From the clothes we wear to the products we use daily, synthetic materials have become the backbone of global industry. However, this convenience comes with a steep, often invisible price tag. Microplastics—tiny plastic particles less than 5mm in size—have quietly infiltrated every corner of our day-to-day lives.
Addressing a leading source of leakage
Plastic pollution goes beyond food packaging, water bottles, and bags. Research indicates that synthetic textiles are the leading source of primary microplastics in the world's oceans, accounting for approximately 35% of the total released. These tiny strands, known as microfibers, are released during the routine use and laundering of synthetic garments like polyester and nylon.
Unlike natural fibers, these polyester microfibers do not break down. They bypass wastewater filtration systems, traveling through rivers and lakes until they reach the ocean. Once there, they persist for decades, accumulating in the environment and entering the global food chain.
Assessing the risk to human health
Microplastics have been detected in indoor and outdoor air, soil, and drinking water. More concerningly, they have been identified within various human tissues, including the lungs, blood, placenta, and even the brain, raising critical health questions.
A 2025 New Mexico study of over 50 human brain samples from cadavers found that microplastic concentrations in 2024 were roughly 50% higher than in 2016—a preliminary finding that suggests a sharp upward trend despite the need for broader global data. Recent studies in China and Italy have documented microplastics in the human cardiovascular system, including an analysis of artery samples of patients that revealed plastic presence in the carotid, coronary, and aorta arteries. In the China study of 17 arterial samples, polyethylene terephthalate (PET) accounted for 74% of the plastics identified via mass spectrometry, though researchers noted that larger-scale studies are required to confirm if these proportions are consistent across broader populations. The 2024 study in Italy followed 257 carotid surgery patients for 34 months and found microplastics and nanoplastics in the carotid plaques of 58% of patients. These results do not prove causality and may not be generalized to all populations, however the full extent of health effects remains an active area of scientific investigation.
Choosing cotton: the natural alternative
The environmental fate of a fiber is determined by its composition. Cotton, for instance, is composed of approximately 95% cellulose, a fundamental component of plant cell walls and the most abundant plant-based compound on Earth. Because it is a natural resource, cotton is part of Earth's carbon cycle and can readily biodegrade.
The difference in decomposition rates is stark. In freshwater environments, studies have shown that cotton can biodegrade in freshwater by as much as 77% within 40 days, whereas polyester shows no appreciable biodegradation. Even when treated with common textile finishes, cotton fibers break down at rates similar to natural materials like oak leaves within 102 days in realistic environmental conditions. Composting studies have also shown that cotton fabrics degrade substantially in both laboratory and industrial settings, whereas polyester shows little to no biodegradation over comparable timeframes.
Moving toward a sustainable future
From the contamination of our oceans to the accumulation of plastic in the human brain, the microplastics problem highlights an urgent need to shift how we produce and consume textiles. While the global apparel industry is a significant source of plastic leakage, it can also provide the solution.
Choosing natural, renewable fibers like cotton offers a path forward. By opting for materials that can seamlessly reintegrate into the environment, we can reduce the plastic footprint we leave behind. As we continue to uncover the true impact of microplastics, material selection becomes more than a fashion choice — it's a critical decision for people and the planet. Get the facts about microplastics at CottonWorks.com/microplastics.
