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1.
本文采用盆栽试验，研究了在砷污染土壤上，水稻叶面分别喷施硅溶液、硒溶液和硅硒混合溶液对籽粒砷含量相对较低的水稻品种旌1优华珍和C两优华占以及籽粒砷含量相对较高的水稻品种丰优香占砷积累和光合参数的影响。试验结果表明，3种叶面喷施处理相比较而言，以叶面单独喷施硅降低水稻籽粒砷含量效果最好，优于叶面单施硒和叶面喷施硅硒混合液处理。叶面单独喷施硅与对照相比，显著降低了籽粒砷含量相对较低的两个水稻品种的籽粒砷含量，但对籽粒砷含量相对较高的水稻品种则没有显著影响。籽粒砷含量相对较低的水稻品种更多比例的砷固定在茎中使其稻米砷积累量较低。3种叶面喷施处理与对照相比均提高了水稻光合参数(如光合速率、气孔导度、胞间CO2浓度)，光合参数与水稻砷浓度呈负相关关系，叶面喷施硅或硒对水稻叶片光合参数的影响差异可能是造成籽粒砷含量差异的重要原因，不同水稻品种叶片光合参数对外源硅或硒的敏感度或响应度不同。总之，叶面喷施硅溶液对改善水稻光合参数的效果最好，是减少水稻籽粒砷含量一项经济有效的措施，在生产应用实践中，要注意作物品种间的差异。 相似文献
2.
盆栽试验条件下,通过外源添加DBP/DEHP制成0,20,50,100,200 mg/kg的浓度梯度,来研究PAEs对烟草生长的影响及其在土壤-烟草系统的累积特征。结果表明:外源DBP/DEHP的添加对烟草地上部生物量和茎粗无显著影响,烟草株高随外源DBP/DEHP浓度的增加呈现不同的变化趋势,其中黄棕壤烟草株高显著降低,红壤的显著增加,而黄壤的无变化;黄壤根系活力随外源DBP/DEHP浓度先增高后降低,而黄棕壤和红壤的无显著变化。DBP/DEHP浓度对部分烟草抗氧化酶活性有显著影响,而对土壤的脱氢酶和和脲酶活性基本无影响。随外源PAEs浓度的增加,土壤中DBP/DEHP含量均呈现上升的趋势,以黄棕壤DBP含量增加幅度最大,添加200 mg/kg DBP时是CK(外源不添加DBP/DEHP)的3.56倍;黄棕壤和红壤DEHP浓度大幅增加,黄棕壤和红壤添加200 mg/kg DEHP时分别是CK的27.47,27.34倍。相比于CK大多数烟叶中和根系中DBP/DEHP有不同程度的提升。随外源DBP/DEHP浓度的增加,会在一定程度上促进土壤和烟叶DBP/DEHP的积累。 相似文献
3.
为了探索外源氨基酸对水稻干重及含氮量的影响,本试验采用500mg·L~(-1)L-亮氨酸-~(15)N在分蘖期、抽穗期、蜡熟期喷施水稻叶面,并以清水为对照。结果表明,喷施外源L-亮氨酸-~(15)N处理组中的叶、茎鞘、稻谷的干重及含氮量均显著高于对照组,分蘖期、抽穗期、蜡熟期3个时期喷施L-亮氨酸-~(15)N比分蘖期、抽穗期2个时期喷施其干重及含氮量高,分蘖期、抽穗期2个时期喷施L-亮氨酸-~(15)N比只喷施分蘖期其干重及含氮量高,叶面吸收~(15)N约50%运输到水稻的籽粒。本研究对提高稻米产量及品质具有重要的实际生产意义。 相似文献
4.
不同磷肥浓度下土壤-水稻系统重金属的时空累积特征 总被引：1，自引：0，他引：1
针对磷肥是水稻田重金属污染的主要来源,采用田间试验与室内分析相结合的研究方法,在吉林省九台市饮马河老稻田区,开展5种磷肥浓度处理对土壤-水稻系统重金属Cd和Pb的时空累积、分布特征研究。结果显示,磷肥中Cd和Pb含量高于土壤背景值,但没有超出国家土壤环境质量（二级）限定范围。磷肥施入土壤后,部分滞留在土壤里,少量向地上部分迁移,水稻根部累积重金属含量较高。随水稻生育期的变化,成熟期重金属在根、叶和籽实累积量最大,茎的重金属累积量在孕穗期达到最大。重金属Cd在水稻各器官的迁移能力为根〉籽粒〉叶〉茎,Pb的迁移能力为根〉叶〉籽粒〉茎,Cd在水稻地上部分的迁移能力要明显强于Pb。磷肥施用量和重金属含量的关系可用线性回归方程来模拟,相关性检验显示重金属累积量与磷肥施用浓度均达到显著相关（P〈0.01）（除根中Cd含量与磷肥浓度达到0.05显著水平）,说明水稻栽培生产中过量使用磷肥,能产生重金属对土壤和稻米的污染,进而导致重金属对人畜健康的潜在威胁。 相似文献
5.
紫云英还田对水稻镉和铅吸收积累的影响 总被引：9，自引：1，他引：8
通过水稻盆栽试验研究紫云英还田对污染水稻吸收积累镉(Cd)和铅(Pb)的影响.结果表明:(1)与对照(不施肥)相比,纯化肥处理对土壤pH及土壤有效Cd、Pb含量没有显著影响;而紫云英还田可以显著提高土壤pH,显著提高土壤有效Pb的含量,对Cd无显著影响;在紫云英还田的基础上添加石灰虽然可以进一步提高土壤pH,但对土壤有效Cd、Pb含量并没有产生显著影响.(2)施用紫云英可以提高水稻根系对Pb的吸收,地上部分则呈现为分蘖期促进、成熟期抑制的作用,最终可显著降低糙米中的Pb含量.(3)施用紫云英可显著抑制水稻植株地上和地下部分对Cd的积累,尤其是地上部分的Cd含量,无论是分蘖期和成熟期均显著低于对照和纯化肥处理,其中糙米中的Cd含量降幅可达80％.研究结果还表明,紫云英还田不仅可以增加肥力,还可以显著抑制糙米对土壤Cd、Pb的吸收;但紫云英还田量不能太高,以30 000kg/hm2较佳. 相似文献
6.
土壤中兽用抗生素污染对水稻生长的影响 总被引：1，自引：0，他引：1
为了解农田土壤兽用抗生素污染对粮食作物水稻生长的潜在影响,选择我国养殖业中常用的抗生素之一土霉素作为目标化合物,试验研究了不同土霉素浓度水平对水稻苗期、生长期生长与产量的影响,探讨了水稻各器官中土霉素积累与土壤中土霉素浓度水平的关系。结果表明,土壤土霉素污染对水稻生长的影响主要发生在苗期,对地下部分的影响显著大于地上部分;苗期地下部生物量、根系活力、叶片叶绿素含量和氧化酶活性随浓度水平(30 mg·kg~(-1)以上)的升高而显著降低。苗期受到土霉素污染影响的水稻其影响一直可延续至整个生育期,表现在分蘖数降低、产量减少等。土霉素在水稻各器官中的积累量大小顺序:根系叶片茎秆籽粒。水稻对土壤中的土霉素富集能力较小,土霉素由根部向地上部分叶、茎、籽粒的迁移作用也较弱。考虑到当前农田土壤中土霉素污染水平一般较低(多在10 mg·kg~(-1)以下),且在谷物中土霉素积累水平较低,推断在目前农地土壤中土霉素污染水平下,其对水稻生长的直接危害相对较小。 相似文献
7.
土壤、水稻籽粒镉含量相关性分析及水稻产地土壤镉临界值的研究 总被引：4，自引：0，他引：4
在全国采集8个水稻产区、不同镉(Cd)含量的水稻土,添加0~4 mg/kg外源Cd,通过盆栽试验,分析水稻土、水稻籽粒Cd含量间的相关性,基于水稻籽粒Cd含量符合食品安全国家标准污染物限值(GB 2762–2012)的前提,确定8个水稻产地土壤的Cd临界值。结果表明:水稻土中Cd含量为0.20~6.27 mg/kg时,随土壤Cd浓度增加,水稻生长没有出现Cd毒害症状。籽粒Cd含量随水稻土Cd浓度的增加而增加,Logistic方程拟合表明籽粒Cd含量和水稻土Cd浓度间相关性显著;依据食品安全国家标准中稻米Cd限量值(0.2 mg/kg),反推得到8种水稻土Cd临界值范围为0.70~4.79 mg/kg,与现行土壤环境质量标准(GB15618–1995)相比,均高于其相应限值(0.3 mg/kg、pH≤7.5,0.6 mg/kg、pH7.5);对土壤理化性质和水稻土Cd临界值间关系进行多元回归分析,发现水稻土Cd临界值与pH和土壤黏粒显著相关(R2=0.83,P0.01)。 相似文献
8.
土壤与水稻籽粒镉含量相关性分析及水稻产地土壤镉临界值的研究 总被引：2，自引：0，他引：2
《土壤》2018,(2)
在全国采集8个水稻产区、不同镉(Cd)含量的水稻土,添加0~4 mg/kg外源Cd,通过盆栽试验,分析水稻土、水稻籽粒Cd含量间的相关性,基于水稻籽粒Cd含量符合食品安全国家标准污染物限值(GB 2762–2012)的前提,确定8个水稻产地土壤的Cd临界值。结果表明:水稻土中Cd含量为0.20~6.27 mg/kg时,随土壤Cd浓度增加,水稻生长没有出现Cd毒害症状。籽粒Cd含量随水稻土Cd浓度的增加而增加,Logistic方程拟合表明籽粒Cd含量和水稻土Cd浓度间相关性显著;依据食品安全国家标准中稻米Cd限量值(0.2 mg/kg),反推得到8种水稻土Cd临界值范围为0.70~4.79 mg/kg,与现行土壤环境质量标准(GB15618–1995)相比,均高于其相应限值(0.3 mg/kg、pH≤7.5,0.6 mg/kg、pH7.5);对土壤理化性质和水稻土Cd临界值间关系进行多元回归分析,发现水稻土Cd临界值与pH和土壤黏粒显著相关(R2=0.83,P0.01)。 相似文献
9.
为研究叶面喷施氨基酸螯合硒对水稻籽粒硒含量及形态的影响,以水稻品种百香 139 为材料,通过大田试验,在水稻破口期叶面喷施不同用量的氨基酸螯合硒,并在水稻拔节孕穗期、始穗期、扬花授粉期、灌浆期、蜡熟期 5个不同生育期叶面喷施 13.5 g/hm2(以硒计)的氨基酸螯合硒,在水稻成熟期测定、分析各处理组水稻地上部不同组织器官硒含量和籽粒硒形态。结果表明,喷施外源氨基酸螯合硒可提高水稻各器官硒含量,在适量范围内水稻植株各器官硒含量随着喷硒浓度的增加而提高;水稻籽粒中硒主要以硒代蛋氨酸存在,水稻籽粒中硒代蛋氨酸含量与总硒含量的变化规律相一致。喷施氨基酸螯合硒用量为 6.75、13.5、27.0 g/hm2 时水稻籽粒中硒含量分别为 0.168、0.431、0.439 mg/kg,均达到《富硒农产品硒含量分类要求》(DB45/T 1061-2014)的要求。拔节孕穗期至灌浆期喷硒处理水稻籽粒硒含量呈现增高趋势,灌浆期喷硒处理的水稻籽粒总硒含量最高,达到 0.320 mg/kg;水稻籽粒中硒代蛋氨酸含量占总硒含量的比例为 43% ～ 91%,硒代蛋氨酸含量占总硒含量的比例由大到小依次为:拔节孕穗期 >始穗期>扬花授粉期＝灌浆期>蜡熟期,硒代蛋氨酸比例随着施硒时期越靠近水稻成熟期越低,表明水稻叶片中硒的转化时间对稻米中硒形态有显著影响,提早喷施硒有利于有机态硒的形成,提高稻米中有机态硒的比例。在硒的生物强化生产富硒水稻中,水稻破口期叶面喷施氨基酸螯合硒的最佳用量为 13.5 g/hm2,在 5 个不同生育期喷施 13.5 g/hm2 的氨基酸螯合硒均能生产出富硒大米,且最佳喷施外源硒的时期为灌浆期。 相似文献
10.
不同土壤中镉对大麦和多年生黑麦草毒性阈值的研究 总被引：1，自引：0，他引：1
根据不同终点、不同农田土壤的植物毒性测试可为基于生态毒理效应的土壤镉(Cd)环境质量标准值的修订提供基础数据。以大麦和黑麦草为供试植物,研究了中国14种不同农田土壤,添加多水平外源Cd对大麦根的相对伸长量和黑麦草的发芽率、地上部生物量的影响,并结合Log-Logistic分布函数模型确定不同土壤中大麦和黑麦草Cd毒性的剂量-效应关系和毒性阈值(EC50、EC10),也测定了黑麦草地上部的Cd含量。结果表明,外源Cd含量在0～200 mg/kg时,大麦根长随土壤Cd含量的增加显著降低,EC50值为7.8～61.7 mg/kg,EC10值为0.2～5.4 mg/kg,均与土壤pH显著正相关。外源Cd含量在0～500 mg/kg时,黑麦草地上部生物量随土壤中Cd含量的增加呈先上升(5 mg/kg)后下降(≥25 mg/kg)趋势,EC50值为29.7～499.7 mg/kg,EC10值为4.4～200.0 mg/kg,二者与土壤性质均无显著相关性。与对照相比,外源Cd含量为5～25 mg/kg时,外源添加Cd对黑麦草种子发芽有促进作用,当外源Cd含量为500mg/kg时,仅有5种土壤中种子发芽率明显下降。黑麦草地上部Cd含量随着外源Cd含量(0～100mg/kg)的增加而显著升高。黑麦草地上部对土壤Cd的富集程度与土壤pH极显著负相关。黑麦草具有作为草坪草中Cd污染修复植物的潜力。大麦对土壤Cd污染胁迫比黑麦草更为敏感,总体上,pH是影响土壤Cd植物毒性的重要因素。 相似文献
11.
Little information is available on the interactive effects of inorganic and organic pollutants on carbon utilization by soil microorganisms.This study examined the effects of two common soil pollutants,lead (Pb) and bensulfuron-methyl herbicide (BSM),on decomposition of an adscititious carbon source (14C-glucose).Two contrasting paddy soils,a silty clay soil and a clay loam soil,were incubated with different concentrations and combinations of pollutants for 60 days.Orthogonal rotatable central composite design was adopted to design the combinations of the pollutant concentrations so that rate response curves could be derived.Rapid decomposition of 14C-glucose occurred in the first three days for both soils where no Pb or BSM was added (control).Overall,63%-64% of the added 14C-glucose was decomposed in the control over the 60-day incubation.The addition of Pb or BSM significantly decreased the decomposition of 14C-glucose during the first week but increased the decomposition thereafter;as a result,the percentages of 14C-glucose decomposed (57%-77%) over the 60-day period were similar to or higher than those of the control.Application of the pollutants in combination did not further inhibit decomposition compared with the control.Overall,decomposition rates were lower in the silty clay soil than in the clay loam soil,which was related to the soil texture,cation exchange capacity,and pH.The relationship between the decomposition rates and the pollutants could be well characterized by the quadratic regression orthogonal rotation model.The initial antagonistic effects of the pollutants followed by the synergistic effects on microbial activity might result from changes of the concentrations of the pollutants. 相似文献
12.
Effects of lead pollution on different soil enzyme activities 总被引：8，自引：0，他引：8
We studied the effects of Pb pollution on soil dehydrogenase and phosphatase activity. Samples of four soils (Saxe, Podestà, Porto Teulada, and Sa Xia Manna) were collected from various locations in southwestern Sardinia, Italy. The soils, which differ mainly in heavy metal contents of pedologic origin (Cu, Zn, Cd, and Pb), were treated with Pb (0, 100, 500, 1000, and 5000 g Pb g-1 soil) and incubated in the laboratory. Samples of the incubated soils were collected periodically (0, 1, 2, 4, 8, and 16 weeks) and the enzymes were measured. Soil dehydrogenase activity was influenced by both the Pb additions and variations in soil moisture content. Only the addition of 5000 g Pb g-1 soil led to a significant decrease in dehydrogenase activity compared to the controls, while the other doses of Pb did not always result in a clear reduction in enzyme activity. Drying the soil led to a considerable reduction in dehydrogenase activity, sometimes so far as to render the differences found between the various treatments not statistically significant. Soil phosphate activity was also influenced by the Pb additions, but the effect of the variation in soil moisture content was less than that found for the dehydrogenase. After the 2nd week of incubation, the phosphate activity in the Podestà and Saxe soils had decreased proportionally to the increase in Pb content. At the end of the incubation period, in the Porto Teulada and Sa Xia Manna soils, a net reduction in phosphatase activity versus controls was found only at the highest Pb concentration. Although both enzyme activities were influenced by the Pb additions, the phosphate activity was less sensitive to variations in the soil moisture content and may thus be a more suitable indicator for soil pollution by Pb. 相似文献
13.
铁碳复合材料催化内电解技术处理模拟农村铅污染水体效果 总被引：1，自引：1，他引：0
为考察基于新型铁炭复合填料的催化内电解技术处理模拟农村铅污染水体的特性,该文采用单因素试验设计和八因素三水平(考虑交互作用)正交试验设计,研究了初始pH值(1.0~8.0)、反应时间(10~90 min)和曝气量(0~12 L/h)对Pb~(2+)去除效果的影响。结果表明:初始pH值从1.0升高到8.0,铅(Pb~(2+))去除率先缓慢上升后急剧降低;反应时间从10 min提高到60 min,Pb~(2+)去除率稳步上升,继续延长至90 min,去除率趋于稳定;曝气量从0增大到12 L/h,Pb2+去除率先快速增加后缓慢降低;3个因素对Pb~(2+)去除效果的显著影响大小依次为:曝气量初始p H反应时间,最佳反应条件是:初始p H值3.0、反应时间60 min、曝气量6 L/h。按照一级动力学模型对反应阶段进行拟合,采用电子扫描显微镜(scanning electron microscope,SEM)观察了反应前后铁炭填料表面形态和结构变化,并利用X射线衍射(X-ray diffraction,XRD)分析了反应后溶液组分,推断得出催化内电解去除铅的机理是氧化还原和化学沉淀。当初始Pb~(2+)浓度为1.0 mg/L,在最佳试验条件下,处理后Pb~(2+)浓度降至0.037 mg/L,满足《地表水环境质量标准》(GB 3838-2002)Ⅲ类水体限值要求。研究结果可为农村铅污染水体修复提供理论和设计依据。 相似文献
14.
使用海泡石、磷酸二氢钙、钙镁磷肥、氧化钙和氧化镁等土壤改良剂及其组合,对湖南省某铅锌矿冶炼厂附近的重金属污染土壤进行了稳定化修复试验,利用BCR连续提取法进行形态分析,并进行稳定化效果的评价。结果表明,各改良剂组合均能够有效改变土壤中Zn、Cd和Pb的形态分布,弱酸提取态含量的减少率分别为Zn:17.03%~83.13%,Cd:45.03%~99.17%,Pb:54.05%~99.44%,降低重金属的不稳定形态和生物可利用性,稳定化效果显著。改良剂对Zn元素的稳定化效果影响程度为:钙镁磷肥+氧化钙钙镁磷肥+氧化镁钙镁磷肥海泡石+磷酸二氢钙海泡石;对Cd元素的稳定化效果影响程度为:钙镁磷肥+氧化钙钙镁磷肥+氧化镁钙镁磷肥海泡石+磷酸二氢钙海泡石;对Pb元素的稳定化效果影响程度为:海泡石+磷酸二氢钙钙镁磷肥+氧化镁钙镁磷肥+氧化钙钙镁磷肥海泡石。该复合污染土壤中,Zn、Cd、Pb稳定效果最优处理为10%钙镁磷肥+5%氧化钙组合。 相似文献
15.
《Communications in Soil Science and Plant Analysis》2012,43(1):25-37
A method is described for the determination of total lead in soil by atomic absorption spectrophotometry. The sample is digested with hot nitric acid. The dry residue is taken up in hydrochloric acid and excess iron is removed by extraction with acetylacetone‐chloroform. Lead is then extracted using the system DDC‐MIBK. The organic phase can be sprayed directly into the flame. The method is not affected by elements occurring in contaminated soils. Iron is removed because a slow‐forming precipitate of the Fe‐DDC‐complex blocks the nebuliser system. The method is an improvement on other methods because no sulfuric acid is used for digestion, and therefore losses of lead by precipitation or occlusion are avoided. Tests confirm that the recommended method gives complete recovery of lead. Lead can be determined in the range from 4 to 240 ppm in the soil. A standard soil sample has been analyzed, yielding a mean value of 125 μg Pb/g soil with a relative standard deviation of 2.4%. 相似文献
16.
Toxic effect of lead(Pb) pollution on Collembola in soils has seldom been studied in depth, which is especially true for growth responses since the juveniles are very small and numerous. A single species test was conducted using the collembolan Folsomia candida as the indicator species, and soil Pb pollution(at Pb concentrations of 0, 300, 600, 1 200, 2 400, and 4 800 mg kg~(-1)) was simulated by mixing Pb(NO_3)_2 with a natural unpolluted soil. Adult survival, reproduction, body length, and body Pb concentration were determined. Adult survival and reproduction started to decrease at soil Pb concentrations of 1 200 and 600 mg kg~(-1), respectively. Lead concentrations in adult and juvenile bodies increased with increasing Pb concentration in soil. The percentage and individual abundances based on body length analysis showed that the larger adults(2.1–2.6 mm, P 0.01) were more sensitive to soil Pb concentration than the intermediate(1.9–2.1 mm, P 0.001) and smaller(1.7–1.9 mm, P 0.001) adults. Similarly, the larger juveniles(1.0–1.4 mm, P 0.001) were more sensitive to soil Pb concentration than the intermediate(0.6–1.0 mm, P 0.001) and smaller(0.3–0.6 mm, P 0.001) juveniles. For both adults or juveniles, the abundance and percentage of larger individuals declined significantly with increasing soil Pb concentration, suggesting that larger individuals were more sensitive to soil Pb pollution. Therefore, body length features, especially the percentage and abundance of larger individuals, would be potential bio-indicators of soil Pb pollution and possibly other types of soil pollution. 相似文献
17.
该研究以水环境中重金属铅离子(Pb2+)为研究对象,简化现有的Pb2+比色体系,基于比色法和光谱法,开发了一款用于Pb2+快速检测的便携式测定仪。该研究简化了繁琐复杂的前期处理,完成了比色试验。该测定仪主要分为光路模块与电路模块,光路模块将铅离子的浓度转化为光信号,电路模块实现了光信号的转换、放大、数据处理以及查看管理数据、上传数据等功能。检测仪完成后,对其进行了若干项系统性能分析,采取了低功耗、抗干扰以及重复性测试,以验证测量的精确度。试验结果表明:经比色反应的建模集中预测值与化学值的决定系数R2=0.934,检测线性范围0.01~0.2 mg/L,铅含量指标变异系数低于1.0%,测试结果表明该测定仪具有良好的准确度与重复性。 相似文献
18.
《Communications in Soil Science and Plant Analysis》2012,43(9):733-740
Abstract The major purpose of these experiments was to determine if Pb uptake by plants was significantly increased by chelating agents used in plant nutrition. The interaction of Pb with some other elements in barley plants (Hordeum vulgare L. C.V. Atlas 57) and bush bean (Phaseolus vulgaris L. C.V. Improved Tendergreen) was studied in a glasshouse with different rates of Pb in solution culture and in amended (control, S, CaCO3, MgCO3) Yolo loam soil with and without the chelating agent DTPA (diethylene triamine pentaacetic acid). In a solution culture experiment, 10‐3 M Pb significantly decreased bush bean yields in both control and DTPA treatments. The CaCO3 added to nutrient solution decreased the concentration of Pb in leaves, stems, and roots and prevented the toxicity of 10‐3 M Pb++. At high Pb levels, interactions between Pb and Mn and Pb and Fe were observed, except with CaCO3. In the soil experiment, the yields of barley and bush bean were influenced only slightly by Pb. The Pb concentration in barley shoots and bush bean leaves and stems was increased considerably in the presence of DTPA, however. In the absence of DTPA, the effect of added Pb was very small in the control and S amended soil treatments and almost negligible in the CaCO3 and MgCO3 amended soil treatments. Application of DTPA facilitated the translocation of Pb, Fe, Mn, Cu, and Zn to shoots. The effect was dependent upon soil pH. Particularly, the Fe was increased by DTPA at low pH while the effect was negligible at high pH. This was opposite the effect on Pb. The DTPA resulted in considerable Pb transport to leaves and stems at high soil pH. The uptake pattern of Zn and Cu was similar to that of Pb. It can be expected that chelating agents can increase the migration of Pb to plants andincrease its uptake by plants, and hence, entry into food chains. 相似文献
19.
滇东农田土壤铅污染健康风险评价及基准研究 总被引：3，自引：3，他引：0
农田土壤重金属污染造成农产品中重金属含量超标进而通过食物链对人体健康的风险和隐患不容忽视,滇东农田土壤同时受到高地质背景与矿业活动叠加的双重影响,铅污染的问题开始受到广泛关注。为了掌握滇东地区土壤-作物系统铅累积规律及其健康风险以及农田土壤铅健康风险基准,通过对滇东6个市(州)农田土壤和农产品点位协同采样,探讨滇东土壤及其种植农作物中铅的累积特征及健康风险状况,并基于物种敏感分布模型(Log-logistic)反推滇东农田土壤铅安全基准值。结果表明:1)滇东不同市(州)农田土壤中铅含量平均值从大到小依次为红河州、曲靖市、昭通市、文山州、玉溪市、昆明市,其中,昭通市、曲靖市、文山州和红河州农田土壤均存在轻微程度的铅超标问题;2)滇东6个市(州)农产品总的点位超标率为11.9%;不同类别作物吸收富集铅的能力不同,豆类的豌豆和花生对铅具有较高的富集能力,其次是根茎类的莴笋、叶菜类的油菜和谷物类的小麦。3)健康风险评价结果表明,滇东各区域农田土壤重金属铅对居民不存在明显的非致癌风险和致癌风险,铅在不同区域对儿童产生的非致癌风险大于成人,不同暴露途径非致癌健康风险指数从大到小依次为手-口摄入、皮肤接触、呼吸吸入;4)基于物种敏感性分布模型反推滇东农田土壤铅健康风险基准值,种植根茎类、茄果类、叶菜类、豆类、谷物类物时,其临界值分别为13.0、19.7、35.1、11.3、18.1 mg/kg;其警戒值分别为269.5、481.3、500.7、367.5、560.3 mg/kg。研究结果可为滇东以及类似区域铅高背景区农田土壤制定更为精准的地方标准、实现铅污染土壤安全利用提供科学依据。 相似文献