Element differences and evaluation of the dietary intake from farmed oysters and mussels collected at different sites along the Croatian coast of the Adriatic Sea

Concentrations of the macroelements Ca, Mg, K and Na, microelements Cr, Cu, Fe, Mn and Zn and toxic metals As, Cd, Hg and Pb were determined in oysters and mussels collected at farming sites in the northern, central and south Adriatic Sea. Mean concentrations in oysters were (mg kg⁻¹): As 4.51, Ca 1551, Cd 1.44, Cu 53.6, Cr 0.23, Fe 45.9, Hg 0.047, K 2476, Mg 895, Mn 2.80, Na 7148, Pb 0.52, Zn 675. Mean values in mussels were (mg kg⁻¹): As 4.71, Ca 601, Cd 0.37, Cu 1.91, Cr 0.29, Fe 49.6, Hg 0.026, K 2246, Mg 1043, Mn 2.49, Na 7992, Pb 0.58, Zn 28.8. Significant differences in the concentrations of toxic metals and elements were found in oysters and mussels among farming sites. Obtained Cd, Hg and Pb concentration in oysters and mussels were lower than the limit levels set by the European Community. However, Cd concentration exceeded the limit level of 1 mg kg⁻¹ in oysters from all locations except Lim Bay. The estimated daily intakes (EDIs) indicate that oysters are a good source of Ca, Cu and Zn. The higher Cu and Zn concentrations than the toxicity reference values suggest a risk for consumers if larger quantities of oysters are consumed frequently.     

Impact of atmospheric trace metals on rice roots

Concentrations of trace and major metals in dry fallout, bulk precipitation, and rice roots were determined in the Takahashi River basin on whose estuary stands the Mizushima industrial area, one of the largest in Japan. The data were analyzed by principal components factor analysis.The amounts of volatile metals Zn, Cd, Pb, Cu, Ni, V, Cr, Be, Sn, and Ag were delivered from the atmosphere as dry fallout and precipitation, especially within the industrial and highly populated areas. Concentrations of trace metals such as Zn, Cd, Pb, Cu, V, Ni, Cr, and Be in rice roots were 2–4 times higher in the industrial, urban, and roadside areas when compared with those in sparsely populated areas.     

Assessment of Heavy Metal Contamination in Roadside Surface Soil and Vegetation from the West Bank

Concentrations of heavy metals (Pb, Cd, Cu, Zn, Fe, Mn, Ni, and Cr) were investigated in roadside surface soil and the common perennial herb inula (Inula viscosa L., Compositae). Samples were collected at different distances (0–200 m) perpendicular to a main road that connects two main cities in the West Bank. Average concentrations of metals in soil samples were: Pb, 87.4; Cd, 0.27; Cu, 60.4; Zn, 82.2; Fe, 15,700; Mn, 224; Ni, 18.9; and Cr, 42.4 g · g^–1. In plant leaves, concentrations were: Pb, 7.25; Cd, 0.10; Cu, 10.6; Zn, 47.6; Fe, 730; Mn, 140; Ni, 4.87; and Cr, 7.03 g · g^–1. Roadside contamination was obvious by the significant negative correlations between concentrations of metals in soil and plant samples and distance from road edge. Only cadmium concentrations in soil and plant samples were not associated with roadside pollution. Roadside contamination in plants and soil did not extend much beyond a 20 m distance from road. I. viscosa reflected roadside contamination better than soil and their metal concentrations showed much less fluctuations than those in soil samples. Washing plant leaves decreased Pb and Fe concentrations significantly, indicating a significant aerial deposition of both. I. viscosa can be considered as a good biomonitor for roadside metal pollution.     

Assessment of trace elements in canned fishes (mackerel, tuna, salmon, sardines and herrings) marketed in Georgia and Alabama (United States of America)

The concentrations of mercury and 13 other trace metals in 104 canned fish samples purchased within the states of Georgia and Alabama (United States of America) were determined using the direct mercury analyzer (DMA) and the inductively coupled plasma-optical emission spectrometer (ICP-OES). The ranges obtained for the elements analyzed in mg/kg (wet weight) are as follows: Hg (0.02–0.74), Ag (0.0–0.20), As (0.0–1.72), Cd (0.0–0.05), Cr (0.0–0.30), Fe (0.01–88.4), Pb (0.0–0.03), Mn (0.01–2.55), Ni (0.0–0.78), Co (0.0–0.10), Cu (0.01–5.33), Sn (0.04–28.7), V (0.0–0.31) and Zn (0.14–97.8). Three tuna samples had Hg level above the European dietary limit of 0.5 mg Hg/kg. The mean Hg concentrations in the tuna (285 μg/kg) and sardine (107 μg/kg) brands were higher than the averages posted by the pink salmon (36.1 μg/kg), red salmon (32.8 μg/kg) and mackerel (36.4 μg/kg) brands. Two tuna samples and a sardine sample exceeded the Australian permissible limit of 1 μg/g inorganic arsenic (wet weight). Two samples (brand 15: herring) had zinc levels exceeding the Food and Agriculture Organization (FAO) recommended limit of 40 mg/kg and two pink salmons also exceeded the Brazilian regulatory limit of 0.1 mg Cr/kg. One tuna sample had a cadmium level slightly exceeding the Codex Committee on Food Additives and Contaminants draft guideline of 0.50 mg Cd/kg. However, the concentrations of lead, cadmium and copper were below the corresponding MAFF guidelines of 2.0, 1.0 and 30 mg/kg, respectively. Also, based on the United States Environmental Protection Agency (US EPA) health criteria for carcinogens, there are no health risks with respect to Pb, Cr, Cu and Zn concentrations in canned fishes analyzed. The result of the one-way analysis of variance (ANOVA) conducted on the data suggested that significant variations (P<0.05) existed in the concentrations of Hg, As, Co, Cr, Cu, Fe, Mn, Sn, V, and Zn across the various fish species and canned fish brands analyzed. The estimated weekly intakes of Hg, As, Cd, Pb, Sn, Fe, Cu and Zn for a 60 kg adult consuming 350 g of fish/week were below the respective provisional tolerable weekly intakes (PTWI) in μg/kg body weight for: Hg: 5; As: 15; Cd: 7; Pb: 25; Sn: 14000; Fe: 5600; Cu: 3500; and Zn: 7000.     

Anthropogenic Contamination of Metals in Sediments of the Santa Rosalía Harbor, Baja California Peninsula

To know the environment impact on a harbor of the Santa Rosalía port on the Baja California peninsula, the concentrations of metals (Cd, Co, Cu, Mn, Pb, U and Zn) in harbor sediments were determined for 13 stations and compared with their average upper Earth´s crust abundance. The mean enrichment factors, calculated using Al as a normalizer, were higher than the unity for Ag, Ba, Bi, Cd, Co, Cu, Mn, Ni, Pb, Sb, U, V and Zn. Concentrations of slightly enriched Cd in the sediments are below the effect range low (ERL) sediment quality guidelines value only at three stations. The levels of Pb in the harbor sediments at four stations (1, 6, 9 and 11) are between the ERL (46.7 mg kg^?1) and the effect range medium (ERM) (218 mg kg^?1), and Pb content in the rest of the sediment samples is higher than the ERM, demonstrating the high extent of the anthropogenic impact of this metal on the sedimentary environment. The total concentrations of the potentially toxic elements Cu (3,390 ± 804 mg kg^?1) and Zn (1,916 ± 749 mg kg^?1) very strongly exceed their ERM, showing a high possibility of toxicological danger for marine biota, living inside or entering the harbor.     

Heavy Metals in Livers of Waterbirds from Spain

Wetlands tend to accumulate heavy metals from local sources, such as Pb shot used for waterfowl hunting, and from regional sources, such as atmospheric deposition and riverine or marine inputs. We determined concentrations of six heavy metals (Cr, Mn, Cu, Zn, Cd, and Pb) in livers of waterbirds shot by hunters in five Spanish wetlands to study the different factors that can contribute to the accumulation of these metals (sex, age, diet, grit, and Pb shot ingestion). Differences among wetlands were observed only for Cr, Cu, and Cd. Differences among species were observed for all the metals, and Cu was notably higher in pochards (Aythya and Netta genus) than in other waterfowl. Cu, Zn, and Cd concentrations increased with age, and only Pb showed differences related to sex, with males having higher concentrations than females. Most metals other than Pb were correlated with each other. Lead was dependent on Pb shot ingestion. Grit ingestion positively correlated with concentrations of Cr and to a lesser extent with Mn, Zn, and Cd. Ingestion of grit or shot may obscure relationships between metals and diet. Herbivorous species, which had more grit in the gizzard, had higher Cr, Zn, and Cd concentrations. Granivorous birds, which have the highest rates of Pb shot ingestion, had the highest concentrations of Pb. Grit and Pb shot ingestion are both important sources of heavy metals for waterbirds. Lead was the single metal studied whose concentrations exceeded toxicity thresholds. Received: 5 March 2002/Accepted: 12 June 2002     

Assessment of human health risk for heavy metals in fish and shrimp collected from Subarnarekha river,India

Five fish species and one shrimp species from the Subarnarekha river were analyzed for heavy metals using inductively coupled plasma-mass spectrometry. The geometric mean concentration of As, Cd, Cu, Fe, Pb, Ni, Zn, Cr, Co, and Sr for all the samples was found to be 0.248, 0.031, 5.16, 104.9, 0.121, 4.68, 52.2, 0.784, 0.207, and 42.86 mg kg^?1_fresh, respectively. The concentrations of metals in the fish and shrimp exceed the limits of Indian and FAO standards for food for As, Cu, Ni, Cd, and Zn in many samples. The mean target hazard quotient (THQ) values for the 10 metals were below one for all the samples; however, the maximum THQ was more than one for shrimp in case of As, Cu, and Cr. The results indicate that the concentration of metals in some species, especially shrimp, at some locations is alarming and do present an appreciable hazard risk on human health.     

Tissue Distribution and Correlation Profiles of Heavy-Metal Accumulation in the Freshwater Crayfish Astacus leptodactylus

The present work details the analysis of heavy-metal and metalloid concentrations in exoskeleton, gill, hepatopancreas, and abdominal muscle tissues of 60 crayfish (Astacus leptodactylus) specimens collected from Lake Hirfanl?, a dam lake located in K?r?ehir (Turkey) with a low metal-contamination profile. Concentrations of 11 metals (aluminum [Al], chromium [Cd], manganese [Mn], cobalt [Co], nickel [Ni], copper [Cu], molybdenum [Mo], silver [Ag], cadmium [Cd], mercury [Hg], and lead [Pb]) and a metalloid (arsenic [As]) were measured by inductively coupled plasma–mass spectrometry, and the relative frequencies of the most abundant isotopes of Cr, Cu, Ag, Cd, Hg, and Pb were evaluated. Three correlation trends were evaluated between the following: (1) different elements in the each individual tissue, (2) individual elements in different tissues, and (3) different elements in different tissues. In addition, correlation rates of growth parameters (weight, cephalothorax length, and total length) with heavy-metal and metalloid concentrations in each tissue were investigated. Our results suggest that substantial differences in metal and metalloid-accumulation levels exist between male and female specimens, with stronger correlations between the heavy-metal concentrations observed in the male cohort. It is notable that correlation trends of Co, Cu, ⁵²As, Cr, and Ni in exoskeleton of the male specimens display strong similarities. Likewise, a very strong correlation is present in Ni–Cd and Ni–Pb accumulations in abdominal muscle of the male specimens; a similar trend is present between Cd and Pb concentrations in the same tissue of female specimens. For correlation rates of different heavy metals and metalloid in different tissues, the strongest positive association observed was between ⁶³Cu in gill and As in hepatopancreas, whereas the strongest negative correlation was between accumulated Ni in abdominal muscle and As in exoskeleton. Strong correlations between metals and metalloid accumulations were observed between exoskeleton and gill. In many cases, metal and metalloid accumulation was negatively correlated with growth parameters. Preferential accumulation of Cr and Cu isotopes was observed in different tissues, suggesting that significant amounts of isotope fractionation occur during heavy-metal accumulation. Relatively low correlation rates were observed between ⁵²Cr/⁵³Cr and ⁶³Cu/⁶⁵Cu concentrations in several tissue types in both male and female cohorts, whereas no such trend was observed between Cd and Pb isotopes.     

Influence of water movements and other factors on distribution and transport of heavy metals in a shallow Bay (Canada)

Concentrations of heavy metals and cyanide in water and sediments were determined from December 1974 to February 1976 in Yellowknife Bay situated in northern Canada. The bay receives a continuous discharge of liquid waste effluents from an operating gold mine. Arsenic reached a maximum concentration of 3100 mg kg^–1 in sediments near the waste source and decreased to a minimum of <12 mg kg^–1 moving away from this area; corresponding ranges for Pb, Cu, Zn, Hg, and Fe were 13–800 mg kg^–1, 45–785 mg kg^–1, 23–935 mg kg^–1, 35–505 mg kg^–1 and 1.9–6.3% respectively. Although most pollutants were recorded at low levels in the water, arsenic and copper rose to 0.75 and 0.29 mg L^–1 coincident with maximum discharge from the waste source. Overall, water movement (generated by inflowing rivers and wind) was the most important factor governing the distribution of metals in the bay. Although surrounding islands also restricted the movement of pollutants through the bay, water depth, slope of the bottom and organic content of the substrate did not have a measurable impact on concentrations in sediments.     

A study of air pollution with heavy metals in Thessaloniki city (Greece) using trees as biological indicators

The air pollution of the city of Thessaloniki was studied, using park trees as biomonitors. The species analyzed were Ligustrum japonicum, Nerium oleander, Olea europea, Pinus brutia, Platanus orientalis, Populus alba, Populus nigra, and Robinia pseudoacacia. Acid digestion of leaf tissues and subsequent use of atomic absorption spectrometry was the analytical methodology used for the determination of heavy metals (Cu, Zn, and Pb). The concentration of heavy metals in the tree leaves depended on the metal species as well as on the position of the tree in the city. The mean concentrations of Cu ranged between 5 and 10 mg kg^–1 dry weight, of Zn between 19 and 85 mg kg^–1 DW and of Pb between <1.5 and 4.5 mg kg^–1 DW. In some cases, the effect of road junctions proved more significant than the traffic load for the contamination of leaves. Some differentiation was also observed between tree species. Old leaves collected during the fall were more contaminated than young leaves collected during the spring. The roughness of the outer surface leaves contributed to the trapping and retention of air particles. The results were compared with corresponding results from lichens and mosses which were also collected for a similar study.     

Evaluation of Sediment Contamination by Heavy Metals, Organochlorinated Pesticides, and Polycyclic Aromatic Hydrocarbons in the Berre Coastal Lagoon (Southeast France)

During the last decades, the Berre lagoon, located in southeastern France, has been deeply affected by strong contaminant inputs. Surveys of surface sediment contamination have been sparsely performed since 1964 with data often disconnected with regard to time and space. To contribute to filling this gap, this study examined the pollution status of the lagoon during a 2012 sampling. Concentrations of heavy metals (HMs) (cadmium [Cd], chromium [Cr], copper [Cu], lead [Pb], and zinc [Zn]), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons were examined. The available seawater metal fraction was also investigated. Water from the Vaine basin (VB; stations 1 through 6) exhibited the lowest oxygen concentration (mean O₂ % saturation 38.9 %). HM loads were in the order of Zn > Cr > Pb > Cu > Cd with overall concentration ranges of 0.20–1.40 mg kg^?1 for Cd, 17.1–119 mg kg^?1 for Cr, 7.0–60.7 g^?1 for Cu, 12.0–104 mg kg^?1 for Pb, and 56.5–215 mg kg^?1 for Zn. Although HMs accumulated at levels largely exceeding their relative natural background level of 11-fold for Pb and 80-fold for Zn, their mean concentrations decreased largely to below the acceptable legal limits. HM loads were 20 to threefold the relative corresponding value of the threshold effect level benchmark of potential biological risk. Metals were only scantly released by sediments with mean percentage release of 0.99 % for Cd and 40.2 % for Cr with a peak for this latter element of 99 % in the VB sector. In the case of OCPs, sediments appeared to be significantly polluted, especially in the VB area, with a mean lindane concentration of 0.05 mg kg^?1, which is ≤fivefold the legal threshold. Among PAHs, benzo[a]pyrene exceeded the permitted limit of 0.1 mg kg^?1 mainly in the VB sector.     

Level of Heavy Metals in Some Edible Marine Fishes of Mangrove Dominated Tropical Estuarine Areas of Hooghly River, North East Coast of Bay of Bengal, India

The muscles of some important marine fishes collected in and around Hooghly estuarine coastal areas were analyzed for the heavy metals Cu, Zn, Ni, Cd, Cr and Pb. The concentration range of Cu (16.22–47.97 ppm), Pb (12.40–19.96 ppm) and Zn (12.13–44.74 ppm) were recorded comparatively higher and were similar to that found in contaminated areas. On the other hand the ranges of Ni (2.20–3.69 ppm), Cr (0–3.89 ppm) and Cd (0.62–1.20 ppm) were almost equal to those carried out over a wide range of geographical areas. The degree of bioaccumulations was metal-specific as well as species-specific in nature. The toxic groups of metals (Pb and Cd) showed higher variability than the essential metals (Cu, Zn and Ni). The calculated intake value of metals (week⁻¹ kg⁻¹ body wt) varied from 14.88 to 27.60 of Pb, 0.87 to 1.68 of Cd, 0.0 to 5.45 of Cr, 22.70 to 137.16 of Cu, 3.08 to 5.17 of Ni and 16.98 to 62.60 of Zn through human consumption of these fishes and were compared with those of standard Provisional Tolerable Weekly Intake value (PTWI) per kg body weight as stipulated by WHO. The PTWI_Cal values of Pb in some of the fishes recorded marginally excess values and may indicate a health risk through consumption of successive 7 days in a week.     

A Preliminary Study on Metal and Nutrient Concentrations in Running Water Systems in Southern New Caledonia

Metal and nutrient concentrations were measured in five running water sampling sites of New Caledonia. Metal concentrations were homogeneous (Ni; 22.7–50.6 μg L⁻¹) or not (Fe; 37–749 μg L⁻¹). Concentrations of Ni, Cr, Fe were high, including high dissolved fractions (up to 47.8, 70.8 and 417 μg L⁻¹, respectively). Concentrations of anthropogenic metals (Ag, As, Cd, Cu, Pb, Sb, V, Zn) were low (maximum: total Cu, 0.6 μg L⁻¹). The contamination of waters is presumably due to soil weathering and mining activities. Metal concentrations and phosphate depletion (<0.04 μmol L⁻¹) suggest constrained conditions for the development of aquatic life.     

Anthropogenic Sources of Heavy Metals in the Indian Ocean Coast of Kenya

Water and surface sediment samples from Rivers Sabaki, Ramisi and Vevesi that flow into the Indian Ocean coast of Kenya were analysed for heavy metals. The sediment concentrations of exchangeable cations (in μg/g) for Co, Cu, Mn, Ni, Pb, Sn and Zn ranged from 0.10 to 506.75 (for Mn at Sabaki), constituting between 2% and 20% of the total metal concentrations obtained by digestion with strong acid. Cu, Mn, Ni, Pb and Zn were more leachable with 0.1 N HCl. The total dissolved metal in water and the total sediment concentrations for Ag, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sn and Zn are given in the text. For dissolved metals, the metal/Mn ratios indicated higher concentrations of Ag in Sabaki River, Cd in Ramisi, Ni in Sabaki and Pb in Ramisi, respectively. In sediments, the metal/Mn ratios showed higher enrichment of Ag in Ramisi, Cd in Sabaki and Vevesi, and Zn in Sabaki, respectively. Enrichment factors showed elevated levels of Cd, Pb and Zn in sediment in River Sabaki and River Vevesi that were due to anthropogenic inputs through Athi River. The total dissolved metal concentration ranges for the three rivers were comparable with those ranges reported in rivers in South Africa but the sediment concentrations were below those of rivers in Europe and Asia where anthropogenic addition of some of the toxic elements such as Cu, Pb and Cd is evidently higher.     

Distribution and Association of Trace Metals in Soft Tissue and Byssus of Mytilus edulis from the East Coast of Kyushu Island, Japan

Concentrations of Cd, Pb, Zn, Cu, Ag, Cr, Co Ni, Mn, and Fe in soft tissues and byssi of blue mussel (Mytilus edulis) from three sites along the east coast of Kyushu Island, Japan, were determined by AAS method. Large inter-regional differences in metal concentrations in both soft tissues and byssi (Cu, Cd, and Pb and Cu, Pb, Co, Ni, Mn, and Fe, respectively) were recorded. Highly significant correlations (p < 0.01) were observed between tissue and byssal concentrations of Pb, Cu, Zn, and Mn. The tissue concentrations of Cu, Cd, and Pb were two orders of magnitude greater in Mytilus edulis from expected to be the most contaminated locations compared to those from a nonindustrialized area. Intercomparison of the present study data with those published previously indicates that the soft tissue and especially byssus are useful in detecting some areas of some metallic contaminants. The high concentrations of Cd, and especially Pb and Cu, in Saganoseki mussels and moderately elevated concentrations of these metals in Akamizu mussels may be attributed to the anthropogenic emissions from a metallic refinery and an artificial fiber factory, respectively. It is evident that, compared to the soft tissue, the increase of Cu levels relative to Zn levels in the byssi of M. edulis are eight times higher, with a slope b (Cu/Zn) of 7.5 for byssus and 0.93 for soft tissue. This suggests that byssus, as compared to soft tissue, is a more sensitive bioindicator for Cu. From the data obtained, the soft tissue and especially byssi of M. edulis appear to be good bioindicators for identification of coastal areas exposed to metallic contaminants. Received: 29 January 1996/Revised: 19 June 1996     

Uptake of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe, Zambia

Concentrations of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe (Zambia), which is ranked among the 10 worst polluted places on earth, were compared with other Zambian towns. Metal concentrations were measured in the liver and kidneys of 51 cattle from Kabwe and other Zambian towns. The maximum metal concentrations, expressed in mg/kg and dry weight, in the liver or kidneys were 398.4 (Cu), 252.6 (Zn), 77.81 (Cr), 19.37 (Cd), 7.57 (Ni), 1.8 (Pb), 1.04 (Co), 0.112 (Hg), and 0.05 (As). Concentrations of Pb and Cd in Kabwe cattle were higher than levels in other Zambian towns. The mean concentration of Cd exceeded benchmark values in offal destined for human consumption. Levels of Ni and Cr may also pose public health concerns. Concentrations of Pb and Cr, Pb and Cu, Cd and Zn, Cd and Hg, Zn and Cu, Cu and Co, as well as Co and Ni were positively correlated. The present study also highlighted the dangers of exposure of animals and humans to a mixture of toxic metals.     

Metal accumulation and toxicity measured by PAM—Chlorophyll fluorescence in seven species of marine macroalgae

The effects of five metals, copper (Cu), chromium (Cr), Zinc (Zn), cadmium (Cd) and lead (Pb), on photosynthetic activity, measured as pulse amplitude modulation (PAM) chlorophyll fluorescence yield, was monitored in seven species of green, red and brown macroalgae over a 14 d period. The 10 μmol l^?1 of Cr and Zn reduced chlorophyll fluorescence of all species by day 4, and 10 μmol l^?1 of Cu and Cd reduced the fluorescence of some species; however, fluorescence yields of all species were unaffected by 10 μmol l^?1 of Pb. Metals were generally accumulated in the order of Cu>Pb>Zn>Cr>Cd. Ulva intestinalis accumulated the highest amounts of all metals, and Cladophora rupestris the lowest. A relationship between internal metal concentration and fluorescence was not always evident as in some cases fluorescence was reduced at low metal contents. In the case of Zn, fluorescence was lowest in plants which contained lowest concentrations after 14 d-exposure, possibly because plants had died and Zn leached out of the algal cells. The relationship between internal metal concentration and fluorescence was algal species and metal-specific.     

Analysis of Heavy Metals in Water and Surface Sediment in Five Rift Valley Lakes in Kenya for Assessment of Recent Increase in Anthropogenic Activities

The concentrations of heavy metals Ag, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sn and Zn were analysed in water and surface sediments of five Rift Valley lakes Nakuru, Elementaita, Naivasha, Bogoria and Baringo in Kenya. The dissolved mean concentration levels (μg/L) in water ranged within 13.0–185.0 (Ag), 2.0–43.0 (Cd), 5.0–316.0 (Co), 25.0–188.0 (Cr), 4.7–100.0 (Cu), 50.0–282.0 (Mn), 19.0–288.0 (Ni), 25.0–563.0 (Pb), 300.0–1050.0 (Sn) and 29.0–235.0 (Zn). The mean sediment concentrations (in μg/g (dry weight)) ranged within 0.1–0.35 (Ag), 0.05–1.18 (Cd), 0.17–1.38 (Co), 1.94–4.91 (Cr), 1.46–20.95 (Cu), 667.7–3946.8 (Mn), 11.69–39.72 (Ni), 10.92–38.98 (Pb), 17.21–56.52 (Sn) and 96.2–229.6 (Zn). The data indicate that some of the sites analysed, especially in Lake Nakuru, had relatively higher concentration levels of heavy metals Cd, Co, Cu, Pb, Ni, and Zn in the water which points to anthropogenic addition. However, potential influence of geochemical processes on the concentration levels in sediment is also shown in Co, Ni, and Cu which were more concentrated in the remote Lake Baringo sediment as well as in Pb and Mn which were more concentrated in the remote Lake Bogoria sediment. Data on some important limnological parameters including pH, salinity, electrical conductivity and temperature are also presented.     

Trace element and metallothionein concentrations in seabirds from the Canadian Arctic

Livers and kidneys were collected for five seabird species from the Canadian Arctic during the 1983 and 1991 to 1993 breeding seasons. Livers were analyzed for Cd, Hg, Pb, and Se, and kidneys were analyzed for Cd, Cu, Zn, and metallothionein (MT). Concentrations of the essential elements, Cu and Zn, were in agreement with those previously published in the literature. Thick-billed murres (Uria lomvia) from Ivujivik on the Hudson Strait/Hudson Bay coast in northwestern Quebec (Canada) had the highest mean renal concentrations of Cu, Zn, and Cd. Among the four species collected from Prince Leopold Island, northern fulmars (Fulmarus glacialis) had the highest hepatic concentrations of both Cd and Hg. The highest Se concentrations were found in northern fulmars and black-legged kittiwakes (Rissa tridactyla) from Prince Leopold Island. Hepatic Pb concentrations were low (<0.3 microg/g dry wt) in all species at all locations. Metallothionein concentrations were positively correlated with Cd and Zn for all species combined but were not correlated with Cu in any species. No significant relationships were found between MT and Cu or Zn in black guillemots (Cepphus grylle) or glaucous gulls (Larus hyperboreus). To our knowledge, this is the first report of MT concentrations and their relationships with trace metals in Arctic seabirds.     

Relationships among developmental stage,metamorphic timing,and concentrations of elements in bullfrogs (Rana catesbeiana)

We collected bullfrog (Rana catesbeiana) larvae from a coal combustion waste settling basin to investigate the effects of developmental stage and timing of metamorphosis on concentrations of a series of trace elements in bullfrog tissues. Bullfrogs at four stages of development (from no hind limbs to recently metamorphosed juveniles) and bullfrogs that metamorphosed in the fall or overwintered in the contaminated basin and metamorphosed in the spring were analyzed for whole-body concentrations of Al, V, Cr, Ni, Cu, As, Pb, Cd, Zn, Ag, Sr, and Se. After the effects of dry mass were removed, tissue concentrations of six elements (Al, V, Cr, Ni, Cu, As, and Pb) decreased from the late larval stage through metamorphosis. Decreases in concentrations through metamorphosis ranged from 40% for Cu to 97% for Al. Tissue concentrations of these elements were also similar or higher in spring; Al and Cr concentrations were 34 and 90% higher in the spring, respectively, whereas As, Ni, Cu, and Pb concentrations were <10% higher. Concentrations of Cd, Se, and Ag varied among seasons but not among stages; Cd and Ag concentrations were 40 and 62% lower, respectively, and Se concentrations were 21% higher in spring. Concentrations of Zn varied only among stages; concentrations decreased gradually through late larval stage and then increased through metamorphosis. Concentrations of Sr varied among stages, but this variation was dependent on the season. Concentrations of Sr were higher in larval stages during the spring, but because concentrations of Sr increased 122% through metamorphosis in the fall and only 22% in the spring, concentrations were higher in fall metamorphs when compared with spring metamorphs. Our results indicate that metamorphosis and season of metamorphosis affects trace element concentrations in bullfrogs and may have important implications for the health of juveniles and the transfer of pollutants from the aquatic to the terrestrial environment.