Exposure to toxic chemical agents

Zabrodskii, P.F., Germanchuk, V.G., Kovalev, A.Yu., Kadushkin, A.M. (2007). Functional disturbance of T-lymphocyte subpopulations under subacute exposure to toxic chemical agents. Rossiyskii Khimicheskii Zhurnal [Russian Chemical Journal] LI(2) 98-100. (In Russian)... 

Detection of Accidental and Deliberate Exposure to Toxic Chemical Agents... 

Respiratory failure following exposure to toxic chemical agents has two causes. The first is the failure of oxygen to be able to difluse across the walls of the alveoli into the pulmonary capillaries and thus into the arteries and cells. The second is the failure of the breathing mechanism to move gas in and out of the lungs leading to a build-up of carbon dioxide in the alveoli. These conditions are known as types 1 and 2 respiratory failure. It should be noted that type 2 respiratory failure has a shorter latency that type 1. 

Medical lessons from the chemical attacks in Syria The August 2013 chemical attack in Damascus provided a dramatic reminder of the constant threat of sudden and unexpected exposure to toxic chemical agents and the medical consequences of the toxic trauma they produced. 

Toxicity tests are necessary tools to evaluate the concentration and duration of exposure of a chemical required to produce certain adverse effects. Molecular processes directly affected by the exposure to the chemical agent are the most liable criterions. Nevertheless, these effects are difficult to detect in aquatic toxicology because the processes are generally not well understood [72], Alternatively, other end points which fulfil the necessary requirements, namely the need to be unequivocal, relevant, easy to observe, describe and measure, biologically significant and repeatable, are used. These include measures of mortality, which is frequently employed in the early evaluation of the toxicity of a pollutant in acute toxicity tests. This criterion allows comparison of toxicity exerted by chemical agents with very different mechanisms of action. 

Cells can be killed by external agents or can be induced to commit suicide via a pattern of events called programmed cell death or apoptosis. Injuries from external agents include mechanical damage and exposure to toxic chemicals (e.g. chemotherapy). Substances toxic to cells are called... 

State and local public health—These are labs run by state and local departments of health. In addition to being able to test for Category A biological agents, a few LRN public health labs are able to measure human exposure to toxic chemicals through tests on clinical specimens. 

Managing pediatric victims of chemical terrorism is an especially difficult challenge. In addition to the obvious physiologic and anatomic differences compared to adults (Table 61.1), there are important psychological and behavioral differences that put children at risk (Rotenberg and Newmark, 2003). Anecdotal reports have claimed that children are likely to be the first to manifest symptoms, to develop more severe manifestations, and to be hospitalized for other related illnesses. In fact, it is anticipated that children will be overrepresented among the initial index cases in a mass civilian exposure to toxic chemicals. Children have many characteristics that make them vulnerable to toxic exposures. The smaller mass of a child automatically reduces the dose of toxic agents needed to cause... 

In order to prevent exposure to certain chemical agents which are regarded as especially hazardous or toxic, EU directive 98/24/EC contains regulations to prohibit the use of specified substances or special work activities to an extent which will be set individually. In general, the prohibition includes production, manufacture, and use. The following derogations have been determined. These can be admitted by the EU member states on their own responsibility ... 

It stands to reason that consideration of response characteristics that have been generated for protection of military combatants against chemical warfare agents can be extended to protection of Chemical Weapons Convention inspectors against exposure to toxic chemicals. An inspector must be protected from both chronic exposures (long term, low concentrations) and acute exposures (short term, higher concentrations). Because of the fact that the inspector has a large number of important tasks to accomplish, the detector or safety device should be of such a size that the device would not be an encumbrance to the inspector. 

Since 1970 tlie field of healtli risk assessment Itas received widespread attention witliin both tlie scientific and regulatoiy committees. It has also attracted tlie attention of the public. Properly conducted risk assessments have received fairly broad acceptance, in part because they put into perspective the terms to. ic, Itazard, and risk. Toxicity is an inlierent property of all substances. It states tliat all chemical and physical agents can produce adverse healtli effects at some dose or under specific exposure conditions. In contrast, exposure to a chemical tliat lias tlie capacity to produce a particular type of adverse effect, represents a health hazard. Risk, however, is tlie probability or likelihood tliat an adverse outcome will occur in a person or a group tliat is exposed to a particular concentration or dose of the hazardous agent. Tlierefore, risk can be generally a function of exposure and dose. Consequently, healtli risk assessment is defined as tlie process or procedure used to estimate tlie likelihood that... 

For additional information see AR 385-61, The Army Toxic Chemical Agent Safety Program, DA Pam 385-61, Toxic Chemical Agent Safety Standards, and DA Pam 40-8, Occupational Health Guidelines for the Evaluation and Control of Occupational Exposure to Nerve Agents GA, GB, GD, and VX. ... 

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