Microbial remediation of pesticides

Abstract

As a generalized definition, a pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests (US EPA 2010c). Pesticides are often referred to according to the type of pest they control. Major types of pesticides are listed in Table 5.1 (modified from US EPA 2010b). Pesticides have been used to control, eliminate, or destroy pests in order to meet the continuously increasing food demand of the world. Therefore, contamination of soils with persistent pesticides is a widespread problem arising from the extensive use of pesticides in agriculture or from industrial chemical wastes. They have harmful effects directly or indirectly on soil, environment, surface water and groundwater, natural flora and fauna, and aquatic life, which will ultimately adversely influence human beings and livestock. So, the impact of pesticides on atmosphere and community health is of great significance regardless of their noticeable benefits (Rashid et al. 2010). Use of pesticides worldwide exceeded 5.0 billion pounds in 2000 and 2001. Herbicides accounted for the largest portion of total use, followed by other pesticides, insecticides, and fungicides (Table 5.2; modified from US EPA 2010a). Pesticides have been used for agriculture, gardening, and controlling of home-based pests. Despite environmental disturbances, harmful effects of pesticides come from direct use. Ironically, pesticide poisoning causes more deaths than infectious diseases in certain parts of the developing world. Use of pesticides in certain parts of the developing world is poorly regulated and often dangerous; their easy availability also makes them a popular method of self-harm (Eddleston et al. 2002).