Atrazine States

Triazines pose rather more of a problem, probably because the carbons are in an effectively oxidized state so that no metaboHc energy is obtained by their metaboHsm. Very few pure cultures of microorganisms are able to degrade triazines such as Atrazine, although some Pseudomonads are able to use the compound as sole source of nitrogen in the presence of citrate or other simple carbon substrates. The initial reactions seem to be the removal of the ethyl or isopropyl substituents on the ring (41), followed by complete mineralization of the triazine ring. 

More controversially, endocrine disruption as a consequence of exposure to the herbicide atrazine (2-chloro-4-ethylamine-6-isopropylamine-s-triazine), one of the most widely used herbicides in the world, has also been hypothesized to explain various adverse biological effects in frog populations in the United States. Exposure to atrazine in the laboratory at high concentrations, far exceeding those found in the natural environment, has been reported to induce external deformities in the anuran species Rana pipiens, Rana sylvatica, and Bufo americanus (Allran and Karasov 2001). Studies by Hayes et al. have suggested that atrazine can induce hermaphroditism in amphibians at environmentally relevant concentrations (Hayes et al. 2002 Hayes et al. 2003). Laboratory studies with atrazine also indicated the herbicide... 

Hayes, T.B., Collins, A., and Lee, M. et al. (2002). Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses. Proceedings of the National Academy of Sciences of the United States of America 99, 5476-5480. 

A direct assessment of multimedia behavior is thus possible by examining the proportions of chemical found at steady state in the source medium and in other media. For example, when discharged to water, an appreciable fraction of the benzene is found in air, whereas for atrazine, only a negligible fraction of atrazine reaches air. 

Although annual use of atrazine in the United States is about 35 million kg (Alvord and Kadlec 1996 Carder and Hoagland 1998), atrazine concentrations in human foods are negligible. Monitoring of domestic and imported foods in the human diet by the U.S. Food and Drug Administration between 1978 and 1982 showed that only 3 of 4500 samples analyzed had detectable atrazine residues. Two samples in 1980 contained 0.01 and 0.08 mg atrazine/kg and one in 1978, following a known contamination incident, contained 47 mg/kg (Reed 1982). 

DeNoyelles, F., W.D. Kettle, and D.E. Sinn. 1982. The responses of plankton communities in experimental ponds to atrazine, the most heavily used pesticide in the United States. Ecology 63 1285-1293. 

Mitchell, C.A. 1985. Effects of Atrazine on Halodule wrightii Ascherson in the Laboratory. M.S. Thesis. Corpus Christi State Univ., Corpus Christi, TX. 82 pp. 

In the United States, about 80% of the 23 million kg of technical PCP produced annually — or about 46% of worldwide production — is used mainly for wood preservation, especially utility poles (Pignatello etal. 1983 Kinzell etal. 1985 Zischke etal. 1985 Choudhury etal. 1986 Mikesell and Boyd 1986 USPHS 1994). It is the third most heavily used pesticide, preceded only by the herbicides atrazine and alachlor (Kinzell et al. 1981). Pentachlorophenol is a restricted-use pesticide and is no longer available for home use (USPHS 1994). Before it became a restricted-use pesticide, annual environmental releases of PCP from production and use were 0.6 million kg to the atmosphere from wood preservation plants and cooling towers, 0.9 million kg to land from wood preservation use, and 17,000 kg to aquatic ecosystems in runoff waters of wood treatment plants (USPHS 1994). There are about 470 wood preservative facilities in the United States, scattered among 45 states. They are concentrated in the South, Southeast, and Northwest — presumably due to the availability of preferred timber species in those regions (Cirelli 1978). Livestock facilities are often constructed of wood treated with technical PCP about 50% of all dairy farms in Michigan used PCP-treated wood in the construction of various components of livestock facilities (Kinzell et al. 1985). The chemical is usually applied to wood products after dilution to 5% with solvents such as mineral spirits, No. 2 fuel oil, or kerosene. More than 98% of all wood processed is treated with preservative under pressure about 0.23 kg of PCP is needed to preserve 1 cubic foot of wood (Cirelli 1978). Lumber treated with PCP retains its natural appearance, has little or no odor, and can be painted as readily as natural wood (Wood et al. 1983). 

Left, Charlie Focht of the Nebraska State Agriculture Laboratory prepares the mobile phase for an atrazine assay. Note that the vacuum flask is positioned in an ultrasonic cleaner bath. Simultaneous vacuum filtration and sonication provide a more efficient means for degassing. Right, Charlie adjusts the flow rate setting on the HPLC pump. 

Several hundred-pesticide compounds of diverse chemical structures are widely used in the United States and Europe for agricultural and non-agricultural purposes (Fig. 10). Some are substitutes for organochlorines, which were banned due to their toxicity, persistence, and bioaccumulation in environmental matrices. According to a report published by the US-EPA, a total of 500,000 tons of pesticides was used in 1985 [144, 145, 148]. As far as specific pesticides are concerned, worldwide consumption of Malathion and Atrazine in 1980 amounted to 24,000 and 90,000 tons, respectively [149,150]. In the Mediterranean countries, 2100 tons of Malathion (active ingredient) were sprayed during the same period compared to 9700 tons in Asia [150]. 

Atrazine, one of the herbicides most widely used in the United States and European countries over the last 30 years, is employed for pre- and post-emergence weed control on corn, wheat, barley, and sorghum fields, and on railway... 

Outside Spain, the profile of pesticide contamination is fairly similar. For instance, Kolpin et al. [28] analysed pesticides in groundwater samples from the United States and found, in samples taken in 2001, triazine concentrations between 50 and 620 ng/L. In groundwater samples collected in Portugal between 2005 and 2008, atrazine and terbuthylazine were also detected [16]. 

Studies were initiated at Iowa State University in 1977 to determine if pesticides would be contained and degraded when deposited in water/soil systems. Although the addition of known amounts of the selected pesticides was controlled, the physical environment was not temperature, humidity, wind speed, etc. were normal for the climate of Central Iowa. Four herbicides and two insecticides were chosen on the basis of three factors. Firstly, they represented six different families of pesticides. The four herbicides, alachlor, atrazine, trifluralin, and 2,4-D ester, represent the acetanilides, triazines, dinitroanilines, and phenoxy acid herbicides, respectively. The two insecticides, carbaryl and para-thion, represent the carbamate and organophosphorus insecticides, respectively. Secondly, the pesticides were chosen on the basis of current and projected use in Iowa Q) and the Midwest. Thirdly, the chosen pesticides were ones for which analytical methodology was available. 

Atrazine was not carcinogenic to mice or Fischer rats after oral administration in the diet. An increase incidence of mammary tumors has been found in female Sprague-Dawley females treated similarly. The lARC has determined that the mammary tumors associated with atrazine exposure involve a mechanism that is non-DNA-reactive and hormonally mediated. They further stated that this mechanism is not relevant to humans. The lARC concluded that there was sufficient evidence for the carcinogenicity of atrazine in experimental animals and inadequate evidence of carcinogenicity in humans. ... 

Atrazine, a triazlne compound, is extensively used as a selective herbicide on corn and sorghum fields for the control of broadleaf and grassy weeds. Depending on soil properties and climatic effects, its persistence from recommended application rates in north central states may extend well beyond one year and crop injury may result when sensitive species are in the rotation (50). 

Su, P.-H. 1994. Sorption studies of atrazine using continuous stirred-flow and batch techniques. Master s thesis. Utah State University, Logan, UT. 

The use volumes in the United States by major crops are shown in Figure 1.4 for atrazine and Figure 1.5 for simazine. 

Figure 1.4 Average atrazine use by crop in the United States for 2000-2002 (Doane Marketing Research, Inc.).

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