Pesticides worker risks

Spittler, T. D. Bourke, J. B. in "Risk Determination for Agricultural Pesticide Workers from Dermal Exposure" Honeycutt, R. C., Ed. ACS SYMPOSIUM SERIES, American Chemical Society Washington, D.C., in preparation. 

If the estimated level of exposure is less than the reference dose (RfD), the pesticide is considered to be safe to use. The aggregation (addition) of the amount of exposnre received from each source will increase the total exposure to a level which may then exceed the RfD. In addition to aggregation increasing the level of exposure, the reference dose is becoming smaller because of the use of extra safety factors to protect children. The trend towards lower reference doses impacts both residential and worker risk assessments. 

In summary, the above studies show that neurobehavioral evaluation of pesticide workers reveal increased prevalence of neurologic symptoms and changes in neurobehavioral performance indicative of mild cognitive and psychomotor dysfunction. These effects appear to be more prevalent during the period of exposure, but also persist beyond the period of exposure. Total cumulative exposure seems to be a greater risk factor for poor performance than any other covariant. Deficits in visuomotor speed as indexed by the digit symbol substimtion test and the trailmaking tests have been shown to be consistently effected as well as tests of selective attention and memory... 

In assessing risk it is necessary to consider each use of the pesticide, the potential alternatives which may be used to fill a pest control vacuum and their relative risk, the individual and collective risks to users of the pesticide, workers exposed in subsequent agricultural or other activities, consumers of treated food, people who live nearby and those exposed through environmental contamination. Other descriptors of the nature of the risks are also germane ... 

Problems that rank relatively high in cancer and non-cancer health risks but low in ecological and welfare risks include hazardous air pollutants, indoor radon, indoor air pollution other than radon, pesticide application, exposure to consumer products, and worker exposures to chemicals... 

Barthel E. 1981. [Cancer risk in pesticide exposed agricultural workers]. Arch Geschwulstforsch 51 579-585. (German)... 

C.P. Weisskopf and J.N. Seiber, New approaches to the analysis of organophosphate metabolites in the urine of field workers, in ACS Symposium Series Biological Monitoring for Pesticide Exposure Measurement, Estimation, and Risk Reduction, eds. R.G.M. Wang, C.A. Franklin, R.C. Honeycutt, and J.C. Reinert, American Chemical Society, Washington, DC, pp. 206-214 (1989). 

Observations of field activities are performed by one or more Field Scientists. Normally, each volunteer worker is observed by an individual Field Scientist. The Field Scientist must remain with the worker at all times and closely observe such activities as loading the chemical, spraying the field, harvesting, scouting, and cleanup activities. The Field Scientist should remain at a safe distance from the worker to avoid any serious exposure to the pesticide which may occur during the course of the replicate. Protective equipment may be necessary for the Field Scientist depending on expected exposure levels and the toxicity of the product. In any event, the Field Scientist should have anticipated the risk of close observation and be aware of what protective measures are necessary. 

R.C. Honeycutt, The Usefulness of Farm Worker Exposure Estimates Based on Generic Data, in Dermal Exposure Related to Pesticide Use Discussion of Risk Assessment, ed. R.C. Honeycutt, G. Zweig, and N.N. Ragsdale, ACS Symposium Series 273, American Chemical Society, Washington, DC, pp. 369-375 (1985). 

The previous chapter presented results from field studies in which exposures were measured for workers involved with the use of the insecticide chlorpyrifos in several use scenarios and for persons who might re-enter treated areas. In this chapter, the results from these studies are handled by several methods to demonstrate the advantages of using probability and distributional analyses, rather than single point values, for the characterization of risks to pesticides. 

Analytical chemistry is a critical component of worker safety, re-entry, and other related studies intended to assess the risk to humans during and subsequent to pesticide applications. The analytical aspect takes on added significance when such studies are intended for submission to the U.S. Environmental Protection Agency and/or other regulatory authorities and are thus required to be conducted according to the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) Good Laboratory Practice (GLP) Standards, or their equivalent. This presentation will address test, control, and reference substance characterization, use-dilution (tank mix) verification, and specimen (exposure matrix sample) analyses from the perspective of GLP Standards requirements. 

In Tables 14.9 and 14.10, the last column reports the environmental impact points (EIPs) for typical applications of organic and conventional pesticides derived from the Pesticide Environmental Assessment System, or PEAS. This model produces relative rankings of risks based on defined use rates and use patterns (the formulation used to apply a pesticide, timing, target of the application, spray equipment used, etc). PEAS scores reflect an equal balancing of acute pesticide risks to farm workers, chronic risks via dietary exposure and exposures to birds, Daphnia and bees. 

In a nested case-control study of cancers associated with chemical exposures in the wood industry, Kauppinen et al. (1986) found a significantly increased risk of respiratory system cancer associated with exposure to phenol and phenol in wood dust. As is often the case in occupational settings, these exposures were confounded by smoking and exposures to other materials like pesticides. The increased risk observed for exposure to phenol was almost 5-fold (odds ratio of 4.94), but showed no dose-related increase. This risk dropped to 4-fold with adjustments for smoking history, and to less than 3-fold (and non-significant) when workers exposed to both phenols and pesticides were excluded from the analysis. 

Public and regulatory concern over the potential cancer risks posed by pesticide residues in the diet has been significant over the past two decades. While the consumption of foods containing residues of pesticides has not been correlated with the development of human cancers, pestieide exposure has been linked to some cancers in agricultural workers. In most cases, however,... 

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