Environmental scientist and professor Dr. Shafi Mohammad Tareq investigates how microplastics are infiltrating our waters, salt, fish, and food chain.
Dr. Shafi Mohammad Tareq obtained an M.S. in Environmental Science and a D.Sc. from Nagoya University, Japan. He completed a Postgraduate Certificate in Higher Education at the University of Nottingham and became a fellow of the Higher Education Academy, U.K. His distinguished postdoctoral work with the Japanese Society for the Promotion of Science and as a Commonwealth academic fellow attests to his international research excellence. Dr. Tareq is a leading expert on emerging pollutants in Bangladesh, including microplastics. In this interview, he explains the findings of his research on microplastics, noting that microplastics have been found in the gastrointestinal tracts and flesh of fish. Alarmingly, microplastic contamination has been observed in all common fish, including marine and farmed species. The conversation sheds light on this emerging issue, emphasising that microplastics in fish pose a significant health risk and underscoring the urgent need for immediate action to minimise water contamination.
Professor
Department of Environmental Sciences
Jahangirnagar University
What are microplastics, and how are they becoming a health risk?
Plastic fragments that are smaller than 5 millimetres are classified as microplastics. The term was coined by biologist Richard Thompson in 2004 after his discovery of the troubling amount of microplastic fragments in the world’s oceans and marine habitats. I am currently conducting research on microplastics, as they are an emerging contaminant in Bangladesh that poses significant risks to human health.
My team started this research in 2019, just before the onset of the coronavirus pandemic. My research team was the first to identify microplastics in the gastrointestinal (GI) tracts of both freshwater and marine fish. Upon further investigation, we also found microplastics in the flesh of the fish, the part we consume. Most of the fish we consume have been found to contain microplastics.
Our research expanded to Cox’s Bazar, where we examined the presence of microplastics in salt, as well as at landfill sites like Aminbazar and Matuail by testing leachate samples. Our analyses revealed that microplastics are present in salt, as well as in both the surface water and groundwater in the vicinity of these landfill sites. These findings indicate that microplastics have infiltrated our entire ecosystem and food chain.
The risk to human health is currently the subject of ongoing global studies, and scientists have warned that there is potential for poisoning due to the microplastics present in our water bodies.
Are there regional microplastic hotspots or periodic rises when microplastics are seen more in fish?
Our logical argument is that areas with high plastic usage are expected to have more microplastics in fish compared to areas with lower plastic use, and our findings support this presumption. In and near urban areas, water bodies such as lakes, rivers, ponds, and canals serve as hotspots for microplastics, while rural areas exhibit a comparatively lower presence.
We have also analysed river water for microplastics on a seasonal basis. We conducted monthly analyses on the Ganges and Brahmaputra and observed that microplastic levels peak during rainy seasons or monsoon periods. We hypothesise that the heavy monsoon rainfall washes surface waste from the land, incorporating it into the water column, which explains the observed high levels during this season.
We also collected fish samples from the Sundarban, an area less impacted by human activities, and still found the presence of microplastics. Similarly, another group of scientists collected fish samples from the Karnaphuli River and detected microplastics there as well.
Although my research team has not studied farmed fish, my scientific colleagues have, and they have indeed detected microplastics in them. The levels vary, influenced by several factors such as fish species, the location of the fish farm, and the fish feed. Farmed fish are typically given a diet that includes fish feed, which itself can contain microplastics, resulting in their presence in the GI tracts of fish that are otherwise raised in controlled environments.
The main challenge is that once plastic is disposed of and enters a water column, it disperses widely with the water flow. Although hotspot locations typically exhibit higher concentrations of microplastics, even remote regions such as the Sundarban are not immune.
MY RESEARCH TEAM WAS THE FIRST TO IDENTIFY MICROPLASTICS IN THE GASTROINTESTINAL (GI) TRACTS OF BOTH FRESHWATER AND MARINE FISH. UPON FURTHER INVESTIGATION, WE ALSO FOUND MICROPLASTICS IN THE FLESH OF THE FISH, THE PART WE CONSUME. MOST OF THE FISH WE CONSUME HAVE BEEN FOUND TO CONTAIN MICROPLASTICS.
Do our fish consumption habits expose us to microplastics?
The way we Bangladeshis cook fish involves discarding the GI tract, which is helpful since most of the microplastics have been found in that part of the fish. However, the concern arises from the detection of microplastics in the flesh, the edible portion of the fish. This presents a challenge that calls for further research. It remains unclear whether the microplastics in the flesh persist during cooking or if the fish’s metabolism impacts these contaminants.
Determining the exact percentage of microplastics present in the flesh is critical and will require dedicated study. Factors such as fish species, type, size, growth rate, and habitat all influence the extent to which microplastics accumulate in the edible parts of fish.
What actions can be taken to prevent further contamination and protect public health?
Scientists like myself are not in a position to change policies directly, as our primary responsibility is to conduct research and publish our findings in scientific journals. However, media outlets such as local newspapers, news channels, and magazines can play a crucial role in disseminating this knowledge to the public, raising awareness about this emerging contaminant. Greater public awareness can, in turn, motivate the government to take appropriate initiatives.
Individuals can contribute by minimising waste generation. Many everyday items, such as cosmetics, toothpaste, lotions, and face wash, are sources of microplastics if not disposed of properly. Moreover, microplastics can also result from the breakdown of large plastic items in water bodies; hence, ensuring proper disposal of plastic is a fundamental first step.
Companies, too, have a role to play by striving to make their products more environmentally friendly. For instance, while cosmetic products containing microbeads are banned in the European Union, such products may still be available in parts of the Indian subcontinent due to a lack of similar restrictions. If companies were to voluntarily phase out microbeads from their products, it could significantly reduce microplastic pollution.
At the governmental level, there is a need for robust laws along with effective enforcement. Although single-use plastics have been banned in Bangladesh for several years, their continued presence in the market indicates issues with compliance and enforcement. This situation underscores the importance of community adherence to regulations as well.
A holistic approach involving active participation from scientists, media, individuals, companies, and the government is essential to mitigate this contaminant and reduce the associated health risks.
Photograph by Shihab Mohammad
