What Are Microplastics?
Microplastics are tiny pieces of plastic, smaller than 5 millimeters, that come from breaking down larger plastic items or are made for specific purposes, like in cosmetics or industrial uses. These tiny plastics are now everywhere—in the air, water, and food we consume.
Where Do Microplastics Come From?
Microplastics come from many sources, including:
- Breaking down of larger plastics: Plastics in landfills and oceans slowly break apart into smaller pieces over time.
- Synthetic clothing fibers: Washing synthetic clothes releases tiny fibers into wastewater, contributing to 35% of global microplastic pollution.
- Personal care products: Some toothpastes, face scrubs, and cosmetics have microbeads made of plastic.
- Industrial uses: Manufacturing and using tiny plastic pellets (called nurdles) adds to microplastic pollution.
Where Are Microplastics Found?
Microplastics are found almost everywhere:
- Air: Urban air contains particles as small as 1–10 micrometers, small enough to be inhaled.
- Water: Studies show that 93% of bottled water contains microplastics, as does tap water.
- Food: Seafood, table salt, and even fruits and vegetables can contain microplastics.
- Human body: Microplastics have been detected in the bloodstream and breastmilk, as small as 700 nanometers (0.7 micrometers), meaning they can cross biological barriers.
How Long Do Microplastics Stay in the Body?
How long microplastics remain in the body depends on their size. Larger particles are usually excreted through stool, but smaller ones (less than 1 micrometer) can pass through the gut lining into the bloodstream. They may then accumulate in tissues. Research is still exploring their persistence and long-term effects.Why Are Microplastics Harmful?Microplastics may be harmful for several reasons:
- Accumulation in tissues: Tiny particles can cause inflammation and oxidative stress, which may damage cells and DNA.
- Chemical exposure: Plastics often contain chemicals like BPA or phthalates, which can disrupt hormones and may lead to reproductive issues, obesity, or diabetes.
- Toxin carriers: Microplastics can carry harmful substances like heavy metals or persistent organic pollutants, which can harm organs and systems.
- Gut microbiome changes: Microplastics may alter gut bacteria, potentially leading to inflammation or digestive issues.
- Impact on development: Microplastics in placentas and breastmilk raise concerns about risks to babies' growth and health.
- Cancer risks: Inflammation and oxidative stress caused by microplastics may increase the chance of developing cancer over time.
The Big Picture
Research estimates that humans ingest between 39,000 and 52,000 microplastic particles every year—and possibly even more through the air we breathe. While the long-term health effects of microplastics are still being studied, their ability to disrupt hormones, cause inflammation, and carry toxins is concerning. Reducing plastic use and addressing pollution are critical steps to limit exposure and protect health.