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Rudrasagar lake- A potential wetland for environmental research prioritization in Tripura

 

Abstract

Priority setting in Environment and Environmental Research is an important activity for conservation and better utilization of available resources, particularly, for the unconscious people of the remote areas like Tripura of the country. Freshwater basins like wetlands are vulnerable to human induced changes for a number of reasons for a long time. Since Wetlands are considered ‘liquid treasures’ of a country, priority attention should be given to conserve Rudrasagar lake, the lone Ramsar Site in the state of Tripura, through Research, Education, Training and Awareness Programmes besides the laws framed by the government to restore the lake ecosystem along with their values in this decade of global warming, decreasing freshwater availability, extinction of different species, loss of environmental balance to gear up the pace of sustainable development for the mankind.

This paper aims to carryout a speculative study to prioritize Rudrasagar Lake as one of the potential area for Environmental Research in Tripura. The paper also highlights the reasons behind prioritization and the deliverables of the lake to the man kind for the sustainable development.

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Key Words: Research Priority, Wetland, Ramsar Site, Rudrasagar lake, Sustainable Development.

(Presented in the Regional Seminar organized by IGNOU at Agartala on 12-13th February, 2011)
For more details Contact at "sanjumon78@rediffmail.com"

Organophosphorus pesticide induced health hazards on living organisms at different Trophic levels.

Pesticides, the biologically active chemicals are used for pest control but their spectrum of activity often extends far beyond the pest. Huge amount of different kinds of poisonous agricultural chemicals such as chlorinated hydrocarbons, organophosphates and carbonates as insecticides and several herbicides for weed control are used now a days which are known to persist for long period in the environment and their concentration builds up geometrically as they are transferred to different higher trophic levels of food web. Although the need for pesticides in the sphere of public health and agriculture is accepted, yet it is also evident that they have at times been over used and misused to such an extent that it has given rise to public concern because some of them at least, have led to wide spread and long term contamination of the environment.

The harmful effects of pesticides on aquatic organisms are due to the indiscriminate use, careless handling, accidental spillage or discharge of untreated effluents into natural water ways. It reaches the aquatic environment by direct application, spray, drift, aerial spraying, and washing from the atmosphere by precipitation, erosion and runoff from agricultural land, in factory effluents and in sewage (Edwards, 1973). Discharge of these toxic chemicals into the aquatic system prone to indicate hazardous on the aquatic animals. The hazardous toxicants have been known to accumulate in tissues of fishes and other edible organisms have a chance to reach the predators like birds and man through food chain. Food organisms may be impacted either directly by the toxic effects of pesticides or marked as unsuitable for human consumption due to elevated level of these substances.

Organophosphorus pesticides can be absorbed by all routes, including inhalation, ingestion, and dermal absorption. The main target organs are the nervous system, respiratory tract and cardiovascular system. The toxicological effects of the organophosphorus pesticides are almost entirely due to the inhibition of acetylcholinesterase (AChE) in the nervous system, resulting in respiratory, myocardial and neuromuscular transmission impairment.  A few organophosphorus pesticides have produced the so-called "Intermediate Syndrome" and delayed neuropathy, the latter apparently unrelated to acetylcholinesterase inhibition.

As many of the first-generation organochlorine pesticides were banned in the 1970s, the agrochemical industry turned to the less persistent, but more acutely toxic organophosphate (OP) and carbamate compounds to control insect pests. At present, organophosphorus (OP) insecticides are widely used in agriculture and public health due to their low chemical and thermal stability, rapidly decomposes in the environment (Soil, water and surface of plants) into none toxic substance. Commercial OP pesticides are commonly used for crop protection and for the control of vector borne diseases. It is well known fact that the organophosphorus insecticides adversely affect the non target species of terrestrial as well as aquatic fauna.

Fishes are frequently exposed to more than one pesticides at a time as these pesticides make their way to the nearby rivers, lakes, ponds, seas etc from the croplands which adversely affect the growth and survival of the fish. Serious cases of fish mortality have occurred following the flow of poisonous pesticides from agricultural fields.

The magnitude of pesticide pollution was studied in the Indian fishes by various workers (Bhattacharya et al., 1975; Dalela et al., 1978; Dubale and Shah, 1979; Pandey and Shukla, 1980; Rashatwar and Ilyas, 1984; Sadhu and Mukhopadhyay, 1985; Shukla and Pandey, 1985, Ghosh and Chatterjee, 1989; Medda, 1994, Munshi JD, Dutta HM, Singh NK, Roy PK, Adhikari S, Dogra JV, Ali MM, 1999, R.S. Tandon and Ajai Dubey, 2003, Yogesh, H. Wasu; Yashshri, A. Gadhikar; Prakash, P. Ade, 2009). Different haematological parameters of the fish are also adversely affected by op pesticides.  

 Organophosphate pesticide exerts deleterious effect on physical, biochemical as well as physiological aspects of different groups of animals. Studies have shown that a fall in brain AChE activity to 50% of normal value can bring about change in behaviour in birds. Though OP pesticides persist in the environment for a short period of time owing to their low stability, human being and other mammals exposed orally or dermally to these compounds die after developing serious toxic symptoms.              

The concentration of insecticide residue in food stuff including aquatic biota particularly in fish is a dual threat to man. There is possibility of man’s food residue toxicity tolerance level being exceeded or total elimination of fish as a source of food. Widespread exposure to the OP pesticides has recently been documented through research done by the U.S. Centers for Disease Control (CDC) and Academic Scientists, which show that most people in the U.S. have breakdown products of these pesticides in their urine. HCH isomers, endosulfan, malathion, chlorpyrifos, and methyl-parathion were monitored in human milk samples from Bhopal, Madhya Pradesh by a group of researcher namely Sanghi R, Pillai MK, Jayalekshmi TR, Nair A. in the year 2003. The endosulfan concentrations were highest and exceeded the sigma-HCH, chlorpyrifos, and malathion concentrations by 3.5-, 1.5-, and 8.4-fold, respectively. Through breast milk, infants consumed 8.6 times more endosulfan and 4.1 times more malathion than the average daily intake levels recommended by the World Health Organization.