THE EFFECT OF HYDROCARBON INSECTICIDES AND THEIR RISK ON ENVIRONMENT AND HUMAN HEALTH
- Background of the study
It is now obvious that the physical, chemical with the biological integrity of our planet is being compromised daily. The destructive processes are increasing both in quantum and in rate. The impacts have resulted in loss of biodiversity and destruction of natural habitat. In developing countries, both nature and man are at work endangering the environment and our health even as we presently lack the knowledge, technology, human capacity, financial wide range of environmental interventions with the objective of reducing to suitable levels of insect pests, weed population and plant pathogens. Most common pesticides include insecticides, fungicides, herbicides, rodenticides, nematicides, et cetera. Among the most effective are the chlorinated hydrocarbons. They are used in controlling a number of diseases, such as malaria, typhus and weed control. Pesticides have been an environmental threat, and why this threat is diminishing in developed countries, it remains a problem in many developing countries (Tovignan et al., 2001). The developed countries have banned many of the older pesticides due to potential toxic effects to man and/or their impacts on ecosystems, in favour of more modern pesticide formulations. Developing countries maintain that they cannot afford, for reasons of cost and/or efficacy, to ban certain older pesticides. The dilemma of cost/efficacy versus ecological impacts, including long range impacts via atmospheric transport and access to modern pesticide formulations at low cost remains a contentious global issue. Pesticides are chemical substances used to kill animals, plants, insects and pests in agricultural, domestic and institutional settings. The main groups of commonly used pesticides include herbicides, insecticides, fungicides, fumigants and rodenticides. Organochlorine, organophosphate and carbamate insecticides are of major concern because of their toxicity and persistence in the environment. Organochlorine insecticides are banned for agricultural and domestic use in most of the developed countries, but they are still in use in developing countries like Nepal. Most of the pesticides are broad spectrum and kill both the target and non-target organisms. Majority of the farmers are unaware of pesticide types, level of poisoning, safety precautions and potential hazards on health and environment (Yassin et al., 2002).