Dermal exposure residue

Mice that were exposed dermally to residues of methyl parathion in emulsifiable concentrate on foliage, and were muzzled to prevent oral intake, developed inhibition of plasma cholinesterase and erythrocyte cholinesterase after two 10-hour exposures (Skinner and Kilgore 1982b). For the organophosphate pesticides tested in this study, cholinergic signs generally were seen in mice with cholinesterase inhibition >50% results for this end point were not broken down by pesticide. 

Serum endosulfan was 4 pg/L at 30 hours after an agricultural pilot was exposed dermally (and probably also by inhalation) for approximately 45 minutes in clothing that was heavily contaminated with endosulfan and methomyl (Cable and Doherty 1999) the dermal exposure level was not estimated and no other measures of tissue levels of endosulfan were obtained. A study by Kazen et al. (1974) has identified endosulfan residues on the hands of workers after relatively long periods free from exposure. Endosulfan residues were identified on the hands of one worker approximately 30 days after exposure and on the hands of one worker who had not used endosulfan during the preceding season. 

Farm worker exposure to pesticides has been studied extensively over the past 30 years.This scientitic discipline has evolved from the days when respiratory exposure of farm workers was measured using gauze dosimeters placed inside respirators to collect airborne pesticide residues to very sophisticated air sampling devices and remarkable dosimeter devices to measure dermal exposure to farm workers. ... 

The purpose of this article is to present a detailed description of the current field methods for collection of samples while measuring exposure of pesticides to farm workers. These current field methods encompass detailed descriptions of the methods for measuring respiratory and also dermal exposure for workers who handle the pesticide products directly (mixer-loaders and applicators) and for re-entry workers who are exposed to pesticide dislodgeable residues when re-entering treated crops. 

The acceptable operator exposure level (AOEL) for each route of exposure is assigned from the no effect level (NOEL) in a specific toxicity test multiplied by a safety factor. The value for samples containing no detectable residues is assumed to be one half the limit of detection. For cyromazine, the seasonal use pattern indicates that the exposure is most comparable to the 21-day dermal exposure interval, and a value of 2000 mg/kg bw/day was taken as the dermal AOEL. The inhalation AOEL was obtained from a 28-day inhalation study with rats. As cyromazine is not a carcinogen, the safety margin used for calculation of the of the results using the EEC method... 

Research has shown a clear relation between the amount of dislodgeable residues on the crop and the level of dermal exposure (van Hemmen, 1995). The maximum amount of dislodgeable residues is found immediately after application and depends on ... 

Re-entry exposure can be considered to be the result of a chain of processes ending with the transfer of pesticide residues to the worker. Popendorf (1985) assumed a linear relationship between dermal exposure (DE) and the amount of residue available to transfer from the foliage to the worker. This is called the dislodgeable foliar residue (DFR) ... 

There are no data on intermediate-duration inhalation or dermal exposures in either humans or animals. Data on intermediate inhalation and dermal exposures would be useful since the inhalation of vapors or direct contact with residual heptachlor from residential pesticide application or at NPL sites may be potential routes of exposure for the general population. 

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,... 

Polybrominated Biphenyls. No studies were located regarding absorption of PBBs in humans or animals after dermal exposure to PBBs. However, absorption of PBBs through the skin in humans can be inferred by the relatively high levels of PBB residues detected in the adipose tissue and seniin of w orkers involved in the manufacturing of these chemicals (Brown etal. 1981 Landrigan et al. 1979 Stress et al. 1981). It is assumed that dermal route predominates, but inhalation and/or oral exposure cannot be ailed out. 

The total hourly dermal exposures (HDE) were calculated from the residues on exposure pads by the equation of Durham and Wolfe (3) as follows ... 

Here information on contaminant concentration in the environmental media (surface residue, dust, soil) is combined with factors that estimate the contact rate and the transfer rate. For dermal exposure, information on surface residues is combined with factors that estimate contact rate and transfer rates to the skin. 

Animals. Rapidly metabolized initially by cleavage of the imidazole ring and quantitatively eliminated from the body. Although absorption following dermal exposure is low, residues in plasma and tissues are rapidly eliminated from the body... 

Doran, E.M., M.G. Yost and R.A. Fenske (2000). Measuring dermal exposure to pesticide residues with attenuated total reflectance Eourier-transform infrared (ATR-FTTR) spectroscopy. Bull Environ. Contam. Toxicol., 64, 666-672. 

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