Plastic particles and fragments smaller than 5 mm in size.
What are microplastics?
Plastic particles and fragments smaller than 5 mm in size are commonly called microplastics. Plastic products, debris, and litter contain microplastics, which are now found everywhere in the ocean and coastal waters, remote shorelines, the seabed of the deep ocean, and the sea surface.
Microplastics are used in manufacturing, industry, and 3D printing, and are in consumer products such as synthetic clothing fabric, toothpaste, and skin care products. They are also formed when plastics, including products made with polystyrene and polyvinyl chloride, break apart and disintegrate into tiny beads, also known as microbeads, or small pieces. Major sources of microplastics include urban runoff and agricultural runoff, stormwater, waste management, cruise ships, aquaculture, ocean dumping, and the shipping and fishing industries.
When microplastics wash down a drain, they are not filtered by wastewater treatment processes and become widely distributed in the water and sediments of the ocean.
Floating plastic and microplastics can be transported by ocean currents for great distances. They can reach ocean gyres, which are circular ocean systems that either trap or repel debris. Converging surface currents in the five subtropical gyres create garbage patches that accumulate microplastics along with other debris suspended below the ocean surface.
Marine species throughout the food chain commonly consume plastics of many sizes, which can harm and even kill them. Plastic and microplastic debris can also damage critical ecosystems such as coral reefs and degrade water quality.
Microplastics are understood to be the most numerous type of plastic in the ocean.How might I be exposed to microplastics?
At work, you can be exposed to microplastics if you work in a manufacturing facility that makes plastics or certain consumer products, such as synthetic clothing fabric, toothpaste, and skin care products. You may be exposed if you work at a waste management, wastewater treatment, or aquaculture facility. You may be exposed if you work on a farm or a cruise ship or in the shipping or fishing industries.
At home, you can be exposed if you use consumer products such as synthetic clothing, toothpaste, and skin care products. You can be exposed to microplastics on shorelines, in the ocean, or in coastal waters.
It is not known if you can be exposed by eating contaminated seafood. There is insufficient evidence to assess the potential for transfer of the contaminants in microplastics to fish flesh.
There is increasing concern about the potential for microplastics to harm human health and marine life as they move through the marine food web. Microplastics both absorb and leach out chemicals and harmful pollutants in the marine environment. The chemical ingredients of plastics or toxic chemicals absorbed by the plastics may accumulate over time and be persistent in the environment. Some of these chemicals are endocrine disruptors and can result in genetic changes and cause cancer. They include:
• the pesticide DDT,
Plastics also can contain the following chemicals, which can be released into the marine environment:
There is scientific uncertainty about microplastic issues, including the potential for bioaccumulation of chemicals in microplastics in the marine environment and food chain, risks to human health from eating contaminated seafood, and environmental impacts, such as affected fish and shellfish, and fisheries decline
This description is based on the information found in the Web links listed with this topic.
Web Links from MedlinePlus (National Library of Medicine)
Great Pacific Garbage Patch (National Geographic Society)
Microplastics Brochure (United Nations Environment Programme) (PDF — 3.40 MB)
New Link in the Food Chain? Marine Plastic Pollution and Seafood Safety (National Institute of Environmental Health Sciences)
Ocean Gyre (National Geographic Society)
Oceans Full of Plastic (Convention on the Conservation of Migratory Species of Wild Animals (CMS)) (PDF — 548.66 KB)
Plastic in Cosmetics. Are We Polluting the Environment Through Our Personal Care? (United Nations Environment Programme)
Tide Turns Against Plastic Ocean Pollution (ShareAmerica.gov)
Toxicological Threats of Plastic (Environmental Protection Agency)
UNEP Year Book 2014 Emerging Issues Update: Plastic Debris in the Ocean (United Nations Environment Programme) (PDF — 1.08 MB)
What Do We Know Today About Microbeads and Microplastics in the Ocean? (National Oceanic and Atmospheric Administration)
Last Updated: April 19, 2017