Temperature, moisture, soil type, microbial activity, oxygen concentration, sunlight, nitrification, and the amount of leaching all have an effect on the breakdown of pesticides in the soil (Extoxnet, 2000a). Rainfall patterns and the timing/intensity of irrigation in relation to high rainfall intensities will also influence herbicide movement in or from soil. Metolachlor is considered to be moderately persistent in different soil types (U. S. EPA, 1997), and has an average field dissipation half-life of 114 days (Kollman and Segawa, 2000).
In relation to high rainfall intensities, the patterns, timing and intensity of irrigation will also have an influence on the herbicide movement in or from soil. Metolachlor has an average field dissipation half-life of 114 days and is considered to be present in a number of different soil types (Kollman and Segawa, 2000). Metolachlor is considered to moderately adsorb to soil. The adsorption of the pesticide increases with increased soil organic matter and clay content, and can slow its movement in soil.
12 Due to the fact that Metolachlor is considered to have a moderate absorbency rate in soil, the rate of absorption of the pesticide will be greater if an increase in clay content and soil organic matter is present; it can also slow the movement in soil. This “chloroacetanilide herbicide first registered in the United States in 1976, is used for general weed control in many agricultural food and feed crops (mainly corn, soybeans and sorghum), turf and other residential applications”.
In 1976, this herbicide was officially registered in the United States for the use of general weed control in many types of agriculture, specifically corn, soybeans and sorghum. When absorbed through the roots and shoots just above the seed of the target weeds, it acts as a growth inhibitor by suppressing synthesis of chlorophyll, proteins, fatty acids and lipids, isoprenoids (including gibberellins), and flavonoids (including anthocyanins). Once absorbed through the roots, it travels just above the seed of the target weeds.
Acting as a growth inhibitor, it suppresses synthesis of chlorophyll, fatty acids, proteins, lipids, isoprenoids and flavornoids. Discussion came up that too much exposure of metolachlor to humans causes deadly diseases, such as cancer. Epidemiologic studies have provided information on the carcinogenicity of metolachlor in humans. Discussion has arisen that excessive Metolachlor exposure can cause deadly diseases such as cancer in humans. These epidemiologic studies have provided researchers with a great deal of information on the harmful of effects in humans.
Alavanja et al. 3, 4 investigated lung cancer risk3 and prostate cancer risk4 with respect to exposure to each of the 50 pesticides measured in the Agricultural Health Study (AHS), one of which was metolachlor. Alavanja studied the risks of lung and prostate cancer in regards of exposure to the number of pesticides that were measured in the Agricultural Health Study (AHS); among them was Metolachlor. An increased risk for lung cancer occurred among applicators reporting the use of metolachlor. No association was found for prostate cancer.
13 An experiment was tested to see if metolachlor can cause any type of chromosome damage. There has been an increased risk for lung cancer among people who report the use of Metolachlor; so far, there has been no association found with prostate cancer. An experiment was put in effect to see if Metolachlor has the ability to cause any type of chromosome damage. Chromosome analysis of human lymphocyte cultures exposed in vitro to the herbicides cyanazine or metolachlor demonstrated chromosome damage at concentrations which did not inhibit cell growth, 1 ? g/ml for cyanazine and 1 ? g/ml or 0. 1 ? g/ml for metolachlor.
14 Human lymphocyte cultures exposed to the herbicides cyanazine and Metolachlor in vitro, demonstrated chromosome damage at concentrations that did not inhibit cell growth under chromosome analysis. These findings were 1 ? g/ml for cyanazine and 1 ? g/ml or 0. 1 ? g/ml for metolachlor. 14 Another study was shown that discussed the contaminations of ground water samples. Ground water samples containing chloroacetanilide herbicides (Kalkhoff et al. , 1998) showed that ESA and OA degradates were present in almost 75% of the samples and were generally present 3-45 times more frequently than the parent compound.
Another study discussing the contaminations of ground water samples showed that samples containing chloroacetanilide herbicides showed the ESA and OA degradates were present in nearly 75 percent of them. These degradates were found to be present 3-45 times more often than the parent compound. In addition 1 or more of the chloroacetanilide degrades were present in 100% of the steam samples. The ESA & OA degradates were found 2 to more than 100 times more frequently than the parent herbicides. The degradates accounted for more than 80% of the measured concentration of chloroacetanilide compounds in surface water.
In addition to those findings, one or more of the chloroacetanilide degrades were present in 100 percent of the steam samples. The ESA and OA degradates were present two or more times more often that the parent herbicides. Over 80 percent of the chloroacetanilide compounds of measured concentration were accounted for by degrades present in water. These results demonstrate that the metolachlor ESA and OA degradates are frequently present in ground and surface water in substantial concentrations in the Midwest.
It also identifies the importance of quantifying both parent compounds and degradates to fully understand the environment fate and transport of herbicides in the hydrologic system. 12 These results were able to identify the importance of taking into consideration both the parent compounds and degradates in oreder to completely understand the effects they have on the environment as well as the ways in which these herbicides are transported in the hydrologic system. It was also found that these results were able to demonstrate how often the Metolachlor ESA and OA degradates are present in ground and surface water throughout the Midwest.
Metolachlor is a pre-emergent herbicide that is used to control certain broadleaf weed species, and annual grassy weeds (yellow nutsedge (Cyperus esculentus), barnyard grass (Echinochloa crusgalli), crabgrass (Digitaria spp. ), fall panicum (Panicum dichotomiflorum), and foxtails (Setaria spp. ). Metolachlor is primarily used on corn, soybean, peanuts, sorghum, potatoes, cotton, safflower, and woody ornaments (Extoxnet, 2000b). 12 Because Metolachlor is a pre-emergent herbicide, it is very useful when it comes to controlling a number of broadleaf weed species, annual grass weeds, barnyard grass, crabgrass, fall panicum, and foxtails.
Metolachlor is primary used of crops such as corn, soybean, sorghum, potatoes, cotton, safflower, woody ornaments, as well as peanuts. Metolachlor has a very high potential to contaminate ground water since it is relatively mobile and persistent in soil. 12 This is a major issue and can cause extreme illnesses if the amount of metolachlor exceeds the drinking limit. The drinking limit for metolachlor is 0. 525 mg/L 12. Due to the fact that it is relatively mobile and persistent in soil, there is no surprise that Metolachlor has a very high potential to contaminate ground water.
This major issue has the ability to cause extreme illness if a person exceeds the 0. 525 mg/L drinking limit that is set on Metolachlor. Very little of the pesticide is accumulated, and it is excreted rapidly when the fish are placed in clean water. Since residues found in fish are low it is not considered to pose a threat to human health (Extoxnet, 2000a). 12 When the fish are placed in clean water, very little amounts of the pesticide are accumulated and are excreted rather quickly. This presence of pesticide is not considered to pose a threat to human life because the residues in fish are found to be so low.