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1.
Observations on renal function in workers exposed to lead 总被引:2,自引:0,他引:2
Renal function was studied in 40 workers chronically exposed to lead at a smelter. The geometric means of lead were 40 (range 24.0 - 63.0) micrograms/dl in blood and 47 (range 19 - 115) micrograms/g creatinine or 71 (range 20 - 250) micrograms/l in urine, respectively. There were no significant differences between the lead-exposed group and a control group in the concentrations of beta 2-microglobulin in serum, urinary total protein and IgG, whereas the level of beta 2-microglobulin in urine was significantly higher in the lead-exposed group (p less than 0.01). No individual lead worker showed abnormally increased level of urinary beta 2-microglobulin. The significance of increased excretion of beta 2-microglobulin on the basis of the group remains to be elucidated. 相似文献
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Yadong Wang Yufei Dai Juan Cheng Chuanfeng Huang Yuxin Zheng 《The Science of the total environment》2009,407(8):2615-2620
The aim was to explore the relationship between the ataxia-telangiectasia mutated (ATM) gene polymorphisms and susceptibility to cytokinesis-block micronucleus among workers exposed to polycyclic aromatic hydrocarbons (PAH). Blood and urine samples of 140 PAH-exposed workers and 66 non-PAH-exposed workers were collected. Seven tagging single nucleotide polymorphisms in ATM gene were selected by pariwise r2 method and minor allele frequency cutoff of 0.05 from Chinese genotype data in HapMap project. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to analyze the polymorphisms of ATM rs600931, rs652311, rs227060, rs227292, rs624366, rs189037 and rs228589. The results showed that ATM rs600931 AG and AG+AA genotypes exhibited significantly higher cytokinesis-block micronucleus (CBMN) frequency (11.14 ± 6.91‰ and 10.57 ± 6.82‰) than did the GG genotype (7.66 ± 5.69‰, P = 0.015 and 0.038, respectively). The subjects with rs189037 GA and GA+AA genotypes exhibited significantly higher CBMN frequency (10.99 ± 6.90‰ and 10.51 ± 6.76‰) than that of the GG genotype (7.72 ± 5.82‰, P = 0.018 and 0.035, respectively). The PAH-exposed workers with rs624366 GC and GC+CC genotypes exhibited significantly higher CBMN frequency (11.34 ± 6.74‰ and 10.73 ± 6.62‰) than did the GG genotype (7.61 ± 6.07‰, P = 0.001 and 0.003, respectively). rs227092 GT genotype exhibited significantly higher CBMN frequency (10.78 ± 6.60‰) than did the GG genotype (7.91 ± 6.30‰, P = 0.025) among the PAH-exposed workers. The haplotype pairs GGGGTGC/AAACATT exhibited significantly higher CBMN frequency (12.05 ± 7.40‰) than did the GGGGTGC/GGGGTGC (7.51 ± 6.19‰, P = 0.007) among the PAH-exposed group. In conclusion, it is suggested that the polymorphisms of ATM were associated with the CBMN frequencies among PAH-exposed workers. 相似文献
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Chromium may affect humoral and cellular immunity, acting on T lymphocytes as well as on granulocytes and monocytes cells. Cytokines play an important role in the immune balance. In this study, the level of IL-12 and IFN-γ were evaluated in the sera and PHA/LPS stimulated culture supernatant of human PBMCs of healthy volunteers and occupationally exposed chromium workers. All the workers were highly exposed to chromium having mean of 104.65 ± 77.21 µg/dL (range 23.7-316.8 µg/dL). A suspension of exposed and unexposed human PBMC (0.5 × 106 cells/ml) prepared and cultured in RPMI-1640 supplemented with 10% FCS for 18 h in the presence or absence of LPS (10 ng/ml) which used for stimulation of IL-12 and IFN-γ. The level of IL-12 and IFN-γ were evaluated in the sera samples as well as LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers. In these chromium exposed workers the level of IL-12 was 433.66 ± 197.49 pg/ml and 983.45 ± 330.99 pg/ml in LPS stimulated culture supernatant of normal individuals and highly chromium exposed workers, which was significant (P < 0.05). Although the level of IL-12 was (78.61 ± 61.03 pg/ml to 146.52 ± 46.37 pg/ml) elevated in unstimulated culture supernatant of h-PBMCs of chromium exposed individuals as compared to control, but it was not significant. This observation also suggests that a significant increase in IFN-γ production in LPS stimulated and unstimulated culture supernatant of h-PBMCs of chromium exposed workers as compared to control. However, IFN-γ level have a significant positive correlation between blood chromium level (r = 0.833, t = 6.3872, P 0.05) and exposure time (in years) (r = 0.8916, t = 8.3540, P 0.05) of the occupationally exposed workers. 相似文献
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Lead poisoning caused by ingested spent lead shotgun pellets has long been known to be a cause of unnecessary mortality in waterfowl and has led to legislation limiting its use in many countries. Recent evidence has shown that the problem extends to terrestrial ecosystems and to fragmented rifle bullets eaten by scavengers as well as shotgun pellets. Dietary exposure of human consumers to lead from spent ammunition in game meat also poses potential risks to human health. To assess the degree of fragmentation of lead bullets used to kill wild deer, twelve deer were shot in the thorax using copper-jacketed lead-cored bullets, as part of planned deer management operations. The thoracic region of the eviscerated carcasses and the abdominal viscera of each deer were X-rayed. An average of 356 metal fragments was visible on radiographs of the carcass and 180 fragments in the viscera. The weight of fragments was estimated by reference to an X-rayed scale of fragments of known weight. The average total weight of metal fragments, likely to be mostly lead, was estimated to be 1.2 g for the carcass and 0.2 g for the viscera. The total estimated weight of fragments in the entire carcass was estimated to be 17% of the weight of the bullet. Most fragments were small in size, with those in the viscera being smaller than those in the carcass. Metal fragments in the viscera were sufficiently small that at least 80% of the metallic bullet-derived lead in the viscera would be expected to be ingested by scavenging birds, such as buzzards and eagles, which feed on them. 相似文献
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High lead levels in drinking water are still a concern for households serviced by lead pipes in many parts of North America and Europe. This contribution focuses on the effect of pH on lead concentrations in drinking water delivered through lead pipes. Though this has been addressed in the past, we have conducted a combined batch, pipe loop and sentinel study aiming at filling some of the gaps present in the literature. Exhumed lead pipes and water quality data from the City of London’s water distribution system were used in this study. As expected, the lead solubility of corrosion scale generally decreased as pH increased; whereas dissolution of other accumulated metals present in the corrosion scale followed a variety of trends. Moreover, dissolved arsenic and aluminum concentrations showed a strong correlation, indicating that the aluminosilicate phase present in the scale accumulates arsenic. A significant fraction of the total lead concentration in water was traced to particulate lead. Our results indicate that particulate lead is the primary contributor to total lead concentration in flowing systems, whereas particulate lead contribution to total lead concentrations for stagnated systems becomes significant only at high water pH values. 相似文献
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A field study was performed in a building complex to investigate the extent and sources of lead (Pb) release in tap water and brass material was found to be the main contributor in the very first draw (250 mL). Based on these results, a pilot installation was built to study Pb leaching from old and new faucets in the presence and absence of a connection to Cu piping. Four water quality conditions were tested: i) no treatment; ii) addition of 0.8 mg P/L of orthophosphate; iii) pH adjustment to 8.4; and iv) adjustment to a higher chloride to sulfate mass ratio (CSMR; ratio from 0.3 to 2.9). Pb concentrations in samples taken from the faucets without treatment ranged from 1 to 52 μg/L, with a mean of 11 μg/L. The addition of orthophosphate @ 0.8 mg P/L (OrthoP) was the most effective treatment for all types of faucets tested. On average, OrthoP reduced mean Pb leaching by 41%, and was especially effective for new double faucets (70%). In the presence of orthophosphates, the relative proportion of particulate Pb (Pbpart) (>0.45 μm) increased from 31% to 54%. However, OrthoP was not efficient to reduce Zn release. The higher CSMR condition was associated with greater dezincification of yellow brass but not of red brass. Corrosion control treatment influenced Pb concentration equilibrium, directly impacting maximal exposure. Significantly higher Pb release (3 fold) was observed for 1 of the 8 faucets connected to Cu exposed to high CSMR water, suggesting the presence of galvanic corrosion. 相似文献
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A bibliometric analysis based on Science Citation Index (SCI) published by Institute of Scientific Information (ISI) was carried out to identify the global research related to lead in drinking water field from 1991 to 2007 and to improve the understanding of research trends in the same period. The results from this analysis indicate that there have been an increasing number of annual publications mainly during two periods: from 1992 to 1997 and from 2004 to 2007. United States produced 37% of all pertinent articles followed by India with 8.0% and Canada with 4.8%. Science of the Total Environment published the most articles followed by Journal American Water Works Association and Toxicology. Summary of the most frequently used keywords are also provided. “Cadmium” was the most popular author keyword in the 17 years. Furthermore based on bibliometric results four research aspects were summarized in this paper and the historical research review was also presented. 相似文献
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Martín Ansaldo Daniel E. Nahabedian Carla Di Fonzo 《The Science of the total environment》2009,407(6):1923-1928
Biomphalaria glabrata is a widespread freshwater gastropod mollusc. The easy aquaculture of these organisms allow its use as an accessible tool for contamination bioassays. B. glabrata showed marked metabolic responses when exposed to cadmium, lead and arsenic. Those responses could also affect the reproduction of the snails. Taking into account this hypothesis, B. glabrata were exposed for 96 h (acute laboratory bioassays) to different concentrations of cadmium (0.1, 0.05 and 0 mg/L), lead (0.5, 0.1, 0.05 and 0 mg/L) and arsenic (0.5, 0.1, 0.05 and 0 mg/L). Snails were removed from the aquaria while eggs were left in the same contaminant concentrations. The effect of the assayed toxicants on snail reproduction was registered as the alterations of the total number of laid eggs (TNLE), hatching time and embryonic survival.At 0.10 mg/L cadmium significantly decreased the TNLE (p < 0.05) and no embryos survived. The lowest assayed level (0.05 mg/L) of cadmium, delayed the hatching time twice when it was compared with the control group (p < 0.01).Lead decreased the TNLE at 0.5 mg/L level (p < 0.01). The other assayed doses (0.05 and 0.10 mg/L) also decreased embryonic survival significantly (p < 0.05 and p < 0.01 respectively) and extended twice the time to hatching (p < 0.01). The 0.50 mg/L level killed all embryos.Arsenic at all studied concentrations decreased the TNLE (p < 0.05) while the hatching time was increased by 50%. Embryo survival only decreased at the highest level (0.5 mg/L) of arsenic assayed.In summary, the acute exposure (96 h) to cadmium lead and arsenic, altered the reproduction of B. glabrata, modifying the TNLE, hatching time and embryonic survival. 相似文献
9.
Omar S. Baghabra Al-Amoudi Mohammed Maslehuddin Taofiq O. Abiola 《Construction and Building Materials》2004,18(10):737-743
The source and dosage of silica fume were varied to investigate their effect on the plastic shrinkage of concrete exposed to hot weather conditions. Highest plastic shrinkage was noted in the concrete specimens prepared with undensified silica fume. The physical properties of silica fume, such as fineness and bulk density, and microscopic properties, such as average pore radius and the total pore volume, were correlated with plastic shrinkage strains. No relationship was noted between the microscopic properties and the maximum plastic shrinkage strains. However, a good correlation was noted between the plastic shrinkage strain and the fineness and bulk density of the silica fume. 相似文献
10.
Lei Zhou Kam Tim Tse Gang Hu Zijian Guo 《The Structural Design of Tall and Special Buildings》2023,32(16):e2050
This study investigates the aerodynamic performance of three square-section buildings with different aspect ratio (AR = 1:1, 1:4, and 1:6) exposed to twisted wind profile (TWP) by pressure measurement test. The effect of AR on the correlation of wind loads specifically for TWP is systematically revealed from both time–frequency domain and local–global perspective. Results show that compared with its counterparts in conventional wind profile (CWP), the effect of AR on aerodynamic load under TWP becomes significantly different and more prominent, which can be categorized into two types of patterns. For pattern low-rise building, TWP is more resembling the condition of CWP with certain attack angle. For pattern high-rise building, TWP results in stronger momentum exchange along building height but suppresses fluctuating feature associated with Karman vortex. As a result, under TWP, mean base moments of all buildings are enhanced except for longitudinal component of case AR = 1:4 and 1:6; while the fluctuating base moment for three AR cases is all reduced, which indicates that dynamic pattern of wake flow is suppressed. Moreover, the discrepancy of local wind load between case CWP and TWP concentrates on the lower-middle location for high-rise building but distributed evenly along all low-rise building height. Additionally, it is found that the effect of AR on aerodynamic correlation exhibits different mechanisms and patterns when building is under the impact of CWP or TWP. 相似文献
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Solís-Domínguez FA Valentín-Vargas A Chorover J Maier RM 《The Science of the total environment》2011,409(6):1009-1016
Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p < 0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by AMF, or a combination of both mechanisms. 相似文献
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S. E. Atkinson T. D. Crocker H. L. Needleman 《The International journal of environmental studies》2013,70(2-3):127-138
Needleman et al. concluded that, on average, an increase in the dentine lead of children from <6 ppm to >24 ppm was associated with a 4‐point IQ decrement. Recently, a spate of papers has conjectured that the reports of Needleman et al. and others could be spurious because of measurement error and omitted variable bias. In this Bayesian analysis of the reconstituted Needleman et al. data set, we replace such conjectures by empirical tests. Even though we structure the tests to provide very favourable opportunities for the conjectures to acquire support, the possibility is seen to be remote that omitted variable bias significantly alters the estimated influence of lead exposures upon childrens’ psychometric intelligence. Similarly, the Bayesian analysis demonstrates that other included covariates are likely to affect the estimated influence of lead exposures only if they are quite poorly measured. 相似文献
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多中心性是(后)现代城市和区域空间演变的共同趋势。本文介绍了多中心性最新发展理念和在现代城市发展中的特点,并以荷兰兰斯塔德地区、欧洲空间发展远景规划和美国大城市地区为例进行典型分析和比较,总结多中心规划或发展在不同尺度和不同维度的特点。最后,在规划实施尺度、战略规划、形成动力、中心区载体、空间与社会经济联系、规划的制度建设和整体考虑社会环境等方面对我国城市和区域规划提出了建议。 相似文献
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Xue-yan Zheng Zhang-long Li Chuan Li Wei-jie Guan Li-xia Li Yan-jun Xu 《Indoor air》2020,30(5):860-871
We sought to investigate the association between active cigarette smoking (ex- and current smokers) with or without exposure to biomass fuels and respiratory symptoms/lung function in middle-aged adults and the elderly. In the chronic obstructive pulmonary disease surveillance conducted in six cities of Guangdong province, China, we surveyed 1986 residents aged 40-93 years. We recorded respiratory symptoms, smoking status, use of biomass fuel, and other covariates by using a structured questionnaire. All models were adjusted for second-hand smoking. Active smoking with or without exposure to biomass fuels was significantly associated with wheezing, chronic cough, and phlegm (all P < .05). Active smoking alone with or without exposure to biomass fuels was associated with 2.5% and 0.6% reduction in the mean forced vital capacity predicted, 6.8% and 4.2% reduction in the mean forced expiratory volume in one second predicted, and 9.0% and 4.7% reduction in the mean maximal mid-expiratory flow predicted compared with the exposure to neither smoking nor biomass fuels, respectively. However, exposure to biomass fuel alone was associated with neither greater lung function impairment nor respiratory symptoms except for chronic cough. Efforts should be made to protect home owners and their family from adverse effects of indoor air pollution. 相似文献
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长久以来俄罗斯、乌克兰之间的天然气争端(简称俄乌天然气争端)已经成为欧盟能源供给安全的最大隐患且对于欧盟能源构架产生深远影响。文章研究了2009年1月的整个事件的过程,分析了事件发生的根源,对中国的跨境长输管线提出了相应建议。 相似文献
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本文以上海地区为例,采用能耗模拟软件ESP-r,模拟分析了体形系数及窗墙比的变化对玻璃幕墙建筑围护结构冷负荷的影响。模拟结果表明,对于玻璃幕墙建筑,冷负荷随体型系数的增大而增大,随窗墙比的增加而增加,所以限制窗墙比、控制体形系数,可以减少建筑冷负荷。 相似文献
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20世纪20年代末至50年代初,中国通过各种途径逐渐受到西方蓬勃兴起的现代主义建筑思想的影响,其主流的"布扎"教育和设计体系也在发生相应转变。文章以40年代后期受教于实施"布扎"体系的之江大学建筑系、50年代初活跃于建筑设计领域的建筑师和教育者黄毓麟(1926-1954)的设计作品为例,分析他在探索现代建筑过程中所具有的特点。论文一方面剖析"布扎"体系在黄毓麟作品中所呈现的基本特征,揭示该体系的本质和核心思想,另一方面考察西方现代建筑如何通过各种方式对于"布扎"教育体系背景的建筑师产生影响,并进而阐述这些思想对于"布扎"体系本身的影响和作用。 相似文献