Abstract
Indiscriminate and incessant use of synthetic pesticides is becoming an increasing global concern. No doubt, the application of conventional synthetic pesticides has enhanced the quality and quantity of agricultural products. However, accumulation of pesticides in freshwater resources has negative effects on aquatic ecosystem and human health. The persistent and toxic nature of pesticides has led to direct or indirect exposure on the biota in aquatic ecosystems resulting in acute (mortality of organisms) and chronic effects (decreased production and change in community structure), thus posing serious consequences for the ecosystem. Biopesticides provides a cost-effective and innovative approach employing bioremediation techniques for the removal of pesticides in water because of its advantage linked with environmental safety, biodegradability, effectiveness, and target-specificity. Furthermore, biopesticides provide an efficient method for detoxification of pesticides and appropriateness in the integrated pest management (IPM) programs.
TopIntroduction
The population of the planet earth is showing increasing trend and is projected to grow around 10.12 billion by the end of 21st Century. The time demands an intensive farming approach to fulfil the food requirements of the growing population. The highest yield of crops is based on the improved variety, the appropriate pest and disease management, and recommended fertilization (Birch, 2011; Nawaz, 2016). The role of chemical pesticides cannot be ignored in terms of increase in crop protection and production over the years. However at the same time chemical pesticides are considered as main causative agents for accelerated contamination of environment. Similarly, they have been the main cause of insect resistance as well as adverse impacts on natural enemies and humans (Alzaidi, 2011; Ishtiaq, 2012).
Before the use of pesticides, pests were responsible for enormous losses of agricultural produce and had grave impact on farming and agricultural practices. About 30% of agricultural produce is lost due to pests. Hence, the use of pesticides has become indispensable in agriculture. As agricultural production increased over the past few decades, farmers became more and more dependent on synthetic pesticides. Intensive use of pesticides over the years for increasing the overall production has resulted diverse types of hazards and toxicity and thus has affected the environment and non-target organisms (Tripathi & Tripathi, 2000). The pattern of pesticide usage in India is different from that for the world in general. As can be seen in Figure 1, in India 76% of the pesticide used is insecticide, as against 44% globally (Mathur, 1999). The use of herbicides and fungicides is correspondingly less heavy. The main use of pesticides in India is for cotton crops (45%), followed by paddy and wheat.
Figure 1. Consumption pattern of pesticides
Key Terms in this Chapter
Detoxification: Detoxification is the physiological or medicinal removal of toxic substances from a living organism, including the human body, which is mainly carried out by the liver.
Bioremediation: Bioremediation is a process used to treat contaminated media, including water, soil, and subsurface material, by altering environmental conditions to stimulate growth of microorganisms and degrade the target pollutants. In many cases, bioremediation is less expensive and more sustainable than other remediation alternatives. Biological treatment is a similar approach used to treat wastes including wastewater, industrial waste, and solid waste.
Biomagnification: Biomagnification, also known as bioamplification or biological magnification, is the increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain.