Chemical agents, effect

REVIEW OF CHEMICAL AGENT EFFECTS Nerve Agents Cyanide Vesicants Phosgene... 

The appearance of streaks with leveling or nonleveling acid and premetallized dye can be subdued by increasing the dye-bath pH from 5.5 to 6—7, at a sacrifice ia dye exhaust, by a dding chemical agents that retard the dye strike or, more effectively, by metering all or a portion of the dye ia a concentrated solution at or near the dyeiag temperature of the fiber (87.8—104.4°C) iastead of at the usual 26.7—48.9°C practiced by the trade (178). 

The use of chemical agents in battie imposes a significant burden on troops because of the cumbersome nature of the protective clothing and the attendant heat load in hot climate situations. This factor alone imposes a burden on potential target personnel, lowering their effectiveness. U.S. troops in the 1991 Mideast war Desert Storm were provided with protective gear that did not deter them with regard to the outcome of the action. 

Decontamination. If contaminated equipment or material does not have to be used immediately, natural aeration is an effective decontaminant procedure, as most chemical agents, including the bHster and V-agents, are volatile to a certain degree. Wind accelerates their evaporation and hastens their dissipation. Rain and dew may also cause sufficient hydrolysis of some agents. Sunlight increases the surface temperatures of military equipment and thus accelerates agent evaporation. 

Thus, there is a clear need to establish the relationship between the health effects of hazardous chemical agents in the environment and the level of occupational exposure to the body by means of an occupational exposure limit, in which a reference figure for the concentration of a chemical agent is set. In fact, occupational exposure limits (OELs) have been a feature of the industrialized world since the early 1950s. They were introduced, primarily in the United States, at a time when measures to prevent occupational diseases were considered more beneficial than compensating victims, and in this sense OELs have played an important part in the control of occupational illnesses. 

The idea behind OELs is to identify the highest level of exposure concentration and the corresponding reference time period for which we can be confident that there will be no adverse effects on health. However, the concentrations and lengths of exposure at which the presence of airborne chemical agents could damage health have not been clear for many years, and even today there are many questions to be answered. 

Literature from industrial experience, especially individual case reports showing relationship between exposure to a chemical agent and specific adverse effects... 

The crucial objective is to identify what effects can be produced by exposure to chemical agents and to select which effects should be considered... 

If workers are exposed simultaneously or successively to more than one chemical agent, the risk shall be assessed on the basis of the risk presented by all such chemical agents in combination. Usually, additive effects are assumed for the mixture of chemical agents, so the cumulative exposure is calculated as follows ... 

The chemical agents should contact the parasite by prevention, or diffusion through the cells and tissues of the host at suitable doses and effective concentrations. 

Environmental stress cracking is the cracking of certain plastic products that becomes exposed to a chemical agent while it is under stress. This effect may be caused by exposure to such agents as cleaners or solvents. The susceptibility of affected plastics to stress cracking by a particular chemical agent varies considerably among plastics, particularly the TPs. 

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