الفهرس 
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Abstract
There is an increasing public concern about environmental risks because many human activities are detrimental to the natural environment, and in turn, environmental changes may lead to many health consequences. The word “environment” has a meaning of location, i.e., “place,” in terms of certain geographical and physical characteristics. However, at the same time, it is also a social concept reflecting the social/economical development of a given location, the qualitative criteria of living conditions of that location. Both of these interpretations are justified as having important effects on health (Pluhar et al., 2009)(1).
Pesticides comprise a variety of toxic substances, and are used in agriculture as well as indoors to kill pests (Bazrafshan et al., 2007)(2). All pesticide compounds pose an environmental health hazard as they are, to greater or lesser degree, chemically tailored to be toxic and persistent (Foster and Chilton, 2003)(3). The health risk of pesticides to humans is worsened by the fact that many of these substances have been shown to be mutagenic and carcinogenic (Zohair, 2001)(4). Pesticide poisoning is an important cause of morbidity and mortality in developing countries although only one-fourth of the total world consumption of pesticides has been reported from these regions. Nevertheless, every year there are three million cases of severe poisoning and 220,000 deaths; the majority of these poisonings and 99% of the resulting deaths occur in the third world (Tinoco and Halperin, 1998)(5).
Pesticides are released into the environment in large quantities each year and are routinely detected in air, dust, ground water, and body tissues of animals and humans. Many pesticides are lipophilic and bioaccumulate in lipid stores and tissues such as in mammary glands or adipose tissues. They are mobilized along with the lipids during pregnancy and lactation, and may be passed to the developing fetus or offspring via placental transfer and milk (Pages et al., 2002)(6). Pesticides may induce oxidative stress, leading to generation of free radicals, oxygen free radicals (Nasir et al., 2008)(7).
Free radicals are defined as atoms or molecules that contain one or more unpaired electrons (Carocho and Ferreira, 2013)(8). While, Oxidative stress can be defined most simply as the imbalance between the production of free radicals capable of causing peroxidation of the lipid layer of cells and the body’s antioxidant defense (Ranjbar et al, 2006)(9). Pesticides producing radicals such as paraquat, diquat and the organochlorine pesticide lindane. Organochlorine pesticides present special toxicological problem due to their long persistence and ability to accumulate in adipose tissue (Saradha and Mathur, 2006)(10).
Normal cellular function depends on a balance between reactive oxygen species (ROS) produced and antioxidant defense mechanisms available to the cell. Reactive Oxygen Species, including the superoxide radical, hydrogen peroxide, and the hydroxyl radical, arise as by-products of normal cellular metabolism or may be the consequence of exposure to certain toxicants. In such cases of overwhelmed antioxidant defense, cellular function can be affected and cells may be damaged (Kerr et al., 1996).