Microplastic Pollution In Marine Environment: Toxicity And Environment Effect

by | Jul 24, 2022 | Plastic Pollution, Pollution

Home » Pollution » Microplastic Pollution In Marine Environment: Toxicity And Environment Effect

Today, microplastics are found all around us, and yet several people still don’t know where they are and what they are. Microplastics can have destructive effects on human and planetary health. However, studies are yet to reveal them. According to a report, four sources of microplastic alone accounted for nearly 1.3 million metric tons of ocean plastic pollution in 2016. Humans and all other species and microorganisms share this planet—ecosystems, habitats, and biodiversity, all influence each other. If one is destroyed and damaged, the others will also share the same fate. Microplastic pollution in the marine environment is destructive despite its small size. We have the ability to stop the effects of microplastics if only we take the proper actions.


We underestimated the amount of microplastic in the ocean – by a lot | World Economic Forum



Microplastic Pollution in Marine Environment

Microplastics are tiny particles of plastic that are less than 5 millimeters in diameter (0.2 inches). Microplastics and plastics of all sizes have become a major part of marine environments. Approximately 5.25 trillion plastic particles weighing around 268,000 tons are in the ocean today.

Plastic’s durability, low cost, and flexibility make it ideal for a wide range of daily use products. The major source of plastic in marine environments are coastal dumping sites and landfills, coastal cities, ports, and shipping activities. Plastic entering the ocean breaks down into microplastics through biological, photolytic, and mechanical degradation.

Floating plastic islands in the oceans, turtles eating plastic bags and straws, and dead whales and dolphins with a stomach full of plastic waste are some of the discoveries of the last couple of years that have received international media attention and coverage.

Microplastics were first discovered in oceans in 2004. With increasing microplastics found in the ocean every year, scientists have made it clear that plastic in oceans and on land does not just disappear. According to an estimate, around 2.41 million tons of plastic transported by the world’s major rivers end up in the ocean annually- approximately 100,000 garbage trucks. If 2.41 million tons of plastic are dumped into the sea annually, imagine the number of microplastics it produces as it degrades.

Toxicity of Microplastics

Microplastic pollution in the marine environment is still a new research area, even though experts detected them in 2004. There are several things experts still do not know about it.

According to a study, microplastics were found in the feces of people from Russia, Europe, and Japan, confirming that humans ingest microplastics. The question now is whether all ingested microplastic is egested or if some remain inside the body?

Scientists have conducted various studies on animals to understand this situation. Scientists found that microplastics can pass through the gut barrier and even enter the bloodstream. Further, the microplastics travel to other areas and organs of the body. For instance, scientists detected microplastics in rats’ hearts, kidneys, stomachs, and intestines. Tiny microplastics were also detected in the fetuses of mice and the brain of fish.

Based on these studies, experts have concluded that human exposure to microplastics could result in DNA damage, inflammation, oxidative stress, and other health issues. If inflammation in the body becomes chronic, it could lead to severe health problems.

The surface of microplastic in the environment is filled with microorganisms- recently identified as human pathogens. These pathogens can strongly bind to microplastics, causing further health damage.

Scientists are currently trying to understand the extent of human exposure to microplastics. It is challenging as current techniques cannot detect microplastics in human blood samples and food. Based on recent data, scientists estimate that an American citizen’s intake of microplastics per year is between 74,000 and 121,000 particles. The data varies depending on the age and sex of the person.

Chart: How We Eat, Drink and Breathe Microplastics | Statista


According to studies, plastic baby bottles and teabags release millions of tiny microplastics into baby formula and tea. However, these numbers are underestimated as only a limited amount of food products were analyzed. There are simply too many things that we do not know yet about the effects of plastic. New research in this field is required.

Environmental Effects of Microplastics

The increasing number of microplastics in the ocean and various ecosystems is a major ecological concern today. As mentioned above, microplastics float throughout the oceans, and some are even trapped in the Arctic ice. Microplastics have the ability to change ecosystems entirely.

Scientists have found microplastics in all animals, from whales and birds to tiny crustaceans. Due to their small size, they are mistaken as food by marine organisms, including sea urchins, corals, lobsters, and fish. The ingestion of microplastics by marine organisms is a major concern as it is extremely harmful.

The impacts of microplastics on corals include the continued presence of microplastics in the mesenterial tissue, which can lead to reduced feeding capabilities and lower energy reserves. It is clear that microplastics damage coral health. More than half a billion people depend on corals for income, food, and protection. They also provide an important ecosystem for marine life. Without them, coastlines would be vulnerable to erosion, and sea levels would rise. Without them, marine species would disappear as most depend on coral reefs for food and protection.

Microplastics also affect planktons which are the most crucial components of marine ecosystems. Zooplankton is essential in marine habitats as they are the main consumers of the marine food chain. According to studies, zooplanktons consume latex beads when exposed to microplastics.

When fish ingest microplastics, it causes histopathological changes in the intestine, increases in the number of global cells, and modifications in the normal structure of the serosa of fish. The eggs of fish exposed to microplastics have a slow hatching rate. Larvae exposed to microplastics are smaller and slower than normal larvae.

Microplastics also affect sea birds which cause a change in their feeding behavior, mortality, and reproduction. Sea birds are essential to ecosystems as they bring nutrients to islands and contribute to other species’ habitats. They are also top predators in the marine food chain and an essential component in the food web.

Microplastic pollution in the marine environment is growing daily. The entire marine ecosystem and human health are severely affected due to it. Is the world willing to stop this life-threatening pollution?

Also Read: UNEP Plastic Pollution Report: A Blueprint For Drastic Change


  • Dr. Emily Greenfield

    Dr. Emily Greenfield is a highly accomplished environmentalist with over 30 years of experience in writing, reviewing, and publishing content on various environmental topics. Hailing from the United States, she has dedicated her career to raising awareness about environmental issues and promoting sustainable practices.

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