Cadmium content of indicator and target organs in rats after graded doses of cadmium

Eleven groups of inbred Wistar rats, five males and five females in each group, received graded doses of CdCl₂, from 0–25 ppm, in the drinking water from conception until sacrifice at ten weeks of age. Litter‐size, weight and water consumption were recorded at different ages of the animals. The Cd levels of indicators as blood, hair, incisors and molars, and target organs as femur, kidney cortex, liver, spleen, heart, gastrocnemius muscle and adrenal glands were recorded by atomic absorption spectrophotometry. Cd in the drinking water had no influence on number of animals in each litter, water consumption and growth of the animals. The results further confirmed that the primary target organs of Cd were the soft tissues, but that Cd can to some degree accumulate in teeth and bone, especially molars. The Cd content of all tissues, both indicators and targets, was positively and significantly correlated with dose. The positive significant correlation between the Cd levels of hair or molars, and every target organ suggests that hair and molars of rats are very useful indicators of a Cd exposure in progress. It is supposed that rodent molars are comparable to human deciduous teeth. It is thus suggested that human deciduous teeth and human hair can be used as an indicator of a Cd exposure in progress.     

Effect of acute exposure to cadmium on zinc,copper and lead contents of hard and soft tissues of rats

Eleven groups of Wistar rats were given 5 ppm cadmium acetate in the drinking water at different and interrupted periods of their life (in utero, during sucking etc.), simulating acute exposure. The Zn, Cu and Pb levels of indicators (teeth and hair) and target organs (soft tissues and bone) were recorded by atomic absorption spectrophotometry. It was concluded that acute exposure to Cd has a somewhat different effect on Zn, Cu and Pb storage in the tissues than chronic exposure. It was further inferred that the effects on Zn, Cu and Pb cannot be used as diagnostic criteria in population screenings at very low doses of Cd.     

Arsenic, cadmium, lead, copper and zinc in cattle from Galicia, NW Spain

Knowledge of trace and toxic metal concentrations in livestock is important for assessing the effects of pollutants on domestic animals and contaminant intakes by humans. Metal levels in cattle have been measured in various countries but not in Spain. In this study, the (wet wt.) concentrations of three toxic elements (arsenic, cadmium, lead) and two trace elements (copper, zinc) were quantified in the liver (Li), kidney (Ki), muscle (M) and blood (Bl) of calves (males and females between 6 and 10 months old) and cows (2-16 years old) from Galicia, NW Spain. For the toxic elements, geometric mean concentrations of arsenic in calves (sexes combined) and cows were 10.8 and 10.2 microg/kg (Li), 11.3 and 15.2 microg/kg (Ki), 3.75 and 4.25 microg/kg (M), 3.23 and 2.92 microg/l (Bl). The corresponding cadmium concentrations were 7.78 and 83.3 microg/kg (Li), 54.3 and 388 microg/kg (Ki), 0.839 and 0.944 microg/kg (M), 0.373 and 0.449 microg/l (Bl). Geometric mean concentrations of lead in calves and cows were similarly low and were 33.0 and 47.5 microg/kg (Li), 38.9 and 58.3 microg/kg (Ki), 6.37 and 12.5 microg/kg (M), 5.47 and 12.2 microg/l (Bl). Sex had almost no effect on the amount of toxic metal accumulated except that kidney cadmium concentrations were significantly higher in females than males. Age did influence accumulation; cadmium and lead (but not arsenic) concentrations in most tissues were significantly greater in cows than female calves. For the trace elements, geometric mean copper levels in calf and cow tissues were 49.9 and 36.6 mg/kg (Li), 4.27 and 3.63 mg/kg (Ki), 0.649 and 1.68 mg/kg (M) and 0.878 and 0.890 mg/l (Bl). The corresponding zinc concentrations were 46.3 and 52.5 mg/kg (Li), 14.2 and 20.7 mg/kg (Ki), 47.3 and 52.5 mg/kg (M) and 2.80 and 2.22 mg/l (Bl). Female calves had significantly higher levels than males of muscle zinc and blood copper and zinc. Female calves accumulated more copper but less zinc in the liver and kidneys compared with cows; this may have been associated with the chronic, low-level cadmium accumulation observed in cows. Overall, the levels of arsenic, cadmium, lead and zinc in cattle in Galicia do not constitute a risk for animal health. However, up to 20% of cattle in some regions in Galicia had levels of copper in the liver that exceeded 150 mg/kg wet wt. These animals may be at risk from copper poisoning.     

The effect of surfactants on the extraction-atomic absorption spectrophotometric determination of copper, iron, manganese, lead, nickel, zinc cadmium and cobalt

Nine surfactants representing pure cationic, anionic and non-ionic detergents, three industrially prepared detergents. sodium pyrophosphate. sodium tripolyphosphate, and a soap were investigated for their effect on the extraction-atomic absorption spectrophotometric determination of copper. iron, manganese and lead. Some results are also given for nickel, zinc, cadmium and cobalt. Cations were extracted into 10 ml of MIBK as APDC chelates. To Avoid emulsion formation, maximum concentration of LAS was 1 mg 1⁻¹, and for formulated and non-ionic detergents and washing powders it was 5 mg 1⁻¹.A standard addition procedure was used to obtain correct results for copper and nickel. Two extractions of iron, cobalt and lead, and one extraction of manganese, zinc and cadmium gave a recovery of 100 ± 5%. Soap gave high recoveries for iron and copper. NTA in concentrations up to 25 mg l⁻¹ did not interfere. EDTA in concentrations up to 25 mg l⁻¹ interfered with iron and nickel determinations, but the addition of 3 mg of aluminium removed the EDTA interference in the determination of copper, manganese, lead, zinc, cadmium and cobalt.For the determination of trace metals in polluted natural waters the amount of 4% APDC was increased to 10 ml and for manganese to 25 ml. An addition of 3 mg aluminium as nitrate after the addition of buffer with subsequent 20 min reaction time is required for the determination of all eight metals by the recommended procedures. The effect of humic acid was also investigated.     

Levels of lead,cadmium, zinc and copper in the blood of an urban population

Levels of lead, cadmium, zinc and copper were measured in the blood of normal children and adults of Greater Bombay, India using differential pulse anodic stripping voltammetry. The median concentrations of Pb, Cd, Zn and Cu in the whole blood of children and adults were 11.54, 0.21, 484.2 and 86.2 μg dl⁻¹, respectively. The blood lead concentration showed an increase with age. Children living in industrial zones with high vehicular traffic have significantly higher blood lead concentrations than their counterparts living in the cleaner suburban parts of the city. The mean levels of Pb, Cd, Zn and Cu in blood of Bombay children and adults are compared with those from other countries.     

The effect of surfactants on the mixed chelate extraction-atomic absorption spectrophotometric determination of copper, nickel, iron, cobalt, cadmium, zinc and lead

Twelve surfactants representing pure cationic, anionic and non-ionic detergents, three commercial detergents, sodium pyrophosphate, sodium tripolyphosphate, a soap, nitrilotriacetic acid (NTA), EDTA, and humic acid were investigated for their effect on the extraction-atomic absorption spectrophotometric determination of copper, nickel, iron, cobalt, cadmium, zinc and lead. Cations were extracted into 10 ml of a solution containing diphenylthiocarbazone, 8-quinolinol and acetyl acetone in ethyl propionate. To avoid emulsion formation, the maximum concentration of linear alkylate sulphonate (LAS) was 10 mg l⁻¹ and for solid industrial LAS-type detergent was 50 mg l⁻¹, but washing powder did not interfere at 100 mg l⁻¹. Cationic and non-ionic detergents gave low recoveries for cobalt. Condensed phosphates at a concentration of 20 mg l⁻¹ did not cause significant interference. NTA interfered with nickel extraction and EDTA with all metals. Humic acid, however, gave no interference. A standard addition procedure can be used to correct the results.A comparison is made between the APDC-MIBK and the mixed chelate-ethyl propionate methods for the determination of trace metals in the presence of various surfactants in natural waters; the latter is preferable.     

Blood levels of cadmium,copper, lead and zinc in children in a British Columbia community

The levels of Cd, Cu, Pb and Zn were measured in duplicate whole blood samples of 946 apparently normal children ranging in age from 2 years to 12 years and living in Kamloops, British Columbia, Canada. The metals were determined using atomic absorption spectrometry: graphite furnace AAS for Cd and Pb, and flame AAS for Cu and Zn. The median and extreme values expressed as milligram of metal per litre of whole blood for the total population were: Cd ? 0.0005, Cu 1.11 (0.69–1.78), Pb 0.112 (0.020–0.400), and Zn 4.30 (2.10–6.53). No significant variations were noted in the median metal values either with age or with sex. The median Cu, Pb and Zn values were within the normal range.     

The distribution of cadmium,copper, lead,and zinc in eelgrass (Zostera marina L.)

The distribution of Cd, Cu, Pb, and Zn in eelgrass (Zostera marina L.) was studied at three locations with different heavy metal loads in the Limfjord, Denmark.The eelgrass was fractionated into roots, rhizome, stem, and leaves according to age, and the heavy metal concentrations in each fraction were determined. The distribution patterns of the four heavy metals in eelgrass were independent of the heavy metal loads at the sampling stations. The concentrations of all metals were greater in the roots than in the rhizomes. In the aerial¹ parts two different age-dependent distribution patterns were observed. The concentrations of Cd, Pb, and Zn increased with age while the opposite was true for Cu. The distribution of lead correlated with the distribution of ash content. These age-dependent distribution patterns were maintained throughout the observation period and were most pronounced for Cu and Zn in winter.The heavy metal distribution in eelgrass is discussed in relation to gross morphology, especially age-structure. It is suggested that the accumulation of Cd, Pb, and Zn is due to a slow irreversible uptake or to the existence of more binding sites in old leaves. The distribution of Cu can be explained by translocation within the plant, dilution due to growth or leakage from the older leaves.     

The depositional environment of zinc, lead and cadmium in reservoir sediments

Despite low water retention dams and intervening reservoirs, reservoirs located downstream from a lead-zinc mining and milling area contain relatively higher concentrations of zinc, lead and cadmium than reservoirs in other areas. These metals are also concentrated in reservoir bottom sediments relative to surrounding soils. The zinc and lead content closely correlates to depth of water, organic content and percentage of clay-sized sediments. Zinc is preferentially weathered and transported from its source relative to lead. A model is developed in which the zinc and lead are transported by ionic and/or organo-metallic solution into reservoirs. Because of the relatively long residency time of water in reservoirs, the zinc and lead in the water is removed by clay minerals. Most of the zinc and lead content of the sediments is shown to be associated with sediments of specific gravity between 2·0 and 2·9. The efficiency of these reservoirs as a sink for zinc and lead results in the removal of an average 0·3 ppm zinc and 0·04 ppm lead from waters passing through Fort Gibson Reservoir.     

Combined effect of copper, cadmium, and lead upon Cucumis sativus growth and bioaccumulation

Cucumis sativus (cucumber) was tested to assess an ecotoxicity in soils contaminated by the heavy metals copper (Cu), cadmium (Cd), and lead (Pb) separately and in combinations. The toxicity endpoint was plant growth, which was measured as shoot and root lengths after 5 day exposure. Sum of toxic unit (TU) at 50% inhibition for the mixture (EC50mix) was calculated from the dose (TU-based)-response relationships by the Trimmed Spearman-Karber method. Binary metal combinations of Cu+Cd, Cu+Pb, and Cd+Pb produced all three types of interactions; concentration additive (EC50mix=1TU), synergistic (EC50mix<1TU), and antagonistic (EC50mix>1TU) responses. Ternary combination of Cu+Cd+Pb produced an antagonistic response for the growth of Cucumis sativus. Bioaccumulations of Cu, Cd, and Pb were observed in Cucumis sativus and the bioaccumulation of one metal was influenced by the presence of other metals in metal mixtures. In general, antagonistic and/or synergistic responses reflected bioaccumulation patterns in some binary combinations, but the patterns in mixtures were not always consistent with toxicity data. This study indicated that TU approach appears to be a good model to estimate the combined effect of metals in plant systems, and mixture toxicity may be closely-related to the bioaccumulation pattern within plants. Combined effects of mixtures have to be taken into account to ecological risk assessment.     

Factors affecting the concentrations of cadmium, zinc, copper and lead in the sediments of the Vesdre River

The main factors influencing Cd, Zn, Cu and Pb concentrations in the sediments of the highly polluted Vesdre River (eastern Belgium) have been investigated. Only negative correlations were demonstrated between the clay content and heavy metals. The composition of the clay minerals could partially explain this paradox. However, the pretreatment of the minerals might influence the geochemical data obtained from analysis. Iron-hydroxides and phosphates seem to be the main sinks for Pb, Cd and Zn whereas organic components might play a less important role.     

Scavenging cadmium,copper, lead,nickel and zinc ions from aqueous solution by modified cellulosic sorbent

The adsorption of cadmium, copper, lead, nickel and zinc ions on maize Zea mays stalk meal was examined by equilibrium studies at 29°C. The amounts of the metal ions removed from solution depended on the metal ion type, the ionic size of the metals and were enhanced by EDTA (% N = 12.05) modification of the cellulosic sorbent. The sorption coefficient, K_d, of the metal ions between the adsorbent phase and the bulk aqueous phase was found. The sorption on the unmodified sorbent of lead ions from solutions containing zinc ions shows that lead ions are preferentially removed from solution.     

Concentrations of cadmium, lead and zinc in livestock feed and organs around a metal production centre in eastern Kazakhstan

This paper presents results of analysis of animal feed and meat (cattle, horse and sheep) products from a metal processing region (Oskemen) in east Kazakhstan. Samples were collected from a range of districts of differing distances from the main source of anthropogenic pollution and with differing underlying metal-containing geologies. Analyses for cadmium, lead and zinc revealed high concentrations in many feed and meat samples. Horse (an important food animal) samples had higher levels of contamination than cattle, which were higher than sheep. For example, mean cadmium concentrations in horse kidneys in one district were found to be 128 mg/kg and lead concentrations for liver 2.2 mg/kg. These, and other, results are generally higher than reported in many other studies in contaminated regions of eastern Europe and they can exceed State Maximal Allowed Concentrations by many times. As such levels of contamination pose a significant potential risk to human health, these results have formed the basis for subsequent research on levels of metal contamination in human tissues from affected populations.     

A 1500-year record of lead, copper, arsenic, cadmium, zinc level in Antarctic seal hairs and sediments

To reconstruct the profiles of heavy metal levels in the South Ocean ecosystem of Antarctica, the concentrations of lead (Pb), copper (Cu), arsenic (As), cadmium (Cd), and zinc (Zn) in seal hairs and lake sediments spanning the past 1500 years from Fildes Peninsula of King George Island and in weathering lake sediments from Nelson Island of West Antarctica were determined. The lead contents in the seal hairs and the weathering sediments show a sharp increase since the late 1800s, very likely due to anthropogenic contamination from modern industries. After the 1980s, the Pb content in seal hairs dropped by one-third, apparently due to the reduced usage of leaded gasoline in the Southern Hemisphere. Copper arises mainly from the weathering process, and its level may be substantially affected by climatic conditions. The concentrations of Cd, As, and Zn do not show any clear temporal trends.     

Monitoring of cadmium, copper, lead and zinc status in young children using toenails: comparison with scalp hair

Cadmium, copper, lead and zinc concentrations were determined (atomic absorption spectrometry) in the proximal end of scalp hair (n = 474) and in toenail clippings (n = 461) of children, aged 3-7 years, living in an industrialized and in a rural area of the Federal Republic of Germany. With the exception of Zn in hair, levels of the elements were log-normally distributed. Data are presented as geometric means. Toenail Cd and Pb levels were much higher than those in hair (Cd, 457 vs 90 ng g-1; Pb, 8.5 vs 2.7 micrograms g-1), while Cu and Zn values were similar in both biological media (toenail vs hair: Cu, 7.5 vs 10.6 micrograms g-1; Zn, 129 vs 108 micrograms g-1). In toenails, all elements were positively correlated with each other. In hair, there was a close relationship only between Cd and Pb; Cd and Pb were inversely related to Zn. With the exception of Zn (no correlation), there was a minor relationship between metal levels in hair and those in toenails. Using stepwise regression analysis, seasonal variation was found to be the main factor influencing hair metal levels, while nail metal levels were mainly influenced by place of residence (with the exception of Cu concentrations, for which there were no significant predictors). Multiple correlation coefficient was higher for hair than for nails. It is concluded that, for biological monitoring, toenail clippings are less suitable than hair samples.     

The lead, copper and zinc content of tree rings and bark. A measurement of local metallic pollution.

Analysis of samples of wood taken from different tree rings for lead by atomic absorption spectrometry showed that there was little correlation between the sample site or ring age and air borne lead concentrations. However, the concentration of lead in tree bark at several sites was particularly sensitive to traffic flow at that site. The concentration of lead, zinc and copper in the tree bark decreased with increased distance from the road and with height above the ground. The method offers a simple technique for effectively tracing atmospheric metal concentrations.     

The determination of cadmium. lead, copper and zinc in ground water, estuarine water, sewage and sewage effluent by anodic stripping voltammetry

Anodic stripping voltammetry (ASV) using the thin-film mercury electrode was shown to be a successful technique for the determination of total (free plus complexed) trace metal concentrations in various types of aqueous sample. The method developed involved the minimum of sample treatment and required only simple and inexpensive equipment. The practical limit of sensitivity was about 0·1 μg I⁻¹ for cadmium, lead and copper. The determination of zinc was found to be complicated by the formation of an intermetallic compound with copper. Interference by other trace metals and by complexing agents was investigated. Photochemical oxidation for the decomposition of complexes of the metals with organic ligands in filtered sewage and sewage effluent was found to be successful, although the process is slower for cadmium than for the other metals. Good agreement with atomic absorption spectroscopy was obtained for all the types of aqueous sample investigated. Possible improvements of the ASV technique are discussed.     

The deposition of lead,cadmium, zinc and copper from motor traffic on brachiaria enimi and soil along a major bombo road in Kampala city

The soil and whole plants of Brachiaria enimi were collected beside a major road (Bombo road) and digested with a mixture of concentrated nitric acid, and perchloric acid. The analysis of the soil digests show that lead, cadmium, zinc and copper contents are high close to the road and decrease with distance from the road edge. Also the Pb, Cd, Zn and Cu concentrations in soil fall off rapidly with increasing distance from the road edge, in agreement with previous investigations. The major traffic effect is mainly limited to the surface soil and to a narrow zone within 40 m of the road. Therefore, land use for vegetable production or for livestock foraging should be avoided in a strip of this width.     

Total arsenic, lead, cadmium, copper, and zinc in some salt rivers in the northern Andes of Antofagasta, Chile

Lake Velenje is located in one of the most polluted regions in Slovenia, the Salek Valley. The major source of pollution in the valley is the coal-fired thermal power plant in Sostanj (STPP, capacity 775 MW). It has five separate units. All units have electrostatic precipitators for fly ash removal. Unit 4 also has installed a wet flue gas desulfurisation system (FGD system). Total mercury (THg) concentrations were measured in lignite, slag and ash samples from the STPP. In flue gas, different mercury species (THg, MeHg, Hg2+, Hg0) were determined separately for unit 4 and unit 5 which use different flue gas cleaning technology. Mercury and methyl mercury (MeHg) concentrations were also measured in lake water at different depths, in inflow water, outflow water, rain, snow and lake sediments in order to establish the influence of the power plant on the lake. Most mercury emitted from the power plant is in the elemental form. The ratio between oxidised and elemental Hg depends on the flue gas cleaning technology. Mass balance calculations have been performed for the STPP. The results show that the major sources of mercury in Lake Velenje are wet deposition and lake inflows. Total and MeHg concentrations in the water column are very low and can be compared to other non-contaminated freshwater lakes in the world.     

Effects of copper, zinc and cadmium on Selanastrum Capricornutum

The algicidal and algistatic effects of copper, zinc and cadmium on Selanastrum capricornutum, a unicellular green algae were analyzed by using a modification of the Algal Assay Procedures Bottle Test.Algicidal concentrations of copper, zinc and cadmium were 0.30, 0.70, and 0.65 mg 1⁻¹. Treatment of Selanastrum with various concentrations of the metals resulted in similar growth rates characterized by extended lag growth phases.Combinations of copper, zinc and cadmium were similar in toxicity to equal concentrations of zinc. Combinations of copper and cadmium resulted in a greater growth rate than equal concentrations of copper suggesting that cadmium inhibits copper toxicity.Selanastrum was able to exist in waters from the upper South Fork and North Fork of the Coeur d'Alene River where zinc and other metals were in low concentration. However, the algae was not able to tolerate zinc concentrations greater than 0·5 mg 1⁻¹ from waters of other parts of the drainage. These observations were consistent with laboratory findings where 0.7 mg 1⁻¹ zinc was algicidal and 0.1 mg 1⁻¹ inhibited the growth of Selanastrum.