Little is known about the effects on humans—but limiting exposure to them seems prudent.
Ever since Austrian scientists first began looking for them in people in 2018, microplastics have turned up in the blood, lungs, kidneys, liver, heart, and even the brain. They have also been detected in the placenta and breast milk.
Microplastics are tiny particles ranging from 5mm down to less than 2 microns (µm). They enter the human body through air, food, and water, accumulating from degrading plastic waste and the wear and tear of everyday products such as car tires, paints, and synthetic fabrics.
Potential Health Risks #
Whether microplastics are harmful remains unclear. These “forever particles” may contribute to health problems such as infertility, heart attacks, or cancer. They can cause physical damage by blocking ducts or scratching tissues, chemical damage to cells, and act as carriers for heavy metals, allergens, and bacteria.
A 2024 study in the New England Journal of Medicine examined plaque from the arteries of 257 patients undergoing plaque removal procedures. Microplastics were found in more than half of the cases. Over the next three years, those patients had four times the risk of heart attack, stroke, or death compared to patients without detectable microplastics. However, whether the particles caused these outcomes remains uncertain.
Lab studies also suggest that microplastics can damage cells, tissues, and DNA, potentially promoting cancer. Early experiments used larger sterile polystyrene beads, which differ significantly from real-world nanoplastics. Nanoplastics (smaller than 1µm) are of most concern, as they can pass into the bloodstream through the gut and lungs, while particles larger than 10µm are unlikely to enter human cells.
Exposure and Environmental Presence #
Microplastics are virtually impossible to avoid. In 2019, researchers from King’s College London found daily deposits in central London reached 1,000 microplastics per square meter (particles larger than 20µm).
How to Reduce Exposure #
While complete avoidance is difficult, exposure can be reduced by:
- Avoiding food and drinks packaged in plastic
- Reducing synthetic fabric use
- Cleaning household dust regularly
- Avoiding microwaving food in plastic containers
- Limiting use of plastic kettles and heated plastic items
A European research consortium of over 70 organizations is studying the specific health effects of microplastics and potential regulations. For now, there are more questions than answers, but taking simple steps to limit exposure is prudent.
Key Takeaway: Microplastics are ubiquitous, and their potential health risks are still being studied. Limiting exposure through lifestyle choices is a practical approach while research continues.