Exposure to solvents

Contamination affecting community water supplies, food additives, or household chemicals is an important source of solvent exposure. Well-water sampling, both in 

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Strong acids and strong alkaUes can severely bum the skin, chromium compounds can produce skin rashes, and repeated exposure to solvents causes removal of natural oils from the skin. Infection is always a concern for damaged skin. Absorption through the skin is possible for materials that are appreciably soluble iu both water and oil, eg, nitrobenzene, aniline, and tetraethyllead. Other materials can be absorbed if first dissolved iu extremely good solvents, eg, dimethyl sulfoxide. Subcutaneous iujection can occur accidentally by direct exposure of the circulatory system to a chemical by means of a cut or scratch or iuadvertent penetration of the skin with a hypodermic needle. 

A study using skin samples from healthy humans revealed that trichloroethylene extracts lipids from the stratum comeum (Goldsmith et al. 1988). The study indicates that lipid extraction is the reason for whitened skin following exposure to solvents such as trichloroethylene. 

Solvents or their metabolites are commonly determined by GC (Tokunaga et al. 1974) or GC-MS. In spite of the high importance of exposure to solvents, and the great number of determinations performed worldwide, reference materials for solvents in serum or urine are virtually non-existent. There are a number of reference materials used in occupational hygiene, for example the ethanol in water standard from NIST (SRM 1828a) is commonly used in the clinical laboratory. 

Zygourakis (1990 Zygourakis and Markenscoff, 1996) developed a discretized model in which cells are assigned a degradation time, upon exposure to solvent, based on their identity as either drug, polymer, solvent, or void. The initial distribution of cells can be modeled after the microstructure of the polymer matrix and multiple phases are explicitly accounted for. The solution is found numerically. 

Czirjak, L. and Kumanovics, G., Exposure to solvents in female patients with scleroderma, Clin Rheumatol., 21, 114, 2002. 

Bartolucci GB, Perbellini L, Gori GP, et al. 1986. Occupational exposure to solvents Field comparison of active and passive samplers and biological monitoring of exposed workers. Ann Occup Hyg 30(3) 295-306. 

Since tRNA is more varied structurally than DNA, ethidium could reside in pockets as well as intercalate into double-strand regions. The fluorescence decay provides information about the type, or types, of binding sites occupied by ethidium. It is currently believed that the excited state of ethidium is quenched by proton transfer to the solvent0 86-1 and that its lifetime is reduced with increasing solvent exposure. If ethidium occupies two or more kinds of sites with different degrees of exposure to solvent, then its fluorescence decay is expected to be multiexponential. 

Note Phthalates, especially di-2-ethylhexyl phthalate (also known as dioctyl phthalate, DOP), are commonly used plasticizers in synthetic polymers. Unfortunately, they are extracted from the polymer upon exposure to solvents such as dichloromethane, chloroform or toluene, e.g., from syringes, tubing, vials etc. Therefore, they are often detected as impurities. They are easily recognized from their peaks at m/z 149 (often base peak), m/z 167, and [M-(R-2H)] m/z 279 in case of DOP). The molecular ion is often absent in their El spectra. 

Direct contact with the liquid may cause erythema and vesiculation prolonged or repeated contact has been associated with the development of a dry, scaly dermatitis or with secondary infections. Some skin absorption can occur with lengthy exposure to solvents containing benzene and may contribute more to toxicity than originally believed, but the dermal route is considered only a minor source of exposure for the general population. ... 

Jacobsen M, Baelum J, Bonde JP Temporal epileptic seizures and occupational exposure to solvents. Occup Environ Med 51 429-430,... 

Before 1940, most reports on the possible chronic toxicity of xylene also involved exposure to solvents that also contained high percentages of benzene or toluene as well as other compounds. Consequently, the effects attributed to xylene in these reports are questionable. Blood dyscrasias, such as those reportedly caused by benzene exposure, have not been associated with the xylenes. ... 

Solvents are well absorbed following oral or skin exposure. Most solvents are quickly absorbed from the gut, although the presence of food may delay absorption. Alcohol is a good example of a solvent typically consumed orally. The skin offers little barrier to solvents. Skin exposure to solvents can result in local irritation and increased blood levels of the solvent. 

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