Chapter 7: Pesticides and Hematopoietic Stem Cells
Published:09 Aug 2016
Food and Agriculture Organization of the United Nations (FAO) and United Nations Environment Programme (UNEP) have jointly defined the term pesticide as chemicals designed to combat the attacks of various pests and vectors on agricultural crops, domestic animals, and human beings. Functionally, pesticides are categorized into insecticides, fungicides, herbicides, rodenticides, algaecides, and nematocides. Chemical insecticides are classified as organophosphates, organochlorides, pyrethroids, carbamates; and most of the agriculturally important fungicides are covered by benzimidazoles, triazole, etc. Depending upon physiological activity, synthetic pyrethroids are of two types: Type-I pyrethroids (without α-cyano group), and Type-II pyrethroids (with α-cyano group). It is evident that pesticides, so defined and characterized as per their functions, have a number of beneficial effects on modern agricultural practice. In doing so, there are certain undesirable and unwanted effects of pesticide usage, which cannot be ignored. Now, pesticides have become ecotoxicants for their undesirable effects on each and every component of the ecosystem. Millions of people and other non-target organisms are victimized by acute pesticide poisoning. Besides poisoning, pesticide exposures cause chronic health problems including acquired aplastic anemia, agranulocytosis, cancer, neurological disorders and birth defects. Despite a few epidemiological reports, so far we have a meager understanding of the hematopoietic failure and the development of marrow aplasia by pesticide toxicity. Most of the previous works regarding pesticide toxicity ignored the hematopoietic system and hematopoietic stem cells (HSCs). Incidentally, the effect of chronic pesticide toxicity in the hematopoietic system manifests slowly but more deadly than in any other cellular system.