Microplastics

Tiny bits of plastic are in our world.

Some bits are made to be small. They are in things like face wash.

Other bits come from larger things. Sunlight and waves break big plastic apart. This can happen to bottles or bags.

These bits can even come from clothes. Washing clothes can let tiny fibers out. They can end up in the sea.

These small pieces stay in the world for a long time. They are found in the air and the soil too.

Microplastics are very small bits of plastic. They are between 1 micrometer and 5 millimeters in size. A micrometer is a tiny unit of measure.

There are two main types of microplastics. The first type is called primary microplastics. These are made to be small from the start. They are used in things like face scrubs. They are also used to clean engines.

The second type is called secondary microplastics. These come from larger plastic items. Sunlight and waves break big items apart. This is called fragmentation. It happens to things like water bottles and fishing nets.

Many microplastics come from our clothes. Washing clothes lets out tiny fibers. These fibers go into the sea. About 35% of ocean microplastics come from textiles. Tires also make tiny plastic dust as they wear down.

Microplastics can also become even smaller. These are called nanoplastics. They are too small to see with your eyes. They can even enter the bodies of living things. They can move into cells and organs.

Microplastics are tiny pieces of plastic found all over our world. They are very small particles that measure between 1 micrometer and 5 millimeters. These bits are hard to see, but they are everywhere. They can be found in the air, in the soil, and in the water. Even the deep ocean has microplastics in its mud.

Because they do not break down easily, they stay in nature for a long time. Some plastics can last for hundreds or even thousands of years.

There are two main ways these tiny plastics enter our world. The first way is through primary microplastics. These are small pieces made on purpose by people. You might find them as tiny beads in face scrubs or glitter. They are also used as tiny scrubbers to clean rust off boat hulls.

The second way is through secondary microplastics. These come from larger items like water bottles or plastic bags. Over time, sunlight and waves break these big items into smaller bits. This process of breaking down is called fragmentation.

Scientists have studied these tiny particles for many years. The term "microplastics" is often linked to Professor Richard Thompson. He is a marine biologist at the University of Plymouth in the United Kingdom. He published a paper about them in 2004. However, people were already writing about plastic pollution in the ocean in the 1990s.

Researchers continue to use new tools to study how these particles move.

There are huge numbers of these particles in our environment. In 2014, experts estimated there were 15 to 51 trillion pieces of microplastic in the oceans. That is a massive amount of tiny waste. Most of these come from things like clothing and tires. In fact, about 35% of ocean microplastics come from textiles like polyester or nylon. Even tiny bits of rubber from car tires turn into dust that travels through the air.

Microplastics can become even smaller through a process called weathering. These tiny, invisible bits are called nanoplastics. They are smaller than 1 micrometer, which means they are too small for human eyes to see. Because they are so small, they can enter the bodies of living things. They can even move into the cells and organs of fish. This is a big difference from the large plastic bottles we see on beaches.

Microplastics are synthetic solid particles or polymeric matrices that have entered our natural ecosystems. These particles possess regular or irregular shapes and range in size from 1 micrometer to 5 millimeters. They are considered water pollution because they are insoluble in water and persist in the environment for long periods. Some plastics degrade very slowly, often lasting hundreds to thousands of years. Because of this longevity, microplastics have a high probability of being ingested or accumulating in the tissues of many organisms.

Scientists classify microplastics into two distinct categories: primary and secondary. Primary microplastics are particles that are manufactured to be small, often 5.0 mm or less, before they ever enter the environment. These include microbeads used in cosmetics, plastic glitter, and microfibers from clothing. They also include plastic pellets, known as nurdles, which are used to create other plastic products. Secondary microplastics, however, are not made small on purpose. Instead, they arise from the fragmentation of larger plastic items after they have been discarded.

The process of creating secondary microplastics involves several types of degradation. Physical, biological, and photochemical degradation work together to break down large debris. A major driver is photo-oxidation, which is caused by exposure to sunlight. As sunlight, wind, and waves act on items like water bottles, fishing nets, or plastic bags, the structural integrity of the plastic weakens. This leads to fragmentation, where the large object breaks into smaller and smaller pieces. Eventually, these pieces become so small they are undetectable to the naked eye.

There are many specific ways these particles enter our world. Textiles and clothing are a massive source, accounting for approximately 35% of all ocean microplastics. This happens primarily through the erosion of synthetic materials like polyester, acrylic, or nylon during the washing process.

Another major source is tire wear. Tires contain synthetic styrene-butadiene rubber that erodes into tiny particles as they are used on roads. These particles can become dust that travels through the air. Additionally, paint is a significant source of leakage into waterways, estimated at 1.9 million metric tons per year.

The history of the term "microplastics" is closely tied to marine biology. The term is widely attributed to Professor Richard Thompson, a marine biologist at the University of Plymouth in the United Kingdom, who published a paper in 2004. However, researchers were exploring the topic as early as the late 1980s. Evidence shows the term was used in relation to marine pollution throughout the 1990s and early 2000s. Since then, the study of these particles has grown into a global scientific priority.

The scale of microplastic pollution is immense. In 2014, it was estimated that there are between 15 and 51 trillion individual pieces of microplastic in the world's oceans. This equates to a weight between 93,000 and 236,000 metric tons. In some areas, microplastics can contribute up to 30% of the Great Pacific Garbage Patch. In many developed countries, these tiny particles are actually a larger source of marine pollution than the visible, larger pieces of litter.

As microplastics continue to weather, they can degrade into even smaller particles called nanoplastics. Nanoplastics are a subset of microplastics that are smaller than 1 micrometer. Because they are so small, they cannot be seen by the human eye. These particles pose unique risks because they can cross cellular membranes. In fish, nanoplastics have been shown to accumulate in organs like the gallbladder, pancreas, and the brain. They may also cause interruptions in bone cell activities, leading to improper bone formation.