Overview

Microplastics are plastic fragments smaller than 5mm, originating from the breakdown of larger plastics, synthetic textiles, tire wear, and industrial processes. First identified as a distinct environmental concern in 2004, microplastics have since been found in every ecosystem studied—from the Mariana Trench to Mount Everest, and increasingly in human tissues.

Sources & Pathways

Primary sources include synthetic clothing fibres released during washing (35% of ocean microplastics), tire wear on roads, microbeads in cosmetics (now banned in many countries), and degradation of plastic waste. Wastewater treatment plants capture 90–99% of microplastics, but the remainder—billions of particles daily—enters waterways. Atmospheric transport carries microplastics to remote areas.

Health Impacts

Studies have detected microplastics in human blood, lungs, placenta, and breast milk. Research links exposure to inflammation, oxidative stress, and endocrine disruption, though definitive long-term health effects in humans are still being studied. Nanoplastics (under 1μm) can cross cell membranes and the blood-brain barrier, raising particular concern.

Solutions & Policy

The UN Global Plastics Treaty (under negotiation) aims to address the full lifecycle of plastics. Solutions include reducing single-use plastics, developing biodegradable alternatives, improving washing machine filters, advanced wastewater treatment, and enzymatic plastic degradation (PETase enzymes). Extended producer responsibility (EPR) policies are expanding worldwide.