smaller than 1 micrometer. Studies have shown that the average person may inhale or ingest an average of 74,000 – 121,000 microplastics per year, or an average weight of 0.1-5 grams per week.

Microplastics are not only dangerous because they can enter the respiratory system and become embedded in cells. But it also comes with dangerous chemicals such as flame retardants. Ecotoxicologist Dr. Heather Leslie likens these microplastics to "spaghetti noodles" and the chemicals attached to them are like "sauces."

One of the reasons for this problem is that global plastic production has steadily increased, from 2 million metric tons in 1950 to 400 million metric tons today. The rest of the plastic is landfilled, on the beach or the ocean, gradually breaking down into microplastics and contaminating the environment. 

One study found that these tiny plastics can bypass the body's defenses until they reach the ends of the lungs and enter the bloodstream. It causes inflammation and can affect various chronic diseases.

Plastics smaller than 2.5 micrometers can enter the blood and spread throughout the body, accumulating in the liver, lungs, even the placenta and mother's milk. The body's immune cells, called macrophages, attack foreign bodies, but they are not able to destroy microplastics. Eventually, these white blood cells die and this cycle repeats over and over again, negatively affecting the immune system.

The health risks of microplastics not only affect the respiratory and immune systems. But there is also research linking microplastics to cardiovascular disease. A recent study in March 2024 by Dr. Rafael Marfella published in The New England Journal of Medicine found that half of patients who underwent surgery to remove fatty plaque from their arteries. Plastic was detected in grease samples. Polyethylene was found in 150 samples and polyvinyl chloride in 31 samples, a substance commonly found in food containers. cosmetics, including water pipelines.

After nearly 34 weeks of follow-up, people who found microplastics and nanoplastics in fat stains were more likely to develop myocardial infarction. Stroke or death was 4.5 times higher than those who did not find microplastics.

Another 2022 study that looked at the link between microplastics and inflammatory bowel disease found 15 types of microplastics in human feces. In addition, the amount of microplastics found is also correlated with the severity of the disease.

Microplastics are also associated with obesity. The researchers compiled the study and published a review in the journal Frontiers in Endocrinology, assuming that microplastics are "obesogens," chemicals that promote the accumulation of white adipose tissue. It reduces the metabolism of energy and fat through interference with genes such as CYP7a1 and ABCb11 that are related to cholesterol, and microplastics also result in an imbalance of bacteria in the intestines, leading to an imbalance of other body systems.

Although the effects of microplastics on human health have only recently begun to be researched and documented. There are no studies yet to show a clear link between microplastics and certain diseases, but the concern is microplastics smaller than PM2.5, which can reach very deep into the respiratory tract. This results in chronic inflammation and may be a risk factor for lung and heart disease.

However, one thing is for sure: the risks from microplastics are constantly increasing. Gathering more information and creating policies to limit plastic use and reduce microplastic pollution is something that should be urgently implemented to protect the health of all of us.

Understanding the effects of microplastics on health still needs more research. However, the current evidence is sufficient to prompt serious consideration of limiting the use of plastics, as well as accelerating the creation of policies to limit the use of plastics and reduce microplastic pollution in the environment, which will have a positive impact on both human health and the health of the planet in the long term.

References

1. Ducroquet S, Osaka S. The plastics we breathe [Internet]. Washington Post. 2024 [cited 2024 Oct 10]. Available from: https://www.washingtonpost.com/climate-environment/interactive/2024/microplastics-air-human-body-organs-spread/

2. Microplastics are everywhere — we need to understand how they affect human health. Nature Medicine. 2024;30(4):913-.

3. Senathirajah K, Attwood S, Bhagwat G, Carbery M, Wilson S, Palanisami T. Estimation of the mass of microplastics ingested–A pivotal first step towards human health risk assessment. Journal of Hazardous Materials. 2021 Feb 15;404:124004.

4. Kannan K, Vimalkumar K. A review of human exposure to microplastics and insights into microplastics as obesogens. Frontiers in Endocrinology. 2021 Aug 18;12:724989.