Dermal exposure, reducing

Procedures that have been used to reduce absorption of methyl parathion include the following. In inhalation and dermal exposures, the exposed person is first removed from the source of exposure. 

No reports were located regarding death in humans that could be associated with acute-, intermediate,- or chronic-duration dermal exposure to americium. An explosion and accidental exposure of a 64-year-old man to 1-5 Ci (37-185 GBq) of241 Am was followed by immediate treatment to reduce contamination to approximately 6 mCi (222 MBq) and to 1 mCi (37 MBq) after the first day (Thompson 1983 Toohey and Kathren 1995). Survival was likely the result of intense and long-term chelation therapy, such as with diethylenetriaminepentaacetic acid (DTPA). The patient lived until natural death 11 years after the accident (see Section 3.2.3.2 for more detailed information regarding this accidental exposure and subsequent treatment and follow-up). 

Methods for reducing peak absorption of americium after inhalation or oral exposure have not been described. Topical applications of saline containing DTP A, tartaric acid, or citric acid (e.g., Schubert s solution) have been used to remove americium from the skin and wounds after accidental dermal exposures (Breitenstein 1983). These agents form stable, water soluble complexes with americium. 

Chester, G., Loftus, N.J., Woollen, B.H., and Anema, B.P. (1990b) The effectiveness of protective clothing in reducing dermal exposure to, and absorption of, the herbicide fluazifop-P-butyl by mixer-loader-applicators using tractor sprayers, in Book of Abstracts, Seventh International Congress of Pesticide Chemistry, Vol. Ill, Freshe, H. and Kesseler-Smith, E., Eds., Conway, Hamburg. 

Dermal exposure by direct contact with contaminated surfaces was the main route of exposure this could be greatly reduced by proper use and removal of nitrile gloves. 

In animals, deaths from acrylonitrile have been reported in several species following inhalation, oral or dermal exposure. In most species, death appears to be related to cyanide poisoning. That the cyanide moiety is involved in human toxicity of acrylonitrile has been reported in a case study in which a human male was sprayed with acrylonitrile when a valve burst (Vogel and Kirkendall 1984). This individual suffered symptoms characteristic of cyanide poisoning, and treatments designed to reduce cyanide levels in the blood were required in order to save his life. 

Incapacitating concentrations (ICtso) for dermal exposure to these agents at moderate temperatures (i.e., between 65 and 85°F) are as low as 2 ppm for a 30-minutes exposure. Temperatures above 85°F reduce the concentration necessary to produce similar effects. 

Neurological Effects. No studies were located regarding neurological effects in humans after exposure to hexachloroethane. Inhalation, oral, and dermal exposure of animals to moderate or high doses (260 ppm, 5,900 ppm, 375 mg/kg/day, 750 mg/kg/day) resulted in hyperactivity, tremors, fasciculation of the facial muscles, ataxia, convulsions, and/or prostration (Fowler 1969b NTP 1977, 1989 Southcott 1951 Weeks et al. 1979). Reduced motor activity has also been observed following oral exposure of pregnant rats (167 mg/kg/day) (Shimizu et al. 1992). Inhalation exposure of rats to 260 ppm for 6 weeks did not have any effect on spontaneous motor activity or shock avoidance behavior (Weeks et al. 1979). 

Reproductive Effects. It has not been definitively determined whether chloroform exposure induces reproductive effects in humans. No studies were located regarding reproductive effects in humans after inhalation or dermal exposure to chloroform. Only one study was located regarding reproductive effects in humans after oral exposure to chloroform. Bove et al. (1995) studied the effects of drinking-water consumption on birth outcomes and found that exposure to TTHM at levels >0.1 ppm resulted in reduced birth weight and size as well as an increased risk of oral cleft, central nervous system, and neural tube defects. These results should be viewed with caution since the authors did not specifically monitor chloroform levels. The effects seen may be due to exposure to other THMs or non-THM contaminants in the drinking water. 

In order to reduce absorption of 1,3-DNB or 1,3,5-TNB following inhalation exposure, patients should be moved to fresh air (HSDB 1994). Following recent ingestion of a substantial amount of either chemical, emesis may be indicated unless the patient is obtunded, comatose, or convulsing (HSDB 1994). Administration of a charcoal slurry, aqueous or mixed with saline cathartic or sorbitol, has also been recommended (HSDB 1994). Following dermal exposure, it is recommended that the exposed area be washed extremely thoroughly with soap and water (HSDB 1994). Eye contamination should be treated by irrigating with copious amounts of tepid water for at least 15 minutes (HSDB 1994). 

Intermediate-Duration Exposure. No data are available on the effects of hexachlorobutadiene in humans after intermediate-duration inhalation, oral, or dermal exposures. In animals, data on inhalation exposure are limited to one developmental toxicity study in rats in which maternal body weights were reduced at a concentration (15 ppm) that was also fetotoxic (Saillenfait et al. 1989). Oral studies revealed kidney damage in female mice at dose levels of 0.2 mg/kg/day (NTP 1991 Yang et al. 1989). This LOAEL was used to derive an intermediate-duration oral MRL of 0.0002 mg/kg/day. 

No reports were found in the open literature on methods to reduce the body burden of HDl after inhalation, oral or dermal exposures. No blood, tissue or urine concentrations of HDl have been reported... 

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