品名

碳酸钡; Barium carbonate; CAS：513-77-9

理化性质

白色重质粉末。分子式BaCO3。分子量197.35。相对密度4.43。熔点1740℃(90在气压下)。不溶于水; 微溶于含有二氧化碳的水; 溶于稀盐酸、硝酸、乙酸、氯化铵水溶液及硝酸铵水溶液。加热到约1450℃时可分解成氧化钡和二氧化碳。不能与三氟化溴、2-呋喃过甲酸共存。

接触机会

用于杀鼠剂、陶瓷与搪瓷的釉料、油漆、人造大理石、颜料、焰火、光学玻璃、橡胶、制钡盐等。亦有误食者。

国内主要生产厂商:河北辛集化工厂、山东青岛红星化工厂、山东胶县铺集化工厂、云南昆明市太和化工厂、广西三江县钡盐厂、辽宁海城县化工厂、湖南衡南县三塘公社化工厂

侵入途径

消化道为主。

毒理学简介

人（男性）经口LDLo: 800 mg/kg; 女性TDLo: 800 mg/kg。另有报告，人经口 TDLo: 11 mg/kg; LDLo: 17 mg/kg; TDLo: 29 mg/kg。

大鼠经口LD50: 418 mg/kg。小鼠经口LD50: 200 mg/kg。狗经口LDLo: 400 mg/kg。

碳酸钡虽不溶于水,但食入后与胃酸起反应,可变为氯化钡而中毒。参见<钡及其化合物>。

临床表现

参见<钡及其化合物>。

美国HSDB引用文献：

*ACUTE: EXCESSIVE SALIVATION, VOMITING, COLIC, VIOLENT DIARRHEA, CONVULSIVE TREMORS, INCR BLOOD PRESSURE, HEMORRHAGES IN GI TRACT & KIDNEYS, MUSCULAR PARALYSIS. [R2]

*... A benign pneumoconiosis (baritosis) may result from inhalation of ... barium carbonate. It is not incapacitating and is usually reversible with cessation of exposure. [R27, 624]

*Of over 100 patients who ate sausage contaminated with barium carbonate, 19 required hospital admission. Symptoms included: diarrhea, vomiting, general weakness, dryness of the mouth, paralysis, tightness in the throat, dysarthria, and headaches;  other symptoms were muscle twitching, testicular tenderness, urinary retention, and gatro-intestinal hemorrhage. Two severely affected patient had hypokalemia with associated ECG changes. [R28]

*Severe reactions have also been reported from the inhalation of barium carbonate ... . [R29,p. III-61]

*... The major accident involving barium carbonate was one in which 85 British soldiers were poisoned by eating pastry made from flour accidentally contaminated by the cmpd intended for use as rat poison. ... Three poorly defined stages ... recognized: (1) an acute gastroenteritis with mild sensory disturbance, (2) loss of deep reflexes and the onset of muscle paralysis, and (3) progressive muscular paralysis. The first symptoms, which appeared 45 to 90 min after the contaminated food was eaten, were tingling around the mouth and in the neck, vomiting, and precipitate action of the bowels. Some ... complained of midabdominal colic ... . Others had giddiness and palpitations. Pupils, at first dilated, returned to normal within 2 hr;  they reacted to light, but accommodation-convergence was impaired or lost. The heart rate was varied from normal to rapid ... the pulse rate was always slower and sometimes only half as fast. ... The patient complained of coldness ... . Symptoms typical of the second stage usually were noticed 2 to 3 hr after the onset of illness. ... Tingling ... in the hands and feet. Vomiting and diarrhea continued ... . The pupils responded rather sluggishly to light, accommodation was poor, and convergence was lost completely. ... Various degrees of motor paralysis developed. ... Often improvement in all affected systems began 3 to 4 hr after onset, and recovery was complete within 24 to 36 hr. ... Third stage /symptoms/ ... general muscle paralysis began on the 2nd day of the illness and lasted for a further 24 hr. ... Complete muscle paralysis of arms and legs ... patient remained mentally clear, and recovery was surprisingly rapid. ... There were no deaths. [R30, 2]

*When barium carbonate was mistakenly used as an X-ray contrast medium, six patients survived 133 g each (about 1900 mg/kg) but another died after only 53 g. ... Earlier reports indicating that as little as 4 g (about 57 mg/kg) has proved fatal. ... In one large outbreak with no deaths among 85 cases, it was estimated, on the basis of analysis of the contaminated food, that the most severe cases received about 15 g of barium carbonate (about 214 mg/kg). ... One might ... conclude that a dosage of 28 mg/kg/day for barium carbonate is ... toxic dosage ... . [R30, 3]

*... Additional signs and symptoms (thirst, sweating, blood pressure) were recorded in an outbreak caused by substitution of barium carbonate for barium sulfate in preparation of a barium meal. [R30, 3]

*Acute barium toxicity in humans due to accidental or intentional ingestion of barium carbonate ... has been described. Symptoms usually begin with rapid onset of nausea, vomiting, and diarrhea due to stimulation of the GI tract musculature. Other symptoms and signs are hypokalemia, cardiac arrhythmias, cardiac pacemaker malfunctions, muscular weakness, salivation, loss of tendon reflexes, tingling, paralysis and death in the severely poisoned. [R31]

处理

参见<钡及其化合物>。

卫生标准

车间空气卫生标准:美国ACGIH可溶性钡化合物TLV-TWA 0.5 mg/m^3（以Ba计）; 其他国家同上。

参考文献

刘握衡.急性碳酸钡中毒所致低钾症--附17例分析.湖南医药杂志1981; (2):20.

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