Microplastics are abundant in Kochi drains, finds Cochin varsity study

Kochi: There is abundance of microplastics in Kochi drains, reflecting the unscientific waste disposal in a densely populated city, according to a recent study carried out by Cochin University of Science and Technology (Cusat). The study found that the concentration ranged from 39.65 to 56.28 microplastic particles per litre of water whereas sediment samples showed significantly higher concentration ranging from 450.22 to 545.79 particles/kg post-monsoon.Scientists admit that there is no recorded data on the permissible amount of microplastics at the moment. They fear that one should look with utmost seriousness into the presence of microplastics in Kochi drains. Experts who carried out the study said these microplastics reach Vembanad Lake through drains, raising environmental concerns. They eventually appear in human food and water chains, resulting in long-term toxicity in humans.The study showed that in the pre-monsoon period, water samples recorded 12.7 to 82.5 particles per litre, and levels ranged from 216.45 to 785.88 particles/kg in sediment, indicating that rainwater transports non-degradable waste discarded by people to more places and gets settled in the sediment in fragmented form for long.In Kochi, the sediment is removed from drains during pre-monsoon cleaning drive and it is often deposited in public places and at Brahmapuram waste management facility, without being treated. While large plastic debris is cleared along with sediment, microplastics remain settled at the bed of drains.Cusat research fellow Amal R, who was part of the two-member team that conducted the study, said densely populated areas in the city showed higher concentration of microplastics due to greater plastic consumption and improper waste disposal practices. He said microplastics in the water and sediment seep into the soil and contaminate ecology and pose health risks."Studies have shown that microplastics reach our body through plants we cultivate on the land or the water we drink, raising health concerns. We noticed the concentration of microplastics is high in densely populated places along the Perandoor-Thevara canal and Mullassery canal. High-density locations produce more plastic waste as the dense population tends to consume more plastic items and increase the possibility of environmental leakage when they lack civic sense and the facility for proper scientific management of the plastic waste," said Amal.The report also points out that microplastics can act as carriers for secondary pollutants, facilitating the spread of contaminants through water flow. The study also found presence of polymer composition alongside mismanaged plastic waste, validating road-derived urban debris reaching drains. "As vehicle population density is rising, we found microplastics derived from tyre wear particles in the samples and they are becoming one of the growing sources. Despite the authorities removing the waste from drains, management is not properly done. The waste again reaches drains through rainwater. We need a proper facility for treating drainage waste. It is mandatory in developed nations and they test the presence of microplastics from treated water. Here we don't even have a facility to treat drainage waste. An improved civic sense would help enhance plastic waste management," said Amal.Since it is an emerging threat, Amal said, no permissible or acceptable limit for the presence of microplastics in the environment and food web has been set.He said multiple researches are under way to study the potential adverse impacts of the presence of microplastics on human body.