KOCHI:Whenever you do your laundry, you are actually contributing to a marine organism’s early demise! Surprised? Studies conducted by international agencies show more than 4,500 microfibres can be released per gram of clothing per wash. And if you take into consideration each cycle of a washing machine, that will come to around 7 lakh microfibres. Well, a single wash also releases a lot of microbeads, a major constituent in detergents and shower gels, into the ecosystem.
According to experts, these microbeads are added to detergents, face washes and shower gels to provide grittiness. Their abrasive property acts like a brush and helps cleanse dirt from the clothing and body.
“Microfibres and microbeads are commonly known as microplastics. They range from a few microns to several millimetres in diameter. They also include particles of various shapes, from completely spherical to elongated fibres, small particles (<5mm) that are either manufactured as granules or originate from plastic debris,” said Anu Gopinath, assistant professor, Kufos.There are two types of microplastics - primary and secondary.
“Primary microplastics are raw manufactured plastic materials, like virgin plastic pellets, scrubbers and microbeads, that enter the ocean via run-off from land. Secondary microplastic is the breakdown products of meso or macro plastics - through mechanical, oxidative or biological degradation. These can’t be seen by the naked eye,” said Anu.
She said microbeads have various uses.“Besides being used as exfoliants in cosmetics, they are used to deliver medicines,” she said. “But since these microbeads and fibres are very tiny, they pass along with the waste water, via the treatment plants and, finally, into the oceans and other water bodies.”According to her, plastics, especially floating debris act, as a potential vector for sessile organisms and aid them to invade newer habitats threatening native biodiversity.
“Ingestion of microfibres and beads has been widely identified in vertebrates. Over 250 marine species are believed to be impacted by plastic ingestion. Over 80 per cent of incidents between marine organisms and debris have been associated with plastics while 11 per cent encounters are with microplastics,” Anu said.
Also, microfibres and beads are liable to concentrate hydrophobic persistent organic pollutants (POPs). “These pollutants have an affinity for the hydrophobic surface of the plastic compared to sea water. They can concentrate up to six orders of magnitude. This leads to bioaccumulation and biomagnification through the food chain,” said the professor.
Many animals are understood to passively ingest microfibres and beads during feeding. “Many crustaceans like seashore crabs can integrate microplastics into both their respiratory and digestive tracts. Corals, which are primary reef builders, have been found to ingest microplastics. It can take at least 14 days for these microplastics to pass from an animal (as compared to the normal digestive period of two days),” she said.Scientists have reported accumulation of microplastics in the stomach of lantern fish which are filter feeding and prey for bigger fish like the tuna and swordfish.“Since fish is the primary source of protein for nearly one-fifth of the human population, it is important to note these microplastics subsequently enter our digestive tract,” she said.