Microplastics in dried fish raise food-safety concerns

Researchers from the University of Chittagong have detected microplastics in dried fish samples collected from four coastal areas of Bangladesh. Every one of the 24 samples—from Dublar Char in the Sundarbans, Kuakata, Cox’s Bazar and Teknaf—contained plastic particles. The findings highlight a potential pathway through which plastic pollution in coastal and marine environments may enter the food chain through fish and dried-fish products.

The study was led by Professor Dr Md Ashraful Azam Khan of the university’s Department of Fisheries. Postgraduate students Kazi Nusrat Jahan Oishi, Habibur Rahman Pias, Nadia Islam Riya and Sanjida Juthi also contributed. According to the supplied report, the study was published on October 15 in the international scientific journal Marine Pollution Bulletin, published by Elsevier.

Samples from four coastal centres

The research covered four important dried-fish production centres: Dublar Char in the Sundarbans, Kuakata, Cox’s Bazar and Teknaf. The researchers selected six commonly consumed fish and shrimp species: Bombay duck, jewfish, ribbon fish, Phaisa fish, Harina shrimp and black tiger shrimp. A total of 24 samples were collected and analysed in the laboratory.

Microplastics were detected in all 24 samples. Kuakata recorded the highest reported Polymer Hazard Index, at 2,642.7, followed by Cox’s Bazar, at 1,461.1.

The study reportedly identified around nine types of plastic polymers, with polyvinyl chloride (PVC) and polystyrene (PS) among the most prevalent. The Polymer Hazard Index is used to assess the potential hazard associated with different polymers. However, the index should not be interpreted on its own as a direct measure of human disease risk or a definitive verdict on the safety of a food product. Its interpretation depends on the study’s methods and other findings.

Researchers explain possible pollution pathways

Professor Ashraful Azam Khan said municipal, industrial and household waste can reach coastal areas, where plastic debris breaks down into smaller particles. These particles may enter aquatic environments, be ingested by fish and subsequently be present in dried fish made from contaminated catches.

He also said that some dried-fish traders had historically used harmful chemicals and pesticides, including DDT and Nogos, to prevent larval attacks and reduce losses. In his view, both chemical use in dried-fish processing and microplastic contamination require attention.

The researchers raised concerns about the possibility of microplastics entering the human body through food. However, the study does not by itself establish how much microplastic people absorb by eating dried fish or what specific health effects may result. Further food-safety and health research is needed to assess those questions.

Recommendations for safer dried-fish production

Professor Khan called for more hygienic and environmentally responsible dried-fish production. Instead of drying fish in exposed, potentially contaminated areas, he recommended using clean, controlled and covered facilities or suitable solar-drying systems.

Producers should also reduce the risk of plastic particles mixing with fish during processing and packaging. Particular attention is needed for plastic sheets, synthetic ropes and packaging materials. At the same time, coastal communities need stronger systems for collecting, managing and recycling municipal and industrial waste to prevent plastic debris from entering the sea.

The researcher stressed that consumer awareness must be accompanied by scientific production methods, regular quality checks, effective government policies and stronger monitoring. Such measures could help protect food safety and reduce plastic pollution in coastal ecosystems.

//DBTech/MVR/SME/MIST//