Indian Institute of Technology Madras Researchers have found that the waters of River Cauvery are 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.
Of these, pharmaceutical contamination is particularly serious in India, which is the second-largest pharmaceutical manufacturing country in the world. These drug compounds, when released even in minuscule amounts into water bodies, can harm human beings and the ecosystem in the long run.
A team of researchers from IIT Madras led by Dr. Ligy Philip, 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. Assessing the quality of the river water helps understand the factors that influence the distribution of contaminants and their impacts on the ecosystem.
The IIT Madras study 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. The findings of this work also point to the need for more research into assessing the long-term impacts of emerging contaminants on human health and the environment.
This study has been carried out with joint funding from Water Technology Initiatives of the Department of Science and Technology, Government of India and the UK Natural Environment Research Council.
The results of the study have recently been published in the reputed peer-reviewed journal Science of the Total Environment (https://doi.org/10.1016/j.scitotenv.2021.149340), in a paper co-authored by Jayakumar Renganathan, Insamam Ul Huq S, Kamaraj Ramakrishnan, Manthiram Karthik Ravichandran, and Prof. Ligy Philip.
Highlighting the important findings of the research, Dr. Ligy Philip, Nita and KG Ganapathi Institute Chair Professor, Department of Civil Engineering, IIT Madras, said, “We monitored the water quality of Cauvery River for two years to assess the seasonal variation of emerging contaminants, especially pharmaceutically active compounds.”
Further, Prof. Ligy Philip said, “The IIT Madras team collected water from 22 locations along entire stretch of the river. 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. The quality of water the catchment sites was also monitored.”
River networks contribute to 0.006% of global freshwater and often serve as a lifeline for various domestic and industrial activities. Worldwide, water quality of the river systems has been deteriorating due to various anthropogenic activities. One river system in South India that has been subjected to constant human threat is the River Cauvery.
The Research Team 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.
“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.
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.