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Pesticides. There are many reasons why pesticides are used, interspecific competition (competition between members of different species for resources)

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Introduction

Pesticides Pesticide - Any substance used to kill, repel or otherwise control a pest. These include insecticides, herbicides, fungicides, rodenticides and disinfectants. Pesticides are designed to be toxic and can pose a risk to children, adults, pets and other creatures and plants. Common pesticides include herbicides for weed control, indoor ant and roach sprays, outdoor foggers, insect repellents, flea collars and pet shampoos. Synthetic fertilizers and pesticides have played a dominant role in agricultural intensification in industrialised and developing countries for decades. Although both have become widely distributed in the environment, most of the concern related to the health consequences of agriculture now centres on pesticides. 7 There are many reasons why pesticides are used, interspecific competition (competition between members of different species for resources) between weeds and crops as well as insects can cause much economic damage to a community, by causing crops to be lost, property damage from termites and tree roots and also damage caused to clothes from moths. However not only economical damage is caused by pests, also medical damage as Bubonic plague is passed on by fleas on rats, Lyme disease by ticks on deer and other animals and also Encephalitis transmitted by mosquitoes. ...read more.

Middle

and solubility in water (which means they may adversely affect fish and other organisms.) When pesticides are released into the environment, they are either: 1) broken down, or degraded, by the action of sunlight, water or other chemicals, or micro organisms, such as bacteria; or 2) resist degradation and thus remain unchanged in the environment for long periods of time.5 Properties of the Environment The individual properties of soil, water and living organisms affect the fate and behaviour of pesticides. Climate and topography also play a role. Soils vary in their ratios of sand, organic matter, metal content, acidity, porosity, permeability, etc. These soil characteristics influence the behaviour of pesticides. Water characteristics also vary and influence pesticide behaviour. Some of the characteristics are acidity, depth, temperature, clarity, flow rate, presence of biological organisms and general chemistry. Living organisms accumulate certain pesticides. Through the process of bioaccumulation, pesticides accumulate in lower organisms and are passed to higher organisms in the food chain when eaten. The higher organism will accumulate the pesticides at higher levels than their food source. ...read more.

Conclusion

In addition, children have not fully developed their body's defence systems against toxins. Their livers and kidneys, the organs that detoxify and excrete foreign substances, and act as barriers to absorption of toxic substances, have not fully developed. Exposure to pesticides can lead to an array of acute effects, depending on the pesticide's toxicity and the dose absorbed by the body. For pesticides with high acute toxicity, exposure can produce symptoms within minutes or hours, most of which diminish in time. These acute effects known as poisonings or intoxications run from mild headaches and flu-like symptoms, to skin rashes, to blurred vision, and other neurological disorders. The acute effects of pesticide exposure are relatively well understood, whereas much more uncertainty surrounds long-term or chronic effects, especially those believed to arise from low-level exposures to pesticide residues in food or water. There is little dispute regarding the nature of some chronic effects, such as those that follow high-dose exposures. Several studies have shown that many people who experience acute pesticide poisoning from organophosphates later suffer neurological damage. Symptoms of this problem include weakness, tingling, or even paralysis in the legs due to dieback of some nerve endings, and reduced memory and attentiveness. ...read more.

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