Heavy metals in the lagos lagoon sediments

Concentrations of cadmium, cobalt, copper, chromium, iron, manganese, nickel, lead and zinc were determined in surface sediments of the Lagos Lagoon, Nigeria. The results revealed largely anthropogenic heavy metal enrichment and implicated urban and industrial wastes and runoff water transporting metals from land‐derived wastes, as the sources of the enrichment. Higher levels (F < 0.05) of cadmium, iron, manganese, nickel and zinc occurred in sediment samples collected near industrialized‐urban areas than in those from unindustrialized‐rural areas only in the wet season. While iron constituted about 1% of dry sediment by weight, the other metals were present in trace amounts.     

陶瓷地理标志产品微量元素迁移量检测研究

利用电感耦合等离子体质谱仪对20种陶瓷地理标志产品中的砷、镉、铬、镍、铅、锑、锌、铜、锰等9种微量元素迁移量情况进行检测。结果显示,镉、铬、锑在20种地理标志产品陶瓷中均未检出;铅、锌、铜、锰迁移量在有釉瓷（陶）器的多数种类中检出,其中锌迁移量突出;砷、镍迁移量在无釉陶器中检出。     

Trace metal concentrations in Nigerian fruits and vegetables

Eight trace metals, namely cadmium, cobalt, copper, chromium, iron, manganese, nickel and lead, as well as sodium, potassium, calcium and magnesium were determined in fresh Nigerian fruit and vegetables. Soil samples were also analysed for trace metals. The results show that trace metals occurred at low concentrations, and seem to reflect background levels, although higher concentrations and wider distribution were observed in the vegetables than in fruit. Their sodium, potassium, calcium, magnesium and iron content compared well with, values reported for American fruit and vegetables.     

Trace metals in scalp hair of children and adults in three Alberta indian villages

This study examined trace metal levels in scalp hair taken from 122 children and 27 adult residents of three small northern Alberta (Canada) Indian villages, one of which is situated close to the world's first tar sands oil extraction plants. The three communities studied were: Fort McKay (the exposed village), Fort Chipewyan (also in the tar sands ecosystem but distant from the plants), and Garden River (not in the tar sands ecosystem).Inductively coupled argon plasma emission spectroscopy was used to determine hair sample metal content. Nineteen metals were included in data analysis. Children from Fort McKay had the highest average hair lead, cadmium and nickel levels. Chromium levels were approximately equal in hair from Fort McKay and Garden River children, and significantly elevated above levels found in the hair of Fort Chipewyan children. Children from Garden River showed highest hair levels of eight metals: vanadium, aluminum, iron, manganese, barium, zinc, magnesium and calcium. Fort Chipewyan children had the highest hair levels of copper, but the lowest levels of all other metals.Among adults, hair lead, nickel and cadmium levels were highest in Fort McKay residents, while phosphorous and vanadium were highest in hair from Garden River residents.Bioaccumulation of lead, cadmium, nickel and chromium in hair from Fort McKay residents may be related to exposure to extraction plant pollution. Plant stack emissions are known to contain appreciable amounts of lead, nickel and chromium. Spills into the Athabasca River, until recently the source of Fort McKay drinking water, have been reported from plant wastewater holding ponds, known to contain elevated levels of lead, nickel and cadmium. An increased number of significant metal—metal correlations in hair metal levels for Fort McKay children suggests a richer source of multiple metal exposure, relative to children in the other two communities.     

Investigation of mangrove macroalgae as biomonitors of estuarine metal contamination

This study examined the potential use of macroalgae epiphytic on mangrove aerial roots as biomonitors of estuarine contamination. The metal concentrations of macroalgae were investigated in four estuaries in the vicinity of Sydney, Australia, and compared to water and sediment metal concentrations over three seasonal surveys. Macroalgal metal concentrations (copper, zinc, cadmium, chromium, lead, nickel, manganese and iron) appeared to be more associated with sediment metal concentrations than water concentrations, suggesting they may be useful biomonitors of estuarine sediment contamination. Algae in the more contaminated estuaries generally contained higher metal concentrations. However, concentrations of iron, nickel and manganese appeared to be similar in the algae despite the varying sediment concentrations, while accumulation of copper, zinc, lead and chromium appeared to be associated with ambient environmental concentrations. The uptake of metals also varied among the different species, suggesting that algal parameters, such as morphology, may also influence metal uptake and accumulation.     

Changes in the distribution patterns of trace metals in sediments of the mersey estuary in the last decade (1974–1983)

A survey of the trace metal distribution in the sediments of Liverpool Bay, and the Dee and Mersey estuaries in 1972–1974 has been followed by a series of regular monitoring surveys in the Mersey estuary during the last 10 years. Over 15 000 individual observations have been recorded, including measurements of the trace metal content (cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel and zinc), organic carbon content and particle size distribution. In parallel with the physical and chemical measurements, a limited biological sampling programme has also been carried out.These results are discussed in relation to the spatial and temporal variability detected, and in relation to the potential biological effect of the sedimentary trace metals.     

Removal of trace metals from wastewater by treatment with lime and discarded automotive tires

Discarded automotive tires, a solid waste disposal problem of enormous proportions, may provide the answer to another environmental headache—the removal of trace metals from wastewaters.Experiments were designed to evaluate the feasibility of using discarded automotive tires in conjunction with time to remove aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, silver and zinc from aqueous solutions.Continuous bench-scale studies showed that removals in excess of 99.5 per cent for most of the metals can be achieved by treatment with lime and discarded automobile tires.     

Coregionalization analysis of heavy metals in the surface soil of Inner Mongolia

Due to potential problems associated with their deficiencies or toxicities, heavy metals in soils are of great environmental concern. To evaluate heavy metal contents and their relationships in the surface soil of Inner Mongolia, soil samples were collected from 344 sites and contents of copper, lead, zinc, cadmium, nickel, chromium, mercury, cobalt, vanadium and manganese were determined. In this article, coregionalization of these ten heavy metals is investigated using factorial kriging. Vegetation type, parent material type and soil pH, with respective characteristic ranges of 200, 400 and over 1000 km, are identified as the primary factors that control the spatial distribution of soil heavy metals. At the scale of 200 km, heavy metal relationships mainly reflect the result of biocycling. Their relationships at the intermediate scale (400 km) are thought to be derived from the atomic substitution of metals in the parent materials. Effects of soil pH on the adsorption of heavy metals by soil organic materials could explain their relationships at the large spatial scale (over 1000 km).     

Metal loadings and removal at a municipal activated sludge plant

Influent total and dissolved concentrations of cadmium, chromium, copper, nickel and zinc to the Edmonton Gold Bar Wastewater Treatment Plant were measured at hourly intervals for several days. Metal concentrations were generally higher than in other large western Canadian cities and exhibited distinct diurnal variations. With the exceptions of nickel and zinc, the metals existed largely in the particulate phase. Samples collected from various points throughout the plant suggested that removal efficiencies for cadmium, chromium and copper were high and those for nickel and zinc were variable and generally low. Metal concentrations in the final effluent did not generally exceed the maximum levels allowed for Canadian drinking waters.     

Trace metals in the soft tissues of scaup ducks (Aythya marila L.) wintering in Gdańsk bay,Baltic sea

The concentrations of iron, zinc, manganese, copper, lead, cadmium, cobalt and nickel were determined in 107 pooled tissues of scaup ducks (Aythya marila L.). Distinct differences in concentrations of some metals in various tissues were observed; no significant sex-related variations for any of the metals were noted. Results obtained in this study show that kidney contained the maximum concentration of cadmium, while liver had the highest levels of cooper and manganese. Both liver and stomach were characterized by maximum levels of zinc; iron was detected, sometimes at highly elevated levels, in lung and liver. Transfer of metals analysed along a food chain from prey represented by molluscs to predator, i.e. scaup duck, was quantified with a transfer factor.     

Mercury, arsenic, cadmium, chromium lead, and selenium in feathers of pigeon guillemots (Cepphus columba) from Prince William Sound and the Aleutian Islands of Alaska

Arsenic, cadmium, chromium, lead, manganese, mercury and selenium were analyzed in the feathers of pigeon guillemots (Cepphus columba) from breeding colonies in Prince William Sound and in the Aleutian Islands (Amchitka, Kiska) to test the null hypothesis that there were no differences in metal levels as a function of location, gender, or whether the birds were from oiled or unoiled areas in Prince William Sound. Birds from locations with oil from the Exxon Valdez Oil Spill in the environment had higher levels of cadmium and lead than those from unoiled places in Prince William Sound, but otherwise there were no differences in metal levels in feathers. The feathers of pigeon guillemots from Prince William Sound had significantly higher levels of cadmium and manganese, but significantly lower levels of mercury than those from Amchitka or Kiska in the Aleutians. Amchitka had the lowest levels of chromium, and Kiska had the highest levels of selenium. There were few gender-related differences, although females had higher levels of mercury and selenium in their feathers than did males. The levels of most metals are below the known effects levels, except for mercury and selenium, which are high enough to potentially pose a risk to pigeon guillemots and to their predators.     

The efficiency of heavy metal removal by a conventional activated sludge treatment plant

The total and dissolved concentration of cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel and zinc at various points in a conventional activated sludge treatment plant have been measured. The analysis of raw sewage samples collected hourly over a 3-day period showed that metal input to the sewage treatment plant was not a continuous process but consisted of slugs of metal lasting for a discrete time. The efficiency of heavy metal removal by this model treatment plant was determined by monitoring the influent and effluent metal levels over a 4-week period.     

Particle size distribution and atmospheric metals measurements in a rural area in the South Eastern USA

Atmospheric particle mass concentrations were measured at a site adjacent to Lake Hartwell, GA, during six dry sampling events in February-March 2003. The overall average PM2.5 mass concentration was 9.5 microg/m3 and the overall average total suspended particles mass concentration was 19.1 microg/m3. Particulate matter was collected on a deposition plate mounted onto a specially designed wind vane and was subsequently analyzed to determine the particle size distribution. The average geometric particle diameter was found to be 2.8 microm. Particulate matter collected was found to be closely approximately at log-normal distribution, with a count median diameter of 1.5 mum and a geometric standard deviation of 1.8. Individual metal concentrations present in airborne particulate matter were determined for cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc using inductively coupled plasma-mass spectrometry analysis of samples collected on Teflon filters. Ambient metal concentrations were found to range from 0.8 ng/m3 for cadmium to 512 ng/m3 for iron. The dry deposition flux of metals was estimated to be in the range of 0.17 mg/(m2 year) for cadmium to 102 mg/(m2 year) for iron. More samples need to be collected and analyzed, both temporally and spatially, in order to establish atmospheric metals fluxes onto surfaces.     

Treatment of oil well “produced water” by waste stabilization ponds: Removal of heavy metals

Oil well produced water (PW) can serve as an alternative water resource for restricted halotolerant agricultural purposes if the main pollutants, hydrocarbons and heavy metals, can be removed to below the irrigation standards. In this work, the potential removal of cadmium(II), chromium(III) and nickel(II) from PW by chemical precipitation in biological treatment was evaluated. Precipitation as a sulphide salt was found to be a very effective mechanism, which together with biosorption, biological metal uptake, precipitation as hydroxides and carbonates could remove heavy metals down to below irrigation standards. The existence and capability of these various mechanisms was demonstrated in the performance of a continuous artificial pond followed by intermittent sand filter, achieving removals of around 95% for nickel(II) and even higher removal rates for cadmium(II), chromium(III) from artificial PW after the installation of an anaerobic stage. The treated effluent quality was higher than that required by current European standards.     

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.     

Role of bacterial extracellular polymers in metal uptake in pure bacterial culture and activated sludge—I. Effects of metal concentration

A gel filtration technique afforded a good separation between metal complexed with bacterial extracellular polymers and free metal ions. The complexation of polymers extracted from cultures of Klehsiella aerogenes and activated sludge with cadmium, nickel, manganese and cobalt was demonstrated. The extraction of extracellular polymers from cultures of K. aerogenes and activated sludge reduced the capacity of the cells and flocs to adsorb metal. Adsorption and complexation of metals by cells of K. aerogenes and extracellular polymers extracted from activated sludge were fitted to Freundlich equilibrium isotherms. Saturation of activated sludge polymer binding sites occurred at 10 mg 1^?1 metal additions for all the metals studied except manganese which was complexed to a very limited extent. Cells of K. aerogenes exhibited no saturation effects in the range of metal concentrations studied.Precipitation of metals below a concentration of 1 mg 1^?1 was minimal, with the exception of cadmium precipitation. At a concentration of 10 mg 1^?1, precipitation of cadmium, cobalt and manganese may have been the major mechanism of metal removal. The more soluble metals generally displayed the lowest removals. Concentrations of extracellular polymers and soluble chelating agents may be important in controlling removals of metals which are largely soluble in activated sludge.     

An investigation of trace element losses during lyophilization of marine biological samples

Trace element losses during lyophilization of selected macroalgae and marine flesh tissues were investigated. No significant losses (p > 0.1) of arsenic, cadmium, copper, iron, mercury, manganese, nickel, lead, selenium, tin and zinc were found. Significant losses of chromium (3–15%) occurred from several specimens. An all-glass freeze drying apparatus is also illustrated.     

Do powered toothbrushes contaminate toothpaste with metals?

Replaceable brush units of powered toothbrushes (PTBs) can contain metal parts made of nickel and chromium bearing alloy. These alloy ingredients have allergenic potential, and may contaminate toothpaste and the mouth during use. Here I quantify metals abraded from PTBs. A leading brand of PTB was used in a simulated intraoral environment with three leading brand toothpastes, and post-brushing samples were analysed for iron, chromium, nickel, molybdenum, and manganese by certified laboratories using standard methods. Results showed tartar control toothpaste abraded most metal, and caused discolouration of toothpaste slurry. Discolouration of toothpaste slurry, as a useful indicator of metal abrasion, was limited to one toothpaste brand, and not useful across brands.     

Metal concentrations in rural topsoil in South Carolina: potential for human health impact

Rural areas are often considered to have relatively uncontaminated soils; however few studies have measured metals in surface soil from low population areas. Many metals, i.e., arsenic (As), lead (Pb), and mercury (Hg), have well-documented negative neurological effects, and the developing fetus and young children are particularly at risk. Using a Medicaid database, two areas were identified: one with no increased prevalence of mental retardation and developmental delay (MR/DD) (Strip 1) and one with significantly higher prevalence of MR/DD (Strip 2) in children compared to the state-wide average. These areas were mapped and surface soil samples were collected from 0-5 cm depths from nodes of a uniform grid laid out across the sampling areas. Samples were analyzed for As, barium (Ba), beryllium (Be), chromium (Cr), copper (Cu), Pb, manganese (Mn), nickel (Ni), and Hg. Inverse distance weighting (IDW) was used to estimate concentrations throughout each strip area, and a principal component analysis (PCA) was used to identify common sources. All metal concentrations in Strip 2, the MR/DD cluster area, were significantly greater than those in Strip 1 and similar to those found in more urban and highly agricultural areas. Both Strips 1 and 2 had a high number of significant correlations between metals (33 for Strip 1 and 25 for Strip 2), suggesting possible similar natural or anthropogenic sources which was corroborated by PCA. While exposures were not assessed and direct causation between environmental soil metal concentrations and MR/DD cannot be concluded, the high metal concentrations in areas with an elevated prevalence of MR/DD warrants further consideration.     

Metal content of dandelion (Taraxacum officinale) leaves in relation to soil contamination and airborne particulate matter.

The global distribution of the common dandelion (Taraxacum officinale Weber, sensu lato; Asteraceae), along with its ability to tolerate a wide range of environmental conditions, make this 'species' a particularly attractive candidate to evaluate for its value as a biological monitor of environmental metal contamination. To examine the metal content of dandelion leaves in relation to environmental metal levels, the concentrations of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were analyzed in leaf and soil samples collected at 29 sites in the mid-western United States differentially impacted by pollution. Sites were chosen primarily to cover a range of annual mean 24-h airborne particulate matter < or = 10 microm (hereafter, PM10) exposure, with PM10 levels varying from those found in isolated rural areas to levels typical of the most industrialized urban locations in the mid-western United States. A positive. significant correlation was detected between soil concentrations of each metal and measures of PM10 at a site, signifying that airborne particulate matter is a good indicator of soil metal contamination. Leaf concentrations of four of the eight metals (Cr, Mn, Pb and Zn) examined were found to increase significantly as the soil levels of these metals increased, but the percentage of the total variation explained by the relationship in these cases was generally low. This latter finding, along with the lack of a significant relationship between leaf and soil concentrations for the four other metals, indicate that the factors affecting metal absorption from the soil by dandelions are complex and that, aside from soil metal concentrations, other soil, plant and/or other environmental factors affect metal uptake. There was also no evidence that leaf metal concentrations were positively correlated with PM10. In addition, the concentrations of some metals (Cu, Fe, Mn, Pb and Zn) were significantly higher in leaves collected in the fall compared to those collected at the same sites in the spring. These findings suggest that dandelions may not be a particularly effective tool for quantifying levels of environmental metal contamination, at least on the scale of pollution typifying industrialized urban areas of the mid-western United States.