Relationship between cobalt,copper and zinc content of soils and vegetables

The relationship between cobalt, copper and zinc content of soils and the vegetables grown in them is discussed. Samples of soil and edible vegetables were taken from 15 different sites, corresponding to four agricultural areas exposed to different degrees of environmental pollution: high industrial and traffic, high industrial and urban, and low industrial and urban pollution. Elements were determined by atomic absorption spectroscopy. Variance analysis (ANOVA) was applied to cobalt, copper and zinc content of vegetables and soils in order to detect significant differences among soils of different areas and the vegetables grown there. The possible relationship between the heavy metal content of soils (total and extractable) and of the vegetables grown in them was estimated by the correlation coefficient value. Statistically significant correlations were observed between the total and extractable cobalt content of soils and of roots and bulbs (p < 0.1) and between the total copper content of soils and of inflorescences (p < 0.05). In the case of zinc no correlation was found.     

罗平土壤及烟叶主要中、微量元素含量分析

为了解云南罗平县植烟土壤和烤烟烟叶主要中、微量元素含量情况,测定了罗平县369个土壤和对应C3F等级烟叶的钙、镁、硫、铜、锌、铁、锰和硼含量,并评价了丰缺状况,分析了两者之间的关系。结果表明,罗平土壤中钙、镁、铜、锌、铁和锰含量普遍处于丰富和很丰富的水平,而硫和硼含量相对较低,普遍处于缺和很缺的水平,罗平土壤中有效中、微量元素存在空间上的广泛变异;烤烟生产上应适当增施硼肥。烟叶中硫、铜、锌和锰含量的平均值在适中范围内,铁含量较高,钙、镁和硼含量较低。土壤中有效中、微量元素的含量对烟叶中相对应的中、微量元素有促进作用。土壤中交换性镁对烟叶多种中、微量元素有促进或抑制作用,有效铜表现出了对锌的促进作用和对硼的抑制作用。     

Uptake of trace elements and PAHs by fruit and vegetables from contaminated soils

The aims of this study were to investigate the uptake of seven trace elements and five PAHs in crop plants in order to establish advice regarding consumption of fruit and vegetables grown in soils contaminated by trace elements and PAHs. In a field experiment, vegetables were grown in two contaminated soils and in a reference soil, whereas fruits were collected from uncontaminated and contaminated private gardens. The results showed elevated levels of several trace elements and PAHs in the vegetables from contaminated soil. Bioconcentration factors (BCF values), based on dry weight, were below 1, except for those of Cd in lettuce and carrot with peel from uncontaminated soil. In most cases, BCF values were decreasing with increasing concentrations in soil. From the heavily contaminated soil, BCF values for Pb in lettuce, potato, and carrot with peel were 0.001, 0.002, and 0.05, respectively, and those for benzo[a]pyrene were 0.004, 0.002, and 0.002, respectively. For most metals in most vegetables, linear regression showed good correlation between soil and crop concentrations. For PAHs, such good correlation was generally not found. The contents of contaminants in fruits were generally low and no correlation with the level of contamination in the soils was found.     

冀东典型蔬菜种植区设施土壤重金属特征

目的探究冀东典型蔬菜种植区(唐山市和承德市)设施土壤重金属特征。方法对设施大棚进行调查并采集表层土壤样品,检测其重金属,即镉(Cd)、汞(Hg)、砷(As)、铅(Pb)、铬(Cr)、铜(Cu)、锌(Zn)含量,并依据HJ/T 333—2006《温室蔬菜产地环境质量评价标准》进行了土壤质量评价。结果除As外,其他重金属均超过河北省土壤背景值(国家环境保护局),最高为Hg,为背景值的3.46倍。Cd与棚龄呈显著负相关关系(P<0.05)。从地理分布来看,Hg呈现西高东低的分布特征,而As、Pb则呈现南高北低的分布特征。从重金属单项质量指数来看,Cd、Hg、As、Cr、Zn均未超标;Cu、Pb超标率分别为7.37%和22.11%,属轻度污染。从重金属综合质量指数看,3.16%的土壤为超标土壤,属轻度污染,超标率较高的区县为隆化县、乐亭县、滦平县、宽城县和滦南县,重金属综合质量指数与土壤pH呈极显著负相关关系(P<0.01)。结论冀东典型蔬菜种植区设施土壤存在Cu、Pb的轻度污染现象,后续需要对蔬菜中的Cu、Pb进行调查以评估蔬菜产品的安全性。     

厦门市售蔬菜重金属、硝酸盐和亚硝酸盐污染研究及评价

为了解厦门市蔬菜中有害重金属、硝酸盐和亚硝酸盐的污染情况,于2004年8月至2005年12月从厦门市各超市、农贸市场、蔬菜批发市场和蔬菜产地上采集46个品种532份蔬菜样品,用国标法(GB/T5009.11-17-1996、GB/T5009.33-2003)分别分析蔬菜中的重金属、硝酸盐和亚硝酸盐的含量。结果表明,检测样品中Pb、Cd、As、Hg、硝酸盐和亚硝酸盐的平均值分别为0.0099、0.083、0.056、0.003、1090.3、0.59mg/kg;根据国家标准1-2,仅部分品种如菠菜、甘蓝、花菜、萝卜的铅超标,有潜在污染风险;大部分蔬菜中砷、汞、镉三种重金属的含量都较低,潜在的污染风险不大。硝酸盐污染程度严重的占36.5%;中、重度污染的占20.2%;轻度的占43.3%,硝酸盐含量依次为嫩茎叶菜类>根茎类>花菜类>瓜菜类>鲜豆菜>茄果类>水生蔬菜类,各样品间含量差别较大;而蔬菜中亚硝酸盐含量相对较低。     

土壤中铬含量对农产品安全性影响评价

目的 探索土壤中铬含量对农产品质量安全的影响。方法 采集农产品生产基地土壤样品120个,同步采集成熟农产品样品200个,测定土壤样品pH、全量铬和农产品样品总铬含量,协同分析土壤铬污染情况和农产品铬含量情况。结果 土壤铬含量风险筛选范围占9.17%,存在轻微铬污染。农产品中铬含量合格率达100%,安全性高。各类农产品对铬的富集能力排序为谷物＞叶菜类＞豆类＞芸薹属类＞茄果类＞瓜类,且吸收富集作用差异明显。各类农产品对铬的吸收富集作用与土壤pH关联性不强。结论 土壤受铬污染并不一定会造成农产品铬含量超标,这对受铬污染的土壤调整产业结构以保障农产品质量安全很有启发。     

Organochlorine pesticides in agricultural soil and vegetables from Tianjin, China

Samples of eight types of vegetables, the rhizosphere soils, and bulk soils were collected from two sites (A and B) in Tianjin, China for the determination of hexachlorocyclohexane isomers (HCHs) and dichlorodiphenyltrichloroethane and metabolites (DDXs). The average concentrations of total HCHs and DDXs in the bulk soils were 3.6 and 80.1 ng/g for site A and 102 and 235 ng/g for site B, respectively. Relative accumulations of HCHs and DDXs in the rhizosphere soil from site A but not site B were demonstrated. The concentrations of total HCHs and DDXs in vegetable roots were 3.6-60 and 4.2-73 ng/g for site A and 15-152 and 7.1-136 ng/g for site B, respectively. Difference in bioaccumulation among various vegetables, especially between tuber and fibrous vegetables was significant. DDXs in spinach and cauliflower from site B and lindane (gamma-HCH) in cauliflower from both sites and violet from site B exceeded the maximum residual limits. Linear correlation of log-transformed HCHs and DDXs contents between the vegetable roots and the rhizosphere soils suggests the direct uptake of HCHs and DDXs.     

Thorium in soil, vegetables, cereals and fruit

Thorium contents (alpha-activities of the naturally occurring isotopes Th-228, Th-230, and Th-232) were determined in soils, vegetables, cereals, and fruits. The thorium content of plants depends on the degree of contamination by soil resuspension and thus on the specific surface of the plants. The activity of the isotope Th-230 is almost the same as that of the main isotope Th-232. Th-228, with about the same activity as Th-232 in soil, increases to about 10-fold the activity in vegetables, 29-fold in sweet chestnuts and 740-fold in Brazil nuts. Thorium concentration factors from the soil to these vegetable products are calculated; they include the total concentration, not only the soluble portion of thorium.     

Availability of Cu,Zn and Mn in Soils: III.—Predictability of plant uptake

The influence of various chemical soil fractions Of Cu, Zn and Mn in conjunction with plant uptake of any one or two of the elements on the variability of plant uptake of one of them was evaluated by correlation and regression analyses. Plant and soil data were obtained from divergent Wisconsin soils. Inclusion of Zn uptake and the HCl-or EDTA-extractable soil Cu fraction in the regression equation resulted in very high predictability of Cu uptake by oats. High predictability of Zn uptake was likewise realized by using the Mg(NO₃)₂ or DTP A soil Zn fraction along with plant Cu uptake as determinants. Manganese uptake was best predicted by using plant Zn uptake and Mg (NO₃)₂-rextractable soil Mn as predictors. The extractant N ammonium acetate (pH 7)/0·01 M EDTA showed promise as a reliable soil test for predicting the concurrent plant availability of Cu, Zn and Mn in Wisconsin soils.     

An appraisal of currently used soil tests for available copper with reference to deficiencies in English soils

Eight soil tests for plant-available copper were used on twenty English soils of moderate to low copper status. The ability of these tests to predict plant copper uptake, tested in a pot trial, was compared using multiple regression analysis including other soil factors such as pH, organic matter and clay content. The EDTA soil test was found to give the best prediction of plant uptake from a regression equation including EDTA extractable soil copper, pH, free Mn and Fe oxide, clay and organic matter content.     

不同烟区烤烟含钾量差异初步研究

在3个烟区（山东安丘，贵州湄潭和福建永定）采用相同品种（K326）完成的一组四处理（无肥、饼肥、烟草专用肥，饼肥加烟草专用肥）大田试验结果。结果表明，不同烟区烤烟团棵期茎叶中的含钾量相似，随烟株进入旺长期和成熟期，不同烟区的烟叶含钾量出现明显差异，石灰性土壤烟区（山东安丘）烤烟旺长期叶片和初烤叶的含钾量（K％）仅为酸性土壤烟区（福建永定）的60％－40％。作者认为，这种差异的基本原因，是不同烟区土壤溶液中阳离子含量和组成的差异，石灰性土壤溶液中活性Ca,Mg的含量高，在与阳离子K的竞争中处于优势，抑制了烟株对钾的吸收，同时还提供了若干有助于提高烤烟含钾量的措施。     

溶出伏安法测定蔬菜中的铊

在0.025mol/L醋酸-0.025mol/L醋酸钠缓冲介质中加入EDTA(ethylene diamine tetraacetic acid),以差示脉冲阳极溶出伏安法测定蔬菜中的铊。铊浓度在5.0×10-4～1.0×10-1mg/L范围有良好的线性关系,检出限为1.0×10-4mg/L,回收率为97.0%～104%。对部分蔬菜的测定结果表明,铊污染土壤上种植蔬菜中铊含量显著高于空白土壤上种植的蔬菜。     

Evaluation of in Situ DGT Measurements for Predicting the Concentration of Cd in Chinese Field-Cultivated Rice: Impact of Soil Cd:Zn Ratios

DGT (diffusive gradients in thin-films) has been proposed as a tool for predicting Cd concentrations in rice grain, but there is a lack of authenticating data. To further explore the relationship between DGT measured Cd and concentrations in rice cultivated in challenging, metal degraded, field locations with different heavy metal pollutant sources, 77 paired soil and grain samples were collected in Southern China from industrial zones, a "cancer village" impacted by mining waste and an organic farm. In situ deployments of DGT in flooded paddy rice rhizospheres were compared with a laboratory DGT assay on dried and rewetted soil. Total soil concentrations were a very poor predictor of plant uptake. Laboratory and field deployed DGT assays and porewater measurements were linearly related to grain concentrations in all but the most contaminated samples where plant toxicity occurred. The laboratory DGT assay was the best predictor of grain Cd concentrations, accommodating differences in soil Cd, pollutant source, and Cd:Zn ratios. Field DGT measurements showed that Zn availability in the flooded rice rhizospheres was greatly diminished compared to that of Cd, resulting in very high Cd:Zn ratios (0.1) compared to commonly observed values (0.005). These results demonstrate the potential of the DGT technique to predict Cd concentrations in field cultivated rice and demonstrate its robustness in a range of environments. Although, field deployments provided important details about in situ element stoichiometry, due to the inherent heterogeneity of the rice rhizosphere soils, deployment of DGT in dried and homogenized soils offers the best possibility of a soil screening tool.     

重庆市菜园土壤与蔬菜硝酸盐和亚硝酸盐含量及相关性研究

研究重庆4 个农贸市场市售3大类19 种蔬菜73 个样品中硝酸盐含量及重庆市13 个主要蔬菜基地土壤和蔬菜的硝酸盐、亚硝酸盐含量及相关性。结果表明,重庆市售蔬菜不同种类及同种蔬菜不同部位的硝酸盐含量差异显著。大小顺序为叶菜类（X =1 619.73 mg/kg）＞茄果类（X =1 327.67 mg/kg）＞葱蒜类（X =
1 078.39 mg/kg）;莴苣叶（X=1 567.91 mg/kg）＞莴苣茎（X=1 871.62 mg/kg）。叶菜类全部超过了一级标准,污染指数高达9.09,污染程度最为严重;茄果类和葱蒜类超过一级标准的样本占81.3%和87.5%,污染指数分别高达8.85和6.56。重庆市13 个主要蔬菜基地不同蔬菜以及同种蔬菜不同部位的硝酸盐含量差异也显著,大小顺序为萝卜叶（X=745.97 mg/kg）＞莴苣茎（X=730.88 mg/kg）＞莴苣叶（X=693.32 mg/kg）＞白菜（X=617.63 mg/kg）＞萝卜根（X=575.74 mg/kg）。土壤中NO3－-N含量差异也显著,大小顺序为种植莴苣的土壤（X=75.24 mg/kg）＞种植白菜的土壤（X=47.05 mg/kg）＞种植萝卜的土壤（X=33.42 mg/kg）。蔬菜可食部分的硝酸盐与土壤中的NO3－-N含量呈极显著正相关关系,线性方程y=407.872＋4.796x。供试重庆市13 个主要蔬菜基地土壤及蔬菜可食部分的NO2－-N含量均较低且差异不显著,蔬菜中的亚硝酸盐含量和土壤中的NO2－-N含量也无显著相关性。     

Phytoavailability, human risk assessment and transfer characteristics of cadmium and zinc contamination from urban gardens in Kano, Nigeria

BACKGROUND: Quantitative data about phytoavailability and transfer into consumed plant parts for heavy metals in intensively managed urban vegetable production areas of sub‐Saharan Africa are scarce. We therefore studied the transfer of zinc (Zn) and cadmium (Cd) from soil to the root and subsequent translocation to edible portions of four vegetables in six urban gardens. RESULTS: While respective diethylenetriaminepentaacetic acid (DTPA)‐available Zn and Cd concentrations ranged from 18 to 66 mg kg^?1 and from 0.19 to 0.35 mg kg^?1, respectively, in soils, total Zn and Cd were 8.4–256 mg kg^?1 and 0.04–1.7 mg kg^?1 in shoot parts. Metal transfer factor (MTF) ratios were higher in Zn (0.2–0.9) than in Cd (0.1–0.6). Our data suggest that total Zn concentration in soil is a reliable indicator to assess its transfer from soil to crop in lettuce, carrot and parsley, while for Cd DTPA‐extractable concentration may be used to estimate soil–crop transfer of Cd in amaranthus and carrot. Overall, Cd was more easily translocated to the aerial plant parts than Zn. CONCLUSION: Zinc and Cd accumulation by vegetables in our soils is mainly a metabolically controlled process. Such accumulation can contaminate the ecosystem but under our conditions intake and ingestion of these metals will likely have to occur over a prolonged period to experience health hazard. Copyright © 2011 Society of Chemical Industry     

Uptake of metals during chelant-assisted phytoextraction with EDDS related to the solubilized metal concentration

The use of chelants to enhance phytoextraction is one method being tested to make phytoextraction efficient enough to be used as a remediation technique for heavy metal pollution in the field. We performed pot experiments with sunflowers in order to investigate the use of the biodegradable chelating agent SS-EDDS for this purpose. We used singly and combined contaminated soils (Cu, Zn) and multimetal contaminated field soils (Cu, Zn, Cd, Pb). EDDS (10 mmol kg(-10 soil) increased soil solution metals greatly for Cu (factor 840-4260) and Pb (factor 100-315), and to a lesser extent for Zn (factor 23-50). It was found that Zn (when present as the sole metal), Cu, and Pb uptake by sunflowers was increased by EDDS, butin multimetal contaminated soil Zn and Cd were not. EDDS was observed in the sunflower roots and shoots at concentrations equal to metal uptake. The different metal uptake in the various soils can be related to a linear relationship between Cu and Zn in soil solution in the presence of EDDS and plant uptake, indicating the great importance of measuring and reporting soil solution metal concentrations in phytoextraction studies.     

Pesticides and heavy metals levels in Egyptian leafy vegetables and some aromatic medicinal plants

A total of 835 samples of leafy vegetables and some aromatic medicinal plants were collected from five different areas of Egypt during 1999. Ninety-seven per cent of the leafy vegetables were contaminated with heavy metals with 39% exceeding the maximum limits for each element. Cadmium was detected in 78 of 116 samples of leafy vegetable, although without any exceeding the maximum limits. However, lead was detected in 99 samples, of which 39 exceeded the maximum limits (0.3 mg kg^-1) and 56 medicinal plant samples of 70 had lead levels above 0.5 mg kg^-1. Copper was detected in 69 medicinal plant samples, of which 58 samples contained levels higher than 10 mg kg^-1. However, cadmium was only found in 43% of samples with only two of 70 samples above the maximum limit. Seventy-three per cent of the samples of medicinal plants were contaminated with pesticide residues, of which 44% contained amounts that exceeded maximum residue limits. Malathion was the most frequently found pesticide residue, being detected in 203 of 391 (52%.) samples, followed by profenofos, which was detected in 131 of 391 (33%) samples.     

Soil tests for available copper and zinc in soils of Western Nigeria

Four soil tests for copper and zinc were evaluated for their ability to predict Cu and Zn uptake by oats (Avena sativa, L., Lodi var.) grown on 28 soils from Western Nigeria. Statistical analyses showed that EDTA was a better extractant for predicting Cu uptake than was DTPA, 0.1 N -HCl or 1 N -HCl. Copper uptake was more strongly correlated with inorganic soil fractions than with organic matter and was not significantly affected by soil pH. The best prediction of Zn uptake was provided by a combination of 0.1 N -HCl extractable Zn, pH, organic matter and the silt plus clay fraction in a multiple regression analysis. All four extractants predicted plant Zn uptake better on soils of pH less than 6.0 than on soils of pH greater than 6.0. A significant amount of Cu and Zn in the soils appeared to be associated with sesquioxides, part of which was available for plant use.     

Heavy metal concentrations and enzyme activities in soil from a contaminated Korean shooting range

Soil enzyme activities and heavy metal concentrations (Cd, Zn, Cu and Pb) were measured at a general shooting range in South Korea. Total heavy metal concentrations varied with pH, and were negatively correlated with moisture content and organic matter. Most enzyme activities (dehydrogenase, acid phosphatase and beta-glucosidase) and ATP values (measure of biomass) were lower in polluted soils, especially in bald spots contaminated by heavy metals and TNT (2,4,6-trinitrotoluene). These data indicate that concentrated shooting activity inhibits enzyme activity and microbial growth. Soil enzyme activities in richly vegetated spots around the general shooting range were higher (2- to 3-fold) than in bald spots, but lower in areas of heavy metal contamination. Our results demonstrate that the dominant plant species in richly vegetated spots accumulated heavy metals from soils, and suggest certain plants may be useful for decontaminating polluted soil.     

Cadmium content of vegetable foods in the effective range of a lead smelting plant]

In the effective range of a lead smelting plant, the repercussions of cadmium emissions (mainly past) on vegetables, fruit, soil and drinking water as well as of immissions were investigated by means of atomic absorption spectrometry. As compared to the "normal" cadmium level, the cadmium contents in vegetables and fruit were some 2- to 85-fold higher; and those in soils, some 70- to 230-fold. The mean contents in vegetables ranged from 0.4 to 25.5 p.p.m. (on a dry-weight basis); those in fruit, from 0.09 to 1.17 p.p.m. Cadmium concentrations varying from 6.8 to 22.8 p.p.m. were found in soil samples. The drinking water contained 0.009 p.p.m. of cadmium. The mean cadmium contents in the atmosphere and the sedimentary dust were 0.007 mg/m3 and 0.550 mg/m2/30d, respectively. In the territory investigated, the total human uptake of cadmium supplied by vegetables, fruit, potatoes, drinking water and air is 3.3-32.6 microgram/d. The following cadmium levels were found in human organ samples obtained at necropsy: right and left renal cortex, 33.99 and 35.98 p.p.m., respectively; liver, 3.14 p.p.m.; lungs, 0.63 p.p.m.; pancreas, 1.47 p.p.m.; brain stem, 0.16 p.p.m.