Arsenic and lead leaching from the waste derived fertilizer ironite

The toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP) were performed on commercially purchased samples of the waste-derived soil amendment marketed as Ironite. Ten samples of the 1-0-0 grade (the most widely available in Florida) were tested. Two samples of the 12-10-10 grade and three samples of the 6-2-1 grade (a liquid version) were tested as well. TCLP leachate concentrations from the 1-0-0 grade samples ranged from 5.0 to 8.0 mg L(-1) for lead and 2.2 to 4.8 mg L(-1) for arsenic. SPLP concentrations from the 1-0-0 samples ranged from 0.62 to 3.1 mg L(-1) for lead and 1.9 to 8.2 mg L(-1) for arsenic. All of the 1-0-0 grade samples exceeded the U.S. hazardous waste toxicity characteristic (TC) limit for lead (5 mg L(-1)), while five of the 10 SPLP samples exceeded the TC limit for arsenic (5 mg L(-1)). The greater arsenic leachability in the SPLP relative to the TCLP was determined to be a result of lower pH conditions in the SPLP. A composite sample of the 1-0-0 grade was found to leach much greater concentrations of both arsenic and lead using California's waste extraction test (WET). Lead leachate concentrations were much lower in the two 12-10-10 samples (0.03 mg L(-1) or less); arsenic concentrations in these leachates (both TCLP and SPLP) exceeded 5 mg L(-1). None of the 6-2-1 samples contained lead or arsenic above TC limits. An experiment performed on the 1-0-0 grade which examined leachability as a function of pH found that at pH values in the range of what is encountered in the human digestive system (pH 4.0 to 1.5) lead leached 2-36% of its initial content, and arsenic leached 1-6% of its initial content. A simple gastric acid leaching experiment found 83 and 37% of the lead and arsenic present to leach, respectively.     

RCRA toxicity characterization of discarded electronic devices

The potential for discarded electronic devices to be classified as toxicity characteristic (TC) hazardous waste under provisions of the Resource Conservation and Recovery Act (RCRA) using the toxicity characteristic leaching procedure (TCLP) was examined. The regulatory TCLP method and two modified TCLP methods (in which devices were disassembled and leached in or near entirety) were utilized. Lead was the only element found to leach at concentrations greater than its TC limit (5 mg/L). Thirteen different types of electronic devices were tested using either the standard TCLP or modified versions. Every device type leached lead above 5 mg/L in at least one test and most devices leached lead above the TC limit in a majority of cases. Smaller devices that contained larger amounts of plastic and smaller amounts of ferrous metal (e.g., cellular phones, remote controls) tended to leach lead above the TC limit at a greater frequency than devices with more ferrous metal (e.g., computer CPUs, printers).     

Leaching of lead from computer printed wire boards and cathode ray tubes by municipal solid waste landfill leachates

The proper management of discarded electronic devices (E-waste) is an important issue for solid waste professionals because of the magnitude of the waste stream and because these devices often contain a variety of toxic metals (e.g., lead). While recycling of E-waste is developing, much of this waste stream is disposed in landfills. Leaching tests are frequently used to characterize the potential of a solid waste to leach when disposed in a landfill. In the United States, the Toxicity Characteristic Leaching Procedure (TCLP) is used to determine whether a solid waste is a hazardous waste by the toxicity characteristic. The TCLP is designed to simulate worse-case leaching in a landfill environment where the waste is co-disposed with municipal solid waste (MSW). While the TCLP is a required analysis from a regulatory perspective, the leachate concentrations measured may not accurately reflect the concentrations observed under typical landfill conditions. Another method that can be performed to assess the degree a pollutant might leach from a waste in a landfill is to use actual landfill leachate as the leaching solution. In this study, two lead-containing components found in electronic devices (printed wire boards from computers and cathode ray tubes from computers and televisions) were leached using the TCLP and leachates from 11 Florida landfills. California's Waste Extraction Test (WET) and the Synthetic Precipitation Leaching Procedure were also performed. The results indicated that the extractions using MSW landfill leachates resulted in lower lead concentrations than those by the TCLP. The pH of the leaching solution and the ability of the organic acids in the TCLP and WET to complex with the lead are factors that regulate the amount of lead leached.     

Potential environmental impacts of light-emitting diodes (LEDs): metallic resources, toxicity, and hazardous waste classification

Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury-free. This study aimed to determine if LEDs engender other forms of environmental and human health impacts, and to characterize variation across different LEDs based on color and intensity. The objectives are as follows: (i) to use standardized leachability tests to examine whether LEDs are to be categorized as hazardous waste under existing United States federal and California state regulations; and (ii) to use material life cycle impact and hazard assessment methods to evaluate resource depletion and toxicity potentials of LEDs based on their metallic constituents. According to federal standards, LEDs are not hazardous except for low-intensity red LEDs, which leached Pb at levels exceeding regulatory limits (186 mg/L; regulatory limit: 5). However, according to California regulations, excessive levels of copper (up to 3892 mg/kg; limit: 2500), Pb (up to 8103 mg/kg; limit: 1000), nickel (up to 4797 mg/kg; limit: 2000), or silver (up to 721 mg/kg; limit: 500) render all except low-intensity yellow LEDs hazardous. The environmental burden associated with resource depletion potentials derives primarily from gold and silver, whereas the burden from toxicity potentials is associated primarily with arsenic, copper, nickel, lead, iron, and silver. Establishing benchmark levels of these substances can help manufacturers implement design for environment through informed materials substitution, can motivate recyclers and waste management teams to recognize resource value and occupational hazards, and can inform policymakers who establish waste management policies for LEDs.     

TCLP underestimates leaching of arsenic from solid residuals under landfill conditions

Recent revision of the arsenic in drinking water standard will cause many utilities to implement removal technologies. Most of the affected utilities are expected to use adsorption onto solid media for arsenic removal. The arsenic-bearing solid residuals (ABSR) from adsorption processes are to be disposed of in nonhazardous landfills. The Toxicity Characteristic Leaching Procedure (TCLP) tests whether a waste is hazardous or nonhazardous; most solid residuals pass the TCLP. However, the TCLP poorly simulates the alkaline pH, low redox potential, biological activity, long retention time, and organic composition of mature landfills. These same conditions are likely to favor mobilization of arsenic from metal oxide sorbents. This study quantifies leaching of arsenic from Activated Alumina (AA) and Granular Ferric Hydroxide (GFH), two sorbents expected to be widely used for arsenic removal. The sorbents were subjected to the TCLP, the Waste Extraction Test (WET), an actual landfill leachate, and two synthetic leachate solutions. Up to tenfold greater arsenic concentration is extracted by an actual landfill leachate than by the TCLP. Equilibrium leachate concentrations are not achieved within 18 h (the TCLP duration) and an N2 headspace and end-over-end tumbling increase the rate of arsenic mobilization. However, tests with actual landfill leachate indicate the WET may also underestimate arsenic mobilization in landfills.     

Lead content of dietary calcium supplements available in Brazil.

The lead and calcium content of calcium supplements available in Brazil were determined by graphite furnace and flame atomic absorption spectrometry, respectively. Samples were microwave-digested in concentrated HNO(3). Citric acid was used as a chemical modifier in the lead analysis. Supplements were classified into six categories: oyster industrialized (OI, n=4), oyster prepared in pharmacy (OP, n=3), refined industrialized (RI, n=6), refined prepared in pharmacy (RP, n=3), bone meal (B, n=3), and dolomite (D, n=4). Lead levels (microg g(-1) of measured calcium) were higher in D products (2.33), followed by OI, RP, OP, and RI products (1.46, 1.32, 1.29, 0.75), while B products had levels lower than the limit of quantification (0.02 microg g(-1) unit weight). Daily lead intake of eight supplements exceeded the limit of California, USA (1.5 microg g(-1) calcium), but none exceeded the federal limit of USA (7.5 microg g(-1) calcium) or the provisional tolerable lead intake by FAO/WHO (25 microg kg(-1) per week).     

Chemical and mineralogical characterization of blast-furnace sludge from an abandoned landfill

Blast-furnace sludge is generated during the production of pig iron and is disposed of in the environment in large surface landfills. We investigated blast-furnace sludge samples of an abandoned landfill in order to determine its chemical and mineralogical nature and to evaluate some environmental hazards that may arise from this industrial waste. The mineralogical inventory, which was quantified by Rietveld refinement of XRD analyses using the fundamental-parameter approach, revealed that blast-furnace sludge is dominated by X-ray amorphous substances (with a mean of 590 g kg(-1)) including coke and (hydr)oxides of Fe, Si, Al, Zn, and Pb. Calcite (CaCO3) (136 g kg(-1)), dolomite (Ca,Mg[CO3]2) (14 g kg(-1)), quartz (SiO2) (55 g kg(-1)), kaolinite (Al2[OH]4Si2O5) (40 g kg(-1)), graphite (C) (27 g kg(-1)), and chemically not specified layered double hydroxides (28 g kg(-1)) were identified in almost all samples. Iron is present as magnetite (Fe3O4) (34 g kg(-1)), hematite (Fe2O3) (38 g kg(-1)), wuestite (FeO) (20 g kg(-1)) and alpha-iron (Fe0) (6 g kg(-1)). Chemically, blast-furnace sludge is dominated by C (190 g kg(-1)) and Fe (158 g kg(-1)) reflecting the process of pig-iron production. On the basis of total contents, environmentally problematic metals (including As) are Zn (32.6 g kg(-1)), Pb (10.3 g kg(-1)), Cd (81 mg kg(-1)), and As (129 mg kg(-1)). As the forested landfill is used by residents for leisure activities, the exposure assessment by pathway oral uptake of blast-furnace sludge particles by humans has to be critically evaluated, particularly as significant proportions of metals are acid-soluble. However, under the prevailing slightly alkaline pH values of the sludge (pH 7.6-9.2), the solubility of the metals is very low as indicated by low pore water concentrations. Currently, groundwater monitoring should be focused mainly on F- since the F- concentrations in the pore water of blast-furnace sludge are at high level (2.65-24.1 mg of F- L(-1)).     

Elevated serum polybrominated diphenyl ethers and thyroid-stimulating hormone associated with lymphocytic micronuclei in Chinese workers from an E-waste dismantling site

In this study, we recruited 49 subjects from one village close to an electronic waste (e-waste) site (exposed group) and another located 50 km away from the e-waste site (control group). We found that serum levels of polybrominated diphenyl ethers (median PBDEs, 382 ng/g lipid weight; range, 77-8452 ng/g lipid weight) and thyroid-stimulating hormone (median TSH, 1.79 microIU/mL; range, 0.38-9.03 microIU/mL) and frequencies of micro-nucleated binucleated cells (MNed BNC; median, 5% per hundred; range, 0-96% per hundred) were significantly higher in the exposed group than in the control group (158 ng/g, range of 18-436 ng/g, and p < 0.05; 1.15 microIU/mL, range of 0.48-2.09, and p < 0.01; and 0% per hundred, range of 0-5% per hundred, and p < 0.01, respectively). A history of working with e-waste was significantly associated with increased MNed BNC frequencies (odds ratio (OR), 38.85; 95% confidence interval (CI) = 1-1358.71, p = 0.044), independent of years of local residence, a perceived risk factor. However, there was no association between PBDEs exposure and oxidative DNA damage. Therefore, the exposure to PBDEs at the e-waste site may have an effect on the levels of TSH and genetoxic damage among these workers, but this needs to be validated in large studies.     

Lead concentration in meat from lead-killed moose and predicted human exposure using Monte Carlo simulation

Lead-based hunting ammunitions are still common in most countries. On impact such ammunition releases fragments which are widely distributed within the carcass. In Norway, wild game is an important meat source for segments of the population and 95% of hunters use lead-based bullets. In this paper, we have investigated the lead content of ground meat from moose (Alces alces) intended for human consumption in Norway, and have predicted human exposure through this source. Fifty-two samples from different batches of ground meat from moose killed with lead-based bullets were randomly collected. The lead content was measured by atomic absorption spectroscopy. The lead intake from exposure to moose meat over time, depending on the frequency of intake and portion size, was predicted using Monte Carlo simulation. In 81% of the batches, lead levels were above the limit of quantification of 0.03 mg kg(-1), ranging up to 110 mg kg(-1). The mean lead concentration was 5.6 mg kg(-1), i.e. 56 times the European Commission limit for lead in meat. For consumers eating a moderate meat serving (2 g kg(-1) bw), a single serving would give a lead intake of 11 μg kg(-1) bw on average, with maximum of 220 μg kg(-1) bw. Using Monte Carlo simulation, the median (and 97.5th percentile) predicted weekly intake of lead from moose meat was 12 μg kg(-1) bw (27 μg kg(-1) bw) for one serving per week and 25 μg kg(-1) bw (45 μg kg(-1) bw) for two servings per week. The results indicate that the intake of meat from big game shot with lead-based bullets imposes a significant contribution to the total human lead exposure. The provisional tolerable weekly intake set by the World Health Organization (WHO) of 25 μg kg(-1) bw is likely to be exceeded in people eating moose meat on a regular basis. The European Food Safety Authority (EFSA) has recently concluded that adverse effects may be present at even lower exposure doses. Hence, even occasional consumption of big game meat with lead levels as those found in the present study may imply an increased risk for adverse health effects. Children and women of child-bearing age are of special concern due to the neurodevelopmental effects of lead.     

Body loadings and health risk assessment of polychlorinated dibenzo-p-dioxins and dibenzofurans at an intensive electronic waste recycling site in China

This study is one of the very few investigating the dioxin body burden of a group of child-bearing-aged women at an electronic waste (e-waste) recycling site (Taizhou, Zhejiang Province) (24 +/- 2.83 years of age, 40% were primiparae) and a reference site (Lin'an city, Zhejiang Province, about 245 km away from Taizhou) (24 +/- 2.35 years of age, 100% were primiparae) in China. Five sets of samples (each set consisted of human milk, placenta, and hair) were collected from each site. Body burdens of people from the e-waste processing site (human milk, 21.02 +/- 13.81 pg WHO-TEQ1998/g fat (World Health Organization toxic equivalency 1998); placenta, 31.15 +/- 15.67 pg WHO-TEQ1998/g fat; hair, 33.82 +/- 17.74 pg WHO-TEQ1998/g dry wt) showed significantly higher levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/ Fs) than those from the reference site (human milk, 9.35 +/- 7.39 pg WHO-TEQ1998/g fat; placenta, 11.91 +/- 7.05 pg WHO-TEQ1998/g fat; hair, 5.59 +/- 4.36 pg WHO-TEQ1998/g dry wt) and were comparatively higher than other studies. The difference between the two sites was due to e-waste recycling operations, for example, open burning, which led to high background levels. Moreover, mothers from the e-waste recycling site consumed more foods of animal origin. The estimated daily intake of PCDD/Fs within 6 months by breastfed infants from the e-waste processing site was 2 times higher than that from the reference site. Both values exceeded the WHO tolerable daily intake for adults by at least 25 and 11 times, respectively. Our results implicated that e-waste recycling operations cause prominent PCDD/F levels in the environment and in humans. The elevated body burden may have health implications for the next generation.     

火焰原子吸收法检测虾夷扇贝不同部位中 重金属镉

目的 研究贝类不同部位重金属镉的分布情况。方法 以虾夷扇贝为研究对象,采用火焰原子吸收法进行检测, 系统研究了扇贝丁、扇贝鳃、扇贝内脏、扇贝边中重金属镉分布情况。结果 火焰原子吸收法检出限为0.007 mg/L, 线性范围为0.1~0.8 mg/L, 仪器相对标准偏差(relative standard deviation, RSD)为0.4%, 该方法的检出限、线性范围、精密度等指标均满足贝类样品的测定要求。贝类不同部位中的镉含量依次为扇贝内脏>扇贝鳃>扇贝边>扇贝丁, 扇贝丁中重金属镉含量低于国家限量标准2 mg/kg(GB 2762-2012), 扇贝边存在部分样品含量大于2 mg/kg, 扇贝鳃和扇贝内脏含量均大于2 mg/kg, 扇贝内脏含量最高(在9.22~62.50 mg/kg范围内)。结论 本研究为虾夷扇贝食品安全性评价提供基础数据, 对贝类产品安全性的科研、管理工作具有一定参考意义。建议食用虾夷扇贝时去除内脏。     

Vitrification of chromium electroplating sludge

This work investigated the vitrification of hazardous electroplating sludge containing 140 mg/g Cr with/without bottom ash or cullet conditioning to lower specimens' basicities to 0.97-1.17 or 0.18-0.23, respectively. The conditioning was found to enhance the smooth/glassy appearance of slags but no ingot was obtained. Cr was >98% retained in the vitrified slags. Cr2O3 dominated in crystalline structure for the slag vitrified from the sludge, but this domination gradually shifted to Fe2SiO4/Fe3O4/SiO2 or SiO2 crystalline with increasing addition of bottom ash or cullet into the sludge, respectively. Compared to the raw sludge, the sludge-vitrified slag displayed lower leaching concentrations for most metals (particularly Cr (2.54 mg/L)), and smaller leaching ratios for Ag, Cr, and Cu (1.35, 0.02, and <0.01%, respectively) but greater ones for Cd, Pb, and Zn (3.83, 2.46, and 0.36%, respectively). The Cr leaching ratios were approximately 0.01% for the slags vitrified from the conditioned sludge. Independent of the slag basicity and crystalline structure, metal leaching quantity increased but leaching ratio decreased with increasing slag metal content. The slag compressive strengths were improved to >14.7 MPa at the mixing ratios > or = 2/1 and 1/1 for bottom ash/sludge and cullet/sludge, respectively. Fulfilling the criteria of Toxicity Characteristic Leaching Procedure (TCLP), all the slags were recyclable.     

Ochratoxin A in cocoa and chocolate sampled in Canada

In order to determine the levels of ochratoxin A (OTA) in cocoa and cocoa products available in Canada, a previously published analytical method, with minor modifications to the extraction and immunoaffinity clean-up and inclusion of an evaporation step, was initially used (Method I). To improve the low method recoveries (46-61%), 40% methanol was then included in the aqueous sodium bicarbonate extraction solvent (pH 7.8) (Method II). Clean-up was on an Ochratest? immunoaffinity column and OTA was determined by liquid chromatography (LC) with fluorescence detection. Recoveries of OTA from spiked cocoa powder (0.5 and 5 ng g(-1)) were 75-84%; while recoveries from chocolate were 93-94%. The optimized method was sensitive (limit of quantification (LOQ) = 0.07-0.08 ng g(-1)), accurate (recovery = 75-94%) and precise (coefficient of variation (CV) < 5%). It is applicable to cocoa and chocolate. Analysis of 32 samples of cocoa powder (16 alkalized and 16 natural) for OTA showed an incidence of 100%, with concentrations ranging from 0.25 to 7.8 ng g(-1); in six samples the OTA level exceeded 2 ng g(-1), the previously considered European Union limit for cocoa. The frequency of detection of OTA in 28 chocolate samples (21 dark or baking chocolate and seven milk chocolate) was also 100% with concentrations ranging from 0.05 to 1.4 ng g(-1); one sample had a level higher than the previously considered European Union limit for chocolate (1 ng g(-1)).     

Children’s exposures to lead and cadmium: FDA total diet study 2014-16

Children are at potential risk for adverse effects from lead and cadmium exposures due to the effects of these elements on developing brains. Children’s dietary exposures to lead and cadmium were estimated based on lead and cadmium concentration data from FDA’s Total Diet Study (TDS) and on food consumption data from What We Eat In America (WWEIA), the food survey portion of the National Health and Nutrition Examination Study (NHANES). Estimated mean exposures vary based on age range (1–3 y, 4–6 y, or 1–6 y) and on substitution scenarios for values below the limit of detection (non-detects = 0; non-detects = limit of detection; hybrid approach). Estimated mean lead exposures range from 1 to 3.4 µg/day, with major contributions from grains, fruit, dairy, and mixtures (e.g. hamburgers, pizza, lasagna, soups). Estimated mean cadmium exposures range from 0.38 to 0.44 µg/kg bw/day, with major contributions from grains, mixtures, and vegetables. Estimated children’s lead exposures declined slightly since 2004–08, but cadmium exposures did not decline. No safe level has been identified for lead exposures, and toxicologic reference values for cadmium range from 0.1 to 0.83 µg/kg bw/day. The data on lead and cadmium exposures, and on contributors to exposures, will inform research and regulatory priorities on mitigation of exposures to lead and cadmium.     

Deoxynivalenol exposure assessment in a cohort of pregnant women from Bradford, UK

Deoxynivalenol (DON) is a ubiquitous contaminant of cereal crops in temperate regions of the world. It causes growth faltering and immune suppression in animals. Limited information is available on DON exposure in UK subpopulations. The objective of this study was to provide DON exposure assessment in a subset of pregnant women scheduled for an elective caesarean in a large multi-ethnic mother/infant birth cohort from Bradford, UK. Women aged 16-44 years (n = 85) provided a urine sample for DON analysis in the last trimester of pregnancy, and concurrently completed a food-frequency questionnaire (FFQ). The urinary DON biomarker was detected in all measured samples (geometric mean (GM)?= 10.3 ng DON mg(-1) creatinine, range = 0.5-116.7 ng mg(-1)). Levels were higher in women classified as South Asian in origin (GM: 15.2 ng mg(-1); 95% CI = 10.7-21.5 ng mg(-1)) compared with non-South Asians (GM = 8.6 ng mg(-1); 95% CI = 6.6-11.8 ng mg(-1)), p = 0.02). Estimated DON intake from FFQ data and typical levels of DON contamination of food suggest that this was mainly due to higher levels of exposure from bread, particularly daily intake of DON from chapattis in South Asians (estimated mean = 2.4 μg day(-1); 95% CI = 1.2, 3.7 μg day(-1)) compared with non-South Asians (estimated mean = 0.2 μg day(-1); 95% CI = 0-0.4 μg day(-1)), p < 0.001. This is the first biomarker demonstration of DON exposure in pregnant women, and several urinary DON levels were the highest ever recorded in any study. A larger survey within this birth cohort is warranted to investigate any potential risk to mothers and their babies, from DON exposure during pregnancy.     

银川市2015~2020年市售淀粉镉含量检测及消解方法优化

分析银川市2015~2020年售淀粉中镉含量,选择全自动消解仪消解代替传统电热板加热法预处理实验样品,电感耦合等离子体原子发射光谱法测定淀粉中镉的含量。结果表明,该方法在标线范围中标准曲线线性较好,检出限为0.0063 mg/L,定量限为0.001 mg/L,RSD和回收率分别为2.198%,99.16%~107.3%,准确度及精密度较高,与《食品安全国家标准食品中镉的测定》(GB 5009.15—2014)方法检测结果一致,且本方法精密度更优,可以满足使用需求。采集的淀粉样品254份中,重金属镉检出份数为224份,总检出率为88.2%;重金属镉的总检出范围为0.0097~0.1644 mg/kg,均值为0.0631 mg/kg;相较于《食品安全国家标准食品中污染物限量》(GB 2762—2017)中对重金属镉元素的限值0.1 mg/kg,总超标份数为25份,其总超标率为9.4%。     

Atmospheric deposition of halogenated flame retardants at urban, e-waste, and rural locations in southern China

Measurements of atmospheric deposition fluxes and temporal variation of halogenated flame retardants (HFRs) from 2007 to 2008 at urban, electronic waste (e-waste), and rural sites in southern China are presented. The deposition fluxes of total HFRs at the urban (99.3-1327 ng m(-2) day(-1)) and e-waste (79.1-1200 ng m(-2) day(-1)) sites were much higher than at the rural site (9.27-79.5 ng m(-2) day(-1)), demonstrating that e-waste recycling and industrial activities in southern China are two important sources of HFRs in the environment. The urban deposition profile was dominated by current-use HFRs (decabrominated diphenyl ether and decabromodiphenyl ethane), whereas the profile at the e-waste site reflects the past when significant amounts of PBDEs and Dechlorane Plus were used. Source apportionment estimated by principal component analyses with multiple linear regression analysis showed that deposition HFRs at the rural site were primarily contributed by the urban and e-waste sources (45% and 38%, respectively) compared to the contribution from local emission (17%). Our results suggest that the HFRs that are readily present in gas or sorbed onto fine particle phases have enhanced potential for long-range atmospheric transport.     

Toxicity characteristic leaching procedure and iron treatment of brass foundry waste

The Toxicity Characteristic Leaching Procedure (TCLP) is used by the United States Environmental Protection Agency to determine if wastes contain extractable components subject to hazardous waste regulations. This paper examines the limitations of the TCLP and the way it is used by studying a particular example. Waste casting sand from brass foundries to which iron metal has been added passes the TCLP test but when placed in a landfill for several years may start to leach lead, copper, and zinc. Results of TCLP tests of waste sand alone and with the additives iron metal, zinc metal, hydrous ferric oxide, and hematite are reported. Three processes were studied: reduction by metallic iron, sorption by hydrous ferric oxide, and precipitation of hydroxides. Lead, copper, and zinc behave differently with respect to these three processes, and their measurement allows some deductions as to what is occurring in a TCLP test or a landfill. Iron addition does not result in long-term stabilization of a waste placed in the ground. The chemistry of a laboratory extraction can be very different from the chemistry of a waste placed in the environment. Wastes that are treated to pass the TCLP test, but are not permanently stabilized, are a threat to the environment.     

Quality and safety assessment of ginseng extracts by determination of the contents of pesticides and metals.

Ginseng extracts are available as ingredients for improving energy and vitality and can be used in functional foods and as flavouring ingredients. A survey was been performed to determine the content of pesticides and toxic metals in ginseng extracts. Forty-seven samples from 20 suppliers, including both Panax ginseng C. A. Meyer (Asian ginseng) and P. quinquefolius (American ginseng) species, were analysed for arsenic content and for the following metals: aluminium, molybdenum, chromium, copper, magnesium, zinc, cadmium, mercury and lead, while pesticide residues were analysed in 30 samples from 17 suppliers. The results showed that 24 samples (80%) contained pesticides above the detection limit and 13 samples (43%) did not comply with the maximum residue limits (MRL) for total quintozene, hexachlorobenzene, total hexachlorocyclohexane, lindane, total heptachlor, e-chlorpyrifos and folpet, imposed for botanical extracts. Total quintozene, hexachlorobenzene, total hexachlorocyclohexane and lindane were present in all contaminated samples and exceeded the MRL in eleven samples, with levels up to 55 and 30 times their respective MRL. Cadmium (<0.05-259 microg kg(-1)), mercury (<0.3-72 microg kg(-1)), lead (3-2710 microg kg(-1)) and arsenic (<0.3-918 microg kg(-1)) were present in most samples at concentrations lower than the MRL imposed for flavouring substances. Among the other elements, aluminium (0.3-1068 mg kg(-1)) was the most abundant.     

Cadmium in cephalopod molluscs: implications for public health

Cadmium concentrations were measured in the flesh and hepatopancreas (digestive gland) of 1,392 specimens of different species of cephalopod molluscs (broadtail squid, spider octopus, curled octopus, horned octopus, elegant cuttlefish, and pink cuttlefish) to determine whether maximum levels fixed by the European Commission were exceeded. In all species, mean cadmium concentrations were higher in hepatopancreas than in flesh. Large differences among the different species were also observed. Pink cuttlefish and spider octopus had the highest concentrations for both flesh (spider octopus, 0.77 microg g(-1); pink cuttlefish, 0.87 microg g(-1)) and hepatopancreas (spider octopus, 9.65 microg g(-1); pink cuttlefish, 18.03 microg g(-1)), and the lowest concentrations were encountered in broadtail squid (flesh, 0.13 microg g(-1); hepatopancreas, 2.48 microg g(-1)). The other species had intermediate concentrations of 0.20 to 0.30 microg g(-1) in flesh and 5.46 to 8.01 microg g(-1) in hepatopancreas. Concentrations exceeding the limit proposed by the European Commission (1.00 microg g(-1)) were observed in 44.4 and 40.0% of flesh samples of spider octopus and pink cuttlefish, respectively. The estimated weekly intake, 0.09 to 0.66 microg/kg body weigh, was below the provisional tolerable weekly intake set by the World Health Organization.