Pesticides types

Pesticide type H = herbicide I = insecticide SF = soil fumigate F = fungicide and N = nematicide. 

On the whole, 68.7% of 262 types of agricultural and food products that were studied in the USSR in 1988 were contaminated by pesticides in unacceptable quantities. The basic pesticide types led the list OCPs such as DDT (38.8% of 250 types of products studied) and HCH 37.3% of 255 products), OPPs such as methyl parathion (26.5% of 170 products) and trichlorfon (28.4% of 236 products), 2,4-D (43.8% of 144 products), and OMPs (31.0% of 129 products). 

Substance group CAS GUS Introduction Pesticide type Description... 

Fig. 4.1 Annual amount of pesticide active ingredients used in the U.S.A., by pesticide type, from 1982 to 2001 estimates are for aU market sectors (Kiely et al. 2004)...

The hydrolysis of pesticides which are sorbed to sterilized natural sediments has been investigated in aqueous systems at acid, neutral and alkaline pH s. The results show that the rate constants of pH independent ("neutral") hydrolyses are the same within experimental uncertainties as the corresponding rate constants for dissolved aqueous phase pesticides. Base-catalyzed rates, on the other hand, are substantially retarded by sorption and acid-catalyzed rates are substantially enhanced. A large body of evidence will be presented which substantiates these conclusions for a variety of pesticide types sorbed to several well-characterized sediments. The significance of our results for the evaluation of the effects of sorption on the degradation of pesticides in waste treatment systems and natural water bodies will also be discussed. 

The origin, composition, and chemical properties of HAs appear to have a smaller effect than the pesticide type on the extent of adsorption. However, the extent of pesticide adsorption by organic amendment HAs differs from that of soil HAs, and it varies depending on the type of pesticide. The same is true for amended soil HAs when compared to unamended soil HAs. In particular, HAs from sewage sludges show a smaller capacity to adsorb imazethapyr and rimsulfuron than do unamended soil HAs, whereas contrasting results are obtained for alachlor (Table 4.6). Pig slurry HA is less effective than any soil HA in adsorption of trans- and dx-chlordane, whereas the adsorption capacity of this HA for triallate is from about two to four times larger than that of soil HAs (Table 4.7). Similarly, results of Simpson et al. 

A clear and concise description should be provided on relevant human activities in the study area. These should include dams, drainage channels, recharge installations, sewage ponds, industrial effluent ponds, fluid waste disposal installations, pumped well fields, and the nature and extent of agricultural activity, including irrigation schemes and the use of fertilizers (types, quantities) and pesticides (types, quantities). Part of the information may be abstracted from detailed maps, but most information has to be obtained directly from local authorities, farmers, and industry. 

As Table I illustrates, the chemical classes represented by the pesticides studied include thiophosphates [0,0-diethyl-o-p-nitrophenyl phos-phorothioate], carbamates [1-naphthyI-N-methylcarbamate], dinitrophe-nols [2,4-dinitro-o-sec-butylphenol and 2,4-dinitro-o-cyclohexylphenol], and chlorophenoxy acids [2,4-dichlorophenoxyacetic acid, 2,4,5-trichloro-phenoxyacetic acid, and 2-(2,4,5-trichlorophenoxy)propionic acid]. In addition, a number of molecularly related nitrophenols have been studied to establish the effects of molecular geometry and substituent groups on adsorption of pesticide-type materials. 

Following is a representative profile list of the different chemical classes of pesticides, their modes of absorption, toxicities to humans, symptoms of exposure, pesticide uses, and exemplar compounds. The pesticide profiles presented here are for those pesticides that are discussed in the remainder of this chapter. For a more extensive list of pesticide types, including brand names and their toxicities, the reader is referred to the literature.F 5l... 

Since triazines are very mobile in the aquatic environment, the presence of these pesticide types in groundwater samples could be confirmed. Pollution was observed when neutral pesticides contained in shallow groundwater samples from two sandy and two clay catchment areas were analysed in APCI mode [351]. The most frequently (> 300 samples) determined compound was atrazine with its degradation products. 

Pesticides Type of Water Technique Technique Reagent Technique Stationary Phase Figures of Merit References... 

Annual User Expenditures on Pesticides in the U.S. by Pesticide Type, 1982 - 2001 Estimates, All Market Sectors US EPA 2001. 

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