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Ecotoxicology

Ecotoxicology Division

Pesticides regrettably have become an indispensable tool for the Indian agriculture and public health departments for many decades now. Needless to say, the ill-effects out weigh the benefits. Thus virtually there is no produce or ecosystem component that is free from pesticide residues in India. Every bit of surface waters and even ground waters are contaminated with either agricultural run off or industrial effluents. Ecological disturbances caused by the pesticides and other industrial contaminants largely remain under or unreported. Unfortunately,   there is no structured contaminant monitoring programme in place in India. SACON has been working over the last couple of decades in this direction to address the issues on a national as well as local scale. While we continue the work already initiated on pesticides, PCBs, PAHs, metals and even drugs such as diclofenac, we keep our eyes and ears opened to perceive any new challenges.

Impact of contaminants on Indian avifauna

Population of several species of birds including a few so-called common birds, have been on the decline. While there are many reasons postulated, the role of agricultural practices and changes in land use pattern have undoubtedly contributed for the present situation.  Mortality of birds due to pesticide poisoning has become rampant.  Sarus Crane, Peafowl, Great Indian Bustard, Demoiselle Crane are a few notable victims in the recent past. Our research over the years has confirmed several instances of pesticide poisoning and documented varying magnitude of contamination in more than 125 species of birds in the country. Despite the ban on many persistent pesticides, residue levels of certain pesticides in many species of birds are of concern. Unfortunately, birds are the worst affected non targeted organisms

Contamination profile of Indian wetlands

 Agricultural runoff loaded with chemicals of assorted sorts find way into wetlands, the aquatic wealth of our country. Eutrophication and accumulation of chemicals in aquatic organisms slowly deteriorate the system and lead to ecological succession. Fishes due to their position in the aquatic food chain and their nutritive value are considered to be better indicator of wetland contamination than other inhabitants. Our research on 64 species of fishes from many wetlands across the nation and 44 rivers in Kerala reveals, not a single individual to be free from chemical residues. Scenario on the marine fishes was not much different. Hence, it is very imperative to have monitoring system in place to understand the levels of problem chemicals in the environment using indicator organisms such as fishes.

The division Ecotoxicology also addresses issues at local level.   Impact of Agricultural Pesticides on the population status and breeding success of select species of  fish eating birds in Tamil Nadu, Surveillance of waterfowl at Nalabana Bird Sanctuary, Chilika Lake, Odisha  and Monitoring of pesticides residues in select components of an agro ecosystem adopting organic and chemical forming in Palakkad district, are some of our recent / ongoing studies.

Biomarkers

Cytochrome P450, Glutathione, Metallothionein, Acetyl, butyl and carboxyl esterases are some of the biomarkers which are reported to be suitable markers of environmental contamination in European and North American countries. In India although some information is available on the use of such biochemical parameters on contaminants related studies, the status is far from desired. We propose to intensify our research in this domain as well.

 Avian disease

 Mortality of birds due to disease in wetland habitats in India has been rampant off late. Classic example is the episode in Nalabana Sanctuary, Chilika Lake where 100s of ducks died due to avian pasteurellosis. This farms yet another area of our interest.

The infrastructure

The division of ecotoxicology is equipped with analytical instruments such as Atomic Absorption Spectrophotometer (AAS), Graphite Furnace AAS, Gas Chromatograph, High Performance Liquid Chromatograph, UV-Vis Spectrophotometer and Ultra centrifuge towards quantifying different contaminants. Facility with ultra deep freezers, walk-in cold room and ample working space offer wonderful research environment for students. We have augmented the facility with a set of new instruments recently.

Scientist

Dr. S.Muralidharan

Designation : Senior Principal Scientist

Contact :  ecot_mur@yahoo.com, muralidharan.s@sacon.in