A study by researchers of the Indian Institute of Technology - Madras (IIT-M), has found that a range of contaminants including pharmaceutically-active compounds, personal care products, plastics, flame retardants, heavy metals and pesticides pollute the River Cauvery.
Researchers said this indicates a need to regularly monitor the river and its tributaries for pharmaceutical contamination. The contamination is particularly serious, as India is the second-largest pharmaceutical manufacturer in the world, they point out.
Drug compounds, when released even in minuscule amounts, into water bodies can harm human beings and the ecosystem in the long term, researchers said, calling for upgrading wastewater treatment systems to reduce contaminants in receiving water bodies such as rivers. The study also points to a need to assess the long-term impact of such contamination on human health and the ecosystem.
This study was carried out with joint funding from the Water Technology Initiatives of the Department of Science and Technology, and the UK Natural Environment Research Council. The study findings were published in an international peer-reviewed journal.
A team of researchers from IIT Madras, led by Dr. Ligy Philip, who is the Nita and KG Ganapathi Institute Chair Professor, Department of Civil Engineering, IIT Madras, quantified the seasonal distribution of emerging contaminants and pollutants in the River Cauvery.
The researchers had monitored the water quality for two years to assess seasonal variation of emerging contaminants, especially pharmaceutically active compounds.
The team collected water from 22 locations along the entire stretch of the river. The quality of water in the catchment sites was also monitored. It found that water quality and the levels of pharmaceutical contaminants were influenced by the monsoon. The level was high post-monsoon due to reduced riverine flow and continuous waste discharge from multiple sources.
“Our observations are alarming. The team’s risk assessment had shown that pharmaceutical contaminants pose medium to high risk to select aquatic life forms of the riverine system,” the researchers said.
There was significant contamination by metals such as arsenic, zinc, chromium, lead and nickel. 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.
The research article was co-authored by Jayakumar Renganathan, Insamam Ul Huq S, Kamaraj Ramakrishnan, Manthiram Karthik Ravichandran, and Prof. Ligy Philip.
