- Study area was Maheshkhali Channel and adjacent areas
- Researchers found 78-137 particles in each kilogram of raw salt
- Those are mostly white and too small to be found normally
- They are not sure whether the particles remain in refined salt
Sea salt in Bangladesh has recently been found contaminated by plastic pollution, adding to fears that microplastics are becoming ubiquitous in the environment and finding their way into the food chain via dietary uptake, according to research.
The study, conducted by local and foreign researchers, was published in Nature journal on 30 November with the title "Microplastics pollution in salt pans from the Maheshkhali Channel, Bangladesh".
Researchers believe the majority of the contamination in raw salt comes from daily life products, packaging, single-use plastics, and clothes.
Up to 12.7 million tonnes of plastic enter the world's oceans every year, equivalent to dumping one garbage truck of plastic per minute into the world's oceans, according to the United Nations.
"We have collected the samples from eight salt pans located in the country's largest salt farming area in the Maheshkhali Channel and adjacent areas," said Md Refat Jahan Rakib, one of the researchers and a former student of Noakhali Science and Technology University.
"Those particles we found are mostly white and too small to be found normally," he noted. "We found the presence of the contaminants after testing the samples with several chemicals."
The researchers found 78 to 137 particles per kg of unprocessed salt which they labelled as "less risky". In neighbouring India, the presence of the contaminants in salt is 100-5,000 per kg. Plastic contamination in sea salt is much worse in Vietnam, Croatia, Spain and the US.
In contrast, similar research in Malaysia, New Zealand, Japan, France and South Africa found 0-1 particles of contaminants per kg.
The researchers, however, are not sure whether the particles remain in the refined salt that is being sold in retail stores. Rakib said they would conduct further research if they get the funding.
They said the results contribute to a better knowledge of the presence of plastics in sea salts in Bangladesh and may help to prompt actions to reduce human exposure to micro-plastic in the future.