Polyester & Microplastics: What We Know

Every time we wash synthetic athletic wear, thousands of microscopic plastic fibers break free and flow into our waterways. These "microplastics" (fragments smaller than 5mm) have become one of the most pervasive pollutants on Earth, found everywhere from Arctic ice to human blood samples.

Recent research from the University of California found that a single polyester garment can release over 700,000 microplastic fibers in one wash cycle. These fibers are too small to be filtered by wastewater treatment plants, meaning they flow directly into rivers, lakes, and eventually our oceans.

The impact on marine life is devastating. Fish, seabirds, and marine mammals mistake microplastics for food, leading to intestinal blockages, malnutrition, and death. Studies have found microplastics in 73% of deep-sea fish in the Northwest Atlantic, and the problem is only getting worse.

But the issue doesn't stop at environmental damage. Microplastics have been detected in human lungs, liver, and even breast milk. While scientists are still studying the long-term health effects, early research suggests links to inflammation, cellular damage, and potential disruption of our endocrine systems.

The athletic wear industry has been particularly slow to address this crisis. Despite being a major contributor—with synthetic fabrics like polyester, nylon, and spandex dominating the market—few brands have taken meaningful action to reduce microplastic shedding or transition to natural alternatives.

There is hope, however. Natural performance fabrics like merino wool, organic cotton, and hemp offer biodegradable alternatives that perform just as well—and often better—than their synthetic counterparts. By choosing plastic-free athletic wear, we can drastically reduce our contribution to microplastic pollution while supporting brands committed to real sustainability.