Concentrations of arsenic,cadmium, mercury,and lead in common foods and estimated daily intake by children,adolescents, adults,and seniors of Catalonia,Spain

This study was designed to estimate the dietary intake of arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) by the general population of Catalonia, Spain. The concentrations of these elements were determined in food samples randomly acquired in seven cities of Catalonia between June and August 2000. A total of 11 food groups were included in the study. As, Cd, Hg, and Pb levels were measured by ICP-MS and AAS. The dietary intake of these elements was determined by a total diet study. Calculations were carried out on the basis of recent data on the consumption of the selected food items. Trace element intake was estimated for five population groups: children, adolescents, male and female adults, and seniors. The highest dietary intakes of As (223.6 microg/day), Cd (15.7 microg/day), Hg (21.2 microg/day), and Pb (28.4 microg/day) corresponded to male adults. For all analyzed elements, fish and shellfish was the group showing the highest contribution to the respective intakes. In comparison with previous results, a general decrease in As, Cd, Hg, and Pb intake has occurred. The dietary intake of these elements was also compared with the provisional tolerable weekly intake (PTWI). Dietary intakes of As, Cd, Hg, and Pb by the population of Catalonia are currently well below the respective PTWIs.     

Effects of various cooking processes on the concentrations of arsenic, cadmium, mercury, and lead in foods

The effects of cooking processes commonly used by the population of Catalonia (Spain) on total arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) concentrations in various foodstuffs were investigated. All food samples were randomly acquired in local markets, big supermarkets, and grocery stores of Reus (Catalonia). Foods included fish (sardine, hake, and tuna), meat (veal steak, loin of pork, breast and thigh of chicken, and steak and rib of lamb), string bean, potato, rice, and olive oil. For each food item, two composite samples were prepared for metal analyses, whose levels in raw and cooked (fried, grilled, roasted, and boiled) samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The highest concentrations of As, Hg, and Pb (raw and cooked samples) were mainly found in fish, with a clear tendency, in general, to increase metal concentrations after cooking. However, in these samples, Cd levels were very close to their detection limit. In turn, the concentrations of metals in raw and cooked meat samples were detected in all samples (As) or only in a very few samples (Cd, Hg, and Pb). A similar finding corresponded to string beans, rice, and olive oil, while in potatoes, Hg could not be detected and Pb only was detected in the raw samples. In summary, the results of the present study show that, in general terms, the cooking process is only of a very limited value as a means of reducing metal concentrations. This hypothetical reduction depends upon cooking conditions (time, temperature, and medium of cooking).     

Analysis of dietary supplements for arsenic,cadmium, mercury,and lead using inductively coupled plasma mass spectrometry

The arsenic, cadmium, mercury, and lead contents of 95 dietary supplement products were determined using microwave digestion and high-resolution inductively coupled plasma mass spectrometry. Precision and accuracy were demonstrated by element recovery from 17 dietary supplements and replicates of 8 reference materials. The concentration ranges were as follows: arsenic, <5-3770 microg/kg; cadmium, <10-368 microg/kg; mercury, <80-16800 microg/kg; and lead, <20-48600 microg/kg. An assessment of estimated exposures/intakes of the four elements is presented.     

Uptake of SigmaDDT, arsenic, cadmium, copper, and lead by lettuce and radish grown in contaminated horticultural soils

Horticultural soils can contain elevated concentrations of selected trace elements and organochlorine pesticides as a result of long-term use of agrichemicals and soil amendments. A glasshouse study was undertaken to assess the uptake of weathered SigmaDDT {sum of the p, p'- and o, p-isomers of DDT [1,1,1-trichloro-2,2- bis( p-chlorophenyl)ethane], DDE [1,1-dichloro-2,2- bis( p-chlorophenyl)ethylene] and DDD[1,1-dichloro-2,2- bis( p-chlorophenyl)ethane]}, arsenic (As), cadmium (Cd), copper (Cu), and lead (Pb) residues by lettuce ( Lactuca sativa) and radish ( Raphanus sativus) from field-aged New Zealand horticultural soils. Concentrations of SigmaDDT, DDT, DDE, Cd, Cu, and Pb in lettuce increased with increasing soil concentrations. In radish, similar relationships were observed for SigmaDDT, DDE, and Cu. The bioaccumulation factors were less than 1 with the exception of Cd and decreased with increasing soil concentrations. Lettuce Cd concentrations for plants grown on four out of 10 assayed soils were equivalent to or exceeded the New Zealand food standard for leafy vegetables of 0.1 mg kg (-1) fresh weight. Concentrations of As, Pb, and SigmaDDT did not exceed available food standards. Overall, these results demonstrate that aged residues of SigmaDDT, As, Cd, Cu, and Pb in horticultural soils have remained phytoavailable. To be protective of human health, site-specific risk assessments and soil guideline derivations for residential settings with vegetable gardens need to consider the produce consumption pathway.     

Bioaccumulation potential of dietary arsenic, cadmium, lead, mercury, and selenium in organs and tissues of rainbow trout (Oncorhyncus mykiss) as a function of fish growth

The distribution and potential bioaccumulation of dietary arsenic, cadmium, lead, mercury, and selenium in organs and tissues of rainbow trout (Oncorhyncus mykiss Walbaum, 1792), a major aquaculture species, was studied in relation to fish growth over a period of >3 years. Fish were reared under normal farming conditions, that is, fed a standard fish food and exposed to negligible levels of waterborne trace elements. The age-related variations in the content of each trace element in gills, kidney, liver, muscle, and skin were studied through nonparametric regression analysis. A buildup of all elements in all tissues and organs was observed, but due to dilution with growth, the concentrations did not increase, except in a few cases such as cadmium and mercury in liver and kidney. In muscle tissue, the concentrations of mercury, lead, and selenium did not alter significantly with growth, whereas cadmium increased but remained at exceedingly low levels. The concentration of arsenic in muscle tissue peaked at 14 months and then decreased in adult specimens. Arsenic speciation by high-performance liquid chromatography--inductively coupled plasma mass spectrometry revealed that arsenic in muscle was almost exclusively present in the form of nontoxic arsenobetaine. Application of a mercury mass balance model gave predicted concentrations in agreement with measured ones and showed that in farmed rainbow trout the ratio of mercury concentrations in feed and in fish is about 1:1. Therefore, rainbow trout does not approach the limits established for human consumption even when reared with feed at the maximum permitted levels. These findings highlight the low bioaccumulation potential of toxic trace elements such as cadmium, lead, and mercury in rainbow trout following dietary exposure. On the other hand, selenium concentrations in muscle (about 0.2 microg g (-1) of fresh weight) show that rainbow trout may be a good source of this essential element.     

Improved arsenic speciation analysis for extracts of commercially available edible marine algae using HPLC-ES-MS/MS

Their increasing commercial availability and their rather high total arsenic contents necessitate a more detailed arsenic speciation analysis of marine algal products. Compared to current HPLC-ICPMS methods, HPLC on-line with electrospray tandem mass spectrometry in the selected reaction monitoring mode (HPLC-ES-SRM) offers much higher detection selectivity with similarly high sensitivity for most known organoarsenic species. This study demonstrates the advantages of HPLC-ES-SRM for the detection of the main as well as trace arsenic species in extracts of 12 commercially available marine algal powders. The main focus was the unambiguous identification of the detected arsenic species. Four quality control tools were applied for this purpose, including matching chromatographic retention times, comparing SRM transition ratios, recording product ion spectra, and determining accurate masses. As a result, evidence was obtained for the presence of 19 organoarsenic species in the analyzed algal extracts. The method of standard addition was used for quantification. Estimated matrix effects on the analyte signal were similar for most of the investigated arsenic species in extracts of different types of brown algae. This allowed the comparison of the contents of the arsenic species present in the 12 algal extracts on the basis of normalized peak areas. A partial correlation of the arsenic speciation pattern with the algal family or algal order, respectively, was found.     

Quantitative analysis of exudates from soil-living basidiomycetes in pure culture as a response to lead, cadmium and arsenic stress

Six different ectomycorrhizal fungi (Hebeloma velutipes, Piloderma byssinum, Paxillus involutus, Rhizopogon roseolus, Suillus bovinus and Suillus variegatus) and two saprotrophic fungi (Hypholoma fasciculare and Hypholoma capnoides) were exposed to metal stress induced by Pb, Cd and As. After pre-growth in a nutrient solution in Petri dishes, metal exposure was performed either in a nutrient rich solution or in a nutrient poor solution for seven days. The fungi were exposed to two different metal concentrations, low and high (Pb: 10 + 100 μM; Cd: 1 + 10 μM; As: 1 + 10 μM). Exudation of low molecular weight organic compounds (low molecular weight organic acids (LMWOA), amino acids and dissolved monosaccharides), as well as dissolved organic carbon was quantified as a potential response to the metal stress. The main LMWOA identified was oxalate. Oxalate exudation increased significantly in response to both low and high Pb and Cd concentrations, as well as low As exposure, relative to nutrient controls. Exposure to As and mixtures of metals (Pb + Cd, Pb + As) did not result in any significant increase in oxalate production compared to controls. The presence of a carbon source (glucose) in this study is likely to have been important for exudation of organic compounds. For the nutrient rich (+1 mM glucose) metal treatments exposure to Pb and Cd mainly increased exudation of oxalate and total amino acids. Production of dissolved monosaccharides, as well as DOC, did not increase significantly in response to metal exposure, irrespective of nutrient conditions. This may be explained by re-absorption of the organic compounds by the mycelium or by the fact that metals had no effect on exudation of these compounds.     

Determination of water-soluble arsenic compounds in commercial edible seaweed by LC-ICPMS

This paper reports arsenic speciation in edible seaweed (from the Galician coast, northwestern Spain) produced for human consumption. Chondrus crispus , Porphyra purpurea , Ulva rigida , Laminaria ochroleuca , Laminaria saccharina , and Undaria pinnatifida were analyzed. The study focused on arsenosugars, the most frequently occurring arsenic species in algae. As(III) and As(V) were also determined in aqueous extracts. Total arsenic in the samples was determined by microwave digestion and inductively coupled plasma mass spectrometry (ICPMS). For arsenic speciation, a water extraction especially suitable for arsenosugars was used, and the arsenic species were analyzed by liquid chromatography with both anionic and cationic exchange and ICPMS detection (LC-ICPMS). The total arsenic content of the alga samples ranged from 5.8 to 56.8 mg As kg(-1). The mass budgets obtained in the extracts (column recovery × extraction efficiency) ranged from 38 to 92% except for U. pinnatifida (4%). The following compounds were detected in the extracts: arsenite (As(III)), arsenate (As(V)), methylarsonate (MA), dimethylarsinate (DMA), sulfonate sugar (SO(3)-sug), phosphate sugar (PO(4)-sug), arsenobetaine (AB), and glycerol sugar (Gly-sug). The highest concentrations corresponded to the arsenosugars.     

氢化物发生——原子荧光光谱法同时测定肥料中砷、汞的研究

通过对消化体系的选择及双道原子荧光光度计测试条件的优化，建立了氢化物发生-原子荧光光谱法同时测定肥料中砷、汞的方法。方法线性范围宽（As0-100μg／L；Hg0-10μg／L），检出限低（As0．05μg／L和Hg0.07μg／L）。无机肥料中As回收率为98．8％-100．4％，Hg回收率为98．9％-102．2％；有机肥料中As回收率为94．4％-105．6％，Hg回收率为97．6％-103．8％。     

Speciation of cadmium,copper, lead,and zinc in contaminated soils

Abstract

To investigate the activity of free cadmium (Cd²⁺), copper (Cu²⁺), lead (Pb²⁺), and zinc (Zn²⁺) ions and analyze their dependence on pH and other soil properties, ten contaminated soils were sampled and analyzed for total contents of Cd, Cu, Pb, and Zn (Cd_T, Cu_T, Pb_T, and Zn_T, respectively), 0.43 MHNO₃‐extractable Cd, Cu, Pb, and Zn (Cd_N, Cu_N, Pb_N, and Zn_N, respectively), pH, dissolved organic matter (DOC), cation exchange capacity (CEC), ammonium oxalate extractable aluminum (Al) and iron (Fe), and dissolved calcium [Ca²⁺]. The activity of free Pb²⁺, Cd²⁺, Cu²⁺, and Zn²⁺ ions in soil solutions was determined using Donnan equilibrium/graphite furnace atomic absorption (DE/GFAA). The solubility of Cd in soils varied from 0.16 to 0.94 μg L^‐1, Cu from 3.43 to 7.42 μg L^‐1, Pb from 1.23 to 5.8 μg L^‐1, and Zn from 24.5 to 34.3 μg L^‐. In saturation soil extracts, the activity of free Cd²⁺ ions constituted 42 to 82% of the dissolved fraction, for Cu²⁺the range was 0.1 to 7.8%, for Pb²⁺ 0.1 to 5.1% and for Zn²⁺2 to 72%. The principal species of Cd, Cu, Pb, and Zn in the soil solution is free metal ions and hydrolyzed ions. Soil pH displayed a pronounced effect on the activity of free Cd²⁺, Cu^2t, Pb²⁺, and Zn²⁺ ions.     

Effects of cadmium,mercury and lead on the survival and instantaneous rate of increase of Paronychiurus kimi (Lee) (Collembola)

The invertebrate springtail species Paronychiurus kimi (Lee) was selected for use in toxicity testing because it is more ecologically relevant to Korean soils than Folsomia candida Willem, which is the standard animal for toxicity tests. Responses of P. kimi to cadmium, mercury and lead were evaluated in artificial soils following the standardized ISO protocol. Although, reproduction of P. kimi was not as high as that of F. candida, 30 adults produced at least 200 juveniles over 28 days. For each of the three heavy metals, LC₅₀ and EC₅₀ for reproduction and NOEC and LOEC for the effect on reproduction and instantaneous rate of population increase (r_i) were also estimated. The 7 days LC₅₀ was 532, 3.9 and 1322 mg/kg dry soil for cadmium, mercury and lead, respectively. As exposure time increased from 7 to 28 days, the LC₅₀ values decreased for cadmium but not or only slightly for mercury and lead. The 28 days EC₅₀ was 60.0 for cadmium, 0.23 for mercury and 428 mg/kg for lead. Significant changes in r_i of P. kimi were closely followed by the changes in the sublethal endpoint measured (reproduction) and populations were heading toward extinction (r_i = 0) at concentration of 129, 2.0 and 1312 mg/kg dry soil for cadmium, mercury and lead, respectively. P. kimi was found to be more sensitive to all heavy metals tested than F. candida, confirming its suitability as a bioindicator species for soil toxicological testing in Korea.     

Estimation of arsenic bioaccessibility in edible seaweed by an in vitro digestion method

The aim of this study was to examine the bioaccessibility (maximum soluble concentration in gastrointestinal medium) of total (AsT) and inorganic (AsI) arsenic contents and the effect on them of cooking edible seaweed, a food of great interest because of its high As content. An in vitro gastrointestinal digestion (pepsin, pH 2, and pancreatin-bile extract, pH 7) was applied to obtain the mineral soluble fraction of three seaweeds (Hizikia fusiforme, Porphyra sp., and Enteromorpha sp.). AsT was determined by dry-ashing flow injection hydride generation atomic absorption spectrometry. AsI was determined by acid digestion, solvent extraction, and flow injection hydride generation atomic absorption spectrometry. The bioaccessibility of AsI increased significantly after cooking, attaining 73% in Porphyra sp. and 88% in H. fusiforme. For cooked H. fusiforme, the AsI attained in the bioaccessible fraction was 26 microg g(-1) seaweed, a concentration that is a warning of the toxicological risk of this food.     

Plant availability of lead,cadmium, and boron in amended coal ash

Reclamation and revegetation of coal combustion products (ash) are often complicated by high concentrations of metals. The effects of manure and soil additions on the extractability and plant availability of Pb, Cd, and B were examined in ash reclamation plots located in eastern Kansas. Concentrations extracted from the ash by ammonium bicarbonate DTPA were strongly affected by ash type and amendment, but were unaffected by crops. Plant uptake was affected by ash type and plant species and, to a smaller extent, by amendment. Extractable and plant concentrations were very high in some of the material, which was consistent with observed toxicity symptoms. Plant concentrations showed strong, positive correlations with extractable for Cd and B (r values 0.7 to 0.9), but plant Pb was negatively correlated with extractable concentrations (r = –0.66). Correlations were similar for plant uptake vs extractable for Cd and Pb but were much poorer for B.     

Effect of cadmium,lead and nickel on three freshwater green algae

Effects of Cd, Pb, and Ni on three freshwater green algae, Ankistrodesmus falcatus, Scenedesmus obliquus, and Chlorococcum spp., were studied. Cadmium and Pb had slight stimulatory effects on growth at lower concentrations (0.1 to 1.0 ppm) while they were lethal at higher concentrations (> 5 ppm). Nickel was not lethal between 0.1 and 10.0 ppm. When combined, both Cd and Ni and Cd and Pb showed interaction on A. falcatus. No interaction was noted between Pb and Ni.     

Determination of cadmium, copper, and lead in sodium chloride food salts by flame atomic absorption spectroscopy

A method for determination of Cd, Cu, and Pb in sodium chloride food salt samples has been developed. It consists of extraction in 4-methyl-2-pentanone of the complexes formed with ammonium pyrrolidine dithiocarbamate and further analysis of the extracts by flame atomic absorption spectroscopy. Detection limits in ng/g salt were 0.2 for Cd, 0.7 for Cu, and 10.0 for Pb. The coefficients of variation of 12 independent analyses were 13% for Cd (at a level of 0.4 ppb), 18% for Cu (1.6 ppb), and 5% for Pb (40 ppb). The recoveries were 100 +/- 0% for Cd, 115 +/- 14% for Cu, and 100 +/- 13% for Pb.     

Sorption of lead,copper, zinc,and cadmium by soils: effect of nitriloacetic acid on metal retention

Abstract

Laboratory experiments were carried out to evaluate lead (Pb), copper (Cu), zinc (Zn), and cadmium (Cd) sorption‐desorption by three soils of contrasting characteristics. Talamanca (silt loam, montmorillonite, Calcic Haploxeralfs), Mazowe (clay, kaolinite, Rhodic Kandiustalf), and Realejos (sandy silt loam, allophane, Typic Hapludands). A second objective was to study the effect of nitriloacetic acid (NTA) on the sorption process. The Talamanca soil, which had a native pH of 6.4 and presented the highest effective cation exchange capacity (ECEC), sorbed more of each of the metal tested than did the other two soils. When the other two soils were compared metal sorption was also related to pH and ECEC. The very low sorption capacity showed by Realejos may be attributed to the low net surface negative charge density of this soil, arising from its allophanic nature. A common feature of the three soils was the relative strong sorption of both Pb and Cu relative to Cd and Zn with Pb showing the highest sorption levels. The selectivity sequences of metals retention were Pb>Cu>Zn>Cd for Talamanca soil, Pb>Cu>Zn≈Cd for Mazowe, and Pb>Cu>Cd>Zn for Realejos. Metal desorption values were low. The order of metal desorption (Cd≈Zn>Cu>Pb) was the same for the three soils studied. Quantitative differences observed in the extractability of the sorbed metals between the soils (Realejos>Mazowe>Talamanca) indicated that soil properties which enhanced metal sorption contributed at the same time to slow down the backward reaction. The addition of NTA to the soil suspension significantly depressed metal sorption by the three soils investigated. Compared with the free ligand system Pb, Cu, Zn, and Cd sorption in the presence of NTA decreased roughly 50%.     

Effect of excess lead,cadmium, copper,and zinc on water relations in sunflower

The effect of excess concentrations of lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) on water relations in young sunflower (Helianthus annuus L.) plants was studied in water culture under greenhouse conditions. The accumulation of the heavy metals was more intensive in the root than in the shoot. The rates of heavy metal accumulation in root were arranged in the following decreasing order: Cu, Cd, Zn, and Pb. Their transport into the above‐ground parts followed the order: Zn, Cu, Pb, and Cd. Transpiration and relative water content were significantly decreased by excess concentrations of the heavy metals. The number of stomata per unit leaf area was increased while the size of the stomata was decreased. The concentration of free proline significantly increased in the leaves of intact plants as well as in leaf discs incubated in the presence of heavy metals. The concentration of soluble proteins decreased as well, particularly when plants were exposed to high concentrations of the heavy metals. It was concluded that excess concentrations of the heavy metals significantly affected plant water status, causing water deficit and subsequent changes in the plants. The most intensive effect on the plants was exerted by Cd, less intensive by Cu and Zn and the least intensive by Pb.     

Flame absorption spectroscopic determination of cadmium, copper, iron, lead, and zinc in mussels

A rapid method is proposed for determination of Cd, Cu, Fe, Pb, and Zn in mussel samples. The elements are extracted with concentrated nitric acid in borosilicate glass tubes at 90 degrees C for 1 h, and determined by flame atomic absorption spectroscopy. Detection limits for a 300 mg sample corresponded to 0.3 microgram Cd/g, 0.7 microgram Cu/g, 33 microgram Fe/g, 0.7 microgram Pb/g, and 6 micrograms Zn/g. The coefficient of variation for 20 independent analyses was 7% for Cd, 7% for Cu, 6% for Fe, 14% for Pb, and 8% for Zn. Recoveries were 107 +/- 3% for Cd, 90 +/- 3% for Cu, 94 +/- 1% for Fe, 90 +/- 5% for Pb, and 96 +/- 3% for Zn. The accuracy of the method was determined by analyzing NBS Oyster Tissues.     

The methylmercury to total mercury ratio in selected marine,freshwater, and terrestrial organisms

Total and methylmercury concentrations were determined in muscle and organ tissue from a wide variety of marine and terrestrial organisms spanning several trophic levels. Sediment and water samples from many of the tissue sampling sites were also analyzed to assess the degree of mercury contamination to which the animals were exposed. The methylmercury to total mercury ratios were examined to determine whether this ratio is indicative of elevated exposure to organic or inorganic mercury and how it varies relative to tissue type and position in the food chain. As an ancillary study, a subset of these tissues was analyzed as 1) wet tissue, and 2) freeze-dried, ball-milled tissue to determine whether the form of sample preparation can adversely affect mercury analysis. Results indicate that the methylmercury to total mercury ratios generally approach unity only in muscle tissue of higher food chain carnivorous fish residing in waters that are relatively uncontaminated with respect to inorganic mercury species. Herbivorous terrestrial mammals and low food chain marine organisms tend to have very low methylmercury to total mercury ratios. Marine animals placed higher on the food chain, such as crabs and lobsters, exhibit somewhat higher methylmercury to total mercury ratios and can exhibit a large variation in this ratio between, organ tissue and muscle tissue of the same animal. The samples analyzed as both wet and freeze-dried, ball-milled tissue indicate that freezedrying and ball-milling in no way result in mercury loss or contamination and, in fact, result in better replicate analyses and create a sample sufficiently stable to be archived for several years without refrigeration.