Cauvery river is polluted by a range of contaminants, IIT research reveals

A range of emerging contaminants, including pharmaceutically active compounds, plastics, and heavy metals, are found in the waters of River Cauvery in Karnataka and Tamil Nadu, making it polluted, research by the prestigious Indian Institute of Technology (IIT-M) has concluded.

Water collected from 22 points – 11 each in Karnataka and Tamil Nadu – were studied by the IIT-M team as part of the research being carried out since 2018 with joint funding from Water Technology Initiatives of the Department of Science and Technology, and the UK Natural Environment Research Council.

The study, which was recently published in the reputed peer-reviewed journal Science of the Total Environment, found that the water in River Cauvery is polluted by a range of emerging contaminants that include pharmaceutically active compounds, personal care products, plastics, flame retardants, heavy metals, and pesticides, among many others.

Besides, there was significant contamination by metals such as arsenic, zinc, chromium, lead and nickel, while freshwater intake points were also found to be loaded with “extraordinarily high concentrations of pharmaceutical contaminants.”

Also Read | Cauvery crying: Large-scale tree planting not the panacea

The IIT-M study observed that one river system in South India that has been subjected to constant human threat is the River Cauvery. This study has been carried out with joint funding from Water Technology Initiatives of the Department of Science and Technology, the Government of India, and the UK Natural Environment Research Council.

River Cauvery begins its journey in Talakaveri in Karnataka and flows through the state and neighbouring Tamil Nadu before merging into the sea at Kaveripoompattinam (Poompuhar).

DH had published a detailed report on pollution in Cauvery on May 19, 2019, highlighting how governments in both states turn a blind eye to letting industries that pollute the river go scot-free.

Pharmaceutical contamination is serious as these drug compounds when released even in minuscule amounts into water bodies can harm human beings and the ecosystem in the long run, the study noted.

Dr. Ligy Philip, the head of the research, told Deccan Herald that the first collection point of water was Kushal Nagar in Karnataka and the last one was at Alakudi in Tamil Nadu.

“We set up 11 stations each in Karnataka and Tamil Nadu during 2.5 years of the study. Besides this, we also set up 11 sampling stations near discharge points of partially treated or untreated wastewater and 11 locations near intake points of water supply systems,” Dr Philip from the Department of Civil Engineering, IIT-M, said.

She said the study also showed that it was essential to regularly monitor rivers and their tributaries for contamination by pharmaceutical products.

The study also found that water quality and levels of pharmaceutical contaminants in the Cauvery are influenced by the monsoon season. The post-monsoon period showed an increased level of various types of contaminants including pharmaceuticals due to reduced riverine flow and continuous waste discharge from multiple sources.

Also Read | Few restrictions in place for Cauvery Theerthodbhava

Dr Philip stressed the need to upgrade wastewater treatment systems to reduce the levels of emerging contaminants in receiving water bodies such as rivers.

“We will be suggesting a slew of measures in the final report we will be submitting to the ministry in 2022. We feel this study and its findings point to the need for more research into assessing the long-term impacts of emerging contaminants on human health and the environment,” she added.

Terming the observations found in the study as “alarming”, Prof Philip said the team’s environmental risk assessment has shown that pharmaceutical contaminants pose medium to high risk to the selected aquatic lifeforms of the riverine system.

The study also found that the pharmaceutical contaminants included anti-inflammatories like ibuprofen and diclofenac, anti-hypertensives such as atenolol and isoprenaline, enzyme inhibitors like perindopril, stimulants like caffeine, antidepressants such as carbamazepine, and antibiotics such as ciprofloxacin.

Check out the latest videos from DH: