Some of the table salt sold in Kenya is contaminated with tiny plastic particles, which may be a health risk to consumers.
Salt bought from open markets and supermarkets in eight African countries, including Kenya, was tested, and found to contain plastic particles.
The researchers collected samples of different brands of commonly consumed commercial table salts from Kenya, Nigeria, Cameroon, Ghana, Malawi, Zimbabwe, South Africa, and Uganda. All the samples, the report in an ahead of the print issue of Marine Pollution Bulletin states, were contaminated with plastic particles, some not visible to the naked eye.
The microplastics can be ingested by marine life, and eventually, find their way into human food. The new study by Oluniyi, Elvis Okoffo and Emmanuel Olasehinde of University of Queensland, Australia and Federal University of Technology, Nigeria, shows this is the first evidence of plastics in local table salt. “This should be cause for worry as it indicates possible contamination of seafood, including fish, with plastics.”
Kenya’s table salt is mainly harvested from the Indian Ocean waters through solar evaporation. Domestically, salt is used for food preparation, seasonings, preservation and even relieving a sore throat. The World Health Organisation recommends that adults consume about 5 grammes of salt per day because it is crucial for balancing body fluids, maintaining healthy blood pressure, and good nerve and muscle function.
How plastics get into salt
Recent studies, the team says, have reported contamination of commercial table salt with plastic particles, but this is the first study to confirm the same in Kenya.
The researchers suggest the salt may be getting contaminated through plastics in seawater or from additives to the salt. “There are possibilities that additives such as synthetic folates or folic acid may be introduced during manufacturing to enhance the final product,” it says.
To support the suggestion, citing the presence of paste-like materials in some of the sampled salts, which can only be rationalised as additives incorporated during production.
However, the research says there was also evidence that the microplastics could be originating from water sources due to high plastic pollution in salt collection sites. “On the basis of our results, the consumption of table salts in Africa represents a major source of microplastics exposure to humans,” said the study.
Seafood a risk too
Human exposure to plastic particles through the consumption of seafood products is currently a source of concern.
In 2018, researchers at the Kenya Marine and Fisheries Research Institute (Kemfri), Pwani University, and Taita Taveta University, presented the first documented evidence of microplastics ingestion by sea organisms in Kenya’s coastal waters.
The team found high microplastics contamination in the ocean, but also evidence it was being consumed by sea organisms called zooplankton. “A total of 129 particles were found ingested by zooplankton groups, as well as fish larvae,” said the study.