Aerial applicators, exposure

Acheta domestlcus. toxicity of aminocarb, 218-20 Additives for spray dispersion performance, 100-15 ecotoxicity, 351-61 Adsorption of pesticides in aquatic sediment, 267 in soil, 195-96 Aerial applicators, exposure monitoring, 323-29... 

Mental disturbances have been reported after organophosphate exposure. Neuropsychiatric symptoms occurred in two aerial applicators, one of whom used methyl parathion as well as other insecticides. One of these pilots had high levels of exposure to a mixture containing methyl parathion, toxaphene, and Dipterex when his clothing became saturated when the tank of his aircraft accidentally overflowed. Several months after the accident, the subject complained of anxiety, dizziness, emotional lability, and frequent and severe disagreements with family members and associates. Similar observations had been... 

Draper WM, Street JC. 1981. Drift from a commercial, aerial application of methyl and ethyl parathion An estimation of potential human exposure. Bull Environ Contam Toxicol 26 530-536. 

Draper, W.M., R.D. Gibson, and J.C. Street. 1981. Drift from and transport subsequent to a commercial aerial application of carbofuran an estimation of potential human exposure. Bull. Environ. Contam. Toxicol. 26 537-543. 

The aerial applicators also had considerably less exposure than the mixer-loaders. Again, most of this exposure was to the hands and was acquired from adjusting nozzles on the spray equipment. For the 80S and the XLR formulations, the total HDE s were 7.4 and 3.4 mg/h, respectively, and almost 100% of the exposure was to the hands in both cases. Here, as for the ground application, the highest HDE was obtained from Sevimol-4 because of the more frequent plugging of the spray nozzels. Thus the total HDE for Sevimol-4 was 26.5 mg/h, and the HDE on the hands was 25.7 mg/h. 

During one aerial application with XLR (experiment 4) the spray equipment malfunctioned. The applicator, in an attempt to correct the problem, accidently opened the dumping valve to the spray tank and the formulation splashed on him. The result was a total HDE of 367 mg/h, with almost half of it on the forearms. Since such an exposure would not be continuous, the calculation on an hourly basis is unrealistic. Therefore, the data were not used in determining the HDE to applicators. 

The Aerial Flagger. The aerial flagger, who had the highest HDE of all workers monitored, is not now commonly used in the aerial applications of pesticides to crops. Still, a flagger is sometimes used in special situations, and was therefore monitored. The flagger was the only worker that had a discernibly different exposure for different application rates. For example, the total HDE for XLR was 606 mg/h for a rate of 2 lb Al/acre and 408 mg/h for a rate of 1 lb Al/acre. 

D. The participants included 26 ground applicators in North Dakota after a single exposure and 17 aerial applicators in Washington during intermittent exposure. The objective was to ascertain worker exposure base-levels of 2,4-D under normal use conditions. Mean daily urinary excretion of 2,4-D by workers involved in aerial applications was 0.006 mg/kg body weight for pilots and 0.02 mg/kg for mixer/loaders from intermittent exposure. Workers involved in ground applications had maximum mean one-day 2,4-D urinary excretion of 0.002, 0.003, and 0.004 mg/kg, respectively, for applicators, mixer/loaders, and mixer/loader/applicators from a one-time exposure. The Ej/2 (half-elimination time for total... 

Table IV. 1980 2,4-D 12-Day Intermittent to Continuous Exposure to Aerial Applicators in Washington.

Lavy, T. L. Walstad, J. D. Flynn, R. R. Mattice, J. D. 2,4-D Exposure Received try Aerial Application Crews During Forest Spray Operations. J. Agric. Food Chem. (Submitted 1981). 

Inhalation Route - Estimation of Vapour Exposure. In a study of drift exposure following aerial application of an organo-phosphorus pesticide, Crabbe t al (16) found that the vapour concentration in areas remote from the spray line increased gradually up to 10 hours after the spraying. Increasing temperature was undoubtedly the major explanation for this. Other factors such as volatility of the pesticide, windspeed and sorption properties of the target would also influence the actual vapour concentration on the target. 

The introduction in the early 1970 s of the soil-incorporated, water-soluble systemic insecticide/nematicide aldicarb was regarded as a major advance in the technology of pest control. It eliminated the once prevalent hazard of inadvertent exposure of applicators or inhabitants of nearby dwellings, wildlife, and useful insects to toxic chemicals during spraying or aerial application of pesticides. 

A rather unusual case of pesticide exposure repoted to the New Zealand Poisons Information Centre concerned a helicopter pilot who was involved in the aerial application of a carbamate insecticide onto crops. Foolishly, he mixed the dry powder formulation under the still rotating blades of his helicopter, which caused the powder to disperse into... 

The use of closed systems is effective in decreasing worker exposure. Use of closed systems was common for aerial applicators using the more toxic methyl parathion. It was interesting that hand mixing and application was more common when compounds with lower toxicity were being used. 

Table V. Exposure During Aerial Application of Organophosphates, 1978-Present...

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. 

In all the exposure situations, workers wore cloth coveralls. Rubber or some other type of waterproof gloves were worn by all workers except the aerial applicators and flaggers. Respirators and other protective devices were used when required by pesticide labels. 

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