Pesticides quantities

Ostatochnoye soderzhaniye pestitsidov v produktakh pitaniya (Residual Pesticide Quantities in Food Products) / Ed..A.I. Shtenberg. Moscow Meditsina, 1973. 200 pp. 

From these data on pesticide usage, the environmental effects associated with adoption of GM crops will be assessed both qualitatively and quantitatively. Qualitatively, the impact will be predicted based on, for example, properties of pesticides, quantities of applied pesticides, times of application, pest characteristics, and geographic conditions. Subsequently, the quantitative assessment will employ methods such as environmental indicators that allow for a comparison of the environmental impacts of different pesticide regimes. The enviroiunental impact may also cover other important parameters associated with altered agronomic practices under GM crop cultivation, such as tillage practices and farmland biodiversity. 

Pesticide Quantity Used on Crop Small Com Soybeans Grains Alfalfa Hay... 

Between 1979 and 1991, the amounts of herbicide apphed in the United States have remained constant, but the expenditures on herbicides have increased 54%. Agricultural costs accounted for ah. of this increase and more, since herbicide user expenditures in the government/commercial and home sectors combined dropped 3 to 4% during that period. Increased weed control costs related to crop protection have also contributed to the 37% increase, since 1988, in total annual user expenditures for pesticides in general, ie, herbicides, fungicides, and insecticides. In the United States, agricultural uses (ca 1993) account for more than 67% of total pesticide user expenses and 75% of the quantity used annually. Herbicides are now the lea ding type of pesticides in terms of both user expenditures and volumes used (1). 

Isopropjiamine is the most widely used of the propylamines. Most of it is consumed ia herbicide manufacture, primarily ia productioa of 2-chloro-4-ethyl-6-isopropylamiao-yy -tria2iae. A smaller quantity is used for pesticide manufacture (40,44). Diisopropylamine is used chiefly ia pesticides (qv) and as a corrosion inhibitor, eg, diisopropylammonium nitrate (see Corrosion and corrosion control) (44,45). 

Table 2. Quantities of Pesticides Most Commonly Used in U.S. Agricultural Crop Production in 1995 ...

Mono- and dichlorotoluenes ate used chiefly as chemical iatermediates ia the manufacture of pesticides, dyestuffs, pharmaceuticals, and peroxides, and as solvents. Total annual production was limited prior to 1960 but has expanded greatly siace that time. Chlorinated toluenes ate produced ia the United States, Germany, Japan, and Italy. Siace the number of manufacturers is small and much of the production is utilised captively, statistics covering production quantities ate not available. Worldwide annual production of o- and -chlorotoluene is estimated at several tens of thousands of metric tons. Yearly productions of polychlorotoluene ate ia the range of 100—1000 tons. 

AC filtration does remove some organic chemicals that can be harmful if present in quantities above the EPA Health Advisory Level (HAL). Included in this category are trihalomethanes (THM), pesticides, industrial solvents (halogenated... 

Cosmetic Standards. Over the last two decades, the U.S. Food and Drug Administration (FDA) has been lowering the tolerance levels for Insects and insect parts allowed in and on fresh and processed foods (14). Concurrently consumers have sought "more perfect," pest-free produce. To achieve this, farmers have Increased the quantities of pesticide they applied to crops. Although the presence of small amounts of insect parts in such products as catsup and apple sauce, or blemishes on oranges pose no health risk, these stringent standards have stood for many years. 

Spills of endosulfan, according to FAOAVHO (1975a), should be cleaned up by first washing with 5% sodium hydroxide solution and then rinsing with large quantities of water. In addition, empty containers that held endosulfan residues should be rinsed two or three times with water while the sides are scrubbed, and once with 5% sodium hydroxide solution. Thus decontaminated, the empty containers can be recycled and used by pesticide manufacturers to package a chemical similar to endosulfan if the containers remain in good condition and if such reuse is not prohibited by federal, state, or local laws. 

The biological activity of several halogenated herbicides in water is destroyed by ultraviolet irradiation (18). Irradiation seems to be a promising method for decontaminating small quantities of pesticides. The chemical similarity between the chlorinated dioxins and other chlo-rinted aromatic compounds suggested that if there were parallels in their photochemical behavior, sunlight might destroy dioxins in the environment. 

It would be diflBcult to estimate the quantity of TGDD which enters the environment each year. In addition to the common pesticides listed in Table I, other chlorophenols nd their derivatives are used widely. For example, large amounts of the disinfectant, hexachlorophene (2,2 -methylenebis(3,4,6-trichlorophenol)), are used in homes, hospitals, and industry, and the Dowcides 2 and B (2,4,5-trichlorophenol and its sodium salt) are industrial microbiocides. More than 50,000,000 lbs of trichloro-phenol are made in the United States each year (24), and much of it eventually must be dispersed in the environment. The dioxin content seems to be variable but is generally below 0.5 ppm (25). 

Substances hazardous to health include substances labelled as dangerous (i.e. very toxic, toxic, harmful, irritant or corrosive) under any other statutory requirements, agricultural pesticides and other chemicals used on farms, and substances with occupational exposure limits. They include harmful micro-organisms and substantial quantities of dust. Indeed any material, mixture or compound used at work, or arising from work activities, which can harm people s health is apparently covered. 

In recent years greater attention has been given to nitrogen containing pesticides and the possibility of their nitrosation in soil. The N-nitrosamines that form may arise from the parent pesticide or from a pesticide metabolite. The reaction calls for favourable pH conditions (pH 3-4) and excess nitrite. Under field conditions, the nitrosable residues are usually present in traces and only small quantities of these will actually be nitrosated in soils. However, the possibility exists that the small amounts of N-nitrosamines could be assimilated by plants. 

Chemically, nitrosamines are considered to be quite stable compounds and are difficult to destroy cmce they are formed. Reducing or destroying preformed nitrosamines in pesticides offers special challenge, as they occur in trace amounts which require specific selective treatment without effecting the composition of the principal product. Experimental laboratory work revealed that reactions suitable for mass quantities of reactants, that is neat samples, are not necessarily analagous to micro reactions for the reduction of a given trace nitrosamine contaminant or impurity. 

A method for determining the LOD and LOQ for water samples was proposed by the US EPA. This method has also been discussed by Roy-Keith Smith in his book titled Handbook of Environmental Analysis .The method has also been proposed by the US EPA in their guidelines for Assigning Values to Non-detected/Non-quantitied Pesticide Residues in Human Health Pood Exposure Assessments . ... 

Applicators, mixers, loaders, and others who mix, spray, or apply pesticides to crops face potential dermal and/or inhalation exposure when handling bulk quantities of the formulated active ingredients. Although the exposure periods are short and occur only a few times annually, an estimate of this exposure can be obtained by quantifying the excreted polar urinary metabolites. Atrazine is the most studied triazine for potential human exposure purposes, and, therefore, most of the reported methods address the determination of atrazine or atrazine and its metabolites in urine. To a lesser extent, methods are also reported for the analysis of atrazine in blood plasma and serum. 

The quantity of QC samples to be collected is dependent on the study design, but Aeld blanks and held replicates should represent approximately 5-10% of the groundwater samples collected for the study. QC samples should be collected on the same day, using the same supplies and equipment, and be stored and shipped under the same conditions as the groundwater samples collected for pesticide analysis. Document all procedures, equipment, and reference chemicals used to generate the QC samples. 

The test substance may be acquired in a number of ways. One common method is to purchase the product from a chemical dealer. This method of acquiring the test substance for a worker exposure or re-entry study allows one to proceed rapidly with the execution of the field portion of the study without the serious delays encountered while waiting for a test substance to be manufactured, assayed, and shipped to the site. Although having a test substance formulation which has been assayed under GLP standards and for which a certificate of analysis has been shipped to the test site is desirable, there are several instances when this is not practical. For example, one may encounter a worker exposure study where the pesticide to be evaluated is sold only in mini-bulk or even large bulk quantities holding as much as 2000 gal. In this case, duplicate 5-10-g or 5-10-mL retainer samples should be taken from the bulk or mini-bulk tanks for assay after the worker exposure study is in progress. 

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