Microplastics: What you need to know

It's happening every day. From our water, our food and even the air we breathe, tiny plastic particles are finding their way into many parts of our body.

But what happens once those particles are inside?

In a recent paper published in the journal Environmental Health Perspectives, University of New Mexico researchers found that those tiny particles -- microplastics -- are having a significant impact on our digestive pathways, making their way from the gut and into the tissues of the kidney, liver and brain.

Over the past few decades, microplastics have been found in the ocean, in animals and plants, in tap water and bottled water. They appear to be everywhere. Scientists estimate that people ingest 5 grams of microplastic particles each week on average -- equivalent to the weight of a credit card.

Research has found that microplastics can migrate out of the gut and into the tissues of the liver, kidney and even the brain. The study also showed that microplastics changed metabolic pathways in the affected tissues. Furthermore, it has been found that microplastics are also impacting macrophages -- the immune cells that work to protect the body from foreign particles.

In a paper published in the journal Cell Biology & Toxicology in 2021, researchers found that when macrophages encountered and ingested microplastics, their function was altered and they released inflammatory molecules. They are changing the metabolism of the cells, which can alter inflammatory responses. During intestinal inflammation -- states of chronic illness such as ulcerative colitis and Crohn's disease, which are both forms of inflammatory bowel disease -- these macrophages become more inflammatory and they're more abundant in the gut.

Potential Health Implications

Microplastics are detected from the south to Antarctica, north to the Arctic, up to the peak of Mount Everest, and down to the Mariana Trench. In 2017, more than eight million tons of plastics entered the oceans, and the amount is >33 times as much as that of the total plastics accumulated in the oceans by 2015. However, due to the limitation of capture methods, the content of microplastics in the environment may be underestimated.

Humans are potentially exposed to microplastics through oral intake, inhalation, and skin contact. The potential health effects consist of oxidative stress, DNA damage, organ dysfunction, metabolic disorder, immune response, neurotoxicity, as well as reproductive and developmental toxicity. In addition, the epidemiological evidence suggests that a variety of chronic diseases may be related to microplastics exposure.

Landmark study links microplastics to serious health problems

People who had tiny plastic particles lodged in a key blood vessel were more likely to experience heart attack, stroke or death during a three-year study.

The study, published recently in the New England Journal of Medicine, found heart disease patients with microplastics in the blood vessels on either side of their neck, which deliver blood from the heart to the brain and head, were twice as likely to suffer a heart attack or stroke. These patients were also more likely to die over the next three years than people who had no microplastics in their carotid arteries.

Depending on the source of the plastic, microplastics can be contaminated with toxic chemical additives during the manufacturing process. If a chemical additive hitches a ride on a microplastic particle and enters the body, it can leach out into the body and harm the hormone and reproductive systems. Similarly, pollutants or microorganisms can also jump on microplastic particles and pose health risks to humans.

Scientists have researched the impact of microplastics on animals. Studies on mice showed exposure to microplastics can disrupt the gut biome, lower sperm quality and testosterone, and impair learning and memory.

Tips to reduce exposure

1. Dust and vacuum regularly. Removing excess dust from your house can help cut down on the amount of microplastic fibers in the dust you could be breathing or otherwise consuming.

2. Avoid drinking from disposable plastic water bottles. If you have no choice, try to keep them out of the sun, in a cool, dry environment. Disposable plastic water bottles degrade very easily in response to temperature change or friction.

3. Filter your water. Due to widespread use and pollution of plastic, water can sometimes contain microplastic particles. Home water filters can be effective at reducing many contaminants, including microplastics.

4. Avoid plastic cutting boards. There are plenty of alternatives to use, like wood, glass and steel.

5. Microwave your food in glass containers, rather than plastic or takeaway containers, which can release millions of microplastic particles into your food.