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Chlorine gas poisoning, also known as bertholite poisoning is illness resulting from the toxic effect of chlorine in its gaseous states. It occurs after the inhalation of chlorine gas beyond the threshold limit value. Chlorine gas is a toxic gas and pulmonary irritant with intermediate water solubility that causes acute damage to the receptors in the epithelium of the respiratory tract.〔(【引用サイトリンク】title=Acute chlorine gas exposure. )〕 The dose inhaled determines the toxicity on the respiratory tract. Occupational exposures constitute the highest risk of toxicity and common domestic exposure results from the mixing of chlorine bleach with acidic washing agents such as acetic, nitric and phosphoric acid. Prolonged exposure to low concentration of chlorine gas may have lethal effects, as can short-term exposure to high concentrations.〔(【引用サイトリンク】title=Chlorine Gas: An Evolving Hazardous Material Threat and Unconventional Weapon )〕 Chlorine gas damages the respiratory tract using a chloride shift mechanism involving the exchange of bicarbonate (HCO3−) and chloride (Cl−) across the membrane of red blood cells (RBCs). The cell membranes of red blood cells are impermeable to hydrogen ions but exchange bicarbonate ions for chloride ions using the anion exchanger protein Band 3 and a rise in intracellular bicarbonate causes chloride intake and bicarbonate export. As a result, blood chloride concentration is lower in systemic venous blood than in pulmonary circulation because the levels of CO2 and therefore bicarbonate are higher in systemic venous blood, providing less of a driving force for exchange. Excess chlorine gas in the lung and bloodstream deregulate the affinity of hemoglobin for oxygen through the chloride ion acting as an allosteric inhibitor. Symptoms of mild acute poisoning include sneezing, tearing, nose irritation and throat irritation, while larger exposures can lead to significant toxicity of the respiratory tract and heart and sometimes death. Following acute poisoning, long-term sequelae often occur and chronic exposure to low levels of chlorine gas can lead to memory loss.〔(【引用サイトリンク】title=Excerpt from The Residual Effects of Warfare Gases (1933) - Veterans at Risk - NCBI Bookshelf )〕 ==Signs and symptoms== Chlorine gas poisoning only causes severe damage to the respiratory tract and is therefore not harmful to all forms of life like carbon monoxide poisoning. It is easily absorbed through the lungs and its inhalation result in CNS damage and death. Different people and races may have different chlorine gas tolerance levels.〔(【引用サイトリンク】title=ATSDR - Medical Management Guidelines (MMGs): Chlorine )〕 Chlorine gas exposure may lead to a significantly shorter life span due to heart damage. Individual tolerance level for chlorine gas may be altered by several factors, such as metabolic rate, hematological disorders and barometric pressure.〔(【引用サイトリンク】title=Chlorine Gas Toxicity )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Chlorine gas poisoning」の詳細全文を読む スポンサード リンク
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