Assessment of Metal Uptake Capacity of Castor Bean and Mustard for Phytoremediation of Nickel from Contaminated Soil

The effect of increasing level of nickel (Ni) in soil was studied on biomass production, antioxidants, and Ni bioaccumulation and its translocation in castor bean (Ricinus communis) as well as Indian mustard (Brassica juncea) in similar agroclimatic conditions. The plants were exposed to 25, 50, 75, 100, and 150 mg Ni kg^?1 soil for up to 60 days. It was found that R. communis produced higher biomass during the same period at all the contamination levels than B. juncea, and reduction in fresh and dry weights due to the metal contamination in soil was significantly lower in R. communis than in B. juncea. Proline and malondialdehyde in the leaves increased with increase in Ni level in both the species, whereas soluble protein content was found decreased. A correlation between the protein and MDA contents in the leaves and Ni contamination levels revealed that higher r² values for protein and MDA were found in case of B. juncea, which indicates more toxic effects of the metal in this species. R. communis was found to have enhanced proline accumulation (higher correlation value, r²) at different Ni contamination levels. The bioaccumulation of Ni was higher in B. juncea on the basis of the per unit biomass; however, the total metal accumulation per plant was much higher in R. communis than in B. juncea during the same growing periods. The translocation of Ni from roots to shoots was higher in B. juncea at all Ni concentrations. R. communis appeared more tolerant and capable to clean more Ni from the contaminated soil in a given time and also in one crop cycle.     

Phytoremediation of Cd,Ni, Pb and Zn by Salvinia minima

Most metals disperse easily in environments and can be bioconcentrated in tissues of many organisms causing risks to the health and stability of aquatic ecosystems even at low concentrations. The use of plants to phytoremediation has been evaluated to mitigate the environmental contamination by metals since they have large capacity to adsorb or accumulate these elements. In this study we evaluate Salvinia minima growth and its ability to accumulate metals. The plants were cultivated for about 60 days in different concentrations of Cd, Ni, Pb and Zn (tested alone) in controlled environmental conditions and availability of nutrients. The results indicated that S. minima was able to grow in low concentrations of selected metals (0.03 mg L^?1 Cd, 0.40 mg L^?1 Ni, 1.00 mg L^?1 Pb and 1.00 mg L^?1 Zn) and still able to adsorb or accumulate metals in their tissues when cultivated in higher concentrations of selected metals without necessarily grow. The maximum values of removal metal rates (mg m² day^?1) for each metal (Cd = 0.0045, Ni = 0.0595, Pb = 0.1423 e Zn = 0.4046) are listed. We concluded that S. minima may be used as an additional tool for metals removal from effluent.     

Subunit Structure of Castor Bean Hemagglutinin

Two constituent polypeptide chains of castor bean hemagglutinin (CBH-A) were isolated from the performic acid-oxidized or reduced-carboxymethylated CBH-A by chromatography on DEAE-cellulose or Sepharose 4B. From the analyses of the N-terminal amino acids, the amino acid compositions and the tryptic peptides of each chain, it was found that the larger chain with mol. wt. 34,000 and the smaller chain with mol. wt. 31,000 were homologous with the Ala and He chains of ricin D, respectively, and the subunit structure of CBH-A is represented as (α′/β′)₂ in relation to αβ of ricin D.     

花卉植物对Cd、As、Pb污染农田的修复及其精油应用

为提高植物修复的经济价值,该文选取孔雀草、波斯菊和矢车菊三种附加值较高的花卉植物,考察其对广西某矿区Cd、As、Pb复合污染农田的修复潜力,测定分析三种花卉植物对重金属的富集和转运能力,并从修复后植物的地上部提取精油,研究植物精油对病原菌埃希氏大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphyloccocus aureus)、伤寒沙门氏菌(Salmonella typhimurium)的生长抑制效果,进一步探索植物精油作为洗手液添加剂的应用能力。结果表明:(1)试验区域内土壤污染严重,Cd、As全量超过风险管制值,Pb全量超过风险筛选值,属于Cd、As、Pb重度污染。(2)选取的三种花卉植物均可在试验区域较好地生长,其中孔雀草和波斯菊对Cd、Pb的富集与转运能力较强,对As的富集能力最弱但转运能力较强。与孔雀草和波斯菊相比,矢车菊除对Cd的转运能力较强外,对其他重金属的富集和转运能力均较弱。三种植物重金属富集能力大小排序为孔雀草>波斯菊>矢车菊,不同花卉对重金属富集偏好顺序依次为Cd>Pb>As。(3)从修复后的植物地上部提取精油进行研究分析发现,孔雀草精油对三种病原菌都具有良好的生长抑制效果(<10 CFU·mL^-1),且孔雀草体内富集的重金属并未影响精油中的重金属含量。另外,添加了孔雀草精油的洗手液,对金黄色葡萄球菌的生长抑制效果可延长至480 min。因此,孔雀草不仅可作为重金属复合污染农田的修复植物,而且修复后还可从植物体内提取精油作为抑菌剂。该研究结果为修复后重金属富集生物质的新型资源化利用提供了理论基础。     

农作物对Cd毒害的耐性机理探讨

对生长在Ｃｄ污染条件下的８种作物体内Ｃｄ的存在形态分析表明,作物的耐Ｃｄ性与Ｃｄ的形态分布密切相关,在耐性作物体内,蛋白质（多肽）结合Ｃｄ量的比例低于非耐性作物;有机酸盐和一代磷酸盐态Ｃｄ的比例增加;分离得到Ｃｄ诱导蛋白?其中束缚了一定量的Ｃｄ,限制了Ｃｄ以自由态存在,耐性较低的作物本内,大分子量的蛋白质中富Ｃｄ量较高。     

Exogenous Melatonin Enhances Cd Tolerance and Phytoremediation Efficiency by Ameliorating Cd-Induced Stress in Oilseed Crops: A Review

Journal of Plant Growth Regulation - Heavy metal pollution is of increasing global concern as it adversely impacts different spheres including pedosphere, hydrosphere, biosphere, and humansphere....     

Arsenic Speciation in Phloem and Xylem Exudates of Castor Bean

How arsenic (As) is transported in phloem remains unknown. To help answer this question, we quantified the chemical species of As in phloem and xylem exudates of castor bean (Ricinus communis) exposed to arsenate [As(V)], arsenite [As(III)], monomethylarsonic acid [MMA(V)], or dimethylarsinic acid. In the As(V)- and As(III)-exposed plants, As(V) was the main species in xylem exudate (55%–83%) whereas As(III) predominated in phloem exudate (70%–94%). The ratio of As concentrations in phloem to xylem exudate varied from 0.7 to 3.9. Analyses of phloem exudate using high-resolution inductively coupled plasma-mass spectrometry and accurate mass electrospray mass spectrometry coupled to high-performance liquid chromatography identified high concentrations of reduced and oxidized glutathione and some oxidized phytochelatin, but no As(III)-thiol complexes. It is thought that As(III)-thiol complexes would not be stable in the alkaline conditions of phloem sap. Small concentrations of oxidized glutathione and oxidized phytochelatin were found in xylem exudate, where there was also no evidence of As(III)-thiol complexes. MMA(V) was partially reduced to MMA(III) in roots, but only MMA(V) was found in xylem and phloem exudate. Despite the smallest uptake among the four As species supplied to plants, dimethylarsinic acid was most efficiently transported in both xylem and phloem, and its phloem concentration was 3.2 times that in xylem. Our results show that free inorganic As, mainly As(III), was transported in the phloem of castor bean exposed to either As(V) or As(III), and that methylated As species were more mobile than inorganic As in the phloem.Arsenic (As) is an environmental and food chain contaminant that has attracted much attention in recent years. Soil contamination with As may lead to phytotoxicity and reduced crop yield (Panaullah et al., 2009). Food crops are also an important source of inorganic As, a class-one carcinogen, in human dietary intake, and there is a need to decrease the exposure to this toxin (European Food Safety Authority, 2009). Paddy rice (Oryza sativa) is particularly efficient in As accumulation, which poses a potential risk to the population based on a rice diet (Meharg et al., 2009; Zhao et al., 2010a). Other terrestrial food crops generally do not accumulate as much As as paddy rice; however, where soils are contaminated, relatively high concentrations of As in wheat (Triticum aestivum) grain have been reported (Williams et al., 2007; Zhao et al., 2010b). On the other hand, some fern species in the Pteridaceae family are able to tolerate and hyperaccumulate As in the aboveground part to >1,000 mg kg⁻¹ dry weight (e.g. Ma et al., 2001; Zhao et al., 2002); these plants offer the possibility for remediation of As-contaminated soil or water (Salido et al., 2003; Huang et al., 2004). A better understanding of As uptake and long-distance transport, metabolism, and detoxification is needed for developing strategies for mitigating As contamination, through either decreased As accumulation in food crops or enhanced As accumulation for phytoremediation.The pathways of As uptake by plant roots differ between different As species; arsenate [As(V)] enters plant cells via phosphate transporters, whereas arsenite [As(III)] is taken up via some aquaporins (for review, see Zhao et al., 2009). In rice, a silicic acid efflux protein also mediates As(III) efflux toward stele for xylem loading (Ma et al., 2008). Methylated As species, such as monomethylarsonic acid [MMA(V)] and dimethylarsinic acid [DMA(V)], which may be present in the environment as products of microbial or algal methylation of inorganic As or from past uses of methylated As pesticides, are taken up by rice roots partly through the aquaporin NIP2;1 (for nodulin 26-like intrinsic protein; also named Lsi1; Li et al., 2009). Once inside plant cells, As(V) is reduced to As(III), possibly catalyzed by As(V) reductase(s) such as the plant homologs of the yeast (Saccharomyces cerevisiae) ACR2 (Bleeker et al., 2006; Dhankher et al., 2006; Ellis et al., 2006; Duan et al., 2007). As(III) has a high affinity to thiol (-SH) groups and is detoxified by complexation with thiol-rich phytochelatins (PCs; Pickering et al., 2000; Schmöger et al., 2000; Raab et al., 2005; Bluemlein et al., 2009; Liu et al., 2010). As(III)-PC complexation in roots was found to result in reduced mobility for efflux and for long-distance transport, possibly because the complexes are stored in the vacuoles (Liu et al., 2010). Excess As(III) causes cellular toxicity by binding to the vicinal thiol groups of enzymes, such as the plastidial lipoamide dehydrogenase, which has been shown to be a sensitive target of As toxicity (Chen et al., 2010). The As hyperaccumulating Pteris species differ from nonhyperaccumulating plants because of enhanced As(V) uptake (Wang et al., 2002; Poynton et al., 2004), little As(III)-thiol complexation (Zhao et al., 2003; Raab et al., 2004), and efficient xylem loading of As(III) (Su et al., 2008). Recently, an As(III) efflux transporter, PvACR3, has been found to play an important role in As(III) detoxification by transporting As(III) into vacuoles in Pteris vittata (Indriolo et al., 2010).With the exception of As hyperaccumulators, most plant species have a limited root-to-shoot translocation of As (Zhao et al., 2009). The chemical species of As in xylem exudate have been determined in a number of plant species. As(III) was found to be the predominant species (80%–100%) in the xylem sap of rice, tomato (Solanum lycopersicum), cucumber (Cucumis sativus), and P. vittata even when these plants were fed As(V) (Mihucz et al., 2005; Xu et al., 2007; Ma et al., 2008; Su et al., 2010), suggesting that As(V) is reduced in roots before being loaded into the xylem. In other plant species, such as Brassica juncea (Pickering et al., 2000), wheat, and barley (Hordeum vulgare; Su et al., 2010), As(V) accounted for larger proportions (40%–50%) of the total As in the xylem sap. Studies using HPLC-inductively coupled plasma (ICP)-mass spectrometry (MS) coupled with electrospray (ES)-MS showed no evidence of As(III)-thiol complexation in the xylem sap of sunflower (Helianthus annuus; Raab et al., 2005). When rice plants were exposed to MMA(V) or DMA(V), both As species were found in the xylem sap (Li et al., 2009). Generally, methylated As species are taken up by roots at slower rates than inorganic As, but they are more mobile during the xylem transport from roots to shoots (Marin et al., 1992; Raab et al., 2007; Li et al., 2009).It has been shown that phloem transport contributes substantially to As accumulation in rice grain (Carey et al., 2010). However, little is known about how As is transported in phloem (Zhao et al., 2009). There are no reports on the chemical species of As in phloem exudate. The speciation of As in phloem is important because it dictates how As is loaded in the source tissues and unloaded in the sink tissues, such as grain. Questions with regard to the oxidation state, methylation, and complexation of As in phloem sap remain to be answered. Unlike xylem sap, phloem sap is much more difficult to obtain in sufficient quantities for analysis. In this study, we investigated As speciation in phloem and xylem exudates of castor bean (Ricinus communis), which is widely used as a model plant to investigate phloem transport of solutes (e.g. Hall et al., 1971; Hall and Baker, 1972; Allen and Smith, 1986; Bromilow et al., 1987).     

Tissue-Specific Isoforms of Catalase Subunits in Castor Bean Seedlings

Catalases purified from endosperm glyoxysomes and non-specializedmicrobodies from hypocotyls of castor bean seedlings differedin their specific activity [90–164 and 0.89–4.9kunits (mg protein)^–1, respectively] and in their constituentsubunits [two subunits of 54 and 56 kDa for the endosperm enzymeand only one of 56 kDa for the hypocotyl enzyme]. Immunoblotanalysis also showed that particulate fractions from the endospermsand from etiolated and green cotyledons contained two catalasesubunits of 54 and 56 kDa, whereas such fractions from the hypocotylsand roots contained only the 56-kDa subunit. Leaf peroxisomesfrom green leaves had two catalase subunits of around 55 kDaeach. Results of translation in vitro indicated that the 54-and 56-kDa subunits were translated from distinct mRNAs andlevels of both mRNAs increased in the endosperms during germination,prior to increases in levels of catalase proteins. In the hypocotyls,the 56-kDa subunit seemed to be synthesized constitutively. ¹Present addresses: YO, Toyota Central Institute, 31-9 Musashizuka,Nagabuchi, Nagakute, Aichi 480-11, Japan     

Expression of Phospholipase D during Castor Bean Leaf Senescence

Membrane deterioration in plant senescence is commonly associated with progressive decreases in membrane phospholipid content. This study investigated the expression and regulation of phospholipase D (PLD; EC 3.1.4.4) during senescence in castor bean (Ricinus communis L. cv Hale) leaf discs. The rate of leaf senescence was accelerated by 50 [mu]M abscisic acid and was attenuated by 50 [mu]M cytokinin during incubation at 23[deg]C for up to 5 d. Leaf senescence was indicated by decreases in the content of total proteins, chlorophyll, and phospholipids. PLD activity in both membrane-associated and cytosolic fractions showed a gradual increase in the absence of phytohormones. Abscisic acid stimulated an increase in membrane-associated PLD and had little effect on the soluble form. On the other hand, cytokinin retarded the increase in membrane-associated PLD. Immunoblotting analysis using PLD-specific antibodies revealed that the changes in PLD activity were correlated with those of PLD protein. Analysis of PLD by nondenaturing PAGE showed the appearance of a PLD structural variant, PLD 3, in abscisic acid-treated leaf discs. Northern blotting analysis using a PLD cDNA probe revealed an increase in PLD mRNA in senescing leaf discs. These data indicate complex mechanisms for the regulation of PLD during senescence, which include increases in membrane-associated PLD, differential expression of PLD isoforms, and changes in amounts of PLD protein and mRNA. Such controlled expression points to a role for PLD in membrane deterioration and plant senescence.     

Sucrose-Induced Increase of Invertase Synthesis in Castor Bean Cotyledons

Abstract

Aumento della sintesi di invertasi in seguito a trattamento con saccarosio in cotiledoni isolati da semi germinanti di ricino. – L'attività invertasica per cotiledone aumenta durante la germinazione di semi di ricino. In cotiledoni isolati ed incubati in acqua distillata per 15–22 ore, l'aumento di attività invertasica è molto scarso, L'aggiunta di saccarosio 0,1 M al mezzo di incubazione provoca un aumento di circa 40% dell'attività invertasica; aumento che non si riscontra se i cotiledoni vengono incubati in glucosio 0,1 M. La pre-senza di attinomicina D e di puromicina nel mezzo di incubazione previene lo sviluppo dell'attività invertasica. L'apparente specificità del saccarosio nell'indurre l'aumento di sintesi dell'enzima viene brevemente discussa nel quadro piú ampio dei fenomeni di regolazione da substrato delle sintesi di enzimi.     

Chemical Modification of Tryptophan Residues in Castor Bean Hemagglutinin

Modification of tryptophan residues in castor bean hemagglutinin (CBH) with N-bromosuccinimide (NBS) was investigated in detail. Tryptophan residues accessible to NBS increased with lowering pH and six tryptophan residues/mol were oxidized at pH 3.0, while two tryptophan residues/mol were oxidized at pH 5.0. From the pH-dependence curve for tryptophan oxidation, we suggest that the extent of modification of tryptophan in CBH is influenced by an ionizable group with pK_a = 3.6. The saccharide-binding activity was decreased greatly by modification of tryptophan concomitantly with a loss of fluorescence. A loss of the saccharide-binding activity was found to be principally due to the modification of two tryptophan residues/mol located on the surface of the protein molecule. In the presence of raffinose, two tryptophan residues/mol remained unmodified with retention of fairly high saccharide-binding activity. The results suggest that one tryptophan residue is involved in each saccharide-binding site on each B-chain of CBH.     

蓖麻提取物对鼠抗生育作用的实验研究

利用蓖麻提取物对昆明种小鼠进行了短期与长期的抗生育实验,研究发现蓖麻提取物（蓖麻油和蓖麻蛋白）对小鼠有明显的抗生育作用。蓖麻蚩白及其与蓖麻油的混合物在抗早孕方面的效果均可达到100％,蓖麻油抗着床的效果也可达到100％。蓖麻油长期抗鼠生育效果明显,在210d（正常小鼠的妊娠期是21～23d）内有效降低小鼠生育代数与产仔数,生育抑制率达80％以上。蓖麻提取物对离体小鼠子宫的影响也非常显著,通过增强小鼠子宫内部收缩有效减少着床机率。在中止妊娠的实验中发现,服用了蓖麻蛋白及其与蓖麻油的混合物的小鼠子宫内没有着床位点。     

Evidence for the Presence of a Porin in the Membrane of Glyoxysomes of Castor Bean

Glyoxysomes of endosperm tissue of castor bean (Ricinus communis L.) seedlings were solubilized in a detergent and added to a lipid bilayer. Conductivity measurements revealed that the glyoxysomal preparation contained a porin-like channel. Using an electrophysiological method, which we established for semiquantitative determination of porin activity, we were able to demonstrate that glyoxysomal membranes purified by sucrose density gradient centrifugation contain an integral membrane protein with porin activity. The porin of glyoxysomes was shown to have a relatively small single-channel conductance of about 330 picosiemens in 1 M KCl and to be strongly anion selective. Thus, the glyoxysomal porin differs from the other previously characterized porins in the outer membrane of mitochondria or plastids, but is similar to the porin of spinach (Spinacia oleracea L.) leaf peroxisomes. Our results suggest that, in analogy to the porin of leaf peroxisomes, the glyoxysomal porin facilitates the passage of small metabolites, such as succinate, citrate, malate, and aspartate, through the membrane.     

N-Acetylglucosamine Transfer Reactions and Glycoprotein Biosynthesis in Castor Bean Endosperm

N-Acetyl-[³H]glucosamine supplied to intact 3 d old castor beanendosperm tissue was incorporated into TCA-insoluble productpresumed to be glycoprotein. After an incubation time of 2 hthe major paniculate location of this product within the cellwas the endoplasmic reticulum. Cell-free preparations containingparticulate enzymes transferred N-acetyl-[¹⁴C]glucosamine fromUDP-N-acetyl-[¹⁴C]glucosamine into a fraction soluble in chloroform/methanol(2: 1, by vol), a fraction soluble in chloroform/methanol/water(10: 10: 3, by vol.), and an insoluble residue. Mild acid hydrolysisreleased the saccharide moieties from the lipids. Paper chromatographicanalysis of the released saccharides established that the C/M-solubleproducts contained both N-acetyl-[¹⁴C]glucosamine and N, N'-diacetyl-[¹⁴C]chitobiose.In contrast, N-acetyl-[¹⁴C]glucosamine released from the C/M/W-solubleproduct was contained in an oligosaccharide, probably in associationwith unlabelled mannose residues. The stimulatory effect ofdolichol monophosphate and the inhibitory effect of tunicamycinon saccharide-lipid synthesis indicated that N-acetyl-glucosamineis transferred to a glycopolymer by the established reactionsof the dolichol monophosphate pathway. The enzymes catalysingthe constituent reactions of this pathway were exclusively locatedin the ER.     

Vacuolation and Storage Protein Breakdown in the Castor Bean Endosperm following Imbibition

Cytochemical staining of sections prepared for light microscopy,electron microscope sections, and sodium dodecyl sulphate-polyacrylamidegel electrophoresis reveal that, following imbibition, storageproteins are mobilized from the protein bodies of the endospermof castor bean (Ricinus communis L. cv. Hale). This is accompaniedby fusion of protein bodies to form a central vacuole, beforeall the protein is hydrolyzed. Mobilization of the US crystalloidprotein complex and of the 2S albumin fraction commences 2 dafter imbibition and is completed within 2 d. This loss of proteinis accompanied by an increase in activity of three proteolyticenzymes, one carboxypeptidase and two -SH-dependent aminopeptidases.In contrast to the 11S and 2S protein fractions the lectins,located within the protein body, are mobilized only slowly andare present after the other proteins have been completely brokendown. Hence lectins may have a role other than as storage proteins. Key words: Castor bean, Protein breakdown, Storage protein, Lectin, Vacuolation, Seed germination     

蓖麻杂交种的SSR鉴定及遗传变异分析

采用SSR标记对蓖麻CSR24×CSR181杂交所得的F1种子进行分析,为蓖麻早期杂种鉴定和遗传变异分析奠定技术与理论基础。结果表明:(1)各位点鉴定所得结果基本一致,除RCM207和RC129位点鉴定的杂种率未超过10%外,其它位点的杂种率都十分接近,在13.46%～17.27%之间。(2)少数个体在相关位点发生了变异,在引物RC242的扩增图谱中有4个单株出现了双亲特异条带的缺失,产生了双亲都没有的新条带;在引物Rco23、Rco26、Rco29、RC129、RCM613和RCM999的扩增结果中出现了父本特异条带的缺失,同时产生了一条新条带。(3)多样性及UPGMA聚类分析表明杂交后代遗传变异显著,子代个体与亲本间的遗传相似系数在0.45～1.0之间,个体间差异明显。     

Acid Lipase of Castor Bean Lipid Bodies : Isolation and Characterisation

The acid lipase of castor endosperm lipid bodies has been studied using colorimetric assay based on the measure of the hydrolytic activity of p-nitrophenyl ester of palmitate and other acyl derivatives. These substrates are compatible with the natural triacylglycerols for the measure of lipolytic activities. The subcellularly-surveyed acid lipolytic activity in the germinated castor bean endospermal tissue was found to be enhanced in the lipid bodies. The lipase, which is partially latent and tightly associated with lipid bodies, is an exceptionally stable enzyme with an optimum activity at pH 4.5 and displays an inverse relationship between its activity and the acyl chain length of its substrate. To facilitate isolation of the acid lipase, a procedure has been developed to solubilise the membrane-bound enzyme in an active form. The detergent-solubilised acid lipase after two chromatographic steps yielded an eight-fold active preparation which after gel permeation resolved as heterogeneous aggregate in excess of 500 kD. Lipase-enriched preparations showed consistent presence of 14 and 60 kD proteins which constituted the most abundant species of the lipid bodies. Although it has not been possible to obtain an active lipase preparation in a state free of either the 14 or 60 kD protein, the lipase activity in the detergent extracts of lipid bodies was immunoprecipitable with antibodies raised against the 60 kD component.     

蓖麻油微胶囊化及对鼠抗生育研究

以甲苯2,4-二异氰酸酯(TDI)和乙二醇为原料,采用界面聚合法对蓖麻油进行微胶囊化,制成蓖麻油微胶囊。通过正交试验、显微镜计数法、测微尺测量其微胶囊直径等方法来研究影响微胶囊大小、分布和包埋率的各种因素,寻求制备微胶囊的最佳工艺条件,并利用制得的蓖麻油微胶囊对昆明种小鼠进行抗生育实验。实验结果表明:优化后的蓖麻油包埋率达95%以上,其直径分布在4~120μm之间,平均20μm。蓖麻油微胶囊抗着床的有效率可达80%以上,其中200 mg/kg剂量组为100%。抗早孕的效果也可达73%以上,其中400 mg/kg组为100%。     

Estimation of Dietary Pb and Cd Intake from Pb and Cd in Blood or Urine

Successful trials were made to estimate the dietary daily intake of lead (Pb) and cadmium (Cd) via foods from the levels of the metals in blood or urine. In practice, 14 and 15 reports were available for Pb and Cd in blood (Pb-B and Cd-B), urine (Pb-U and Cd-U) and 24-h diet duplicates (Pb-D and Cd-D), respectively, from which 68 pairs each of Pb or Cd in blood and food duplicates [each being geometric mean (GM) values for the survey sites] were obtained. Regression analysis revealed that there was a significant correlation between Pb-B and Pb-D, and also between Cd-B and Cd-D, suggesting that it should be possible to estimate both Pb-D and Cd-D from Pb-B and Cd-B, respectively. For Cd-U, the number of available cases was limited (20 pairs), but a significant correlation was detected between Cd-U (as Cd-U_cr, or Cd levels in urine as corrected for creatinine concentration) and Cd-D. Care should be taken in estimating Pb-D from Pb-B, as the ratio of Pb-D over Pb-B may decrease as a function of increasing Pb-B levels. The Pb-D (μg/day) for typical Japanese women with Pb-B of 15 μg/l was best estimated to be 13.5 μg/day. No Cd-B- or Cd-U_cr-dependent change was detected in case of Cd. The best estimate of Cd-D for Cd-B at 1.5 μg/l should be about 19.4 μg/day.