Whole-body exposures

Based on the patch method to assess worker or re-entry exposure, researchers have developed a database, which may be used to estimate exposure. Each patch from an individual in a study can be entered into the database separately, the residue data from patches from various body areas can be summed to yield a whole-body exposure number, and the data may be sorted as to worker tasks, equipment used, protective clothing worn, formulation types and other parameters. This is the basis for the currently used Pesticide Handlers Data Base (PHED), which was developed through a joint effort in the 1980s of CropLife America [formerly known as American Crop Protection Association (ACPA) and National Agricultural Chemicals Association (NACA)], the Environmental Protection Agency (ERA) and Health Canada. " The PHED is discussed in detail in another article in this book. 

The use of the patch method, although yielding some good data about exposure over the years, started to fade quickly when whole-body dosimeter methodology was introduced. The whole-body dosimetry method gave more precise whole-body exposure values from one worker to another since the whole garment was extracted and analyzed, and one did not have to extrapolate exposure to large areas of the body. ° ... 

Figure 15 illustrates that intraperitoneal injection of l44Ce citrate produced the same amount of chromosome damage as a protracted whole-body exposure to Co on a per rad to liver basis in Chinese hamsters (Brooks et al., 1972). Acute exposure to Co at high dose rates produces a nonlinear increase in damage as a function of dose (Brooks et al., 1971). 

TABLE 1-5 Mortality of Rats Exposed to Aniline via Head-Only or Whole-Body Exposures for 4 h... 

Head-Only Exposures Whole-Body Exposures ... 

Gy, single whole-body exposure 50% dead 30-60 days postirradiation from fatal stomach damage significant liver damage in survivors 47... 

Emmen, H.H., and E.M.G.Hoogendijk. 1998. Report on an ascending dose safety study comparing HFA-134a with CFC-12 and air, administered by whole-body exposure to healthy volunteers. MA-250B-82-306, TNO Report V98.754, The Netherlands Organization Nutrition and Food Research Institute, Zeist, The Netherlands. 

J. C.Ravensberg, D.J.Alexander, D.Borkhataria, G.M.Rusch, and B.Schmit. 2000. Human safely and pharmacokinetics of the CFC alternative propellants HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) following whole-body exposure. Regul. Toxicol. Pharmacol. 32 22-35. 

Finally, comparisons of various techniques for animal exposures indicate that the whole-body exposure technique is the most suitable for safety assessment of gases and vapors and permits simultaneous exposure of a large number of animals to the same concentration of a chug however, this technique is not suitable for aerosol and powder exposures because the exposure condition represents the resultant effects from inhalation, ingestion, and dermal absorption of the drug (Phalen, 1984 Gad and Chengelis, 1998). 

In pregnant Alderley-Park rats, whole-body exposure to 1,4-dichlorobenzene at air concentrations of 74.7, 198.6, or 508.4 ppm, 6 hours a day from Gd 6 to 15 produced no adverse clinical or pathological signs in the heart tissues of the dams (Hodge et al. 1977). 

Typically exposure periods are 1 h daily, 7 days each week using snout-only systems for pharmaceutical products, or 6 h daily, 5 days each week using whole-body exposure systems for industrial chemicals. 

Whole body exposure of rats 6 hours/day, 5 days/week for 13 weeks at levels of 24, 70, and 243mg/m resulted in respiratory effects (keratinization of the metaplastic epithelium in the larynx) at the highest exposure level with complete recovery within 4 weeks after exposure. Treatment-related responses such as labored breathing and nasal discharge were observed during many of the exposures, but these also abated during the recovery period. 

Reinhold RW, Hoffman GM, Bolte HF, et al Subchronic inhalation toxicity study of caprolactam (with a 4-week recovery) in the rat via whole-body exposures. Toxicol Sci 44(2) 197-205, 1998... 

The toxicity profile after exposure to airborne NMP depends strongly on the ratio of vapor to aerosol and on the area of exposure (i.e., head only or whole body). Because of the higher skin absorption for the aerosol, uptake is higher in animals exposed to aerosol than those exposed to vapor at similar concentrations. Rats exposed head only to 1000 mg showed only minor nasal irritation, but massive mortality occurred with whole body exposure to the same concentration of coarse droplets at high humidity. ... 

Tolerance to CS may develop from repeated exposures at low concent rations,20 but it is reduced by hyperventilation, as well as by increased environmental temperature and humidity.2 Whole-body exposure to CS solutions may result in a transient increase in blood pressure, but not to the extent observed with CR.3 20 CS is a hapten and may cause allergic contact dermatitis, with erythema, edema, and vesication, which is less severe than the effects of CN. ... 

---