Environmental fate studies

The group of tests that must be performed for each pesticide depends on how that pesticide is to be used. For example, if a pesticide is not used on food or feed crops, extensive residue and metaboHsm tests in plants and domestic animals might not be required. Similarly, if a pesticide is not used in field crops nor on other extensive outdoor areas, aH the environmental fate studies might not be required. 

Table 1 Analytical parameters of pre-registration and post-registration pesticide environmental fate studies...

Studies conducted in the laboratory provide fundamental data on processes by which a pesticide is degraded and on its mobility. In combination with field observations, which integrate multiple processes, these data describe a pesticide s environmental fate. This section provides a discussion of several important specific analytical issues which should be considered in the design of environmental fate studies to ensure that the data generated address the needs of scientists and regulatory agencies for information on the environmental fate and environmental and ecological impacts of a pesticide to the fullest extent. 

The fundamental issue is to describe how much of the residue can be characterized accurately and whether an accounting of the applied mass of pesticide can be maintained throughout the course of the experiment. A series of environmental fate studies is required for pesticide registration in order to characterize the degradation pathways and formation and decline patterns of each major degradate. These studies are typically conducted in the laboratory under controlled conditions, applying radiolabeled pesticides to evaluate the extraction efficiency of various procedures. When standard extraction methods fail to release a significant amount of the applied radioactivity, more efficient and exhaustive extraction procedures are tried in a stepwise fashion... 

Critical information required at each sampling. The following information must be recorded for an environmental fate study in a paddy fleld ... 

No information was found on the transformation of diisopropyl methylphosphonate in the atmosphere. Based on the results of environmental fate studies of diisopropyl methylphosphonate in distilled water and natural water, photolysis (either direct or indirect) is not important in the transformation of diisopropyl methylphosphonate in aquatic systems (Spanggord et al. 1979). The ultraviolet and infrared laser-induced photodegradation of diisopropyl methylphosphonate in both the vapor or liquid phase has been demonstrated (Radziemski 1981). Light hydrocarbon gases were the principal decomposition products. Hydrogen, carbon monoxide (CO), carbon dioxide (C02), and water were also detected. 

Spanggord, R.J. Mill, T. Chou, T.-W. Mabey, W.R. Smith, J.H. Lee, S. "Environmental Fate Studies on Certain Munition Wastewater Constituents," Final Report, Phase I -Literature Review, Contract No. DAMD 17-78-C-8081, SRI International, Menlo Park, CA, 1980. 

Ag incorporation into the textile. The percentage of the total silver emitted during one washing of the textiles varied considerably among products (from <1 to 45%). In the washing machine, the majority of the Ag (at least 50% but mostly >75%) was released in the size fraction >450 nm, indicating the dominant role of mechanical stress (Figure 8.3). These results have important implications for the risk assessment of Ag textiles and also for environmental fate studies of nano-Ag, because they show that... 

Spanggord, R. J., Mabey, W. R., Mill, T., Chou, T.-W., Smith, J. H., Lee, S. and Roberts, D., Environmental fate studies on certain ammunition wastewater constituents Phase IV. Lagoon Model Studies , Report AD-A138550, US Army Medical Research and Development Command, Fort Detrick, Frederick, MD, 1984. 

Another major type of raw data is samples. These are mainly retained aliquots of test chemicals and the biological samples generated in field residue trials, metabolism studies, and environmental fate studies. The chemical samples are to be archived... 

The purpose of this paper is to describe the GLP compliance system developed for the Residue Chemistry Field Trials Program at ICI Americas Inc. This program covers crop residue and environmental fate studies. 

Environmental Fate. Studies of releases of radium that result from uranium mining and processing would be helpful to fully assess the total amount and environmental fate of radium released to the environment. Field data on the mobility of radium in groundwater would also be helpful in attempts to predict its potential for occurrence in sources of drinking water at remote sites. 

---