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1.
大量的采矿活动导致矿区周边土壤重金属污染, 严重危害土壤生物安全。汞、铊等重金属元素毒性强, 相关污染的土壤生态风险鲜有研究。跳虫作为土壤环境变化指示生物, 能很好地反映土壤质量的健康状况。本研究以贵州省某汞铊矿区周边的农田土壤为研究对象, 按离矿区距离和作物类型设置4个采样区, 每个采样区种植2种作物, 每种作物农田设置3个样方。研究土壤跳虫群落结构和多样性及其影响因子。结果表明, 调查区内跳虫平均密度为12,000 ind./m2; 采样区距离矿区越近, 土壤重金属污染程度越大, 综合污染指数越高, 跳虫种数、密度、多样性和丰富度指数均呈先增加再降低的趋势; 环境因子分析表明重金属显著影响跳虫群落结构: Folsomides americanusIsotomiella minorProtaphorura encarpatus数量与汞、铊和砷含量呈负相关。高有机质含量能缓解重金属对土壤跳虫的影响, 但作物类型(玉米与薏仁)对土壤跳虫群落结构的影响无显著差异。本研究结果表明土壤有机质或能反向调节重金属污染对土壤跳虫群落的影响。  相似文献   

2.
The aim of this investigation was to study the effects of lead and cadmium pollutants from road traffic on fine roots and mycorrhiza and their accumulation in soil. The effects of salt and phosphorus, calcium and pH were furthermore included in the study. Soil sampling was carried out in a Norway spruce (Picea abies (L.) Karsten stand along the European road E18 in the neighbourhood of Västerås. Cylindrical soil samples were taken along two parallel lines at a distance of 20 and 200 m from the about 10 m open area on both sides of the road. There were more root tips per soil core in the FH-horizon 200 m from the road than near the road. The amount of fine roots (dry weight and length) was furthermore higher in the FH-layer in the forest than adjacent to the road. The estimated pH was higher in the FH- and mineral soil horizon near the road than in the forest. The lead concentration was highest in the FH-layer near the road, in spite of the high pH and calcium concentration in the soil. The lead and cadmium concentrations in dead fine-roots were higher close to the road than in the forest. In relation to lead the related cadmium concentration in the soil was very low.  相似文献   

3.
The purpose of this study was to estimate the daily exposure to lead due to food ingestion, air inhalation, and soil ingestion in the Republic of Korea's general population, and to evaluate the level of risk associated with the current lead exposure level using the proportional daily dose (3–4 μg/kg body weight/day) corresponding to the Provisional Tolerable Weekly Intake (PTWI) suggested by the Joint FAO/WHO Expert Committee on Food Additives as the toxicological tolerance level. The estimation of the daily exposure to lead via three pathways including food, soil ingestion and air inhalation was conducted as a chronic exposure assessment. For the lead exposure assessment through dietary intake, 1,389 lead residue data for 45 commodities investigated by the Korea Food and Drug Administration during the period 1995–2000 were utilized (KFDA 1996, 1997, 1998). Six hundred seventy-two air monitoring data from 7 major cities during the period 1993–2000 and 4,500 soil residue data at 1,500 sites during the period 1999–2001 were considered for the lead exposure assessment involving air inhalation and soil ingestion, respectively. The total daily exposure to lead was estimated by combining dietary intake, inhaled amount and soil intake corresponding to the typical activity of the general population, which was treated as a group of adults with a body weight of 60 kg. For risk characterization, the daily exposure to lead was compared with the toxicological tolerance level. The level of risk due to lead exposure was calculated using the hazard ratio (HR). The dietary intake of lead was 9.71 × 10?4 mg/kg/day and the total daily exposure level, including air inhalation and soil ingestion, was 9.97 × 10?4 mg/kg/day. The exposure contributions of foods, air and soil induced from the percentage of each media to the total daily exposure were 97.4%, 2.1% and 0.5%, respectively. Of the different commodity groups, the highest contribution to the total exposure came from grain, which represented 47.7% of the total. Additional exposure to lead occurs in certain population groups due to the use of tobacco, alcoholic beverages, and the intake of other foods, all factors not considered in this study. Through the comparison of the daily exposure to lead with the tolerance level based on the PTWI, the hazard ratio was estimated as being 0.25–0.33. This value implies that no increase in blood lead level is to be expected in the general population at the current lead exposure levels.  相似文献   

4.
Abstract

Lead exposure still represents a matter of health concern especially in Yugoslavia. To assess the exposure of normal urban population to lead and cadmium through food, a preliminary monitoring was performed on a small group of urban population. Lead, cadmium and some essential elements (calcium, zinc, iron, copper and manganese) were analysed in collected duplicate diet samples and compared to similar population in Sweden. We found that dietary exposure to lead and cadmium is similar to other countries although Yugoslav urban population is exposed to much higher concentrations of lead in air than in cities of developed countries, due to high lead in gasoline. However, daily intake of some essential elements was significantly lower.

Also populations living around lead smelters in various parts of Yugoslavia are still exposed to elevated environmental lead and cadmium levels. To assess the exposure of the population living in this area, a cumulative long-term exposure to lead was determined by measuring lead in deciduous teeth. Concentrations of lead and cadmium in vegetables, soil and meals from the same region were also analysed. Values obtained for lead and cadmium in food products grown in exposed and control area were found to be related to respective concentrations of these elements in soil as well as to the distance from the smelter. Meals prepared in this region show the same trend, revealing very high intake particularly of lead.

The influence of nutritional factors, i.e. dietary calcium on lead metabolism, was also studied. Blood lead concentration was determined in two groups of peasant women living in two regions with different dietary calcium intake. Lower blood lead values were found in the higher dietary calcium intake region.  相似文献   

5.
Land snails are highly tolerant to cadmium exposure and are able to accumulate soil cadmium independently of food ingestion. However, little information exists on the kinetics of cadmium retention in terrestrial gastropods exposed to an increase in the soil cadmium content, over time. There is also little knowledge about how exposure to cadmium-polluted soils influences shell growth and architecture. In this context, we examined cadmium accumulation in the hepatopancreas and shell of juvenile Cantareus aspersus exposed to elevating high levels of cadmium in soil. Also, the toxicity of cadmium to snails was assessed using a range of conchological endpoints, including shell height, width, volume, allometry and integrity. Test snails, aged three months, were reared under semi-field conditions, fed an uncontaminated diet and exposed first, for a period of 30 days, to a series of soil cadmium concentrations, and then, for a second period of 30 days, to soils with higher cadmium content. Cadmium showed a dose-dependent accumulation in both the hepatopancreas and shell. The kinetics of cadmium retention in the hepatopancreas of snails previously exposed to cadmium-spiked soils was significantly influenced by a new exposure event. The shell was not a relevant bioaccumulator for soil cadmium. Under the present experimental conditions, only high cadmium exposure significantly affected either the shell growth or snail survival. There was no consistent effect on shell allometry, but the shell integrity, especially in rapidly growing parts, appeared to be affected by high cadmium exposure. Our results attest to the value of hepatopancreas for describing cadmium retention in land snails and to the difficulty of using conchological parameters in field surveys for estimating the environmental hazard of soil cadmium.  相似文献   

6.
选择乐安河—鄱阳湖湿地典型植物群落,采用重要值方法评价各样点植物群落特征并筛选出典型优势植物,通过室内理化测试分析不同生境中优势植物植株及其根区土壤中重金属Cu、Pb、Cd的含量;采用生物富集系数(BCF)方法评价不同优势植物对重金属Cu、Pb、Cd的富集特性。结果表明:研究区湿地植物以草本为主,在各样点共发现124种物种,包括蕨类植物2科2属2种,种子植物40科97属122种,并从中筛选出羊蹄、红蓼、鼠曲草、紫云英、苎麻等5种富集能力较强的优势植物;植物根区土壤中的Cu、Cd含量均超过土壤环境质量三级标准,而且Cu、Cd的最高含量分别为824.03、5.03 mg·kg-1;不同优势植物对Cu、Pb、Cd等3种重金属元素中的1种或2种表现出较强的富集能力,其中优势物种红蓼对Cu具有较强的富集能力,含Cu量最高为148.80 mg·kg-1,另一种优势物种鼠曲草对三种元素的生物富集系数均较高,且对Cd的最高富集含量为15.17 mg·kg-1,对Cd的生物富集系数最高值为19.14,高于其他植物10倍以上,鼠曲草对重金属Cd具有富集植物的基本特征,且对Cu和Cd具有共富集特征并具有较高的耐性,紫云英、羊蹄等对Cd的富集能力也较强。上述5种优势植物种群对鄱阳湖湿地Cu、Pb、Cd等重金属污染物的生态修复具有一定参考价值,可作为鄱阳湖湿地重金属污染修复植物的选择对象。  相似文献   

7.
1. A long term low level exposure experiment was conducted on rats in order to determine the metabolic patterns of realistic environmental dietary levels of cadmium from different sources. 2. Male and female rats were fed a diet for 6 months with a high crab content containing 4 mg Cd/kg as organic bound cadmium from dressed crab, a diet with low crab content containing 0.2 mg Cd/kg as organic bound cadmium, a casein based diet containing 4 mg Cd/kg as cadmium chloride and a low cadmium level control diet. 3. Analysis of the cadmium levels in the kidney, liver and spleen showed that uptake from the dressed crab was only half of that from the diet fortified with cadmium chloride.  相似文献   

8.
To detect the content of 12 heavy metals in blood and hair sample from a general population of Pearl River Delta area, and to analyze the influence of duration of residence, gender, age, smoking and drinking on the heavy metal content. Use inductively coupled plasma mass spectrometry to detect the content of 12 heavy metals lead (Pb), mercury (Hg), cadmium (Cd), aluminum (Al), arsenic (As), copper (Cu), chrome (Cr), manganese (Mn), nickel (Ni), zinc (Zn), tin (Sn) and antimony (Sb) in blood and hair samples of a total of 50 subjects from a general population, collected by multistage stratified cluster random sampling method. The geometric mean of heavy metal content in blood samples of general population (μg/L): blood aluminum 214.00; blood chrome 92.82; blood manganese 21.43; blood nickel 20.59; blood copper 0.67; blood zinc 11.50; blood arsenic 0.55; blood cadmium 2.45; blood tin 0.00; blood antimony 1.92; blood lead 158.84; and blood mercury 1.19. The geometric mean of heavy metal content in hair samples of general population (μg/g): hair aluminum is 84.65; hair chrome 0.00; hair manganese 2.44; hair nickel 0.61; hair copper 28.49; hair zinc 136.65; hair arsenic 0.75; hair cadmium 0.46; hair tin 1.04; hair antimony 0.05; hair lead 8.97; and hair mercury 0.69. Some heavy metals were correlated with duration of residence, gender, age, smoking and drinking. This was the first time that simultaneously detecting heavy metal content in blood and hair was used to analyze the internal heavy metal burden in resident population of Pearl River Delta area. These data can serve as reference for further research.  相似文献   

9.
环境重金属污染物的生物有效性   总被引:24,自引:1,他引:23  
刘宗平 《生态学报》2005,25(2):273-278
利用生态系统研究了白银有色金属冶炼矿区周围环境中重金属的分布及生物有效性。结果表明 ,工厂在冶炼过程中已造成 Pb、Cd、Cu、Zn对周围环境不同程度的污染 ,其含量与距工厂的距离呈负相关 ;重金属在各种生物体内均有不同程度的吸收和累积 ,其吸收累积量随重金属和生物种类的不同而有差异 ;土壤的污染 ,使农作物和牧草中 Pb、Cd含量超过动物的最大耐受量和中毒的临界值 ;动物研究发现 ,肾脏、骨骼和肝脏是机体内重金属蓄积的主要器官。因此 ,放牧动物可作为环境重金属污染状况的标识 ,对评价重金属环境污染对当地人群的危害也有重要意义  相似文献   

10.
 本文研究了北京东郊污灌区重金属在作物—土壤中的迁移、分布、积累规律,证实本区蔬菜中汞含量比粮食作物约大3—15倍,比水果约大6—200倍。麦粒、糙米中的Cu、Hg、Cd、Pb、Ni的含量与土壤含量相关性不显著。架豆中重金属含量与土壤中重金属含量的相关性,只有Zn,Pb达显著水平。白菜土有机质含量与重金属含量相关性达显著水平,而白菜的重金属含量与土壤的重金属含量相关性却不显著。说明除了土壤中重金属的总量外,有效态含量的多少,是影响本区作物吸收积累重金属的主要因素。 本区施污泥的土壤和生长的作物Cd/Zn大部小于1%、盆栽试验证明:施用本区污泥污水对水稻生长发育的影响比施污泥灌清水的影响大些,因此,施用含重金属污泥时,最好不要超过5000斤/亩。大田和室内模拟试验证明:重金属从土壤中迁移到植物,由植物带走输出的量极少,其中以带走输出的Hg、Cd,As相对较多,带走输出的Pb、Cr相对的少些。  相似文献   

11.
The content of elements in rainwater is an indirect indicator of its occurrence in air dust. This is sometimes referred to as rain fallout and is investigated in applied environmental pollution monitoring schemes. The annual content of elements in rainwater may be recognized as good index for assessing influence of those environmental factors on human body. The possible relationship between the concentrations of selected elements in rainwater and the frequency of hospitalization by reason of angina pectoris, stroke, and peripheral venous thrombosis was investigated in the Opole Voivodship (Poland) area during the period 2000–2002. There is a relatively high or partly significant correlation between frequency of hospitalization by reason of these conditions and content of lead, cadmium, chromium, zinc, and chloride in rainwater. Significant gender-dependent differences were observed only in peripheral venous thrombosis, where important correlations with lead, cadmium, and chromium were found only in men.  相似文献   

12.
土壤中镉、铅、锌及其相互作用对作物的影响   总被引:18,自引:0,他引:18       下载免费PDF全文
通过作物盆栽模拟试验(砂壤质褐土、pH值8.2)揭示:土壤中分别施入镉(CdCl2)、铅[Pb(CH3COO)2]或锌(ZnSO4)其影响表现为,植物各器官镉的含量超过对照植物的数倍至500倍。土壤镉浓度<5ppm和<10ppm分别造成某些蔬菜和水稻的污染。铅主要积累在植物根部,土壤铅污染对作物的影响较小。锌主要积累在植物叶片和根部,对水稻产生生长抑制的土壤锌浓度临界值不大于200ppm,此浓度对旱作无影响。土壤中同时施入镉和铅,植物对镉的吸收增加。而土壤中镉的增加却减少了植物体内铅的含量。土壤中由于镉、锌或铅、锌相互作用的结果,水稻对它们的吸收都有增加。在旱地土壤锌浓度的增高,降低了植物对镉、铅的吸收。镉、铅、锌同时施入土壤由于相互作用的结果,除锌之外,植物对镉、铅的吸收有明显下降。评价土壤重金属污染,不仅要看它们的含量及其存在形态,而且要分析它们之间的相互作用(促进或拮抗)特点。  相似文献   

13.
Radian Corporation conducted an investigation of 29 waste sites at an air force base in New Mexico in partial fulfillment of the RCRA operating permit requirements for the facility. The contract required that the investigation be conducted under the Installation Restoration Program (IRP/CERCLA). In an effort to satisfy both RCRA and CERCLA requirements, a hybrid approach was taken for the risk assessment. Site contaminants ranged from petroleum and unconventional fuels to solvents, pesticides, and PCBs. A screening method was developed to classify the level of contamination at each of the 29 sites based on soil and groundwater sampling results. Under this method, sites were classified as “dirty,”; “clean,”; or “borderline.”; Dirty sites did not require a full‐scale risk assessment because some form of remedial action would be necessary. However, clean sites and borderline sites required a full‐scale risk assessment. For clean sites, the risk assessment served as justification for no further action; for borderline sites, the risk assessment determined whether or not remedial action would be required. The screening method used previously developed multipathway and multimedia models for estimating potential human exposure to environmental contaminants in the air, water, and soil through inhalation, ingestion, and dermal contact routes. Pathway exposure factors (PEFs), which combined information on human physiology, behavior patterns, and models of environmental transport, were used to determine the relationship between the concentration of environmental contaminants and human exposure. The PEF converts concentrations in environmental media to lifetime‐equivalent chronic daily intakes (CDI). Three exposure pathways contributing the greatest proportion of the risk were considered for screening these sites: (1) incidental ingestion of soil; (2) dermal contact with soil; and (3) ingestion of water. This project demonstrated that a screening approach could be used effectively to limit the number of full‐scale risk assessments required for a multisite investigation.  相似文献   

14.
This study was performed in order to analyze the relationships between hair zinc, lead, and cadmium with the kind of diet consumed (by recall of the diet consumed the previous 14 days), living area (urban or rural), tobacco smoking, and body mass index (BMI) among 419 individuals of the Canary Archipelago. Median values and interquartile range were 43 μg/g (18.50–132.50) for zinc, 4.09 μg/g (2.19–8.38) for lead, and 0.128 μg/g (0.05–0.30) for cadmium. We observed that hair zinc was markedly elevated among those consuming fish more frequently and, to a lesser amount, among those who consumed meat frequently, among those living in urban areas, and among those with BMI over 25 kg/m2, keeping a significant relationship with BMI. Hair lead was also higher among fish consumers, showed a trend to higher values among inhabitants of urban areas, and was lower among obese individuals. Hair cadmium was higher among those who consumed less vegetables and fruits. By multivariate analysis, introducing the variables meat, fish, and vegetable consumption, urban/rural; sex; age; and BMI values, we observed that fish consumption (beta?=?0.15) was the only variable independently associated to higher zinc levels; fish consumption (beta?=?0.15) and meat consumption (beta?=?0.17) were related to high cadmium levels, whereas meat consumption was significantly associated to higher hair lead levels (beta?=?0.15). Therefore, we conclude that hair zinc, cadmium, and lead seem to depend more heavily on dietary habits than on tobacco consumption or living in rural or urban areas.  相似文献   

15.
Environmental cadmium exposure and forearm bone density   总被引:3,自引:0,他引:3  
Environmental exposure to cadmium may give rise to osteomalacia combined with renal dysfunction, so called 'Itai-Itai disease', which was endemic in the heavily polluted area in Japan. The main focus of this study was to investigate whether environmental exposure to cadmium is associated with low bone mass in a population living near a smelter. A total of 790 persons (302 males and 488 females), who were all over 35 years old and resided in areas near a lead, zinc and cadmium smelter and in a control area in southeast China, completed a questionnaire, and bone mineral density was measured by SPA-4 single photon absorptiometry at the radius and ulna. Cadmium content of urine was determined by graphite-furnace atomic absorption spectrophotometry as a measure of dose. The present study shows that forearm bone densities were negatively correlated with urinary cadmium excretion (p < 0.001) and forearm bone density decreased linearly with age (p < 0.001) and urinary cadmium (p < 0.01), suggesting a dose-effect relationship between cadmium dose and bone mineral density. Based on the World Health Organization criteria, (bone mineral density < -2.5 SDs below the normal young adult), the prevalence of osteoporosis in women increased from 34.0% in the control area to 51.9% in the heavily polluted area (p < 0.01) among subjects over 50 years old, and the odds ratio value was 2.09 (95% CI: 1.08-4.03) for the highly polluted area compared with the control area. A striking observation in the study was a marked increase of the prevalence of fracture in the cadmium-polluted area in both sexes. It was concluded that environmental exposure to cadmium is associated with an increased loss of bone mineral density in both gender, leading to osteoporosis and increased risk of fractures, especially in the elderly and in females.  相似文献   

16.
董艺婷  崔岩山  王庆仁 《生态学报》2003,23(5):1018-1024
为了进一步研究镉、锌、铅 3种重金属元素间的相互作用以及对植物吸收重金属能力的影响 ,在模拟单一重金属污染试验研究的基础上 ,采用正交回归设计方案 ,研究了 Cd、Zn、Pb复合污染情况下紫花苜蓿和披碱草两种敏感性植物对 3种重金属的吸收效应。结果表明 ,在单一污染条件下 ,镉元素对紫花苜蓿生长的影响大于锌、铅 ,铅元素对披碱草生长的影响大于锌、镉 ;紫花苜蓿对于镉的吸收累积显著高于披碱草 ,植物内镉元素浓度最高达到 1 0 88.5 mg/kg,而披碱草对于铅元素的吸收则高于紫花苜蓿 ,植物内铅元素浓度最高达到 1 3 4 5 .5 mg/kg。在复合污染条件下 ,两种植物对铅、锌和铅、镉的吸收在不同浓度范围内分别存在存在着协同效应和拮抗效应 ;同时两种植物对锌、镉元素在实验涉及浓度范围内都存在着拮抗效应。这对于深入研究复合污染条件下重金属的土壤环境化学行为 ,对植物的综合毒性以及不同植物对重金属的吸收累积效应等 ,具有一定的参考意义  相似文献   

17.
在高分辨率影像提取福州市南台岛(仓山区)住宅用地的基础上,从覆盖研究区的30m×30m网格中随机选择50个样方进行表层土壤取样,进而分析这一快速城市化地区住宅用地表层土壤有机碳密度(Soil organic carbon density,SOCD)的变异特征及其影响因素。结果表明:城市地区住宅用地在剧烈的人类活动干扰下,土壤呈现明显的空间变异特征,其SOCD平均值为33.814t/hm~2,变异系数达72.8%,其中郊区村镇住宅用地0—20cm土层的SOCD高于城市居住用地72%,预示着村镇就地城市化后将造成土壤碳储量的下降;然而,表层土壤有机碳含量与密度在建成时间为0—5年和5—10年的城市住宅小区间无显著差异,只有住宅建成时间达到10—15年才有显著提高。基于湿度、热度、绿化率与物业管理费等因子构建的城市住宅区绿化环境管理质量指标,与城市居住区表层土壤有机碳含量及密度存在显著正相关,与土壤容重呈显著负相关,成为快速城市化地区影响SOCD变异的另一主要因素。  相似文献   

18.
The frequency of cytogenetic effects in spring barley intercalar meristem cells was studied in the presence of a range of different stressors. There was a non-linear dependence on the concentrations of 137Cs, Cd, Pb, and dichlorophenoxyacetic acid (2,4-D) herbicide contamination in the exposure ranges used. The frequency of cytogenetic effects increased at the lower concentrations of the pollutants more rapidly than at the higher concentrations. Contamination of the soil by lead at a concentration that meets the current standards for permissible content in soil, and by 2,4-D herbicide at the application levels recommended for agricultural use resulted in a significant increase in aberrant cell frequency. In these cases, the extent of the observed cytogenetic effects was comparable with the effect induced by a 137Cs soil contamination of 49.2 kBq/kg, a level that exceeds by 10-fold the maximum level permitted in radionuclide-contaminated areas where people are resident. In most cases, the experimentally observed combined effects of the pollutants studied differed from those expected from an additive hypothesis. When combined with 137Cs contamination, antagonistic effects became increasingly stronger when the second stressor was changed from cadmium to lead, and then to the herbicide, as measured both by tests of the 'frequency of aberrant cells' and the 'aberrations per cell'. Data from this study and previous reported literature suggest that synergistic increases in cytogenetic effects can be induced by the simultaneous influence of several stressors even at low intensities. This indicates that there is a capability for mutual intensification of the effects of environmental factors that actually occur in situations of low-level exposure.  相似文献   

19.
Summary Studies on levels of lead and cadmium of Indian flue-cured tobacco indicated that the leaf contained very low amounts of these heavy metals as compared to tobacco from other countries. Indian tobacco can therefore be adjudged as ‘safe and clean’ and least hazardous to the smoker. Of the two heavy metals, lead content of soils is higher than cadmium. But in the leaf, cadmium content is more than lead indicating that soil cadmium may be more available to tobacco and hence more readily absorbed by the plant than lead.  相似文献   

20.
The concentrations of heavy metals in both local environmental samples (water and crops) and in the whole blood of 1,152 local residents were determined by atomic absorption spectrometry. We calculated rate ratios and standardized mortality ratios based on age-, gender-, and cause-specific mortality for both the district and province. Multi-regression models were then used to evaluate the associations between the exposure to multiple heavy metals and cause-specific mortality in the studied population. Significant increases in the mean concentrations of cadmium, lead, and zinc in the blood samples were found to be associated with a substantially elevated all-cancer mortality rate in this high-exposure area (HEA). There were also significantly elevated mortality rates in the HEA for both sexes from a wide range of causes (all-cause), including cardiovascular disease (CVD), when compared with a low-exposure area (LEA). Further analysis showed positive correlations between exposure to both cadmium and lead and a higher risk of all-cancer mortality among women and for both sexes combined. In contrast, zinc exposure negatively correlated with the risk of cause-specific mortality, but this was not significant. These results of our current study thus reveal that long-term environmental exposure to both cadmium and lead is associated with an increased risk of all-cause, CVD, and all-cancer mortality, whereas zinc exposure showed a possible weak protection against death from CVD.  相似文献   

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