Extent Of Metal Contamination Research Articles

Toxic Metal Concentrations and Exposure Risks Associated with Surface Water, Seafood (Clarias gariepinus, Oreochromis niloticus, Cottus gobio) and Vegetable (Telfairia occidentalis) from Elebele River, Nigeria

Human exposure to elevated levels of environmental contaminants is an important concern of health toxicology. This study assessed the toxicity level of toxic metals including Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb) and Nickel (Ni) in samples of water, seafood (Clarias gariepinus, Oreochromis niloticus, Cottus gobio) and vegetable (Telfairia occidentalis) from the adjacent area of Elebele River, Nigeria, bioconcentration and toxic metal exposure posed to communities consuming these foodstuffs. The following indices: single-factor index and the comprehensive pollution index, metal pollution index, estimated daily and weekly intakes, hazard index and lifetime cancer risk were applied. Samples of water, seafood and vegetable were analysed using Atomic Absorption Spectrophotometer. The results showed that the concentrations of metals except for Cd in water samples were higher than the permissible limits by international organisations. Results also revealed that the concentrations of metals in foodstuff samples were within limits. Furthermore, the values of estimated weekly intakes calculated were lower than the limits of provisional tolerable weekly intakes established by the Food and Agriculture Organization and World Health Organization. This suggests no health risks and is consistent with the HI results. However, As was a major contributor (96.9%) to health risks associated with the ingestion of water. Lifelong consumption of T. occidentalis might be hazardous in the study locality. The carcinogenic risk was > 1 × 10‒4 for As and Ni. Therefore, to reduce the health risk and the extent of metal contamination, steps must be taken for the efficient removal of metals from the water body.

Pollution and health risk assessment of toxic metals in solid waste dumping site soil and its impact on groundwater: a case study

ABSTRACT Distribution, sources, level of pollution, and associated human health risk assessment of toxic metals in municipal solid waste (MSW) dumping site soil of Tezpur town, located on the northern side of the river Brahmaputra, Assam were investigated. The extent of metal contamination in the MSW dumping site soil was evaluated using enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (Ci f), degree of contamination (Cd), and pollution load index (PLI). Based on these indices it can be concluded that MSW dumping site soil is highly contaminated with Cd and Pb. Moreover, ecological risk indices demonstrated high and low to moderate potential ecological risk due to Cd and Pb, respectively. Although no significant non-carcinogenic risk was found for the measured metals, potential carcinogenic risks of Cr, Pb, Ni, Cd for both children and adults were observed. Source apportionment study was carried out using principal component analysis (PCA) and it was found that metals were mainly originated from two sources: (1) Cu, Pb, Zn, and Cd were mainly from different components of MSW; (2) Mn, Cr, and Ni were from lithogenic materials. The concentrations of Cd and Pb in groundwater source at a radial distance of 20 m from the dumping site exceeded the prescribed limit for drinking water set by World Health Organization (WHO) and raises serious concern to the people residing near the dumping site.

Relationship Between Metal Load (Selenium, Arsenic, Molybdenum) of Soil, Plant and Serum of Buffaloes

Presence of hazardous minerals in three major components (soil, forage and buffalo serum) was evaluated for determining extent of metal contamination in Sargodha, Pakistan. Ten soil and forage samples for each season were taken from ten randomly selected sites. 30 grazing buffaloes of �niliravi� breed (calves, non-lactating and lactating) were also sampled randomly from these sites for collection of serum. Heavy metal quantification via atomic absorption spectrophotometry was carried out for selenium, molybdenum and arsenic. Non-significant but positive correlation was found for selenium (Se) concentrations in soil, forage and serum and molybdenum (Mo) concentrations in soil and serum. Negative correlation (p]0.05) was obtained for Mo level between forage-serum and soil-forage which was indicative of molybdenum deficiency in the soil. The results suggested that the heavy metals remained below maximum permissible levels and were non-toxic for the ruminants of the study area.

Seasonal variations, metal distribution and water quality in the Todos os Santos River, Southeastern Brazil: a multivariate analysis.

In aquatic habitats, metal contamination from natural and anthropogenic sources continues to pose a concern for human and environmental health. Thus, it is important to complete monitoring studies to assess patterns and the extent of metal contamination in these ecosystems. The purpose of this work was to determine the concentrations of 31 chemical elements and water quality parameters of the Todos os Santos River located in the Mucuri Valley, Minas Gerais, Brazil. A multivariate statistical analysis was used to determine any seasonal and spatial patterns from the data. Results demonstrated that metals including Al, Fe, and Ni exceeded Brazilian and international guidelines nutrients as P also exceed water quality standards. Principal components analysis indicated distinct geographical and seasonal patterns for multiple elements with hierarchical cluster analysis confirming the observed spatial patterns of contamination in the Todos os Santos River.

Using public participation to sample trace metals in lake surface sediments: the OPAL Metals Survey

Members of the public in England were invited in 2010 to take part in a national metals survey, by collecting samples of littoral sediment from a standing water body for geochemical analysis. To our knowledge, this is the first national sediment metals survey using public participation and reveals a snapshot of the extent of metals contamination in ponds and lakes across England. Hg, Ni, Cu, Zn and Pb concentrations exceeding sediment quality guidelines for the health of aquatic biota are ubiquitous in ponds and lakes, not just in areas with a legacy of industrial activity. To validate the public sampling approach, a calibration exercise was conducted at ten water bodies selected to represent a range of lakes found across England. Sediment concentrations of Hg, Ni, Cu, Zn and Pb were measured in samples of soil, stream and littoral and deep water sediment to assess inputs. Significant differences between littoral sediment metal concentrations occur due to local variability, but also organic content, especially in upland, peat soil catchments. Variability of metal concentrations between littoral samples is shown to be low in small (<20 ha) lowland lakes. Larger and upland lakes with more complex inputs and variation in organic content of littoral samples have a greater variability. Collection of littoral sediments in small lakes and ponds, with or without voluntary participation, can provide a reliable sampling technique for the preliminary assessment of metal contamination in standing waters. However, the heterogeneity of geology, soils and history/extent of metal contamination in the English landscape, combined with the random nature of sample collection, shows that systematic sampling for evaluating the full extent of metal contamination in lakes is still required.

VegeSafe: A community science program measuring soil-metal contamination, evaluating risk and providing advice for safe gardening

The extent of metal contamination in Sydney residential garden soils was evaluated using data collected during a three-year Macquarie University community science program called VegeSafe. Despite knowledge of industrial and urban contamination amongst scientists, the general public remains under-informed about the potential risks of exposure from legacy contaminants in their home garden environment. The community was offered free soil metal screening, allowing access to soil samples for research purposes. Participants followed specific soil sampling instructions and posted samples to the University for analysis with a field portable X-ray Fluorescence (pXRF) spectrometer. Over the three-year study period, >5200 soil samples, primarily from vegetable gardens, were collected from >1200 Australian homes.As anticipated, the primary soil metal of concern was lead; mean concentrations were 413 mg/kg (front yard), 707 mg/kg (drip line), 226 mg/kg (back yard) and 301 mg/kg (vegetable garden). The Australian soil lead guideline of 300 mg/kg for residential gardens was exceeded at 40% of Sydney homes, while concentrations >1000 mg/kg were identified at 15% of homes. The incidence of highest soil lead contamination was greatest in the inner city area with concentrations declining towards background values of 20–30 mg/kg at 30–40 km distance from the city. Community engagement with VegeSafe participants has resulted in useful outcomes: dissemination of knowledge related to contamination legacies and health risks; owners building raised beds containing uncontaminated soil and in numerous cases, owners replacing all of their contaminated soil.

Distribution Pattern of Some Heavy Metals in the Soil of Silghat Region of Assam (India), Influenced by Jute Mill Solid Waste

Physico‐chemical Analysis of the soil of Silghat region of Nagoan district of Assam, India was carried out to assess the possible effect of jute mill solid waste in the distribution pattern of some heavy metals. Soil samples were collected from ten different locations of the dumping site of the mill and their physico‐chemical parameters were analyzed. Scanning Electron Microscopy‐Energy Dispersive X‐ray analysis (SEM‐EDX) and Inductively coupled Plasma‐Optical Emission Spectrometer (ICP‐OES) analysis of the samples shows that soil of the dumping sites is highly enriched with heavy metals. The concentration of Fe, Cu, Zn and Pb in the contaminated soil was found to be very much higher than both the continental crust and world rock average values. Correlation studies indicate strong positive correlation between organic carbon content (Corg) with all the metals investigated. pH has negative correlation while positive correlation was observed for electrical conductivity with all the metals. Extent of metal contamination was assessed by determining contamination degree (CD) and pollution load index (PLI).

Heavy Metals Contamination in Vegetables Grown in Urban and Metal Smelter Contaminated Sites in Australia

Dietary exposure to heavy metals, namely cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu), has been identified as a risk to human health through the consumption of vegetable crops. This study investigates the source and magnitude of heavy metal contamination in soil and vegetable samples at 46 sites across four vegetable growing regions in New South Wales, Australia. The four regions Boolaroo, Port Kembla, Cowra and the Sydney Basin were a mix of commercial and residential vegetable growing areas. The extent of metal contamination in soils sampled was greatest in regions located in the vicinity of smelters, such as in Boolaroo and Port Kembla. Soil metal concentrations decreased with depth at these two sites, suggesting contamination due to anthropogenic activities. Cadmium, Pb and Zn contamination was greatest in vegetables from Boolaroo, and Cu concentrations were greatest in vegetables sampled from Port Kembla. At Boolaroo, nearly all the samples exceeded the Australian Food Standards maximum level (ML) (0.01 mg kg−1 fresh weight) of Cd and Pb in vegetables. Over 63% of samples exceeded international food standard guidelines set by the Commission of the European Communities and the Codex Alimentarius Commission. All vegetables sampled from Cowra, which is a relatively pristine site had Cd and Pb levels below the Australian and international food standards guideline values. This study suggests that the Australian guideline values are more conservative in defining the ML for Cd and Pb in vegetable crops. This investigation highlights the increased danger of growing vegetables in the vicinity of smelters.

Ventilation, a recently described step limiting heavy metal contamination in aquatic animals

Contamination of surface waters by metals, either in the marine or freshwater environment, is a fundamental question around the world. Bivalves are today largely used as biological monitors to evaluate the extent of metal contamination and to determine impacts on the food web in biogeochemical cycling. A fundamental question is thus the nature of the relationship between water contamination and metal concentration in the bivalve tissues. Indeed, the idea behind most studies is based on tissue accumulation data that is used to estimate the importance of the field contamination either measured by the dissolved, total and/or bound fractions. Until recently, chemical speciation was considered as a major factor controlling bioavailability of metals to organisms in the aquatic environment. However numerous examples show that it cannot explain by itself all changes of metal accumulation process and that biological factors must be included. Up to now salinity, season, temperature, weight, growth rate and diet were reported to belong to these factors. We review recent work from our own laboratory demonstrating that ventilatory activity, i.e. the rate of water flowing over the gills, which is highly variable in water breathers according to the water physico-chemistry and animal metabolic requirement, is also of primary importance.

Metal Contamination in the Republic of Armenia.

/ Air, soil, and water samples were collected throughout the Republic of Armenia both before and after its independence from the Soviet Union in 1991. Reported analyses of those samples indicated that levels of several trace metal concentrations (Ag, Cd, Cr, Cu, Mo, Ni, Pb, Ti, and Zn) exceeded the maximum allowable concentrations established by the former Soviet Union (FSU) and subsequently adopted by Armenia. Although industrial production has declined by more than 80% since the 1980s, the economy is improving and there is potential for a significant increase in the generation of industrial metal emissions. These include automobile emissions, which are now considered to be the primary source of atmospheric lead. Historically, the Soviet Union did not strictly enforce environmental standards, and Armenia is now faced with the resulting environmental problems and the associated risks to public health. Since some trace metal concentrations may be at or near potentially toxic levels, there is a need to accurately assess the extent of metal contamination in order to devise cleanup plans and develop long-term environmental protection and public health strategies in Armenia.

Dynamic workplans and field analytics: Metals assessment by inductively coupled plasma/optical emission spectroscopy

Hazardous waste site investigations were carried out at the Marine Corps Air Station (MCAS) in Yuma, Arizona and at Hanscom Air Force Base (HAFB) in Bedford, Massachusetts. The purpose of the first was to determine the location and extent of metals contamination throughout the base. The objective of the second was to evaluate the risk of metals contamination to groundwater from soil at three locations within the airfield. Dynamic workplans were developed and an adaptive sampling and analysis plan carried out with the data produced in the field used to support the goals of each project. An inductively coupled plasma/optical emission spectrometer (ICP/OES) was modified for field operation. A more efficient microwave digestion method and pressurized Teflon filtration system were developed for the HAFB project. Results were comparable to standard Environmental Protection Agency (EPA) methods, which must rely on two digestion procedures to recover EPA-targeted metals within the prescribed recovery range. The MCAS investigation, conducted over a five-month period, advanced the Navy's efforts from 30 months behind schedule to 18 months ahead of schedule, while the data generated at HAFB showed no risk to groundwater from metals.

Comparison of Techniques for the Analysis of Industrial Soils by Atomic Spectrometry

Methods based on AAS, ICP-AES and XRFS have been developed for determination of Cd, Cr, Cu, Mn, Ni, Pb, V and Zn in soil layers from pits excavated on a redundant industrial site. Samples were dried and sieved, and the < 2 mm fraction was ground in a ball mill prior to analysis. For ICP-AES and AAS, 1 g sub-samples were digested with aqua regia in a microwave oven. The dry weight detection limits of the analytes were in the range 2–25 μg g−1 for FAAS, 0.003–0.2 μg g−1 for ETA AS and 0.04–1.6 μg g−1 for ICP-AES. When digests of the industrial soils were analysed, calibration with acid-matched standards gave acceptable accuracy for all the analytes, except for Cd when determined by ETAAS (30–40 % suppression). Despite lack of reference materials of industrial origin, analysis of two soil reference materials by these techniques produced concentrations that were within ± 10 % of the certified or recommended values for elements extractable with aqua regia. Direct standard-less analysis of a soil reference material with a portable x-ray fluorescence (P-XRF) analyser gave concentrations for a range of elements that were within a factor of 2 of the certified values. When the XRFS and ICP-AES methods were used to analyse the industrial soils, the concentrations obtained were similar (to within 30%) for Cu, Pb and Zn in most of the samples and for Cr, Mn and Ni in some of the samples. The concentrations of V estimated with the P-XRF analyser were 4 to 7-fold higher than those obtained by ICP-AES. The discrepancies were thought to be caused by spectral enhancement interferences in XRFS. Cadmium was not determined accurately by either ICP-AES or P-XRFS owing to spectral interferences. The work has highlighted the importance of analysing samples from across a site and at different depths, when assessing the extent of metal contamination on industrial land.

Rapid measurement of suspended C, N, and P from Precambrian Shield Lakes using Near-infrared Reflectance Spectroscopy

Rapid (<2 min), simultaneous, non-chemical, non-destructive, cost-efficient measurement of the C, N, and P concentrations in suspended, particulate matter in water from lakes of varying trophic status, pH, and extent of metal contamination was attempted by the use of near-infrared reflectance spectroscopy (NIRS). This technique, widely used in the agricultural, food, pharmaceutical, petrochemical, and textile industries, is being explored for its applications to aquatic and environmental sciences. Suspended matter from lake water (10–100 ml) was collected on 2.5 cm dia. G/FC glass fibre filters so that filters bore 10.5–109.2 μg C, 0.8–18.9 μg N, and 0.09-2.67 μg P per filter. Filters were oven-dried and scanned with an NIRSystems 6500 near-infrared spectrophotometer. The spectral data were treated by multiple linear regression analysis to develop mathematical relationships (calibrations) between absorbance at particular wavelengths and amounts of C, N, and P determined by conventional chemical analytical methods. These calibrations were used to predict C, N, and P from an independent set of spectra. Agreement between these NIRS-predicted values and their chemical values was generally greater than 0.9 for C, N, and P ( r 2 from 0.88 to 0.97).

The effects of host metal stress on a parasitoid in an insect/insect relationship (Lymantria dispar L., Lymantriidae lepid.?Glyptapanteles liparidis Bouch�, Braconidae hym.)

A host-endoparasitoid relationship was investigated under metal stress.Lymantria dispar (gypsy moth) larvae were reared on artificial diets contaminated with two concentrations of cadmium (2 and 10 μg/g), lead (4 and 20 μg/g), copper (10 and 50 μg/g) and zinc (100 and 500 μg/g), all based on dry weight. Following parasitization in the first premoulting period byGlyptapanteles liparidis, the eclosal success ofG. liparidis and the developmental rates of both species were investigated and compared with controls. Additionally, metal concentrations were monitored in host individuals and parasitoids by flame and flameless AAS. The developmental rate of the endoparasitoid positively correlated with that of the host. A negative relationship was found between the number of closedG. liparidis and the developmental rate of the host. No correlation was found between the extent of metal contamination and parasitization success.

Geohydrology and water quality in the vicinity of the Silver Creek tailings site, Summit County, Utah : Mason, J L Proc Symposium on Geology and Hydrology of Hazardous-Waste, Mining-Waste, Waste-Water and Repositories Sites in Utah, Salt Lake City, 1989P135–148. Publ Salt lake City: Symposium and Field Conference, 1989 (Utah Geological Association Publication 17)

Abstract The Silver Creek tailings site is in Prospector Square, a commercial development and residential community in Summit County, Utah. The movement and the extent of metal contamination in ground water from the unconsolidated valley fill were assessed in the area. Estimated values of hydraulic conductivity range from 1 to 14 feet per day for the poorly sorted clay, silt, sand, and gravel in the unconsolidated valley fill. An aquifer-interference test indicated that water in the valley fill did not move from the tailings site toward the pumped municipal well completed in the consolidated-rock aquifer. During low flow, concentrations of dissolved and suspended cadmium, manganese, and zinc in surface water downstream from the tailings were substantially greater than background concentrations. Concentrations of dissolved cadmium, manganese, and zinc were greater than background concentrations in water from at least three wells and a drain.