Quantitative analysis and sorption of cadmium in environmental samples with a functionalized synthetic polymer

Quantitative analysis of cadmium in environmental samples was achieved with a polymeric sorbent synthesized by copolymerization of N,N-dimethylacrylamide and allyl glycidyl ether/iminodiacetic acid as chelating monomers with N,N′-methylenebisacrylamide as cross-linker. The polymer was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis, and scanning electron microscopy. The sorption capacity of the functionalized sorbent was 70 mg g^?1. The equilibrium sorption data of Cd(II) on polymeric sorbent were analyzed using Langmuir, Freundlich, Temkin, and Redlich–Peterson models. Based on equilibrium adsorption data, the constants at pH 4.2 and 20 °C were determined for the first three as 0.33 (L mg^?1), 17.5 (mg g^?1) (L mg^?1)^1/n, and 12.9 (J mol^?1). Recovery of 94% of the metal ion was obtained with 0.5 mol L^?1 nitric acid as an eluting agent.     

Spatial distribution of copper in relation to recreational boating in a California shallow-water basin

The overall effect of the number of boats on the copper (Cu) levels in the water column and sediment, along with their spatial variability within Shelter Island Yacht Basin (SIYB), San Diego Bay, California was examined. We identified a horizontal gradient of increasing dissolved Cu and Cu in sediment from outside to the head of SIYB which was coincident with the increasing number of boats. Spatial models of Cu distribution in water and sediment indicated the presence of ‘hotspots’ of Cu concentration. From outside to the head of SIYB, dissolved Cu ranged from 1.3 μ g L^?1 to 14.6 μ g L^?1 in surface water, and 2.0 μ g L^?1 to 10.2 μ g L^?1 in bottom water. Cu in sediment exceeded the Effect Range Low of 34 mg kg^?1 (i.e. where adverse effects to fauna may occur), with a peak concentration of 442 mg kg^?1 at the head of the basin. Free Cu⁺⁺ in surface water was several orders of magnitude higher than in sediment porewater. High-resolution data of Cu species together with probability maps presented in this paper will allow managers to easily visualise and localise areas of impaired quality and to prioritise which areas should be targeted to improve Cu-related conditions.     

Preconcentration of samarium with modified yeast cells for its determination by atomic emission spectroscopy

A chelating-modified biosorbent is produced by coupling of a dye, procion red, to yeast cells. The resulting modified cells have been characterized by Fourier transform infrared, elemental analysis and thermogravimetric analysis and studied for preconcentration and determination of trace Sm(III). The optimum pH value for sorption of the samarium ions is 6.2. The sorption capacity of functionalized modified yeast cells is 7.2 mg g^?1. Recovery was 99% when Sm(III) was eluted with an aqueous solution of 0.1 mol L^?1 ethylenediaminetetraacetic acid. Scatchard analysis suggested that binding sites were homogeneous. The equilibrium data were analyzed using Langmuir, Freundlich, Temkin, and Redlich–Peterson isotherm models, and the respective constants were determined as 1.0 (L mg^?1), 2.9 [(mg g^?1) (L mg^?1)^1/n], 2.4 × 10⁸ (L g^?1), and 30 (dm³ g^?1) at 20 °C. The method was applied for an Sm(III)-containing sample of ceramic industry effluent.     

Depression of feeding and growth rates of the seastar Evasterias troschelii during long-term exposure to the water-soluble fraction of crude oil

To test the effect of petroleum hydrocarbons on predation by the seastar Evasterias troschelii (Stimpson, 1862) on the mussel Mytilus edulis (L.), we exposed the predator with the prey to six concentrations of the water-soluble fraction (WSF) of Cook Inlet crude oil. Seastars and mussels were collected at Auke Bay, Alaska, in November 1980. During a 28 d exposure in a flow-through system, seastars were more sensitive to the WSF than mussels: the LC₅₀ for the seastars was 0.82 ppm at Day 19 and, although no mussels were exposed to WSF for more than 12 d, none died. Daily feeding rates (whether in terms of number of mussels seastar^-1 d^-1 or dry weight of mussels seastar^-1 d^-1) were significantly reduced at all concentrations above 0.12 ppm. At 0.20, 0.28 and 0.72 ppm WSF, daily feeding rates (in terms of dry weight of mussels) were, respectively, 53, 37, and 5% of the control rate; at the two highest concentrations (0.97 and 1.31 ppm WSF), the seastars did not feed. Seastars at concentrations greater than 0.12 ppm WSF grew slower than individuals from the control group and the 0.12 ppm-treatment group combined. These laboratory results show that E. troschelii is more sensitive to chronic low levels of the WSF of crude oil. The possibility that such oil pollution could reduce predation and permit M. edulis to monopolize the low intertidal zone of southern Alaska remains to be studied.     

Rapana venosa as a bioindicator of environmental pollution

The aim of this investigation was to examine biochemical differences in the gastropod Rapana venosa (R. venosa) from polluted (RvP) and nonpolluted (RvN) sites of the Black Sea's Bulgarian coast that may serve as bioindicators of environmental quality. Mussels Mytilus galloprovincialis (MMg) were collected from polluted (MMgP) and nonpolluted (MMgN) sites at the same time for comparison. Bioactive compounds and the antioxidant activity of dry matter (DM) methanol extracts from RvP and RvN were determined. Three-dimensional fluorometry (3D-FL) and Fourier transform infrared (FTIR) analyses were used to evaluate polyphenols and proteins. DM methanol extracts from RvP, and to lesser extent RvN, showed high amounts of total phenolics (23.22±2.9 and 15.60±1.8 mg GAE · g^?1 DW) and exhibited high levels of antioxidant activity in some radical scavenging assays (μ MTE · g^?1 DW): 56.38±5.2 and 33.79±3.3 by 2,2azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diamonium salt (ABTS·⁺); 54.79±5.6 and 33.7±2.6 by cupric reducing antioxidant capacity (CUPRAC); 62.34±6.8 and 30.31±3.9 by the 1diphenyl-2-picrylhydrazyl method (DPPH). A correlation in the above indices was found between R. venosa and M. galloprovincialis, but all results were relatively higher for M. galloprovincialis than for R. venosa. The obtained indices of R. venosa may serve as a bioindicator of environmental ecological quality.     

Cadmium accumulation by green algae Cladophora glomerata (L.) Kutz. (Chlorophyta) in presence of Nile tilapia Oreochromis niloticus (L.)

Accumulation of metals by aquatic organisms is mostly affected by other biological components in environments. In this study, cadmium (Cd) accumulation in green algae, Cladophora glomerata (L.) Kutz., exposed to 0.1 and 1.0 mg L^?1 of Cd for 15 and 30 days was examined in laboratory conditions in the presence of Nile tilapia Oreochromis niloticus (L.). The green algae C. glomerata accumulated Cd concentrations as 690 ± 70 and 3430 ± 470 mg kg^?1 on day 15, and 1130 ± 180 and 6830 ± 1540 mg kg^?1 on day 30. There were significant increases (p < 0.05) in metal accumulation by green algae as the exposure time and metal concentration increased. The results also indicated that the presence of Nile tilapia in the medium led to a significant Cd accumulation in the green algae compared to control (p < 0.05).     

Antioxidant defense properties of Arctic amphipods: comparison between deep-, sublittoral and surface-water species

The toxic reactive oxygen species (ROS), produced naturally in an oxygenated environment, led to the development of antioxidant defenses by aerobic organisms to prevent tissue damage. Polar marine waters are regarded as a strongly prooxidant ecosystem, due to the high dissolved oxygen level and intense UV radiation during summer, while the deep waters are considered refuges against oxidative stress. In order to further elucidate the prooxidant and antioxidant forces associated with cold-water ecosystems and the implications of UV radiation, we sampled three amphipod species living at three different depths in the same water mass of the Arctic Ocean, characterized by low temperature (ca. 0°C), high oxygen level, and high ROS concentration in the surface water. The three species were the deep-sea amphipod Eurythenes gryllus, the benthic sublittoral amphipod Anonyx nugax and the surface-water species Gammarus wilkitzkii inhabiting the ice pack. The total oxyradical scavenging capacity (TOSC) was measured in the cytosolic fraction of the digestive gland and in the cell-free hemolymph of the three amphipod species. A significantly low TOSC toward peroxyl and peroxynitrite radicals (P<0.05) in E. gryllus compared with the shallow-water species (A. nugax) can be explained by the low metabolism of the deep-sea species. In the cell-free hemolymph, TOSC values are similar between E. gryllus and A. nugax, while in G. wilkitzkii a lower and higher TOSC toward hydroxyl and peroxynitrite, respectively, indicate specific adaptation to oxidative stress. Experimental exposure of A. nugax and G. wilkitzkii to H₂O₂ resulted in a significant change in TOSC (P<0.05) measured in the digestive gland and in the cell-free hemolymph of A. nugax, while no change (P>0.05) was noted in G. wilkitzkii. These data suggest that A. nugax is highly susceptible to oxidative stress and that G. wilkitzkii is characterized by a mechanism that prevents the diffusion of exogenous ROS through the gills or allows excretion of internal H₂O₂ through the gills to the environment.Communicated by M. Kühl, Helsingør     

The effects of evening primrose oil on arsenic-induced oxidative stress in rats

Forty-eight male Wistar albino rats were allocated to the four groups such that each comprised 12 animals. The first group was maintained as the control. In group 2, evening primrose oil was administered at a dose of 0.1 mL rat^?1 day^?1 (～500 mg kg^?1 bw) into the stomach via gavage, whilst in group 3 sodium arsenide was administered at a concentration of 100 mg L^?1 in ad-libitum drinking water for 30 days. The fourth group was given 0.1 mL rat^?1 day^?1 evening primrose oil into the stomach via gavage plus 100 mg L^?1 of sodium arsenide in ad-libitum drinking water for 30 days. At the end of the 30th day, tissue (liver, lung, kidney, brain, heart, spleen, and testis) and blood samples were collected from each group. Malondialdehyde (MDA) and nitric oxide (NO) levels and superoxide dismutase, catalase and glutathione peroxidase activities were measured in the samples. Exposure to arsenic in rats causes oxidative stress by increasing lipid peroxidation (increase of MDA and NO levels) and altering the activity of antioxidant enzymes. Evening primrose oil did not have any adverse effects. Furthermore, it was ascertained that the administration of arsenic with evening primrose oil reduced the severity of oxidative stress.     

Hyperaccumulator Thlaspi caerulescens (Ganges ecotype) response to increasing levels of dissolved cadmium and zinc

Hyperaccumulation of metals by plants involves at least three processes: efficient absorption by roots, efficient root-to-shoot translocation and hypertolerance through internal detoxification. In this study, Thlaspi caerulescens was separately exposed to Cd and Zn at 0, 50, 100 and 200 μ M for 7 d to monitor plant responses in hydroponics. Significant dose-dependent accumulation was observed for both metals, mainly in roots (up to 3.2 and 9.2 mg g ^?1 for Cd and Zn, respectively). However, Cd was more phytotoxic in terms of plant growth and photosynthesis. This higher toxicity was also evidenced by MetPLATE bioassay. Root exudation was significantly correlated to Cd and Zn translocation (r>0.85) proving its involvement in facilitating metal uptake. As for antioxidative responses, plants reacted to Cd and Zn by broadly exhibiting an elevation of glutathione reductase activity before declining at 200 μ M due to higher phytotoxicity. By contrast, superoxide dismutase activity was unlikely to be affected by both metals. Root-to-shoot apoplastic flow was traced using a fluorescent dye (trisodium-8-hydroxy-1,3,6-pyrenetrisulfonic acid; PTS), whose concentration in leaves increased to a certain extent with Cd and Zn accumulation, indicating that heavy metals have a comparable effect to drought or salinity in promoting the passive diffusion of water and solutes. Nevertheless, Cd at 200 μ M hindered the diffusion of PTS and consequently affected the apoplastic transport in plants.     

Effect of waterborne boron and molybdenum on survival,growth and feed intake of Indian major carp,Cirrhinus mrigala (Hamilton)

The effect of either boron (B) or molybdenum (Mo) on survival, growth and feed intake of Indian major carp, Cirrhinus mrigala (Hamilton), advanced fry was studied in two separate experiments. Survival rates of C. mrigala fry (2.78±0.14 g) following 50 days’ exposure to B at 0.01 (control), 0.5, 1.0, 2.0, 4.0 and 8.0 mg·L ^?1 were 100% at all concentrations except 8.0 mg·L ^?1 where the survival rate 87.5±7.5%. We observed 100% survival of mrigala fry at all concentrations of Mo, 0.02 (control), 0.5, 1.0, 2.0, 4.0 and 8.0 mg·L ^?1. Both B and Mo at 0.5 mg·L ^?1 showed significantly (p<0.05) higher growth of the fish compared with control and other concentrations. B exposure at 1.0, 2.0 and 4.0 mg·L ^?1 had no significant effect on growth rate, whereas at 8.0 mg B·L ^?1 growth of the fish almost ceased. Mo exposure at 1.0, 2.0, 4.0 and 8.0 mg·L ^?1 caused no significant effect on growth rate of the fish compared to control. Both B and Mo at all concentrations had no significant effect on feed intake of the fish compared with control, except at the highest concentration of boron (8.0 mg·L ^?1).     

Assessment of PAHs in water and fish tissues from Great Bitter and El Temsah lakes,Suez Canal,as chemical markers of pollution sources

Sea water and fish tissue samples were collected from nine sampling stations from the Great Bitter and El Temsah lakes in the Suez Canal and analysed for polycyclic aromatic hydrocarbon (PAH). The compositions of PAH determined in the dissolved fraction of sea water were measured in order to use them as chemical markers for identifying different sources of PAH pollution in this region. PAHs determined in fish tissues were measured for comparison with human health standards as consumption. The total mean PAHs concentrations in the sea water samples ranged from 0.28 to 39.57 μg l^?1 with an overall mean of 10.78 and 12.38 μg l^?1 for El Temsah and Bitter Lakes water, respectively. Total PAHs fractions recorded in muscle tissues of all different Osteicthyes fishes collected from Great Bitter lakes ranged from 5.8 to 218.5 μg g^?1 with an overall mean of 57.98 μg g^?1 during all seasons. However, they ranged from 68 to 623 μg g^?1 with an overall mean of 87.69 μg g^?1 recorded in El Temsah lake during four seasons (2003–2004). Benzo(a)pyrene was the most dominant PAHs found in the sea water samples from both lakes with an average concentration of 3.8 μ g l^?1. Dibenzo(a,h)anthracene (DBA) was the most dominant PAHs recorded in fish samples. A maximum of 533 μg g^?1 of DBA was recorded in Dahbana sp. collected from Bitter lakes during January 2004. However, a maximum of 68.7 μ g g^?1 was recorded in Liza carinata species collected from El Temsah lake during July, 2004. The simultaneous occurrence of isomer ratios PHE/ANT<10 for all stations indicated that the major PAH input to water was from combustion of fossil fuel (pyrolytic source). The average ratios were 1.21 and 12.9 during winter (January 2004) and 4.3 and 8.63 during spring (April 2004) for all water samples of Great Bitter lakes and El Temsah lake, respectively. In addition, the present data demonstrate that PAHs from fossil fuel sources (MW<178) were the least significant source of PAHs in this region.     

Insulative capacity of the integument of the dugong (Dugong dugon): thermal conductivity,conductance and resistance measured by in vitro heat flux

Extant sirenians are restricted to warm waters, presumably due to their low metabolism and poor thermoregulatory capacity, including thin blubber. When subjected to winter waters, Florida manatees (Trichechus manatus latirostris) migrate to warm areas, but dugongs (Dugong dugon) do not and instead live year-round in winter waters as cool as 15–18 °C. Dugongs appear to be more active than manatees and may have higher metabolic rates, but little is known about thermal energetics or the insulative properties of their integument. This study investigated the physical and thermal properties of whole samples of dugong integument, i.e. epidermis, dermis and hypodermis (blubber) sampled from fresh dugong carcasses collected from 2004 to 2012 in Moreton Bay (27.21°S, 153.25°E). Physico-chemical properties (thickness, density and lipid content) of each component tissue layer were measured. Thermal conductance (C) and conductivity (k) were measured for each tissue layer through in vitro temperature flux experiments within an insulated chamber. C and k were higher for dermis (25.7 ± 1.2 W m^?2 K^?1, 0.43 ± 0.02 W m^?1 K^?1, respectively, n = 21) than blubber (24.3 ± 2.4 W m^?2 K^?1, 0.31 ± 0.01 W m^?1 K^?1, n = 21), suggesting that blubber, with higher density and lipid content, affords better insulation. However, because the dermis contributes 65 % of integumentary thickness, both layers contribute significantly to insulation. The integument of dugongs is a poorer insulator compared to many cold-water marine mammals, but the greater thickness of its dermal layer means that despite its relatively thin blubber, its integumentary insulation is similar to warm-water dolphins of similar body size.     

Concentrations of uranium in drinking water and cumulative,age-dependent radiation doses in four districts of Uttar Pradesh,India

The present work deals with the determination of uranium concentrations in drinking and ground water samples by laser fluorimetry and calculation of cumulative, age-dependent radiation doses to humans. The concentrations were found to be between 0.20 ± 0.03 and 64.0 ± 3.6 μg L^?1, with an average of 11.1 ± 1.5 μg L^?1, well within the drinking water limit of regulatory bodies. The concentrations of uranium increase with depth of water samples collection. The estimated annual ingestion dose due to the intake of uranium through drinking water for all age groups varied between 0.2 and 137 μSv a^?1, with an average of 17.3 μSv a^?1. The mean annual ingestion dose is 5% of the global average ingestion dose, for infants, marginally higher than for other age group. Most effective dose values were less than 20 μSv a^?1.     

Optimisation of bisphenol A removal from water using chemically modified pine bark and almond shell

The ability of pine bark and almond shells to remove bisphenol A (BPA) from aqueous solutions was evaluated. Samples of these traditional agro-forestry by-products were milled, sieved into different particle size fractions (0.10–0.15 and 1.5–2.0 mm) and submitted to two different types of treatment. Sorption experiments were conducted in a batch system at room temperature and natural pH. Sorption equilibrium was attained after 48 h for all systems under study. Bisphenol A was adsorbed more effectively on the smaller particles of the sorbents. Pine bark and almond shell pretreated with formaldehyde presented higher sorption efficiency (95%), followed by almond shell (87%) and pine bark (82%) washed with hot water. All the sorption isotherms were found to fit a Freundlich equation, with correlation coefficients (R ²) between 0.823 and 0.989. The sorption coefficient (K _F) ranged from 0.06 to 0.74 (mg^1?1/n ·L ^1/n ·g ^?1). These results indicate that utilisation of both materials as an alternative sorbent for the removal of bisphenol A from contaminated waters is promising because they are available in large amounts and have an acceptable cost–efficiency ratio when compared with traditional adsorbents.     

White blood cell sister chromatid exchange among a sample of Thai subjects exposed to lead: Lead-induced genotoxicity

Epidemiological and experimental studies indicated that inorganic lead compounds are associated with increased risks of tumorigenesis. This study was aimed at determination for sister chromatid exchange (SCE), a marker for genotoxicity with correlation to lead blood levels in Thai exposed subjects. A total of 32 police (all males) were included into this study. The average (mean ± SD) blood lead in these police was 2.1 ± 1 µmol L^?1. The average SCE among the police with high blood lead was significant higher than those with low metal exposure. Data suggest that cytogenetic response to Pb is significantly different between the subjects with high versus low lead exposure. High exposure to lead seems related to high chromosome aberrations.     

Ultrasound-assisted emulsification/microextraction based on solidification of trace amounts of thallium prior to graphite furnace atomic absorption spectrometry determination

In the present work, determination of ultratrace amounts of thallium in water samples was performed by ultrasound-assisted emulsification microextraction based on solidification of a floating organic drop as sample preparation method prior to furnace atomic absorption spectrometry. 1-(2-Pyridylazo)-2-naphthol was used as chelating agent. The factors influencing the complex formation and extraction, such as pH of the aqueous solution, the type and the volume of extraction solvent, the volume of chelating agent solution, and the extraction time were investigated. Under optimized conditions, the enrichment factor was 200. The calibration graph was linear from 0.2 to 10.0 μg L^?1 with a correlation coefficient of 0.9966, the detection limit was 0.03 μg L^?1 and reproducibility was ±3.3% (C = 5.0 μg L^?1, n = 8). The method was successfully applied for the determination of thallium in water samples.     

Ultrastructural responses and oxidative stress induced by cypermethrin in the liver of Labeo rohita

The present study was conducted to establish the relationship between selected oxidative stress parameters and ultrastructural responses in liver tissue of Labeo rohita fingerlings exposed to cypermethrin. Fish were exposed to lethal (4.0 μg L^?1) and sublethal (0.4 μg L^?1) concentrations of cypermethrin for a period of 24, 48, 72 and 96 h for acute studies and 1, 5, 10 and 15 days for subacute studies, respectively. Results showed increased catalase (CAT) and protease activity, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), protein carbonyls and free amino acid (FAA) levels at both concentrations. This suggests participation of free-radical-induced oxidative cell injury in mediating the hepatotoxicity of cypermethrin. In corroboration of this, ultrastructural lesions witnessed a reduction in the number of cell organelles, swollen, vacuolated and condensed mitochondria, dilated rough endoplasmic reticulum, and reduced numbers of smooth enodplasmic reticulum, peroxisomes and lysosomes at the lethal (4.0 μg L^?1) concentration. At the sublethal (0.4 μg L^?1) concentration, cytoplasmic vacuolation, condensed, vacuolated and swollen mitochondria, dilated rough endoplasmic reticulum and an absence of hepatocyte microvilli were prominent. Ultrastructural changes were exhibited as subcellular responses due to the imbalance in cellular oxidative status by means of oxidative damage.     

Life under Arctic sea ice – reproduction strategies of two sympagic (ice-associated) amphipod species, Gammarus wilkitzkii and Apherusa glacialis

The reproductive strategies of two gammaridean amphipod species, Gammarus wilkitzkii and Apherusa glacialis, that permanently inhabit the Arctic sea ice were investigated. G. wilkitzkii reaches sexual maturity at an age of 2 years and produces 128 ± 54 eggs fem.⁻¹ yr⁻¹. Mating takes place during fall and winter, and the development of the large eggs (0.60 to 0.80 mm diam.) lasts 6 to 7 months. The sex ratio of G. wilkitzkii was dominated by males in a proportion of 1.5:1. In vivo studies showed that juveniles are released in batches from the brood pouches of the females during April and May. A. glacialis reaches sexual maturity at the age of 1 year and produces 555 ± 151 eggs fem.⁻¹ yr⁻¹. The eggs are between 0.18 and 0.23 mm in diameter, and are the smallest known for gammaridean amphipods. Eggs are kept in packages of two to eight in the brood pouches of females. The sex ratio of A. glacialis was dominated by females in a proportion of 3:1. The high fecundity of both amphipod species, the release of juveniles in batches over a period of time, a high proportion of females (A. glacialis), and an elongated life-span with multiple spawnings (G. wilkitzkii) are discussed as possible adaptations to the specific and highly variable conditions under Arctic sea ice. Received: 29 December 1999 / Accepted: 8 March 2000     

Development of a complex-based flow injection spectrophotometric method for determination of the herbicide pinoxaden in environmental samples

A flow injection (FI) spectrophotometric method for the determination of the herbicide pinoxaden (PXD) has been proposed. PXD was converted in alkaline media with hydroxylamine hydrochloride to the hydroxamate salt. The salt was reacted with iron(III) chloride, and the absorbance of the red colored tris iron hydroxamate complex was measured at 500?nm using a FI system. The method was found to be linear between 0.5 and 40?mg?L^?1 with a molar absorptivity of 1.53?×?10^4?L?mol^?1?cm^?1. The limit of detection and limit of quantification were found to be 0.1?±?0.01?mg?L^?1 and 0.6?±?0.05?mg?L^?1, respectively. Any interference of fenoxaprop-p-ethyl (FE) was avoided by the separation of PXD by liquid chromatography with a mixture of dichloromethane and n-hexane (1?:?1) as eluent. The method was applied to the determination of PXD in soil, water, and wheat grains with percent recoveries of 98?±?2, 100?±?2, and 98?±?5, respectively. Sample throughput of 60 samples per hour was achieved under optimized conditions.     

Metal levels in computer monitor components discarded in the vicinities of electronic workshops

Levels of Pb, Ni, Cr, Cu, Zn, and Cd in the glass screens (GS) and printed wiring boards (PWBs) of obsolete computer monitors (OCMs) were determined by flame atomic absorption spectrophotometry (FAAS) following standard digestion. Metal concentrations (mg kg^?1) in GS were in the following ranges (medians in brackets): Pb ND – 3100 (46), Cd 0.5–2.6 (0.8), Cr ND – 18.7 (3.1), and Zn 8.1–600 (37) and in PWBs (mg kg^?1): Pb 34,600 ± 17,000, Cd 11 ± 9, Cr 59 ± 45, Zn 15,900 ± 7800, Cu79,000 ± 22,600, and Ni 3200 ± 2500. In GS, the levels of the six metals were lower than their total threshold limit concentrations (TTLC), except for Pb with a TTLC of 1000 mg kg^?1 in 10% of the samples. In the PWBs, the TTLC of Pb and Cu (2500 mg kg^?1) was exceeded many fold. For Zn (5000 mg kg^?1) and Ni (2000 mg kg^?1); they were exceeded by 90% and 65%, respectively. For OCMs manufactured in 2001 and later, Pb and Zn levels in GS and Cr, Zn, and Ni in PWBs were significantly reduced.