Organic skin exposure

These factors have been used to develop the tables of maximum permissible concentrations (16) in air and in water for various conditions (40-hour week or 168-hour week) and for various organs (skin, bone, kidney, liver, brain, GI tract, and total body), but all assuming an occupational exposure and an exposure period of 50 years. MPC values have been developed for 234 radionuclides found in nature, in radioactive fallout, and in neutron activation studies. 

Most published OELs are derived on the basis of preventing adverse effects arising from occupational exposures due to contaminant concentrations in the air. However, dermal exposures may also contribute to the overall body burden. Most OEL-setting organizations have developed qualitative notations to identify those substances for which dermal exposure may contribute significantly to the total body burden. For substances with a skin notation, caution should be used in interpreting the level of protection afforded by the OEL if skin exposure may occur. 

SLE is a chronic autoimmune connective tissue disease characterized by inflammation and injury to the joints, tendons, and other connective tissues. Organs affected include the lungs, heart, blood vessels, brain, kidneys, and skin. SLE onset is associated with exposure to silica. Though earlier studies have suggested that organic solvent exposure can also be causative for SLE, more recent studies have refuted thisJ2,3,9 No literature references were found associating SLE onset with exposures to chemical mixtures. 

Absorption into the skin is the primary reason for having a separate skin compartment. A skin compartment based on Pick s law is a good tool for extrapolation to other skin exposure situations. Without a predictive model, it is necessary to do experiments at each of the concentrations of interest because of the nonlinear pharmacokinetics involved. The permeability coefficient is concentration independent (Scheuplein, 1977) therefore, it can be used to extrapolate from one exposure concentration to another. When the exposure conemtration is doubled, the model predicts that the total amount of chemical absorbed would also double (Figure 6.3). This simulation is of an occluded exposure to an organic chemical in an aqueous vehicle. This figure shows that nearly all the chranical is absorbed from the water vehicle during 24 h. 

Methyl bromide (bromomelhane [CAS 74-83-9]) Causes severe Irritation and burns upon direct contact. Vapors irritating to the lung pulmonary edema may result. The CNS, liver, and kidneys are major target organs acute poisoning causes nausea, vomiting, delirium, and convulsions. Both inhalation and skin exposure may cause systemic toxicity. Chronic exposures associated with peripheral neuropathy in humans. Evidence for adverse effects on fetal development in test animals. Limited evidence of carcinogenicity in test animals (lARC 3). See also p 263, and chloropicrin in this table. 

In order to facilitate data handling, several mini-computers were interconnected and the system directly connected to balances and apparatus for counting radioactivity. By use of Che occlusive method, an organic base and a ChiocarbamaCe insecticide were shown Co be absorbed and excreted readily. Very little material was retained in Che tissues of Che rats. By use of Che non-occlusive method, the insecticide, mechidathion, was shown Co be absorbed about 3 times faster Chan Che herbicide, aCrazine. Also, Che mouse absorbed the insecticide faster than Che rat. In the case of atrazine, use of four different treatment amounts showed a direct relationship between the amount placed on the skin and the amount found in the urine. This shows that urine analyses for atrazine residues would measure the amount of skin exposure. 

Toxicology LC (inh., rat, 2 h) > 20 pph asphyxiant inh. may cause nausea, vomiting, disorientation, narcosis, tingling, suffocation, convulsions, coma skin exposure may cause blisters, frostbite eye exposure may cause frostbite target organ heart TSCA listed Precaution Fire and explosion hazard ... 

Sulfur mustard, 2,2 -dichlorodiethyl sulfide, is a chemical warfare agent (Newman-Taylor and Morris 1991 Smith and Dunn 1991 Ruhl et al. 1994). It has been dumped into the sea, and fishermen have been injured when leaking containers get in their nets. The chemical is a viscous liquid below and a gas above 14 °C. On the skin, the liquid causes blisters and necrosis 10-12 h after skin exposure. The gas attacks mainly the eyes and the respiratory organs. Sometimes the skin is also affected by direct contact with the gas, and the chemical burn then clinically appears 3-6 h after exposure initial redness is followed by blisters and ulcers. Tear gas can give a bullous dermatitis (Zekri et al. 1995). 

Table 5. Individual susceptibility on skin exposure to organic solvents...

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