铊——人体的毒害元素

介绍了铊及其化合物在工业中的作用、铊元素主要的理化性质以及铊对人体的毒性、铊中毒的诊断和治疗。     

孕期铊暴露的不良母婴健康效应

铊是一种剧毒重金属,孕期铊暴露引起的不良母婴健康效应也得到了越来越多的学者关注。本研究从铊暴露的来源及其影响因素、孕期铊暴露与妊娠并发症及新生儿不良出生结局的关联、孕期铊暴露对儿童出生后生长发育的影响以及孕期铊暴露引起不良母婴健康效应的潜在机制等方面,综述了相关研究进展,可为深入研究孕期铊暴露的危害、预防和控制提供新的依据。     

铊及其对人体的生物学效应

通过铊及对人体生物学效应的分析 ,强调了防治铊污染的必要性和紧迫性。     

血液灌流治疗急性铊中毒2例血铊尿铊观察

分析2例急性铊中毒患者采用血液灌流(hemoper-fusion,HP)治疗前后血铊和尿铊的变化,并计算下降率。观察治疗前后患者血电解质,肝、肾功能及血常规变化并评价临床症状的改变。HP治疗可显著减低血铊、尿铊水平,血铊的下降率为(40±10)%,尿铊的下降率为(90±5)%,患者分别经5～6次治疗后血铊、尿铊水平基本接近正常,临床症状明显改善。其中1例重症患者血液灌流过程中曾出现一过性的血钙、血钾、血小板减少。血液灌流能有效清除人体内已吸收的铊,临床需密切观察血电解质、肝、肾及血常规的变化,及时给予对症和支持治疗。     

铊与人体健康

本文简略介绍了铊对人体的影响、铊中毒及其处理方法     

某地区居民生物材料中铊含量分析

对铊污染区内的慢性铊中毒者，非铊中毒者及非污染的正常人进行发铊、尿铊、指甲铊的含量分析，结果为慢性铊中毒者＞污染区非铊中毒者＞晨污染区正常人，且都有显著性差异。发、尿、指甲锭含量，可作为评价铊接触水平的重要参考依据。     

原子发射光谱法测定被污染矿石中的铊

本语文介绍了用原子发射光谱法测定被车厢污染的矿石中的铊，对仪器工作参数，共存物质的光谱 电离效应及准确度试验进行了探讨，试样经稀酸浸泡后直接进行测试，结果令人满意。     

桂东南某河流铊污染后人群铊暴露状况初步调查

目的了解桂东南某河流铊污染3年后沿岸某村井水、土壤、地产食用农产品以及居民重金属铊含量水平,评估当地居民健康风险。方法于2016年,选择2013年发生铊污染事件的某河流沿岸某村作为污染区,选择该河流污染段上游沿岸的1个自然村作为对照区。采集井水、土壤、地产食用农产品及(18～75)岁常住居民尿液样品,采用电感耦合等离子体质谱仪(ICP-MS)测定井水、土壤、食物及尿液铊含量水平。结果污染区井水铊含量(M=0.290μg/L)高于对照区(未检出),差异有统计学意义(z=-6.51,P<0.01),污染区井水铊合格率(24.6%)低于对照区(100.0%),差异有统计学意义(χ~2=42.48,P<0.01);污染区土壤铊含量(M=0.755 mg/kg)高于对照区(M=0.595 mg/kg),差异有统计学意义(z=-2.02,P<0.05);污染区食物铊含量(M=1.861μg/kg)高于对照区(M=0.250μg/kg),差异有统计学意义(z=-4.14,P<0.01);污染区人群尿铊含量(G=0.70μg/g肌酐)与对照区(G=0.67μg/g肌酐)相比差异无统计学意义(F=1.18,P>0.05)。结论污染区人群存在一定水平的铊暴露,但人群尿铊水平与对照区人群水平相当。     

急性铊中毒4例临床分析

结合有关文献,分析4例铊中毒的临床特征、铊定量结果及治疗方法。     

贵州省赫章县45岁以上成人尿铊含量调查

目的针对贵州赫章县多年矿山开采重金属污染地区开展人体铊含量特征调查。方法在开采污染最严重的妈姑镇和未曾有过开采的撒拉溪镇随机选取45岁以上村民作为研究对象,采集村民的尿液进行铊含量检测。结果妈姑镇人群尿铊含量高于撒拉溪镇,女性尿铊含量高于男性,两地区人群尿铊多数在正常人尿铊的生物接触上限值内。结论调查地区村民没有慢性铊接触中毒,妈姑镇45岁以上女性非职业人群尿铊95%上限为8μg/gCr,其余45岁以上非职业人群尿铊95%上限为5μg/gCr。     

桂东南某河流铊污染后人群铊暴露状况初步调查

目的 了解桂东南某河流铊污染3年后沿岸某村井水、土壤、地产食用农产品以及居民重金属铊含量水平,评估当地居民健康风险.方法 于2016年,选择2013年发生铊污染事件的某河流沿岸某村作为污染区,选择该河流污染段上游沿岸的1个自然村作为对照区.采集井水、土壤、地产食用农产品及(18-75)岁常住居民尿液样品,采用电感耦合等...     

Thallium poisoning from eating contaminated cake--Iraq, 2008

Thallium is an odorless, tasteless, heavy metal formerly used in rodenticides and still used in some manufacturing processes (e.g., electronics, pharmaceuticals, and glass). Thallium also has been used for intentional poisonings. Acute thallium poisoning produces gastrointestinal symptoms and signs, such as vomiting and acute abdominal pain, in the first few hours after ingestion, and initially is indistinguishable from other causes of acute gastrointestinal toxicity. However, within several days of ingestion, acute thallium poisoning often produces neurologic symptoms, such as extreme pain and acute muscle weakness ascending from the lower extremities, consistent with heavy metal toxicity. On January 22, 2008, 10 of 12 members in two families in Baghdad, Iraq, developed gastrointestinal symptoms; four of those 10 persons subsequently died from acute thallium poisoning, and five developed neurologic symptoms but survived. The Jordan Field Epidemiology Training Program investigated this cluster at the request of the World Health Organization (WHO) representative in Iraq. The preliminary investigation indicated this was an intentional poisoning, and law enforcement officials began a criminal investigation. Physicians who see the sudden onset of painful peripheral neuropathy and hair loss in patients should consider the possibility of thallium poisoning.     

Thallium: Occurrence in the environment and toxicity to fish

Conclusions Thallium is present in the effluents of the base-metal mining industry, and its acute toxicity to juvenile Atlantic salmon is approximately equal to that of copper. The usual treatment of waste water with alkali to remove heavy metals by precipitation has little effect on thallium. The limited use of thallium will not lead to a global contamination of the environment, but localized problems may exist or develop in the future, mainly as a result of mineral processing.     

Assessment of Extractants for the Determination of Thallium in an Accidentally Polluted Soil

Thallium is a rare and easily dispersed element with high toxicity to organisms. Relatively high levels of thallium ( approximately 9.58 mg kg(-1)) had been found in aqua regia soil extract of an accidentally polluted soil from south of Spain. To assess the available and leachable portions of thallium in the polluted soil, single and sequential extraction procedures have been utilized. Further, X-ray diffraction and scanning electron microscopic studies have also been used to find out the mineral phases. The amount of thallium extracted by the extracting agents in comparison to aqua regia, as well as the different phase associations are discussed.     

Thallium induced changes in behavioral patterns: correlation with altered lipid peroxidation and lysosomal enzyme activity in brain regions of male rats

The effects of exposures to low levels of heavy metals is a complex and serious problem. Thallium is a metal which produces behavioral sequelae in human poisoning and is potentially hazardous with low level exposures. A test battery is presented which utilizes biochemical and behavioral testing to assess the effects of low levels of thallium on central nervous system chemistry and function in rats. The doses of thallium used (4 and 8 mg/kg) produced no overt signs of behavioral toxicity but did produce dose-related increases in lipid peroxidation and activation of the lysosomal enzyme beta-galactosidase in selected brain regions. At these dose levels, thallium also selectively altered the patterns of behavior. The study suggests that the target regions of thallium in the brain include the cortex, the cerebellum and the brainstem. The dose-response relationships, found for certain pairs of behavioral acts, were correlated with biochemical changes in one or more brain regions.     

Changes in Histopathology,Enzyme Activities,and the Expression of Relevant Genes in Zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) Following Long-Term Exposure to Environmental Levels of Thallium

Thallium is a rare-earth element, but widely distributed in water environments, posing a potential risk to our health. This study was designed to investigate the chronic effects of thallium based on physiological responses, gene expression, and changes in the activity of relevant enzymes in adult zebra fish exposed to thallium at low doses. The endpoints assessed include mRNA expression of metallothionein (MT)2 and heat shock protein HSP70; enzymatic activities of superoxide dismutase (SOD) and Na⁺/K⁺-ATPase; and the histopathology of gill, gonad, and liver tissues. The results showed significant increases in HSP70 mRNA expression following exposure to 100 ng/L thallium and in MT2 expression following exposure to 500 ng/L thallium. Significantly higher activities were observed for SOD in liver and Na⁺/K⁺-ATPase activity in gill in zebra fish exposed to thallium (20 and 100 ng/L, respectively) in comparison to control fish. Gill, liver, and gonad tissues displayed different degrees of damage. The overall results imply that thallium may cause toxicity to zebra fish at environmentally relevant aqueous concentrations.     

Oxidative stress and DNA damage in broad bean (Vicia faba L.) seedlings induced by thallium

Thallium (Tl) is a metal of great toxicological concern because it is highly toxic to all living organisms through mechanisms that are yet poorly understood. Since Tl is accumulated by important crops, the present study aimed to analyze the biological effects induced by bioaccumulation of Tl in broad bean (Vicia faba L.) as well as the plant's antioxidative defense mechanisms usually activated by heavy metals. Thallium toxicity was related to production of reactive oxygen species in leaves and roots of broad bean seedlings following short-term (72 h) exposure to thallium (I) acetate (0, 0.5, 1, 5, and 10 mg/L) by evaluating DNA damage and oxidative stress parameters as well as antioxidative response. The possible antagonistic effect of potassium (K) was tested by combined treatment with 5 mg/L of Tl (Tl+) and 10 mg/L of potassium (K+) acetate. Accumulation of Tl+ in roots was 50 to 250 times higher than in broad bean shoots and was accompanied by increase in dry weight and proline. Despite responsive antioxidative defense (increased activities of superoxide dismutase, ascorbate peroxidase, and pyrogallol peroxidase), Tl+ caused oxidative damage to lipids and proteins as evaluated by malondialdehyde and carbonyl group levels, and induced DNA strand breaks. Combined treatment caused no oxidative alternations to lipids and proteins though it induced DNA damage. The difference in Tl-induced genotoxicity following both acellular and cellular exposure implies indirect DNA damage. Results obtained indicate that oxidative stress is involved in the mechanism of Tl toxicity and that the tolerance of broad bean to Tl is achieved, at least in part, through the increased activity of antioxidant enzymes.     

Highly toxic thallium in plants from the vicinity of Olkusz (Poland)

Thallium is a highly toxic metal that plays no role in the metabolism of plants or animals. Recent studies using small mammals and bird feathers as bioindicators demonstrated for the first time that animals from the vicinity of the Boles?aw metal works near Olkusz (southern Poland) had large amounts of thallium in their tissues. Because of concern over these reports, four plant species (Plantago lanceolata, Biscutella laevigata, Dianthus carthusianorum, Silene vulgaris) growing wildly in the same area on a 100-year-old calamine waste heap, as well as the waste heap soil, were examined. The average concentration of thallium in the waste heap soil was 43 mgTl/kg dry wt, with the highest value 78 mg Tl/kg dry wt. P. lanceolata accumulated extremely large amounts of thallium (average, 65 mg Tl/kg dry wt; maximum 321 mg Tl/kg dry wt in roots). S. vulgaris and D. carthusianorum accumulated much less (averages, 10 and 6.5 mg Tl/kg dry wt, respectively). On the other hand, B. leavigata accumulated negligible amounts of thallium in its tissues. The concentration of thallium in plants (shoots, roots) from the calamine waste heap was 100-1000 times the level normally found in plants (0.05 mg Tl/kg dry wt). Possible sources of thallium are discussed and the urgent need for large-scale studies on thallium contamination of soils and vegetation in Poland, especially its southern regions, which are the most industrialized, is pointed out.