MUMBAI – Synthetic microfibres from clothing have been found in leading brands of sea salts by Indian researchers. Eight brands of sea salts were tested and all were found to have been contaminated with microplastic particles, as a consequence of using contaminated sea water. Sea salt is a salt that is produced by the evaporation of seawater and is used as a seasoning in foods and for cooking. This latest study is significant because India is a leading producer and exporter of sea salt. Moreover, it offers further evidence that microfibre pollution is finding its way into the human food chain.
In the study, samples from all eight brands of investigated sea salts were found to be contaminated, with both the fibres and fragments observed to have a large variation in size. 80 per cent of the extracted fibres and fragments were smaller than 2000 μm and 500 μm respectively (μm equals one millionth of a metre).
Extracted particles were found by the researchers to be mostly polyesters, polyethylene terephthalate (PET), polyamide, polyethylene, and polystyrene. Their total mass concentration was also estimated as 63.76 μg kg−1 of salt.
The researchers claim that simple sand filtration of artificially contaminated sea water could effectively remove up to 90 per cent of the microplastics.
Last month, environmental group Friends of the Earth launched a campaign to educate consumers on microplastics and ultimately try shift the apparel industry away from polyester. The campaign warns consumers they could be eating tiny plastic particles which enter the food chain via the world’s oceans. Many clothes contain plastics like polyester, nylon, acrylic and polyamide, with almost two thirds of new fabrics containing such materials.
Reference:
Seth, C.K. & Shriwastav, A. Environ Sci Pollut Res (2018). https://doi.org/10.1007/s11356-018-3028-5