Microplastics: Invisible particles entering human body, increasing risks

Sohel Rahman, employee of a private company, had come shopping after office hours at the Karwan Bazar kitchen market in the capital. He had not brought any bag with him. Vendors were packing fish, vegetables, meat, and grocery items one after another in polythene bags. Sohel did not object. Rather, he finds it convenient and economical. Smiling, he said, “I forgot to bring a cloth bag. And polythene bags are free anyway.”

Asked whether he knows about the harmful effects of plastic, Sohel paused for a moment and replied, “I know rivers get polluted because of it. But I didn’t really know that tiny plastic particles can enter the body.”

Sohel’s story is not unique. Every day, hundreds of millions of people use plastic because of convenience, habit, and low cost. But that very plastic is gradually emerging as a major threat to the planet through pollution. And among these concerns, microplastics have become particularly alarming.

Tiny plastic particles—microplastics—are now being found in rivers, oceans, soil, fish, salt, rainwater, and even in human blood, lungs, breast milk, and placentas. Plastic particles smaller than five millimeters are called microplastics. Large plastics break down into smaller fragments, while some microplastics are manufactured in tiny sizes from the beginning.

Scientists worldwide now view microplastics as a form of “silent pollution,” because they are gradually accumulating in the environment and in human bodies. A recent study found the presence of microplastics in soil, water, and aquatic animals at at least 56 important locations across Bangladesh. These microplastics are entering human bodies and creating health risks.

In Adabor, Dhaka, Abu Sayeed was collecting discarded plastic items with a van cart. After collecting them, he sells them to different establishments. Abu Sayeed said he has been doing this work for at least 18 years.
Now he collects at least 30 kilograms of plastic items daily. About ten years ago, the amount was only 8 to 10 kilograms a day. His experience reflects how rapidly plastic use has increased.

The issue of microplastic risks was highlighted anew in the study titled “From Pollution to Policy: A Holistic Review of Microplastics in the Environment in Bangladesh” conducted by researchers Rahat Mostafa Prantor and his colleagues from the Islamic University of Technology (IUT).

Among the 56 locations where microplastics were found in soil, water, and aquatic organisms, high concentrations were detected in the riverbeds of the Buriganga, Turag, Balu, the Andharmanik river in the Sundarbans, and the Meghna. Similar findings were observed in landfill areas.

According to the research report, the most common plastic particles found in Bangladesh’s environment are polyethylene and polypropylene. Much of these originate from polythene bags, bottles, packets, and synthetic clothing.

Many people think plastic only means bottles or polythene. In reality, clothing has also become a major source. When synthetic fabrics such as polyester, nylon, or acrylic are washed, tiny fibers mix with water. These fibers released from washing machines eventually reach rivers or oceans. Researchers say a significant portion of the microplastics found in Bangladesh’s environment comes from such synthetic fibers.

These tiny particles float in the air, mix with water, enter the bodies of fish, and eventually make their way into human food. The biggest characteristic of plastic is its durability. A plastic bottle may take 400 to 500 years to fully decompose. But even then, it does not completely disappear. Instead, it breaks into smaller particles and remains in the environment. In other words, plastic becomes “invisible,” but it does not “vanish.” Scientists say plastic has now become part of the Earth’s environmental cycle.

Microplastics are now entering the human body in various ways. A study by Australia’s University of Newcastle and the World Wide Fund for Nature (WWF) found that an average person consumes around 5 grams of plastic every week—roughly the weight of a credit card.

Plastic particles can enter the body through fish, salt, bottled water, and even air. Italian researchers have detected microplastics in human placentas as well, findings that were published in the journal ‘Environment International.’

A research paper published in The New England Journal of Medicine in 2024 stated that the presence of microplastics in blood vessels may increase the risk of heart disease and stroke. Scientists say these tiny particles may cause inflammation in the body, disrupt hormonal balance, and in some cases even increase cancer risk.

Professor Gawsia Wahidunnesa Chowdhury of the Department of Zoology at Dhaka University has long worked on the presence, use, risks, and sustainable solutions regarding microplastics in different ecosystems.

Under her leadership, the Bangladesh Aquatic Zoology Research Group has been working on plastic pollution for years. The group has adopted an integrated strategy to tackle the problem. Their work proceeds in three stages: identifying the sources and extent of pollution through various methods, assessing the current state of plastic pollution in the country’s aquatic environment, and finally proposing possible solutions to reduce it.

Gawsia Wahidunnesa Chowdhury told Prothom Alo, “In our research, we have seen how microplastics circulate through aquatic food chains and enter the human body through aquatic organisms such as fish.”

Describing the impact on fish, she said, “Research has proven that discarded fishing nets are one of the main causes of plastic pollution in our rivers and marine environment. In our studies using fish as model organisms, we found that microplastics drastically alter cellular structures in fish, hindering their normal growth and reducing both their quality and nutritional value.”

Many countries around the world have already taken strict measures to reduce single-use plastics. The European union has banned plastic straws, cotton buds, and some other plastic products. Canada has restricted the production and import of harmful single-use plastics. African countries such as Rwanda and Kenya have enacted strict laws against plastic bags. India has also banned 19 types of single-use plastics. The United Nations is currently discussing an international treaty to combat global plastic pollution.

The hopeful news is that although the problem is serious, the path to solutions is not entirely closed. Researchers say that with proper planning and coordinated initiatives, plastic pollution can be significantly reduced. Laws alone will not be enough—affordable alternatives for people must also be created.

The biggest reality of microplastics is that although people are aware of its negative impact, they cannot stop using plastic. A sociological study by researcher Md Sakhawat Hossain published in the journal Marine Policy found that nearly 66 per cent of people in coastal areas know nothing about microplastic pollution. Another 22 per cent had at least heard about it before.

The survey also found that around 54 per cent of people admitted they use polythene bags simply because they forget to carry reusable bags. In other words, the issue is not just about awareness—it is also about habit, convenience, and affordable alternatives. Standing in a Dhaka market, Sohel Rahman echoed the same sentiment, “You don’t always remember to bring a cloth bag. And everyone in the market gives polythene bags anyway.”

Sakhawat Hossain’s research found that around 64 per cent of people believe plastic use could be reduced if the government provided cloth bags free of charge or at low cost.

Multiple studies among people dependent on aquatic ecosystems have shown a close relationship between poverty and the use of plastic products. Research has also shown that behavioral changes can help reduce plastic production and use.

Gawsia Wahidunnesa Chowdhury said such behavioral change requires “active learning”-based environmental education from the school level. When people learn from childhood what should and should not be done to keep the environment healthy, the environment will improve and pollution will decrease. Everyone must respect science-based environmental education, research, and the law.

At the same time, she emphasised the importance of research, saying that due to lack of financial grants, many high-quality research initiatives cannot continue despite researchers’ willingness. Greater awareness from the government and all stakeholders is needed in this regard.

The severe environmental threat posed by microplastics is now being discussed in various government circles, including the Department of Environment. Additional Director General Md Ziaul Haque said the issue is a matter of concern for the environment. However, various initiatives are underway to address this pollution.

Abdullah Al Mamun, Deputy Director (Waste and Chemical Substance Management) at the Department of Environment, told Prothom Alo that several targets have been set to address the microplastics problem. By 2030, the government aims to reduce the use of plastic raw materials by 30 per cent, cut the use of recyclable plastics by 50 per cent, reduce single-use plastics by 90 per cent, and lower plastic waste by 30 per cent.

Abdullah Al Mamun added that 17 types of single-use plastics have already been identified. He also said that research and training initiatives are already underway to reduce microplastic pollution.