Excessive use of pesticides - Essay Example

Excessive use of Pesticides A pesticide is a substance or mixture of substances which is used to prevent or control or reduce the damage caused by apest. This substance could a chemical one, a biological agent, an antimicrobial, a disinfectant or a even a device which can be used against any pest to eliminate or reduce its damage. A pest is the name given to any insect, plant, weeds, birds, fish, roundworms and microbes which compete with humans for food; they may destroy property, may spread a disease or act as a vector for disease (http://en.wikipedia.org/wiki/Pesticidea). Types of Pesticide Solid: This type includes a solid carrier, a pesticide and an amount of flour and/or starch to promote the dispersion of the pesticide into the wax. The solid carrier includes paraffin oil, paraffin wax and microcrystalline wax. A solid pesticide composition is provided without having to include a chemical surfactant (http://www.epa.gov/opp00001/about/types.htm). Liquid: These chemicals can be classified in a variety of ways; the two most common major classes are (http://en.wikipedia.org/wiki/Pesticide): Based on the choice of killing a pest, like: algaecides, bactericides, fungicides, nematicides, herbicides, and nematicides. Some pesticides have been given the name of broad spectrum pesticides which can damage a number of pests as compared to the narrow-spectrum pesticides which are selective in damaging the specific types of pests. Based on the composition as, synthetic or biopesticides (biological pesticides). Some of the most commonly used pesticides are ((http://en.wikipedia.org/wiki/Pesticidea): Organochlorine (Chlorinated hydrocarbons), Organophosphate, Carbamate, Phenoxy, Trazine, Amide, Benzimidazole, Benzonitrile, Dinitroaniline, Phathalate, Pyrethroid, Thiocarbamate, Triazole, Pyrethrum, Rotenone, Ryania, and Sabadilla. These substances have different modes of action which are common among some groups ((http://en.wikipedia.org/wiki/Pesticidea). Inhibits acetocholinesterase and damages nerve function; Act as synthetic growth hormones in plants; in animals it is poorly understood; May disturb the metabolism of vitamins and interferes with cellular respiration; Uncoupling of oxydative phosphorylation and inhibition of electron transport, with inhibition of some enzymes; Interfere with cell respiration; Inhibit sodium and potassium conduction in nerve cells and block nerve impulse transmission; Inhibits acetaldehyde dehydrogenase, which is essential in conversion of acetaldehyde to acetic acid; Inhibition of liver enzymes; Blocks nerve impulse transmission; and Inhibits cell respiration and blocks conduction of nerve impulses. Effects of pesticides on human and environment Immediate effects Skin, mucous membrane, sensory and behavioral, depressed motor functions, motor weakness, vomiting and diarrhea; Long term effects Memory loss, confusion, behavioral defects, carcinogens, cataract, bone marrow, liver and testicular damage, heart, immunotoxins; Environment effects Teratogen to fish, earthworms, bees, aquatic arthropods. Why and when pesticides become toxic Human beings use antibiotics to kill microorganisms; in a similar manner pesticides are used to kill insects, fungi and other pests which damage human food. Antibiotics, utilized by humans also produce side effects; in a similar way pesticides also produce some side effects. There is difference in the two; side effects of the antibiotics are usually experienced by those who take these antibiotics while the side effects of the pesticides affect the environment as they are distributed widely in the air, most of the time. To inform the public and an ordinary citizen about the level of danger potentially existing in some of the chemicals and especially pesticides, the US Environment Protection Agency (EPA) provides guidance. The agency places a label which carries information related to the danger present. The level ranges from caution to warning to danger; caution means the lowest level of threat of poison (toxicity category I), warning is mild level of threat (toxicity category II) and the danger points towards the high level of threat (toxicity category III and IV) when the poison is either eaten, applied to skin or inhaled. The assessment of risk, due to the pesticides, can be carried out based on the guidelines provided by the EPA. Risk assessment (http://www.epa.gov/ncea/risk/basicinformation.htm#arisk) Step One: Hazard Identification (Toxicology) Health is at risk due to different types of exposures. At the outset, the potential health effects are identified which may occur as a result of pesticide exposure. The range of adverse effects is wide, from as simple as skin or eye irritation to birth defects or cancer in laboratory animals; EPA assesses the effects of pesticides on animals. Step Two: Dose-Response Assessment The effect of any pesticide is determined by the quantity or the dose of the pesticide which when applied to the human being then how will human being react This is again performed in laboratory animals and based on the findings estimation is done for human beings about the dose of a pesticide. Step Three: Exposure Assessment A person can be exposed to a pesticide through one or more of the following routes: Inhalational; Dermal; and Oral In majority of the cases, this exposure occurs when some one eats contaminated food; the food items, like: vegetables or fruits which are grown by the intervention of pesticides may be one of these exposures. While these pesticides are under use in farm, they can go down to the earth and get absorbed in the water which is eventually used for drinking and or cooking purposes At times, these chemical are use din the house as well for the control of weeds, molds and other insects; usually, this happens in the lawns and small gardens alongside the houses. Exposure to the workers who are involved in the handling of pesticides can take place at the work place. They may be at the original place of production, or transportation of pesticides or by the terminal user of these chemicals, usually the farmers in the fields. There are strict instructions for the use of these chemicals in the lawns and other purposes. It is very important for the uses to observe these instructions. Step Four: Risk Characterization Finally, risk characterization is carried out in the process of the assessment of human health risks which can occur from pesticides. At this step, actually, all the previous steps, hazard; dose-response and exposure, are combined to determine the final effect. In fact, this is the cumulative effect of all three steps. It can also be presented through an equation: RISK = TOXICITY x EXPOSURE. Risk Management (http://www.epa.gov/ncea/risk/basicinformation.htm#a1) The information produced after the health risk assessment, then it is utilized in the process of making decision about the level of toxicity or danger a pesticide can produce. Based on this judgment and decision, the specific label is applied. The process further goes on when decisions are made about the approval of the pesticide to be used or not; if used how much additional protection is required. One case could be when the US EPA stops the use of a pesticide on some crops as this may indirectly pose danger to human life if that food is consumed with excessive pesticide cover. The other way could be to prevent exposure to the workers as much as possible; this could be in the form of wearing personal protective equipment (PPE) such as or prohibiting the entrance to danger zone till that is declared as no more dangerous. Even in the situation when risk still exists after all preventive and protective measures, and EPA is not satisfied about the safety then it may decide in not using that pesticide. In fact, the first objective of the agency is to keep the environment as beneficial as possible for the health of the human specifically the children as possible. The exposure to pesticides may result in some morbid conditions which may range from mild allergic reactions which may get prolonged (Hoppin et al, 2008) to some real long term problems, either in the shape of some cancers (Baris et al, 2004) or when a pregnant woman gets exposed to these chemicals then even the developing fetus faces a greater risk (Arbuckle, Lind & Mary, 2001). In a case control study carried out by Hoppin et al to compare the effect of pesticides on women with two different types of asthma, atopic and non atopic (2008). They found that those women who had grown up in the farm had stronger association with pesticides. This association was found for atopic asthma while those women who did not apply these pesticides or not grown up in the farm were not found to be associated with atopic asthma. Arbuckle and colleagues followed up more than two thousand women in a prospective study to assess the effects of these chemicals on the pregnant women (2001). It was found that exposure to various types of pesticides before pregnancy or during the firs trimester of pregnancy resulted in early as well as late abortions. In another population based case control study concluded that the farm workers who used pesticides were at moderately increased risk of developing multiple myeloma (Baris et al, 2004). Summary There is variety of pesticides available in the market. The sole purpose of their use is to control different types of insects, weeds, pests and molds wither in and around houses (the lawns, small gardens) or in the farm which is the largest use. They act like antibiotics in human but their side effects are wide spread as their use is not localized because they affect the surrounding environment to a greater extent. The US EPA regulates the use of pesticides along with other chemicals. The same agency also determines the risk a specific chemical can produce to a human body. This risk may occur to the occasional users in the houses or frequent users in the farms. This risk may range from a simple allergic episode to spontaneous abortions in pregnant women or cancer. Reference list: Arbuckle TE, Lin Z, Mery LS. (2001). An exploratory analysis of the effect of pesticide exposure on the risk of spontaneous abortion in an Ontario farm population. Environ Health Perspect. 109(8):851-7. Baris D, Silverman DT, Brown LM, Swanson GM, Hayes RB, Schwartz AG, Liff JM, Schoenberg JB, Pottern LM, Greenberg RS, Stewart PA. (2004). Occupation, pesticide exposure and risk of multiple myeloma. Scand J Work Environ Health. 30(3):215-22. Hoppin JA, Umbach DM, London SJ, Henneberger PK, Kullman GJ, Alavanja MC, Sandler DP. (2008). Pesticides and atopic and nonatopic asthma among farm women in the Agricultural Health Study. Am J Respir Crit Care Med. 177(1):11-8. Pesticide, accessed from http://en.wikipedia.org/wiki/Pesticide on April 21, 2008. Risk assessment http://www.epa.gov/ncea/risk/basicinformation.htm#arisk on April 21,2008. Types of pesticides, accessed from http://www.epa.gov/opp00001/about/types.htm on April 21,2008. Read More