Exposure detection, pesticides

In this study a series of surface water and deep soil samples were analyzed to detect ai migration or runoff of waste pesticides from typical Chemical Control Centers. Entomological evaluation of soil biota and monitoring of dermal exposure to pesticides of mlxer-appllcators took place throughout the 1980 season. No adverse effects as a result of the Chemical Control Centers were detected. 

While the depression of plasma and/or RBC cholinesterase may be detected after exposure to very large amounts of carbamates, enzyme activity usually recovers rapidly--within minutes to hours. Hence these tests can be misleading unless one of the rapid methods for testing cholinesterase activity has been employed. A more sensitive and specific absorption test for several of the carbamate pesticides is the measurement of their metabolites in the urine within 48 hours of exposure. Carbamate pesticides are sufficiently acutely toxic that those attending the victim must avoid contact with contaminated apparel or vomitus, and should wear rubber gloves during decontamination of hair and skin of the victim. 

Liver failure from acute exposures to pesticides is rare as lethality usually results from toxicity to other organ systems. Fatty liver, centrilbular necrosis, and cholestasis with destruction of bile duct epithelia have resulted from exposure to the herbicide paraquat and elevated serum enzymes have been detected in workers employed in... 

Wilson, B.W., Arrieta, D.E., Henderson, J.D. (2005). Monitoring cholinesterases to detect pesticide exposure. Chem. Biol. Interact. 157-8 253-6. 

Georgellis A, Kolmodin-Hedman B, Kouretas D. Can traditional epidemiol ogy detect cancer risks caused by occupational exposure to pesticides J Exp Clin Cancer Res 1999 18(2) 159—66. 

Exposure to pesticides may occur in a variety of different ways including worker exposure during manufacture, during transport, and exposure to residues in edible crops, soil and water. Adverse effects on man may result from the compound itself, its mammalian metabolites, plant and soil metabolites or, possibly, from breakdown products in the environment. Pesticides are often dispersed widely in the environment as stable materials, such as DDT, which may remain as virtually permanent contaminants, though at detectable concentrations. This, together with the fact that pesticides are highly biologically-active molecules, requires a fine balance to be set between the benefits of pesticides and their possible hazard to man or the environment. 

The feasibility of employing fluorescent tracers and video imaging analysis to quantify dermal exposure to pesticide applicators has been demonstrated under realistic field conditions. Six workers loaded a tracer with the organophosphate pesticide, diazinon, into air blast sprayers, and conducted normal dormant spraying in pear orchards. They were examined prior to and immediately after the application. UV-A illumination produced fluorescence on the skin surface, and the pattern of exposure was digitized with a video imaging system. Quantifiable levels of tracer were detected beneath cotton coveralls on five workers. The distribution of exposure over the body surface varied widely due to differences in protective clothing use, work practices and environmental conditions. This assessment method produced exposure values at variance with those calculated by the traditional patch technique. 

In most of developed countries, programs to monitor the presence of pesticides in the environment are being carried out, dealing with air, water and soil contamination. These programs detect exposures to pesticides or other chemicals that are likely to cause disease. The goal for public health agencies is to obtain the amounts of these pesticides that are to be found in the population [21]. 

The air and dust concentrations for the five most frequently detected pesticides in 18 homes showed significant correlations ranging from r =. 63 to r =. 88 (Camann et al. 1991, 1993). However, in a Florida study 13 pesticides were found in dust in nine homes when these same pesticides could not be detected in the air (Budd et al. 1990). These pesticides and PAHs in rug dust may result from carry-home from a job or other sources away from the home. Carpet dust may, therefore, be a broader indicator of a child s exposure for some pesticides, PAHs, and other toxicants than indoor air, outdoor air, or soil samples. 

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