四种抗寒花卉对镉的生理响应和富集特征

以矮型四季菊、羽扇豆、欧报春和虞美人等冬春季常见花卉为试验材料,通过盆栽试验,研究了不同浓度Cd处理下4种花卉对Cd的生理响应和富集特征,探讨利用这4种花卉在冬春季寒冷时期修复Cd污染土壤的可行性,为提高植物修复技术的效率提供参考。结果表明:(1)在所有Cd处理下,羽扇豆各部位生物量与对照均无差异;欧报春仅根系生物量在80 mg·kg^-1Cd处理时显著低于对照,为对照的74.51%;矮型四季菊和虞美人全株生物量分别在Cd处理浓度高于10、40 mg·kg^-1时开始显著低于对照,并在80 mg·kg^-1Cd处理时全株生物量均达到最小值,分别为对照的41.21%和64.15%。(2)在所有Cd处理下,羽扇豆体内抗氧化酶活性均显著高于对照,MDA含量与对照无显著性差异,清除活性氧能力最强,未受到伤害;欧报春体内抗氧化酶活性升高幅度较小,MDA含量和REC有小幅度增加,清除活性氧的能力较强,受到的伤害程度较低;矮型四季菊和虞美人对活性氧清除能力最差,受到了严重的氧化伤害。(3)在所有Cd处理下,Cd在矮型四季菊体内的分布均为地上部>根系,BCF和TF均大于1,地上部含量和富集量最大值分别为136.20mg·kg^-1和1118.20μg·plant^-1;Cd在羽扇豆、欧报春、虞美人体内表现为地上部<根系,TF均小于1,地上部Cd含量、富集量、BCF和TF均为羽扇豆>欧报春、虞美人。综上所述,与欧报春和虞美人相比,矮型四季菊对Cd耐性相对较差,但对Cd有较强的吸收转移能力,适合用于冬春季Cd污染土壤的修复;羽扇豆对Cd的耐性强,对Cd吸收转移能力也较强,也适合用于冬春季Cd污染土壤的修复。     

美人蕉对镉的胁迫反应及积累特性

美人蕉(Canna indica)是我国城区普遍栽植兼具绿化、观赏和净化环境等重要价值的地被植物。为研究美人蕉对Cd的胁迫反应及积累特性, 使用盆栽方法对美人蕉进行不同含量水平Cd处理, 测定其生长过程中部分形态、生态、生理指标的变化和收获后体内Cd含量。结果表明, Cd含量小于1 mg·kg^-1时对美人蕉生长影响不大, 大于5 mg·kg^-1时抑制美人蕉生长。Cd含量小于5 mg·kg^-1时延长了美人蕉的花期。随着Cd含量的增大, 美人蕉根系活力、叶绿素含量和含水量逐渐降低, 可溶性糖含量先升高后降低, 游离脯氨酸含量和细胞膜透性逐渐升高。Cd在美人蕉体内的分布为根系>地上部分, 随着Cd含量的增大, 美人蕉根系和地上部分Cd含量逐渐升高、富集系数和转运系数逐渐降低; Cd含量为20 mg·kg^-1时美人蕉对Cd的积累量最大, 为5.89 mg·株^-1。综合分析美人蕉的生长、生理生态变化及富集Cd的能力, 美人蕉适于土壤Cd含量小于1 mg·kg^-1条件下的园林应用。     

芦竹对不同重金属耐性的研究

研究芦竹(Arundo donax)在不同重金属污染湿地中的耐毒性能,测定了不同生长时段芦竹的生物性状和叶绿素含量,以及土壤中重金属含量的变化.结果表明,芦竹分别在浓度为100 mg·kg^-1左右的CuCu²⁺、Pb²⁺、Cd²⁺、Zn²⁺、Ni²⁺、Hg²⁺和50 mg·kg^-1以下的Cr⁶⁺污染环境中能正常成活,在40 d的生长期内,植物体内叶绿素有不同程度降低,下降比率在20%～56%,植物出现叶片软化,叶尖枯黄等症状,但植株仍呈现增长趋势.与对照植物相比较,在重金属胁迫下,植株细长,茎、叶呈黄绿色,除Cr⁶⁺、Hg²⁺外,植物高度基本不受重金属胁迫的影响.芦竹在高浓度(100mg·kg^-1)Cr⁶⁺污染环境中耐性较弱,表现出生长缓慢,部分地下茎腐烂,叶片短时间内出现枯萎等症状.结果还表明,土壤中重金属浓度随植物生长期增长而降低,除被植物吸收,植物挥发外,还存在着重金属向根际圈环境迁移的趋势,根周边湿土中重金属含量,明显高于试验缸外围湿土中重金属含量.可以认为,芦竹具有生物量大,根系发达,适应性强等特点,对修复湿地重金属污染蕴藏着巨大潜力,研究芦竹在植物修复技术中的应用,具有一定的现实意义.     

铜尾矿区土壤与凤丹植株重金属富集研究

对安徽铜陵铜尾矿区凤丹种植地的土壤和凤丹中重金属污染状况进行了研究.结果表明,尾矿库区种植地极端贫瘠,有机质含量仅1.1～3.4g·kg^-1,而土壤Cu、Cd、Pb、Zn含量皆高于对照土壤,其中Cu含量达587.43～1176.44mg·kg^-1,Cd含量达3.08～5.16mg·kg^-1,约达国家土壤二级标准的10倍.凤丹各部位的Cu、Cd和Pb含量均超过了药用植物的限量标准,尤其是根皮部位Cu含量达31.50～64.00mg·kg^-1,Cd含量达0.98～1.45mg·kg^-1,超出标准1.6～3.6倍,表明种植地和凤丹都受到严重污染.凤丹不同部位中的Zn、Cd、Pb和Cu分别以茎、叶、叶和根皮中的含量最高.凤丹对Cd、Zn的富集比Cu和Pb高,但在根皮中的富集系数均较小.     

Cd胁迫下苎麻的生长响应与富集、转运特征研究

通过盆栽试验,分析了苎麻湘苎三号在Cd胁迫下生长响应及其富集、耐性和迁移特征.结果表明,低浓度Cd处理(≤100mgmg·kg^-1)能促进苎麻生长发育,株高、茎粗、有效分蘖数和生物量都有所增加,以50mg·kg^-1胁迫处理最佳;此后则随处理浓度增加抑制效应越明显,到500mg·kg^-1时,各营养生长指标较对照显著减少,但仍生长较好,表明苎麻对重金属Cd胁迫具有很强的耐性.地下部与地上部Cd含量随处理浓度提高而增加,至500 mg.k g-1浓度时达最高值,分别为221.95mg.kg-1和390.61mg·kg^-1.苎麻Cd富集系数和转运系数分别为0.47～1.10和0.57～0.94.因此,苎麻不属于Cd超富集植物,而只是Cd富集植物,鉴于其具有根系发达、保水固土能力强和地上部生物量大等特点,苎麻是目前重金属Cd污染修复较理想的植物.     

大花萱草对镉的耐性及积累特性

通过盆栽试验研究了大花萱草对镉(Cd)的耐性及积累特性。结果表明:Cd浓度为0.5mg·kg-1时刺激大花萱草的生长,大于5mg·kg-1时抑制大花萱草生长,Cd浓度小于5mg·kg-1时延长了大花萱草的绿期和花期;随着Cd浓度的增大,大花萱草根系活力、叶绿素含量和含水量逐渐降低,游离脯氨酸和可溶性糖含量先升高后降低,细胞膜透性逐渐升高;Cd在大花萱草体内分布为根系>地上部分,随着Cd浓度的增大,大花萱草根系和地上部分Cd含量逐渐升高、富集系数和转运系数逐渐降低;Cd浓度为20mg·kg-1时大花萱草对Cd的积累量最大,为1.489mg·株-1。综合分析大花萱草的生长、生理变化及富集Cd的能力,大花萱草适用于浓度小于1mg·kg-1的Cd污染土壤的修复。     

铊和镉胁迫对芦竹生长及光合特征的影响

芦竹(Arundo donax)对多种重金属都有较好的耐受性,是植物修复技术较理想的选择,而关于芦竹对Cd和Tl胁迫生理反应的相关研究却较少,为了有效治理Cd和Tl的污染,本研究以芦竹为材料,通过添加不同浓度重金属Tl(4,10和20 mg·kg~(-1))、Cd(50,100和200 mg·kg~(-1))进行芦竹盆栽试验,测定芦竹的株高、分蘖数、叶绿素含量、光合生理指标以及Tl和Cd在芦竹中的累积量,探讨芦竹对Tl和Cd胁迫的响应机制。结果表明:Tl(4~20 mg·kg~(-1))和Cd(50~200 mg·kg~(-1))对芦竹株高、分蘖数以及叶绿素含量均无显著影响(P0.05);芦竹体内Tl和Cd含量随着Tl和Cd浓度的升高呈上升趋势,芦竹体内Tl含量的分布规律为根茎叶,Cd含量的分布规律:Cd浓度50 mg·kg~(-1)时为茎叶根,Cd浓度100和200 mg·kg~(-1)时为根茎叶,表明Tl和Cd主要分布在根部,芦竹对Tl、Cd有一定的富集能力。Cd和Tl处理均显著降低芦竹叶片的胞间CO2浓度,在Tl浓度为10 mg·kg~(-1)时,净光合速率、气孔导度和蒸腾速率得到显著提高,当Cd浓度为50 mg·kg~(-1)时,净光合速率、气孔导度和蒸腾速率得到显著提高。这表明芦竹对重金属Cd和Tl有较强的耐受性,可为Cd和Tl污染土壤的治理和修复提供参考。     

中国沙棘幼苗对土壤镉生理耐性和富集转运特征的性别差异

为探究中国沙棘对土壤镉(Cd)胁迫的性别响应差异,该研究以中国沙棘2年生幼苗为材料,利用盆栽试验研究在不同浓度Cd处理下(0(CK)、25、50、100和200 mg·kg^-1)雌、雄株幼苗的生长、叶片生理特性以及Cd富集特征的差异。结果表明：(1)Cd处理下中国沙棘幼苗雌、雄株的株高和基径生长以及各器官生物量均表现出低浓度(<50 mg·kg^-1)促进,高浓度(> 100 mg·kg^-1)抑制的现象;低浓度Cd处理下雌株的株高、基径增长率和生物量的增幅均高于雄株;高浓度Cd处理下(200 mg·kg^-1)雄株株高增长率、叶生物量和总生物量分别较CK显著降低,而雌株均未显著下降。(2)随着Cd浓度升高,雌、雄株叶片光合色素含量和抗氧化酶活性呈先升后降的变化趋势,丙二醛(MDA)和渗透调节物质含量呈上升趋势;Cd浓度为50～200 mg·kg^-1时,雌株叶片的光合色素含量、抗氧化酶活性和渗透调节物质含量均高于雄株,而MDA含量始终低于雄株。(3)随着Cd浓度升高,雌、...     

镉胁迫对紫花苜蓿幼苗生理特性和镉富集的影响

以"甘农三号"紫花苜蓿幼苗为材料,在水培条件下,探究了在10 d内不同浓度(0～2.0 mmol·L^-1)镉(Cd)胁迫对其根长、茎长、生物量、叶绿素和丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、Cd富集及其亚细胞分布的影响。结果表明:低浓度(0.125 mmol·L^-1) Cd能促进幼苗根和茎的生长,增加叶片叶绿素含量,较高浓度(0.5～2.0 mmol·L^-1) Cd显著抑制幼苗根和茎的生长,叶绿素及生物量显著降低; Cd胁迫使MDA含量显著增加,而SOD和POD活性显著增强,其中Cd胁迫浓度为0.5mmol·L^-1时,SOD和POD活性达到最大值,这可能是植物对环境胁迫的一种应激保护反应; Cd在各亚细胞组分中的含量依次为细胞壁>细胞质>线粒体>叶绿体,且均随Cd胁迫浓度的升高而增加。当Cd胁迫浓度为0.125 mmol·L^-1时,水培10 d的紫花苜蓿幼苗单株地上部对Cd的净化率最高可达0.214%,而整盆植株在单位体积内对Cd的净化率最高可达15.5%;当Cd胁迫浓度为2.0 mmol·L^-1时,紫花苜蓿幼苗地上部Cd含量达89.36μg·g-1。这些结果表明紫花苜蓿对Cd具有很强的富集能力,虽未达到Cd超富集植物的临界标准,但从植株生物量、耐Cd能力、富集Cd量及对Cd的净化率等方面综合考虑,紫花苜蓿在Cd污染土壤的植物修复中具备良好的应用价值。     

镉和铅污染对烤烟根区土壤微生物及烟叶品质的影响

通过盆栽试验,研究了Cd和Pb污染对烤烟根区微生物和烟叶品质的影响.结果表明,随着Cd、Pb处理浓度的增加,烤烟根区4种微生物数量均呈减少趋势;低浓度Cd(≤10 mg·kg^-1)和Pb(≤300 mg·kg^-1)下,烤烟根区4种微生物数量降幅最大;烤烟烟叶中品质指标糖/碱比和氮/碱比升高,化学成分组成趋于不协调,不利于烟叶香味的形成.烟叶K含量与Cd和Pb污染浓度呈负相关,与Cd污染下根区钾细菌数量呈显著(或极显著)正相关,与Pb污染根区钾细菌数量相关不显著.     

Accumulation and translocation of heavy metals in the canola (Brassica napus L.)—soil system in Yangtze River Delta, China

Aims and methods

Concentrations of heavy metals such as Cd, As, Hg, Pb, Cr, Cu, Zn and Ni in different tissues (seeds, roots and shoots) of the mature canola (Brassica napus L.) plants and in the associated rhizosphere soils from Yangtze River Delta (YRD) region of China, were determined to evaluate the heavy metals’ pollution in the soils and the canola seeds, and to discuss their accumulation and translocation characteristics in canola plants. At the same time, the phytoextraction potential of the canola plant for the above heavy metals was theoretically calculated and discussed on the basis of above measured data.

Results

The results showed that the concentration ranges of Cd, As, Hg, Pb, Cr, Cu, Zn and Ni in the rhizosphere soils were 0.115–0.481, 3.40–20.5, 0.069–0.682, 9.92–27.4, 46.8–86.6, 17.7–253.3, 65.2–511.7 and 16.0–37.8?mg?kg^?1, respectively. The concentrations of Cu, Zn and Hg at some sampling sites exceeded the 2nd grade threshods of Chinese national environmental quality standard for soils. The potential ecological risk of heavy metals in the canola rhizosphere soils decreased in the order of Zhejiang > Shanghai > Jiangsu provinces. The concentration ranges of above heavy metals in the canola seeds were 0.032–0.067, 0.002–0.005, 0.001–0.005, 0.053–0.165, 0.191–0.855, 3.01–13.20, 34.82–96.95 and 0.343–2.86?mg?kg^?1, respectively, with Cu and Zn at some sampling sites exceeding the permissible concentrations in foods of China. Heavy metals’ concentrations in canola seeds didn’t increase with their increasing concentrations in the rhizosphere soils. The bioconcentration factors (BCFs) of most heavy metals in the canola seeds decreased with their increasing concentrations in the associated rhizosphere soils. The average BCFs of heavy metals decreased in the order of Zn (0.488)>Cd (0.241)>Cu (0.145)>Ni (0.038)>Hg (0.021)>Pb (0.005)=Cr (0.005)>As (0.000) in the canola seeds, Cd (1.550)>Cu (0.595)>Zn (0.422)>Hg (0.138)>Ni (0.085)>Pb (0.080)>As (0.035)>Cr (0.031) in the roots, and Cd (0.846)>Zn (0.242)>Cu (0.205)>Hg (0.159)>Ni (0.031)>Pb (0.025)>As (0.012)>Cr (0.007) in the shoots, respectively. The accumulation capacity for most of the above heavy metals in the mature canola tissues was root > shoot > seed, with the exceptions of seed > root > shoot for Zn and shoot > root > seed for Hg. Except Hg from root to shoot and Zn from root to seed, translocation factors (TFs) of above heavy metals were lower than 1.0.

Conclusions

The concentrations, BCFs and TFs of above heavy metals in the canola tissues indicated that the investigated canola plants did not meet the criteria of hyperaccumulators for the above heavy metals. The phytoextracton potential of the studied canola plants for the above heavy metals from the polluted soils was very limited. It would take 920, 3,170 and 3,762?years (assuming two crops per year) to reduce the initial soil Zn, Cu and Hg concentrations, respectively, from the most polluted soil concentrations to the 2nd grade thresholds of Chinese national environmental quality standard for soils.     

铜尾矿区土壤与凤丹植株重金属富集研究

对安徽铜陵铜尾矿区凤丹种植地的土壤和凤丹中重金属污染状况进行了研究,结果表明,尾矿库区种植地极端贫瘠,有机质含量仅1．1～3．4g·kg^-1,而土壤Cu、Cd、Pb、Zn含量皆高于对照土壤,其中Cu含量达587．43～1176．44mg·kg^-1,Cd含量达3．08～5．16mg·kg^-1,约达国家土壤二级标准的10倍,凤丹各部位的Cu、CA和Pb含量均超过了药用植物的限量标准,尤其是根皮部位Cu含量达31．50～64．00mg·kg^-1,Cd含量达0．98～1．45mg·kg^-1,超出标准1．6～3．6倍,表明种植地和凤丹都受到严重污染．凤丹不同部位中的Zn、Cd、Pb和Cu分别以茎、叶、叶和根皮中的含量最高．凤丹对Cd、Zn的富集比Cu和Pb高,但在根皮中的富集系数均较小。     

越冬期大鸨羽毛九种重金属测定

本文对陕西黄河湿地越冬期大鸨(Otis tarda)羽毛中重金属Mn、Cd、Cr、Cu、Ni、Pb、Zn、As、Hg含量采用等离子体发射光谱仪、测汞仪、原子荧光光谱仪进行了测定。其中,Zn含量最高,为147.05 mg/kg,其次为Mn含量93.03 mg/kg,而Cd、Hg含量最低,分别为0.46 mg/kg和0.03 mg/kg。     

Bioaccumulation of cadmium, chromium and copper by Convolvulus arvensis L.: impact on plant growth and uptake of nutritional elements

The remediation of heavy metal-contaminated sites using plants presents a promising alternative to current methodologies. In this study, the potential accumulation of Convolvulus arvensis L. for Cd(II), Cr(VI), and Cu(II) was determined using an agar-based medium. The shoots of C. arvensis plants exposed to 20 mgl(-1) of these heavy metals, demonstrated capability to accumulate more than 3800 mg of Cr, 1500 mg of Cd, and 560 mg of Cu per kg of dry tissue. The outcome of this study and the field data previously reported corroborate that C. arvensis is a suitable candidate for the phytoremediation of Cd(II), Cr(VI), and Cu(II) contaminated soils. Furthermore, the concentration of Cr determined in the dry leaf tissue (2100 mgkg(-1)) indicates that C. arvensis could be considered as a potential Cr-hyperaccumulator plant species.     

贵州水银洞金矿紫茎泽兰重金属元素测定与分析

利用原子吸收法对贵州水银洞金矿紫茎泽兰及其基质中Cr、Pb、Zn、Cd、Hg和As含量进行了测定和分析。结果表明,贵州水银洞金矿废水处理区土壤Hg(12.575 mg·kg^-1)和As(501.374 mg·kg^-1)已严重超标,Hg和As的平均含量分别是国家土壤环境质量三级标准(GB15618-1995)的8.383倍和12.534倍,污染极为严重;紫茎泽兰对该矿区不同的重金属富集能力不同,尤其对该矿区Cr有较强的富集作用,具有一定的Cr污染修复潜力。紫茎泽兰对所测定的6种重金属元素的吸收转移能力有较大的差异,整个植株对Pb、Zn 和Cr具有很强的吸收转移能力。其茎、叶对不同的重金属元素的吸收转移能力也呈现出很大的差异,紫茎泽兰茎对Cr、Pb和Cd具有很强的吸收转移能力,而叶对Zn、Pb和Hg具有很强的吸收转移能力。除As外,紫茎泽兰对Cr、Pb、Zn、Cd和Hg都具有不同程度的耐受能力,对该矿区的生态恢复具有重要的作用。     

Performance of rose scented geranium (Pelargonium graveolens) in heavy metal polluted soil vis-à-vis phytoaccumulation of metals

An investigation was carried out to evaluate the effect of heavy metal toxicity on growth, herb, oil yield and quality and metal accumulation in rose scented geranium (Pelargonium graveolens) grown in heavy metal enriched soils. Four heavy metals (Cd, Ni, Cr, and Pb) each at two levels (10 and 20 mg kg–1 soil) were tested on geranium. Results indicated that Cr concentration in soil at 20 mg kg–1 reduced leaves, stem and root yield by 70, 83, and 45%, respectively, over control. Root growth was significantly affected in Cr stressed soil. Nickel, Cr, and Cd concentration and accumulation in plant increased with higher application of these metals. Chromium, nickel and cadmium uptake was observed to be higher in leaves than in stem and roots. Essential oil constituents were generally not significantly affected by heavy metals except Pb at 10 and 20 ppm, which significantly increased the content of citronellol and Ni at 20 ppm increased the content of geraniol. Looking in to the higher accumulation of toxic metals by geranium and the minimal impact of heavy metals on quality of essential oil, geranium can be commercially cultivated in heavy metal polluted soil for production of high value essential oil.     

八种水生植物对重金属富集能力的比较研究

通过野外采样和系统分析方法,研究了芜湖市四褐山工业区附近水域中Cu、Pb、Cd、Zn和Mn5种重金属的含量及其在8种水生植物体内的积累特性。结果表明,工业区水体污染严重,重金属含量严重超标,分别为标准值的9、10.1、400、3和438倍;8种水生植物的重金属积累量均较大,其中以水鳖根、茎叶的Cu、Pb、Cd、Zn含量最高,分别为水体中重金属浓度的9.12和2.59倍、33.41和5倍、0.8和0.3倍、26.9和9.1倍,明显高于其它7种水生植物;8种水生植物不同器官对Cu、Pb、Zn的富集系数均>1,富集能力较强。其中,香蒲对Pb、Cd的吸收能力表现为茎叶>根。结果表明,在Cu、Pb和Zn等重金属复合污染水域的植物治理中,浮萍、香蒲、水鳖、中华慈姑、芦苇、空心莲子草等植物有着较大的发展潜力和应用前景。     

包头南海子湿地三种鹭鸟羽毛与环境中重金属含量的关系

于2016年7至10月采用电感耦合等离子体发射光谱法(ICP-OES),测定了内蒙古包头南海子湿地繁殖期过后的白琵鹭(Platalea leucorodia)、苍鹭(Ardea cinerea)和夜鹭(Nycticorax nycticorax)3种鹭鸟初级飞羽及环境因子(水、土壤、食物)中As、Cd、Cr、Cu、Ni、Pb、Zn、Fe、Mn、Hg 10种重金属的含量,采用单因素方差分析方法比较了不同鹭鸟种类羽毛重金属含量差异,并通过生物富集系数及Pearson相关性检验分析了羽毛与环境因子间重金属含量之间的关系,以揭示包头南海子湿地环境中重金属污染现状及生物富集特征。结果表明:(1)被检测的10种重金属中,As、Cd、Cr、Cu、Pb、Zn、Hg 7种元素在湿地环境中均已超标,尤其土壤中Fe、Zn、Cu已达到重度污染的程度。(2)不同重金属元素在鹭鸟羽毛中的含量存在差异,其中Fe元素在白琵鹭羽毛中的含量水平最高(388.77 mg/kg),Cd元素在夜鹭羽毛中的含量最低(0.12 mg/kg)。在鹭鸟羽毛中重金属含量由高至低的顺序分别为,白琵鹭Fe、Zn、Mn、Cu、Hg、Cr、Ni、Pb、As、Cd,苍鹭Zn、Fe、Cu、Cr、Ni、As、Mn、Hg、Pb、Cd,夜鹭Zn、Fe、Mn、Cu、Ni、Pb、Hg、Cr、As、Cd。除Pb和Cd元素外,其他8种元素含量在3种鹭鸟羽毛中的含量种间差异显著。(3)相关分析表明,鹭鸟羽毛中的重金属含量与环境因子中的重金属含量显著相关且呈现富集特征,为此可作为监测当地环境污染的指示性材料。     

Health risk assessment via consumption of Pb and Cd contaminated vegetables collected from fresh markets in the lower north of Thailand

This study aimed to investigate the Pb and Cd contamination and health risk assessment for population via consumption of vegetables sold in fresh markets around the lower north of Thailand. The concentrations of Pb and Cd in various vegetables such as root/tuber, stem, inflorescence, fruit, and leaf vegetables were analyzed using an atomic absorption spec-trophotometer. Human health risks of these metals in vegetables were assessed based on target hazard quotient (THQ). The results indicated that more than 80% of the Pb and Cd in almost all vegetable samples exceeded the maximum allowable concentration by National Food Institute criteria with an average range of 0.96–3.39 and 0.48–1.40 mg/kg, respectively. The estimated daily intakes (EDI) of Pb and Cd via dietary consumption of vegetables were between 0.001–0.010 and 0.002–0.008 mg/kg/d, respectively. All EDIs of Pb contaminated vegetables were higher than the reference dose recommended by the USEPA except for leaf edible vegetables, while all EDIs of Cd contaminated vegetables were higher than the reference dose recommended by the USEPA. THQ indicated that the consumption of Pb contaminated root/tuber, stem, inflorescence, and fruit edible vegetables and Cd contaminated leaf vegetable for the local population in the lower north of Thailand could be a severe health risk problem.