Pharmaceutical contaminants polluting Cauvery river: Study

Bengaluru: Researchers from IIT-Madras found that the lifeline of Karnataka- Cauvery river is polluted with a wide range of contaminants ranging from pharmaceutically-active compounds to heavy metals and pesticides.

A team of researchers led by Dr Ligy Philip, Nita and KG Ganapathi Institute Chair Professor, Department of Civil Engineering, IIT Madras conducted experiments on the river Cauvery to determine the seasonal distribution of contaminants in the river Cauvery. The study was conducted with joint funding from Water Technology Initiatives of the Department of Science and Technology, Government of India and the UK Natural Environment Research Council.

Talking about the research, the team said, "We monitored the water quality of Cauvery River for two years to assess the seasonal variation of emerging contaminants, especially pharmaceutically active compounds.". In India, pharmaceutical contamination is of grave concern as India is the second-biggest pharmaceutical manufacturing country in the world. Even a minuscule amount in the water body could have harmful effects on humans and the ecosystem in the long run.

For the experiment, the team collected water from 22 different sites along the stretch of the river and set up 11 sampling stations near discharge points of partially treated or untreated wastewater and 11 stations near the intake point of these water supply systems. The team also checked the quality of water at the catchment sites.

The findings of the study were published in the reputed peer-reviewed journal journal 'Science of the Total Environment. The research group discovered that the water quality and the levels of pharmaceutical contaminants in the Cauvery river was heavily influenced by the monsoon season. The post-monsoon period displayed a substantial increase in the level of contaminants flowing into the river body due to restricted riverine flow along with continued disposal of waste from multiple sources. The study showed that "Freshwater intake points were also found to be loaded with extraordinarily high concentrations of pharmaceutical contaminants. These 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. There was also significant contamination by metals such as arsenic, zinc, chromium, lead and nickel. ."

"Our observations are alarming. So far, not much is known about how pharmaceutical contaminants affect human health and the ecosystem over time. 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," said Prof. Ligy Philip. Rivers contribute to 0.006% of global freshwater and serve as the primary source for multiple domestic and industrial activities.

The study emphasises the need for regular monitoring of rivers and their tributaries for pharmaceutical contaminants. It also suggested a need to improve wastewater treatment plans in our country and for further research on the long-term effects of the contaminants on human health and the environment.