Distribution of heavy metals in rice farming soils

The distribution of Cd, Co, Cu, Ni, Pb, Zn, Mn, and Fe in soils dedicated to rice crops have been studied. Total content and extractable fraction have been determined by acid digestion and extraction with EDTA, respectively. A method of selective sequential extraction (SSE) has been applied to determine the fraction of the metals bound to organic matter, soluble plus exchangeable, precipitated with carbonates, associated to Fe and Mn amorphous oxides, precipitated with sulfides, and the residual; all the elements show their most important fraction as precipitates, mainly as forms of sulfides and carbonates. The forms available by plants and bound to the organic matter are less represented, except for Cu and Ni.     

Subchronic effects of methylmercury on plasma and organ biochemistries in great egret nestlings

In recent years, high concentrations of mercury have been found in wading birds in Florida, USA. Great egret (Ardea alba) chicks (2 weeks old) were dosed orally daily with the equivalent of 0, 0.5, or 5 microg/g Hg as methylmercury chloride in the diet for up to 12 weeks. Weakness of the legs or paralysis occurred in all high-dosed birds. Geometric mean blood Hg concentrations were 0.17, 10.3, and 78.5 microg/g (wet wt), respectively. Mercury concentrations for organs (microg/g wet wt), including brain (0.22, 3.4, and 35, respectively), liver (0.34, 15.1, 138, respectively), and kidney (0.28, 8.1, and 120, respectively), increased in a dose-dependent manner. Total glutathione (GSH) peroxidase activity was significantly lower in the plasma, brain, liver, and kidney of the high-dosed group. Plasma aspartate aminotransferase activity increased with mercury treatment, whereas lactate dehydrogenase activity decreased. Four other plasma chemistries were decreased significantly in the high-dosed group and included uric acid, total protein, albumin, and inorganic phosphorus. Lipid peroxidation increased in liver (low and high dose) and brain (high dose). Tissue changes in concentrations of reduced thiols included decreased total thiols and protein-bound thiols in liver, decreased protein-bound thiols in kidney, and increased GSH in kidney and brain. Activities of GSH S-transferase and oxidized glutathione reductase increased in liver. In kidney, GSH S-transferase and glucose-6-phosphate dehydrogenase activities increased with mercury dose. These findings, including apparent compensatory changes, are compared to other Hg studies where oxidative stress was reported in egrets, herons, and diving ducks in the field and mallards in the laboratory.     

Impact of local agricultural and industrial practices on organic contamination of little egret (Egretta garzetta) eggs in the Rhone Delta, southern France

The purpose of this study was to determine the importance of the effects of local agricultural and industrial activities on the contamination of little egret eggs laid in the Camargue area, a protected wetland area in the Mediterranean region. Despite the fact that human activity is widespread in the Camargue, concentrations of lindane (0.01-0.7 microg/g wet wt) and of polycyclic aromatic hydrocarbons (<0.5 microg/g wet wt) do not seem to be deleterious-at least for herons. Residues of dichlorodiethyltrichlorethylene (DDE) were usually below 1 microg/g wet weight. The principal threat comes from high concentrations of polychlorinated biphenyls (PCBs; 0.1-12 microg/g wet wt), which are known to have teratogenic effects in other bird species at similar concentrations and are thought to originate locally (sediments of the delta and industrial complex of Fos/Mer). For this reason, particular interest should be focused on the water/sediment quality of the Rh?ne River (France), on industrial sewage, and on wildlife contamination. A significant but weak link between colony site and lindane concentration was detected in eggs and may be attributed to the fact that our egg collection from each sampled colony was not synchronized with pesticide spread. A stronger site effect was observed for PCBs. Eggs collected near the industrial complex of Fos/Mer (petroleum, power plants) displayed the highest median concentration and the most contaminated eggs. Such results warrant thorough monitoring of this colony.     

Distribution of heavy metals in atmospheric air of the arid zones in Central Asia

The concentrations of heavy metals (HMs) in the airborne particulate matter (PM) from the background areas in Сentral Asia, namely, Abramov Glacier, Sary-Chelek Biospheric Reserve, and Chatkal Biospheric Reserve, were studied by using a high sensitive neutron activation analysis. The annual concentration change in HMs in the PM from Аbramov Glacier was investigated in more detail as an environmental clean area compared to other remote areas. It was found that the concentrations of HMs in the PM from Abramov Glacier varied from 5,960 ng/m³ for Fe to 0.0005 ng/m³ for Au. High concentrations of Au, Cr, Sb, Sc, Fe, Co, and PM were observed in summer season due to the contribution of soil dust from the arid territories. A general increase in the concentrations of Hg, Zn, and Br in the PM of Аbramov Glacier in a cold season specified mainly anthropogenic sources. Data of lognormal trends for the distribution of HMs in the PM of Abramov Glacier showed that a strongly pronounced bimodal distribution was characteristic for Au, Sb, Hg, Na, Co, Zn, and PM. The high concentration of Fe, Na, Sb, and Sm in the fractions containing large particles of PM was related to the contribution of the local lithogenic natural aerosols. The high concentration of Cr, Zn, Sb, Br, Na, Cu, and Au in the fractions containing small particles less than 0.4 μm might be related to the contribution from the thermal power stations, metallurgical enterprises, forest fires, etc. The obtained data are important for an estimation of background level pollution of atmospheric air of the remote regions in Central Asia with heavy metals.     

Accumulation of heavy metals in cereal crops and ways of reducing their levels

The study deals with the levels of heavy metals in the raw grain grown in the agricultural lands of the Oryol Region and provides the results of a trial of a complex enzymatic agent based on phitase and succinic acid used to reduce the levels of heavy levels in the wheat and rye grains during manufacture of grain bread. The use of the complex-acting enzymatic agent based on phitase obtained from the fungus Penicillium canescens in combination with 0.1% succinic acid of the mass of wheat and rye grains when the latter is prepared for the manufacture of grain bread has been established to reduce the concentrations of nickel, lead, cadmium, and chromium, by lowering the levels of MAFAM, spore-forming bacteria, moulds, and yeasts in the raw materials.     

某金矿综合回收伴生金属试验研究

近几年我国的黄金行业迅猛发展,包括金矿的开采。金矿的生产工艺一般包括凿岩、破碎、搬运、研磨、冶炼等过程,整个开采过程和尾矿矿渣的处理阶段均会释放多种重金属（如铜、铅、汞）。重金属具有长期性、隐蔽性和不可逆性的特点,不仅会对环境造成污染还会对矿址周围居民及矿工的健康形成威胁。机体铜过量与多种疾病如阿尔茨海默病和糖尿病之间有密不可分的关系,铅摄入过多则会导致DNA损伤及氧化损伤,严重则可致癌,汞在体内累积超标则会损害多个器官系统。了解金矿开采释放重金属的途径及重金属对人群产生的健康损伤,有助于金矿周边居民采取防护措施,保护健康。     

产妇和新生儿体内重金属水平及其影响因素分析

目的了解某地区产妇及新生儿血砷、汞和铅的水平,分析其相关影响因素。方法在某地区随机抽取A、B两所医院,选择2012年4—5月间住院分娩的产妇共226名,采集产妇静脉血和新生儿脐带血,采用电感耦合等离子体质谱法测定全血中砷、汞和铅的浓度,并对产妇进行问卷调查。结果 226对产妇和新生儿血铅浓度范围分别为2.65~67.00μg/L和4.05~70.89μg/L,均低于100μg/L的限值;A医院产妇和新生儿血砷平均浓度分别为1.20μg/L和1.23μg/L,均高于B医院(0.62μg/L和0.71μg/L),差异具有统计学意义(P0.05),血汞和血铅浓度差异均无统计学意义(P0.05);新生儿脐带血中砷、汞和铅浓度与产妇静脉血中同种元素浓度呈显著正相关(P0.01),相关系数分别为0.925、0.832和0.765;多重线性回归分析结果显示,家庭年收入越高,产妇及其新生儿血砷浓度越高(P0.05);产妇文化程度则对血铅水平有显著影响,文化程度越高,产妇及其新生儿血铅浓度越低(P0.05)。结论该地区产妇和新生儿体内砷、汞、铅暴露水平较低,但胎盘对重金属缺乏有效屏障作用,仍应采取有效措施减少产妇和新生儿重金属暴露。     

西安城墙内古城区域土壤重金属分布富集特征及环境风险

目的 分析西安城墙内古城区域土壤重金属的分布富集特征和环境风险.方法 以西安市城墙内城市表层土壤为研究对象,随机采集67个土壤样品.通过X-射线荧光光谱仪、土壤重金属积累速率、潜在生态风险和人群健康风险评价来分析土壤重金属Cr、Co、Pb、Sr、Zn含量分布、富集特征以及环境风险.结果 除Zn含量外其他4种重金属的平均含量都超过陕西省土壤背景值,其中Pb和Co的平均含量分别达到了背景值的2.74和3.07倍.HAKANSON潜在生态风险指数评价表明,Pb和Co元素属于强风险等级,其他元素轻微,5种重金属总的潜在生态风险指数RI=34.92,属于中等风险.人群健康风险评价表明,5种重金属的非致癌风险指数都小于1,但儿童小于成人,尤其是重金属元素Cr和Pb.另外,重金属Cr对儿童和成人存在一定的致癌风险,且元素Cr和Co致癌风险儿童小于成人.结论 重金属Pb、Cr和Co是本区域最主要的环境风险因子,特别需持续监测和及早采取预防措施.     

我国113个城市大气颗粒物污染的健康经济学评价

  目的  了解山东省潍坊市大气颗粒物中6种重金属元素的时间、空间分布及其来源,评价其人群健康风险。  方法  于2014年1 — 10月在潍坊市5个采样点采集PM₁₀和PM_2.5样品,采用原子吸收法分析6种重金属元素含量,因子分析法识别其主要来源,采用美国环保署推荐的健康风险评价模型进行呼吸途径摄入的人群健康风险评价。  结果  PM₁₀和PM_2.5样品中除了Cd浓度水平具有季节差异（P < 0.05）外,Pb、Cu、Mn、Ni、Cr浓度水平均无季节差异（P > 0.05）,而6种重金属元素浓度水平均表现为功能区差异（P < 0.05）;因子分析结果表明,PM₁₀中重金属主要来源于交通污染、工业污染和道路扬尘,分别占44.85 %、22.09 %和18.16 %;PM_2.5中重金属主要来源于工业污染、道路扬尘和交通污染,分别占48.54 %、23.60 %和14.10 %;颗粒物样品中重金属通过呼吸道暴露的非致癌风险均 < 1,致癌风险接近于阈值水平。  结论  潍坊市普通人群吸入颗粒物中重金属的非致癌风险处于可接受水平,但致癌风险接近阈值范围。     

佛山市禅城区蔬菜重金属污染现状及对人体健康风险分析

目的了解佛山市禅城区居民食用蔬菜重金属的污染状况,评价重金属经蔬菜途径摄入的健康风险。方法按照均匀分散多点的原则随机采集佛山市禅城区城郊4个主要种植地及市区内4个主要市场售卖的根茎、瓜果、叶菜3大类别73份蔬菜,对样品的锌（zn）、铜（Cu）、镉（cd）、铅（Pb）、铬（Cr）5种重金属元素含量进行测定。采用单因子污染和尼梅罗综合污染评价指数法评价蔬菜重金属污染状况,采用暴露剂量一反应外推法对蔬菜重金属进行健康风险评价。结果所抽取的蔬菜样品中有46．6％（34／73）的蔬菜重金属含量超标,Ph和cr超标率分别为32．9％（24／73）和19．2％（14／73）,2种金属同时超标的有4份,其余金属无超标。根茎类和瓜果类的综合污染指数分别为1．27及1．06,属轻度污染,主要受污染的品种为马铃薯、芹菜、丝瓜、茄瓜;叶菜类的综合污染指数为0．65,属安全级别;蔬菜中Cr、Cd、Ph、zn、cu的年平均个人摄入健康风险评价结果分别为4．43×10^-6、4．44×10^-6、7．40×10^-8、8．18×10^-9、1．02×10^-7,联合作用评价结果为4．48×10^-4,高于美国环保局与国际放射防护委员会分别推荐的标准。结论佛山市禅城区居民经蔬菜途径摄入重金属对人体具有一定潜在的健康风险,其风险主要来自化学致癌物Cr。应加强对蔬菜从种植至市场各环节监督和管理,确保人们的饮食安全。