Lead is absorbed following inhalation, oral, and dermal exposure. It is then distributed mainly to the bones and red blood cells. In the blood lead may be found bound to serum albumin or the metal-binding protein metallothionein. Organic lead is metabolized by cytochrome P-450 enzymes, whereas inorganic lead forms complexes with delta-aminolevulinic acid dehydratase. Lead is excreted mainly in the urine and faeces. (L136)
Lead is absorbed following inhalation, oral, and dermal exposure. It is then distributed mainly to the bones and red blood cells. In the blood lead may be found bound to serum albumin or the metal-binding protein metallothionein. Organic lead is metabolized by cytochrome P-450 enzymes, whereas inorganic lead forms complexes with delta-aminolevulinic acid dehydratase. Lead is excreted mainly in the urine and faeces. (L136)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
毒性总结
识别和使用：氧化铅存在两种形式：红色至红黄色的四方晶体和黄色的正交晶体。它用于制造蓄电池、陶瓷产品、油漆和橡胶。人类暴露和毒性：在一项中东研究中，报告了14名婴儿在使用含有91%氧化铅的传统药物Bint al Dahab后，早期婴儿期出现了急性铅脑病。将22名蓄电池厂工人的1至6岁儿童与22个邻近对照家庭的1至6岁儿童进行比较，以寻找铅吸收增加的证据。工人儿童的血铅和红细胞原卟啉值显著高于对照组儿童。对来自氧化铅工厂的44名男性工人的培养淋巴细胞进行了染色体分析，以及来自15名未暴露个体的对照组。暴露对象的血铅浓度范围为30至75微克/100毫升，对照组为15至35微克/10毫升。铅暴露时间从一个月到11年8个月不等。在职业暴露于铅的受试者中，发现了染色单体和染色体畸变的显著增加。这种发现的频率与铅暴露时间平行。动物研究：30只雄性和30只雌性仓鼠每周一次通过气管内注射1毫克氧化铅，单独或与1毫克苯并(a)芘一起注射10周。氧化铅单独诱导肺泡上皮化生（19）和腺瘤样增生（3）。与苯并(a)芘联合使用时，氧化铅在肺的外围区域引起腺瘤（9）和腺癌（1），以及肺泡上皮化生（23）和腺瘤样增生（5）。在雄性大鼠中，吸入氧化铅并不影响生育力，但精囊重量显著下降，这可能表明睾酮分泌模式的变化。在吸入铅的父系后代的雄性中，附睾精子数量减少，但这并不影响生育力。将家兔暴露于30微克/立方米的PbO，每天3小时，连续4天，然后在最后一次暴露后立即、24小时和72小时对其肺部进行灌洗。在灌洗液中测量的乳酸脱氢酶（肺细胞损伤的标志物）和溶酶体活性（溶酶体渗透性的标志物）在暴露后24小时和72小时显著增加。PbO产生中性粒细胞浸润。对巨噬细胞功能的影响也注意到了。生态毒性研究：氧化铅对蚯蚓（Eisenia fetida, Savigny）的行为、形态和病理学有显著影响。
IDENTIFICATION AND USE: Lead oxide exists in 2 forms: red to reddish-yellow, tetragonal crystals and yellow, orthorhombic crystals. It is used in manufacturing of storage batteries, ceramic products, paints, and rubber. HUMAN EXPOSURE AND TOXICITY: Acute lead encephalopathy in early infancy has been reported in a Middle Eastern study for 14 infants following the use of Bint al Dahab, a traditional medicine containing 91% lead monoxide. Twenty-seven one- to six-year-old children of 22 workers at a storage battery plant at high risk of exposure to lead oxide were compared with 32 one- to six-year-old children in 22 neighborhood control families for evidence of increased lead absorption. Workers' children had significantly higher blood lead and erythrocyte protoporphyrin values than control children. Chromosomes were analyzed in cultured lymphocytes of 44 male workers from a lead oxide factory, and from a control group of 15 nonexposed individuals. Lead concentration in blood ranged from 30 to 75 ug/100 mL in exposed subjects and from 15 to 35 ug/10 mL in controls. Length of exposure to lead ranged from one month to 11 years eight months. In subjects occupationally exposed to lead, a significant increase in chromatid and chromosome aberrations was found. The frequency of such findings parallels exposure time to lead. ANIMAL STUDIES: 30 male and 30 female hamsters were intratracheally injected with 1 mg lead oxide, alone or with 1 mg benzo(a)pyrene once a wk for 10 wk. Lead oxide alone induced alveolar metaplasia (19) and adenomatous proliferation (3) in the lungs. In combination with benzo(a) pyrene, lead oxide caused adenoma (9) and adenocarcinomas (1) in the peripheral area of the lungs, as well as alveolar metaplasia (23) and adenomatous proliferation (5). In male rats inhalation of lead oxide did not affect fertility, but seminal vesicle weight dropped significantly, which might suggest an alteration in the pattern of testosterone secretion. In the male progeny of sires that inhaled lead, the number of epididymal spermatozoa decreased but this did not interfere with fertility. Rabbits exposed to PbO at 30 ug/cu m for 4 days (3 hr/day) were sacrificed and their lungs lavaged immediately, 24 hr, and 72 hr after the final exposure. Lactate dehydrogenase (a marker of lung cell damage) and lysozyme activity (a marker of lysosome permeability), measured in the lavage fluid, were significantly increased 24 and 72 hr after exposure. PbO produced neutrophil infiltration. Effects on macrophage functions were also noted. ECOTOXICITY STUDIES: Lead oxide has a significant effect on behavior, morphology, and histopathology of earthworms (Eisenia fetida, Savigny).
Lead mimics other biologically important metals, such as zinc, calcium, and iron, competing as cofactors for many of their respective enzymatic reactions. For example, lead has been shown to competitively inhibit calcium's binding of calmodulin, interferring with neurotransmitter release. It exhibits similar competitive inhibition at the NMDA receptor and protein kinase C, which impairs brain microvascular formation and function, as well as alters the blood-brain barrier. Lead also affects the nervous system by impairing regulation of dopamine synthesis and blocking evoked release of acetylcholine. However, it's main mechanism of action occurs by inhibiting delta-aminolevulinic acid dehydratase, an enzyme vital in the biosynthesis of heme, which is a necesssary cofactor of hemoglobin. (T4, A20, A22, L136)
Lead mimics other biologically important metals, such as zinc, calcium, and iron, competing as cofactors for many of their respective enzymatic reactions. For example, lead has been shown to competitively inhibit calcium's binding of calmodulin, interferring with neurotransmitter release. It exhibits similar competitive inhibition at the NMDA receptor and protein kinase C, which impairs brain microvascular formation and function, as well as alters the blood-brain barrier. Lead also affects the nervous system by impairing regulation of dopamine synthesis and blocking evoked release of acetylcholine. However, it's main mechanism of action occurs by inhibiting delta-aminolevulinic acid dehydratase, an enzyme vital in the biosynthesis of heme, which is a necesssary cofactor of hemoglobin. (T4, A20, A22, L136)
There is limited evidence in humans for the carcinogenicity of inorganic lead compounds. ... There is sufficient evidence in experimental animals for the carcinogenicity of inorganic lead compounds. There is sufficient evidence in experimental animals for the carcinogenicity of lead acetate, lead subacetate, lead chromate, and lead phosphate. There is inadequate evidence in experimental animals for the carcinogenicity of lead oxide and lead arsenate. ... There is inadequate evidence in experimental animals for the carcinogenicity of lead powder. Overall evaluation Inorganic lead compounds are probably carcinogenic to humans (Group 2A). /Inorganic lead compounds/
CLASSIFICATION: B2; probable human carcinogen. BASIS FOR CLASSIFICATION: Sufficient animal evidence. Ten rat bioassays and one mouse assay have shown statisticlly significant increases in renal tumors with dietary and subcutaneous exposure to several soluble lead salts. Animal assays provide reproducible results in several laboratories, in multiple rat strains with some evidence of multiple tumor sites. Short term studies show that lead affects gene expression. Human evidence is inadequate. HUMAN CARCINOGENICITY DATA: Inadequate. ANIMAL CARCINOGENICITY DATA: Sufficient. /Lead and Compounds (inorganic), Based on former classification system/
The aim of this study was to investigate the percutaneous penetration of lead oxide (PbO) powder and the effect of rapid skin decontamination with two different detergents. Franz cells were used to study in vitro PbO skin penetration through human skin during a 24-hour period. The tests were performed without or with decontamination using either Ivory Liquid soap or a new experimental cleanser 30 minutes after the start of exposure. We confirm that PbO can pass through the skin with a median penetration of 2.9 ng/cm (25-75th percentiles 0.35-6). The cleaning procedure using Ivory Liquid soap significantly increased skin penetration with a median value of 23.6 ng/cm (25-75th percentiles 12-47.1; Mann-Whitney U test, P = 0.0002), whereas the new experimental cleanser only marginally increased penetration (7.1 ng/cm). Our results indicate that it is necessary to prevent skin contamination from occurring because a short contact can increase skin content and penetration even if quickly followed by washing. This study demonstrated that PbO powder can pass through the skin and that skin decontamination done after 30 minutes of exposure did not decrease skin absorption occurring over 24 hours and stresses the need to prevent skin contamination when using toxic substances.
14 male volunteers were exposed to a lead oxide aerosol for 23 hr per day at an average concentration of 10.9 ug/cu m for up to 17 weeks. ... The air contribution to the lead blood levels was approx 1.4 ug of lead per 100 mL blood per 1 ug of lead per cu m.
Data obtained from a feeding study in rats /showed that/ lead uptake into rat femurs was highly dependent on the chemical form of lead administered. Bioavailability was highest for lead acetate, intermediate for lead oxide, and lowest for lead sulfide and Alaskan mixed ore concentrate. This uptake was linearly related to dose over the range studied.
The objective of this study was to determine percutaneous absorption of lead compounds, including lead sulfate, lead oxide, lead powder, and lead stearate. The lead content on the skin surface of 10 lead-battery workers was measured by the method of skin stripping, and urinary lead content of rats was measured with epicutaneous application of four lead compounds: lead sulfate, lead oxide, lead powder, and lead stearate. There were significant amounts of lead on the 9th and 10th skin strippings of the dorsal hand and the back of lead workers. The amount of lead on the dorsal hand was significantly correlated with the amount in the blood (n = 10, r 2 = 0.66, p < 0.05, linear regression). In rats, after lead compounds were applied for 12 days, total lead amount in urine significantly increased to 146.0 + or - 6.4 ng (SD) for lead stearate, 123.1 + or - 7.2 ng for lead sulfate, 115.9 + or - 5.3 ng for lead oxide, 47.8 + or - 6.9 ng for lead powder, and 10.3 ng for the control, which indicated significant skin absorption. It was concluded that significant amounts of inorganic lead compounds can be absorbed through the skin, and skin protection in lead-working or any contaminated environment should be carefully considered.
The chemiluminescence observed during the reactionbetweenlead vapor and ground state oxygen (13ΣO 2) was analyzed. The spectral bands could be assigned to transitions from the a, A, B and C electronic states to the ground state. Evidence is presented to indicate that the reactive lead vapor is generated thermally rather than electrically.
The chemiluminescence from electronically excited lead oxide formed during the reaction between lead vapor and either 3Σ O2 or 1Δ O2 has been studied. The reactions were accomplished in a flow tube reactor. A microwave discharge was used to generate 1Δ O2. The vibronic spectrum was analyzed and the band head assignments were used in a linear least-squares calculation to obtain the vibronic molecular
Process for the production of basic soaps of divalent metals in powder
申请人：Neynaber Chemie GmbH
公开号：US04927548A1
公开（公告）日：1990-05-22
Powdered basic metal soaps having a composition corresponding to the formula (MO).sub.n.M(RCOO).sub.2, where MO represents CaO, ZnO, MgO, BaO, PbO, or a mixed oxide PbO/CaO, CaO/ZnO, BaO/CdO, or BaO/ZnO, M is one of the metals mentioned above, RCOO represents an anion of a fatty acid containing 8 to 34 carbon atoms, and n has a value of 0.2 to 2, may be obtained by reaction of powdered fatty acids with powdered metal oxides in the presence of small amounts of water, alcohol, and/or an acid at temperatures between ambient temperature and 100.degree. C. and under a pressure not greater than ambient. Preferably, there is continuous removal of water formed during the reaction, and the reaction mixture is present as free flowing particles throughout the reaction.
Method for the preparation of IV-VI semiconductor nanoparticles
申请人：Cho Kyung-Sang
公开号：US20060110313A1
公开（公告）日：2006-05-25
A high temperature (on the order of about 90° C. or above) non-aqueous synthetic procedure for the preparation of substantially monodisperse IV-VI semiconductor nanoparticles (quantum dots) is provided. The procedure includes first introducing a first precursor selected from the group consisting of a molecular precursor of a Group IV element and a molecular precursor of a Group VI element into a reaction vessel that comprises at least an organic solvent to form a mixture. Next, the mixture is heated to a temperature of about 90° C. or above and thereafter a second precursor which is different from the first precursor and is selected from the group consisting of a molecular precursor of a Group IV element and a molecular precursor of a Group VI element is added into the heated mixture. The reaction mixture is then mixed to initiate nucleation of IV-VI nanocrystals and the temperature of the reaction mixture is controlled to provide substantially monodispersed IV-VI nanoparticles having a diameter of about 20 nm or less.
[1-Oxo-2-thienyl-2-substituted-5-indanyloxy (or thio)]alkanoic acids and
申请人：Merck & Co., Inc.
公开号：US04177285A1
公开（公告）日：1979-12-04
[1-Oxo-2-aryl or thienyl-2-substituted-5-indanyloxy (or thio)]alkaoic acid, derivatives thereof, their salts, esters and amides are disclosed. The products display a dual pharmaceutical utility in that they exhibit diuretic, saluretic and uricosuric activity. Also disclosed are processes for the preparation of such [1-oxo-2-aryl or thienyl-2-substituted-5-indanyloxy (or thio)]alkanoic acids, pharmaceutical compositions comprising therapeutically effective amounts of such compounds and methods of treatment comprising administering such compounds and compositions.
