Applicators dermal exposure monitoring

Appendix One Dermal Exposure Monitoring of Mixers, Loaders, and Applicators of Pesticides in California... 

CDFA conducted dermal exposure monitoring of workers involved in the application of parathion, mevinphos (Phosdrin), nitrofen (TOK), DEF/Folex, and chlorobenzilate (Acaraben) (13-18). Exposures of... 

In order to evaluate "within-worker" variances of dermal exposure and its distribution over the body, whole-body monitoring during three applications and concomitant re-entry was performed for high-volume (HV) applicators (n = 4) and harvesters of carnations (n = 6). 

The first pesticide exposure study was reported by Griffiths et al. (1951). Parathion was trapped on respirator filter discs during application to citrus trees. Batchelor and Walker (1954) expanded exposure monitoring to include the estimation of potential dermal exposure using pads attached to workers clothing. Durham and Wolfe (1962), in their classic review of worker exposure methodologies, also provided some experimental validation for the best available methods. 

Pesticide mixers and applicators at Farms A and B, and also at an active farm not having a CCC, were monitored for topical (dermal) exposure throughout the 1980 season. No Increased exposure was measured as a result of using the Chemical Control Centers. A paper addressing potential applicator exposure In this and similar situations Is In preparatlon( ). 

In addition to its presence in the ambient atmosphere, diazinon also has been monitored in both outdoor and indoor air associated with its use in a variety of domestic, commercial, and occupational exposure situations. Exposure to diazinon from its use in lawn and home garden applications was evaluated by Davis et al. (1983). Diazinon was mixed with water and sprayed using compressed air sprayers or hose-end sprayers, and potential respiratory and dermal exposures were estimated from residues collected from respirator filters, body pads, and hand rinsings. These authors reported mean respiratory exposures of 1.9,... 

Occupational pesticide exposure holds a peculiar status within the field of occupational health and safety, both from a scientific and regulatory perspective. Methods for personal monitoring of dermal exposure first arose in the context of pesticide applications in agriculture, pioneered by scientists in the USA Public Health Service (Batchelor and Walker, 1954 Durham and Wolfe, 1962). These methods gained worldwide recognition in the early 1960s, and remain a component of exposure assessment practice today. This work pre-dated most personal monitoring methods that were developed for industrial workplaces. 

The behavioral effects of dermal exposure to maneb were studied in adult male Swiss mice (Mitchell et al. 1989). Five mice per dose group were dermally exposed to either 16, 160, or 1,600 mg/kg maneb in a conditioned taste aversion assay. Aversion to a saccharin solution was tested 24 hours following the dermal application of the compound to a shaved area on the mouse s back, immediately caudal to the skull. Maneb application did not affect taste aversion compared to water controls. Activity was measured for both ambulatory and nonambulatory activity ambulatory was when a subject sequentially disrupted at least two adjacent infrared beams in an activity monitor nonambulatory activity was when a subject sequentially broke the same beam. When given at a dose of 1,600 mg/kg, maneb increased the activity levels of a tested group (5 subjects) by 3-fold over controls. When the mice were tested individually, however, there were no... 

Kamble et al. (1992) studied the exposure of 29 commercial applicators exposed to Termide EC (technical chlordane 39.22% plus heptachlor 19.6%), diluted to 0.75% (active ingredient) during subterranean termite treatment of homes. Dermal exposure was monitored using 14 gauze pads for each applicator attached to exterior and interior parts of clothing for an average duration of 138 minutes. Exposure to hands was monitored by hand rinses immediately after application. 

During most of these studies we have analyzed samples from three different sources 1) air monitors for determining the concentration of pesticide in the air, 2) patches attached to the applicators clothing to obtain an estimate of dermal exposure, and 3) urine to determine the absorbed dose. 

SAB has reviewed many field studies of pesticide applicator exposure, and the dermal route is typically the route of highest potential exposure. For many agricultural work activities, most of the potential dermal exposure occurs to the hands. In some instances, field studies have been carried out to assess exposure for a particulcir pesticide/ai ication methoexposure assessment is required. This primary stud is evaluated, and if judged scientifically acceptable, would be used directly in the exposure assessment. Miile it would be highly desirable to have the results of such a scientifically valid, statistically designed field exposure monitoring stud for each assess-itent we are requested to perform, this is Epical ly not the case. 

Maddy (16) monitored dermal and Inhalation exposures for mlxer/loaders, flaggers and pilots associated with the aerial application of mevlnphos, using Che methods described In Peoples (15). In this study the mlxer/loaders operating closed transfer systems wore gloves but others associated with the spray operation did not. The mlxer/loaders received 74% of their total dermal exposure on Che hands, flaggers received 42% and pilots received 27%. Pilots received a considerably lower proportion of Che total exposure Co the hands Chan In the study by Peoples (15). 

Everhart (17) monitored 8 mlxer/loaders who each prepared one tankful of benomyl for aerial application. Five gauze pads and cotton gloves were used to measure exposure. Most workers wore additional protective gloves over the cotton gloves. Regardless of this additional precaution 96% of the total dermal exposure was found on Che cotton gloves. In almost all other cases Che forearm patches had the highest levels of contamination. 

The actual biological monitoring of workers to detect evidence of exposure such as a drop in blood cholinesterase levels or the presence of a urinary metabolite is superior to the indirect techniques employed in this study. Realizing the difficulties in accurately determining the dermal exposures of mixers, loaders, and applicators to pesticides, the employment of simpler monitoring techniques than the ones performed by CDFA in this report might... 

Honeycutt, R.C., Day, Jr., E.W., Shurdut, B.A., and Vaccaro, J.R., Use of simultaneous biological monitoring and dermal dosimetry techniques to determine the exposure of chlorpyrifos to applicators and re-entry workers, in Worker Exposure to Agrochemicals Methods for Monitoring and Assessment, Honeycutt, R.C. and Day, E.W., Jr., Eds., Lewis Publishers, Boca Raton, FL, 2000, chap. 2. 

In several studies carried out during aerial agricultural applications, a large portion of the total exposure was also seen on the hands, especially for mlxer/loaders. Peoples (15) monitored the potential dermal and Inhalation exposure of mlxer/loaders, pilots... 

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