Microplastics enter the environment in many different ways, often starting with how we use and throw away plastic products. These tiny plastic particles can come from larger plastic items—like bottles, bags, and packaging—that break down over time into smaller pieces through weathering, sunlight, or friction. This process happens in landfills, on streets, and in natural areas like rivers, lakes, and oceans.

Another major source of microplastics is everyday household activities. For example, washing clothes made of synthetic fabrics like polyester or nylon can release thousands of plastic fibers into the water. These tiny fibers are too small to be fully removed by water treatment plants, so they end up in rivers and oceans. Personal care products, like older face scrubs and toothpastes, once contained plastic microbeads that also passed through drains and into waterways—though many countries have now banned them.

Microplastics can also come from car tires, which shed tiny plastic particles as they wear down on roads. These particles can be picked up by rainwater and carried into storm drains. Agricultural practices, like using plastic mulch films or fertilizers made with plastic waste, can add microplastics to soil. Even littering and poorly managed recycling systems can allow plastic waste to break apart and scatter throughout the environment.

Because plastic is used so widely and takes so long to break down, microplastics are now found almost everywhere—from mountain air to deep ocean trenches. Reducing plastic use and improving waste management are key steps in slowing the spread of microplastics in the environment.

Microplastics can have serious impacts on wildlife, especially animals that live in or near water. Fish, birds, turtles, and other animals often mistake microplastics for food. When they eat these tiny particles, the plastic can fill up their stomachs and make them feel full even when they haven’t eaten real food. This can lead to malnutrition, slower growth, and even death.

Beyond just taking up space in the digestive system, microplastics can also cause physical damage. Sharp or rough particles can injure internal organs, and plastic can build up in the gut over time. Some studies show that animals exposed to high levels of microplastics may have reduced fertility or problems with their immune system, making them more vulnerable to disease.

Another major concern is that microplastics often carry toxic chemicals—either from the original plastic or from pollutants they pick up in the environment. These chemicals can leach into an animal’s body and affect important processes like hormone regulation and reproduction. For example, seabirds that consume plastic debris have shown changes in hormone levels and organ damage.

Because many animals are part of the larger food chain, microplastics can move from one species to another. This means that pollution in small animals like plankton can eventually impact larger animals, including those that humans rely on for food. Protecting wildlife from microplastic pollution helps keep entire ecosystems healthy.

Microplastics have a growing influence on rivers, lakes, and oceans, affecting both the health of these water systems and the creatures that live in them. Once microplastics enter the water—through littering, stormwater runoff, or wastewater—they can travel long distances. Because they are so small and light, they can float on the surface, sink to the bottom, or stay suspended in the water depending on their size and material.

In rivers and lakes, microplastics can be trapped in sediment or picked up by insects, fish, and other freshwater animals. Over time, this pollution builds up and may alter the natural balance of these ecosystems. In some areas, microplastics are now found in nearly every part of the water system, from surface water to riverbeds.

In the ocean, microplastics are even more widespread. Ocean currents can carry them across the globe, and they’ve been found in some of the most remote places on Earth, including deep-sea trenches and Arctic ice. Microplastics in the ocean can be eaten by plankton, which are tiny organisms at the bottom of the food chain. This means that microplastic pollution can work its way up the food web, eventually reaching larger animals like whales, seals, and seabirds.

In all of these environments, microplastics can release harmful chemicals or absorb pollutants already in the water, acting like sponges that carry toxins to new locations. These changes can weaken entire ecosystems, harm water quality, and reduce the health of wildlife that depends on clean, stable habitats.

Unfortunately, even protected natural areas like national parks are not free from microplastics. While these places are set aside to preserve nature and wildlife, they are still part of the larger environment—and microplastics are now so widespread that they’ve been found in some of the most remote and pristine locations on Earth.

Microplastics can reach national parks through many routes. Wind can carry plastic particles through the air, allowing them to settle in forests, mountains, and lakes far from cities. Visitors to parks can also bring in plastic items like water bottles, clothing made from synthetic fibers, or packaging, which may break down and contribute to pollution over time. Even tiny plastic fibers from outdoor gear or laundry can enter the air or water systems through dust or runoff.

Studies have found microplastics in national parks across the U.S., including in park soils, streams, and even snow. This shows that microplastic pollution is a global issue, not just something that happens in cities or oceans. While national parks still offer valuable protection for wildlife and ecosystems, the presence of microplastics highlights the need for broader solutions—like reducing plastic use and improving waste management—beyond park boundaries.

Microplastics can stay in the environment for a very long time—often hundreds to thousands of years. Because they are made from plastics that don’t easily break down, these tiny particles tend to persist in soil, water, and air long after they are released.

Unlike natural materials that rot or dissolve, microplastics break into smaller and smaller pieces over time, but they don’t fully disappear. Sunlight, wind, and water can cause them to fragment, but this only makes them harder to detect and remove. These smaller fragments, called nanoplastics, can be even more difficult to clean up and may pose additional risks to health and the environment.

Once microplastics enter ecosystems, they often settle into sediments, float on the surface of water, or travel through the air. They can move between places and across long distances, meaning that even remote areas—like mountain lakes or deep-sea trenches—can end up contaminated. Because of their durability and ability to spread, microplastics can remain part of the environment for generations unless strong efforts are made to reduce plastic pollution at the source.

Microplastics can travel through both the air and water to reach remote ecosystems—even places far from cities or human activity. Because microplastics are extremely small and lightweight, wind and water can carry them over long distances. This means that areas once thought to be untouched by pollution, like mountaintops, deserts, or deep oceans, are now being found to contain microplastic particles.

In the air, tiny plastic fibers and fragments can become airborne through wind, dust, or even human activities like walking or shaking out clothing made from synthetic fabrics. These particles can ride air currents and eventually settle in remote places through rain, snow, or dry fallout. Studies have discovered microplastics in snow in the Arctic, high in the Alps, and in remote national parks, showing how far they can travel.

Water is another major pathway. Microplastics in rivers, lakes, and oceans can drift with currents across great distances. They can also be carried by rainwater and storm runoff, spreading from cities into rural and wild areas. Once in a new location, these plastics can enter food chains, settle into soil or sediment, and become part of the local ecosystem.

This ability to spread so widely makes microplastic pollution a global concern. It also shows that even places that seem clean and wild are not completely protected from the effects of plastic waste.