Given the tendency of heavy metals to accumulate in soil and plants,the purpose of this study was to determine the contamination.levels of Cd,Ni,Pb,and Zn on peppers(leaves.and fruit),grown in contaminated soils in in...Given the tendency of heavy metals to accumulate in soil and plants,the purpose of this study was to determine the contamination.levels of Cd,Ni,Pb,and Zn on peppers(leaves.and fruit),grown in contaminated soils in industral centers.For this purpose,we measured the uptake of the four heavy metals by peppers grown in the heavy metal contaminated soils throughout the four growth stages:two-leaf,growth,fiowering,and fruiting;and calculated various vegetation indices to evaluate the heavy metal contamination potentials.Electromagnetic waves were also applied for analyzing the responses of the target plants to various heavy metals.Based on the relevant spectral bands identified by principal component analysis(PCA)and random search methods,a regression method was then employed.to determine the most optimal.spectral bands for estimating,the target hazard quotient(THQ).The THQ was found to be the highest in the plants contaminated by Pb(THQ=62)and Zn(THQ=5.07).The results of PCA and random search indicated that the spectra at the bands of b570,b650,and b760 for Pb,b400 and b880 for Ni,b560 and b880 for Cd,and b560 b910,and b1050 for Zn were the most optimal spectra for assessing THQ.Therefore,in future studies,instead of examining the amount of heavy metals in plants by chemical analysis in the laboratory,the responses of the plants to the electromagnetic waves in the identified bands can be redily investigated in the field based on the established correlations.展开更多
采用盆栽试验,利用开顶式气室(Open Top Chamber,OTC)研究了5个籼稻品种在高、低铜镉复合污染土壤上,CO2浓度升高对水稻生长及吸收Cu、Cd和矿质元素Fe、Zn、Ca、Mn的影响,并对稻米中Cd的安全性进行了评价,了解Cd污染对人类健康的潜在风...采用盆栽试验,利用开顶式气室(Open Top Chamber,OTC)研究了5个籼稻品种在高、低铜镉复合污染土壤上,CO2浓度升高对水稻生长及吸收Cu、Cd和矿质元素Fe、Zn、Ca、Mn的影响,并对稻米中Cd的安全性进行了评价,了解Cd污染对人类健康的潜在风险。结果表明:CO2浓度升高,显著降低了低复合污染土壤上稻米的生物量,而显著增加了高复合污染土壤上的稻米生物量。CO2浓度升高降低了低污染土壤上稻米Cu含量,降低幅度为4.75%—24.49%,增加了高污染土壤上稻米Cu含量,增加幅度为6.60%—40.37%;而稻米Cu的总吸收量在低、高复合污染土壤上均是降低的。低、高复合污染土壤上,CO2浓度升高显著降低了三香优974稻米的Cd含量和吸收量;增加了其他4个品种稻米Cd含量和吸收量。CO2浓度升高对不同品种稻米中Fe、Zn、Ca、Mn含量影响存在显著差异。CO2浓度正常、升高条件下,两种污染土壤上金优463稻米中Cd含量超过食品卫生标准(Cd≤0.2mg/kg),三香优974在正常CO2浓度条件下其稻米Cd含量超过食品卫生标准。在低、高复合污染土壤上,金优463和三香优974稻米中Cd的THQ值均大于1,说明对人体暴露接触的潜在风险比较严重。CO2浓度升高显著降低了三香优974稻米中Cd对人体暴露接触的潜在风险,而对其他4个水稻品种稻米Cd的THQ值影响不明显。展开更多
采用原子吸收光谱法测定北京市10个郊区县25种蔬菜154个样品中Cr,Cd,Cu和Zn重金属含量,并与中国食品中污染物限量标准进行比较;运用目标危害系数方法 (the target hazard quotient,THQ)评价当地居民摄食蔬菜导致的健康风险,比较成人和...采用原子吸收光谱法测定北京市10个郊区县25种蔬菜154个样品中Cr,Cd,Cu和Zn重金属含量,并与中国食品中污染物限量标准进行比较;运用目标危害系数方法 (the target hazard quotient,THQ)评价当地居民摄食蔬菜导致的健康风险,比较成人和儿童居民THQ值大小。结果显示,蔬菜中Cr,Cd,Cu和Zn的平均含量分别是0.210,0.0123,1.034,3.343mg/kg,均未超过中国食品中污染物限量标准,但根茎类蔬菜Cr含量均值超过限量标准,在根菜类中其超标率为41.2%;部分生菜样品的Cr含量有超标,在叶菜类蔬菜中的超标率为2.22%;蔬菜重金属综合污染指数的评价结果属于优良,在安全级别之列,其中Cr为轻污染,Cd,Cu和Zn为优良。成人摄食蔬菜导致的Cr,Cd,Cu和Zn的THQ值分别为1.134,0.199,0.419和0.181,儿童为1.490,0.262,0.550和0.237,两者均存在因摄食蔬菜导致的Cr潜在健康风险。成人和儿童重金属复合风险系数分别为1.932和2.539,复合风险主要由Cr引起。各单一重金属的复合风险对成人和对儿童贡献率基本上一致,儿童因为摄取蔬菜而引起的重金属健康风险相对大于成人。展开更多
基金The authors would like to acknowledge the Shiraz University for funding this research(238726-141).
文摘Given the tendency of heavy metals to accumulate in soil and plants,the purpose of this study was to determine the contamination.levels of Cd,Ni,Pb,and Zn on peppers(leaves.and fruit),grown in contaminated soils in industral centers.For this purpose,we measured the uptake of the four heavy metals by peppers grown in the heavy metal contaminated soils throughout the four growth stages:two-leaf,growth,fiowering,and fruiting;and calculated various vegetation indices to evaluate the heavy metal contamination potentials.Electromagnetic waves were also applied for analyzing the responses of the target plants to various heavy metals.Based on the relevant spectral bands identified by principal component analysis(PCA)and random search methods,a regression method was then employed.to determine the most optimal.spectral bands for estimating,the target hazard quotient(THQ).The THQ was found to be the highest in the plants contaminated by Pb(THQ=62)and Zn(THQ=5.07).The results of PCA and random search indicated that the spectra at the bands of b570,b650,and b760 for Pb,b400 and b880 for Ni,b560 and b880 for Cd,and b560 b910,and b1050 for Zn were the most optimal spectra for assessing THQ.Therefore,in future studies,instead of examining the amount of heavy metals in plants by chemical analysis in the laboratory,the responses of the plants to the electromagnetic waves in the identified bands can be redily investigated in the field based on the established correlations.
文摘采用盆栽试验,利用开顶式气室(Open Top Chamber,OTC)研究了5个籼稻品种在高、低铜镉复合污染土壤上,CO2浓度升高对水稻生长及吸收Cu、Cd和矿质元素Fe、Zn、Ca、Mn的影响,并对稻米中Cd的安全性进行了评价,了解Cd污染对人类健康的潜在风险。结果表明:CO2浓度升高,显著降低了低复合污染土壤上稻米的生物量,而显著增加了高复合污染土壤上的稻米生物量。CO2浓度升高降低了低污染土壤上稻米Cu含量,降低幅度为4.75%—24.49%,增加了高污染土壤上稻米Cu含量,增加幅度为6.60%—40.37%;而稻米Cu的总吸收量在低、高复合污染土壤上均是降低的。低、高复合污染土壤上,CO2浓度升高显著降低了三香优974稻米的Cd含量和吸收量;增加了其他4个品种稻米Cd含量和吸收量。CO2浓度升高对不同品种稻米中Fe、Zn、Ca、Mn含量影响存在显著差异。CO2浓度正常、升高条件下,两种污染土壤上金优463稻米中Cd含量超过食品卫生标准(Cd≤0.2mg/kg),三香优974在正常CO2浓度条件下其稻米Cd含量超过食品卫生标准。在低、高复合污染土壤上,金优463和三香优974稻米中Cd的THQ值均大于1,说明对人体暴露接触的潜在风险比较严重。CO2浓度升高显著降低了三香优974稻米中Cd对人体暴露接触的潜在风险,而对其他4个水稻品种稻米Cd的THQ值影响不明显。
文摘采用原子吸收光谱法测定北京市10个郊区县25种蔬菜154个样品中Cr,Cd,Cu和Zn重金属含量,并与中国食品中污染物限量标准进行比较;运用目标危害系数方法 (the target hazard quotient,THQ)评价当地居民摄食蔬菜导致的健康风险,比较成人和儿童居民THQ值大小。结果显示,蔬菜中Cr,Cd,Cu和Zn的平均含量分别是0.210,0.0123,1.034,3.343mg/kg,均未超过中国食品中污染物限量标准,但根茎类蔬菜Cr含量均值超过限量标准,在根菜类中其超标率为41.2%;部分生菜样品的Cr含量有超标,在叶菜类蔬菜中的超标率为2.22%;蔬菜重金属综合污染指数的评价结果属于优良,在安全级别之列,其中Cr为轻污染,Cd,Cu和Zn为优良。成人摄食蔬菜导致的Cr,Cd,Cu和Zn的THQ值分别为1.134,0.199,0.419和0.181,儿童为1.490,0.262,0.550和0.237,两者均存在因摄食蔬菜导致的Cr潜在健康风险。成人和儿童重金属复合风险系数分别为1.932和2.539,复合风险主要由Cr引起。各单一重金属的复合风险对成人和对儿童贡献率基本上一致,儿童因为摄取蔬菜而引起的重金属健康风险相对大于成人。
