Chennai, Oct 7 (IANS): The waters of the Cauvery river are polluted with an extraordinarily high concentration of pharmaceutical contaminants like ibuprofen, plastics, flame retardants, heavy metals and pesticides, increasing the risk to human health and environment, according to a study by the Indian Institute of Technology (IIT) Madras released on Thursday.

A team of researchers from IIT Madras quantified the seasonal distribution of emerging contaminants and pollutants in the Cauvery.

The team collected water from 22 locations along the entire stretch of the river. They 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. The quality of water at the catchment sites was also monitored.

They found pharmaceutical contaminants including 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," said Dr Ligy Philip, Nita and KG Ganapathi Institute Chair Professor, Department of Civil Engineering, IIT Madras, in a statement.

"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," she added.

The 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.

Worldwide, water quality of the river systems has been deteriorating due to various anthropogenic activities.

The findings, published in the peer-reviewed journal Science of the Total Environment, showed that it was essential to regularly monitor rivers and their tributaries for contamination by pharmaceutical products.

There was also a need to upgrade wastewater treatment systems to reduce the levels of emerging contaminants in receiving water bodies such as rivers.