Metal (Cu, Ni, Fe, Co, Zn, Pb) and Ra-226 levels in tissues of meadow voles Microtus pennsylvanicus living on nickel and uranium mine tailings in Ontario, Canada: Site, sex, age and season effects with calculation of average skeletal radiation dose

Metal and metalloid accumulation in shrews (Soricomorpha, Mammalia) from two protected Mediterranean coastal sites

Although ecotoxicological data on heavy metals are abundant, information on other potentially toxic elements with attributed deficiency and/or toxic disturbances is scarce. Here we quantify zinc, copper, iron, manganese, chromium, molybdenum, strontium, barium, and boron in bones of greater white-toothed shrews, Crocidura russula, inhabiting two protected Mediterranean coastal sites: the Ebro Delta, a wetland impacted by human activities, and the Medas Islands, a reference site. Natural and anthropogenic inputs significantly increase Fe, Mn, Mo, Sr, Ba, and B in specimens from the Ebro Delta, whereas Cu and Cr were higher in Medas' shrews. Principal component analysis allowed complete separation between sites along the first two axes in particular due to B, Sr, and Cu. This study provides metal reference values in bones of insectivores, explores their variability and bioaccumulation patterns in depth, and assesses the potential environmental risk and toxicity for biota exposed to the above elements.

How does the greater white-toothed shrew, Crocidura russula, responds to long-term heavy metal contamination? -- A case study

Heavy metals accumulation in parallel with the evaluation of physiological and biochemical effects resulting from continued metal exposure were considered here using for the first time the great white-toothed shrew Crocidura russula as an in vivo model. Shrews were originated from an abandoned lead/zinc mining area and from a reference area, both in Alentejo, southern Portugal. Hepatic contents of nickel, copper, zinc, cadmium, mercury and lead were quantified by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Haematological parameters (white blood cells, red blood cells, haemoglobin and haematocrit) were obtained in a Coulter Counter Analyser and biochemical markers of the redox balance (glutathione S-transferase, glutathione peroxidase, and glutathione reductase) activities were measured spectrophotometrically using a Duo-50 spectrophotometer. Compared with control animals, significantly higher concentration of hepatic cadmium (9.29 vs. 1.18 micorg/g dry weight) and nickel (1.56 vs. 0.343 microg/g dry weight) were detected in the shrews collected in the mining area. However, no significant changes were observed on haematological or enzymatic parameters in animals exposed to metal pollution. The obtained results show that shrews are good bioaccumulators of toxic heavy metals, but very tolerant to their effects, revealing an interesting long-term adaptation to polluted environments. In addition, this study provides reference values for haematological parameters and antioxidant enzymes levels in C. russula, which may be relevant for comparative purposes in further studies.

Metal bioaccumulation in the greater white-toothed shrew, Crocidura russula, inhabiting an abandoned pyrite mine site

Hepatic and renal concentrations of iron, magnesium, zinc, lead, copper, manganese, mercury, cadmium, molybdenum, chromium, and nickel were quantified in shrews (Crocidura russula) inhabiting a pyrite mine site in Portugal. Several morphological parameters (body weight, residual index, and relative weights) were also examined to clarify the physiological effects of pollution. Shrews from the mine showed increased bioavailability of Fe, Pb, Hg, Cd, Mo, and Ni in comparison with reference specimens. Adult shrews had the highest Cd levels while Cr and Ni concentrations diminished. Intersexual differences were found for Mo and Ni. As a consequence of metal pollution, the relative hepatic weight was higher in shrews from the mine site when compared with reference specimens. These data indicate that C. russula is a good bioindicator of metal pollution. We also evaluated the toxic effects of Pb, Hg, Cd, and Ni, because several shrews from the polluted site showed high concentrations of these metals. To approximate at the real biological impact of abandoned mines, after this first step it is necessary to associate the bioaccumulation levels and morphological effects with other physiological, ecological and genetical biomarkers.

Trace elements accumulation and their variations with growth, sex and habitat: effects on Formosan squirrel (Callosciurus erythraeus)

Formosan squirrels are considered a useful bio-indicator because their habitat exists within that of humans. Therefore, concentrations of 19 trace elements were determined in tissues of this species for assessment of environmental pollution in urban Kamakura and rural Izuohshima. Results of analyses revealed high Cu concentrations in the livers of Formosan squirrels. Moreover, concentrations of some trace elements from automobile exhausts-V, Zn, Cu and As-in the specimens from Kamakura were higher than those from Izuohshima. These results reflect the presence of pollution caused by human activities in Kamakura.

The heavy metal content of the teeth of the bank vole (Clethrionomys glareolus) as an exposure marker of environmental pollution in Poland

This investigation is based on the premise that heavy metals are sequestered by the mineral phase of teeth, hydroxyapatite, during their formation. Once formed these tissues are not subject to significant turnover and it is suggested, therefore, that they provide a permanent and cumulative record of heavy metal exposure during the development of the teeth. The teeth of the bank vole (Clethrionomys glareolus) were analysed by inductively coupled plasma mass spectrometry to monitor the animals' exposure to lead, cadmium, zinc, copper and strontium. Animals were trapped in clean and polluted areas in Poland in and around Krakow in 1996 and in Olkusz and Legnica in 1996 and 1997. The control area in 1996 was Bieszcady National Park and in 1997 Borecka Forest. The results showed that there were statistically different concentrations of heavy metals in the teeth of animals from different sites. The high levels of pollution from industrial emissions were related to higher concentrations of heavy metals in the teeth. Unexpectedly high levels of heavy metals in the teeth of animals from Bieszczady National Park, thought to be environmentally clean, suggested cross-border pollution from Slovakia and the Ukraine. It was concluded that the teeth of small mammals, such as the bank vole, are a sensitive and reliable marker of environmental pollution by heavy metals.

U- and Th-series radionuclides in snowshoe hare (Lepus americanus) taken near U mill tailings close to Elliot Lake, Ontario, Canada

Snowshoe hare (Lepus americanus) trapped near U tailings had higher concentrations of (226)Ra in their bones (250 +/- 94 mBq g(-1) dry wt) than those from local control sites 3-15 km from the tailings (20-30 mBq g(-1) dry wt) and those from a distant control site 880 km away from the U mining area, which were below the detection limit (DL) (3.7 mBq g(-1) dry wt). Most chyme (stomach content) samples contained 226Ra below DL. Concentration ratios of 226Ra from tissues of local plants, considered important in the hare's diet, to bone ranged from 0.22 to 8.60. Concentrations of 210Pb and 210Po (95-245 mBq g(-1) dry wt) were not significantly different among tailings and control site populations. Disequilibrium between these isotopes and their precursors was noted. No significant accumulation of U and Th was noted at any site. Higher concentrations of 228Th compared to 232Th are attributed to accumulation of 228Ra in a manner similar to that of 226Ra. Based on bone 226Ra and 210Po contents, the maximum internal dose rates to the skeleton and the maximum life-time dose of hare living near tailings were 3.9 x 10(-5) Gy d(-1) and 4.2 x 10(-2) Gy, respectively. These rates were below the threshold required to produce osteosarcoma in other mammals and were considered unlikely to adversely affect hare during their lifetime. Radionuclide uptake by the animals was concluded to have no environmental significance in the transport of radionuclides from tailings to other locations.

Radium-226 in cattails, Typha latifolia, and bone of muskrat, Ondatra zibethica (L.), from a watershed with uranium tailings near the city of Elliot Lake, Canada

Radium-226 concentrations were measured in the main food plants (cattails, Typha latifolia) and bone of adult muskrats (Ondatra zibethica (L.)), taken from a study area near Quirke Lake in the Serpent River drainage basin. This watershed receives drainage containing radionuclides from the U tailings near the City of Elliot Lake, Ontario, Canada. Two control sites (one local, one 130 km distant) were also sampled. Radium-226 levels in cattails varied by plant part and place of collection. Roots sampled in the study area had the highest mean (226)Ra level (1135.0 mBq g(-1)), stems and leaves had 284.2 and 275.9 mBq g(-1), respectively (dry-weight basis, n = 6 in all cases). Local and distant control cattails carried much lower (226)Ra levels (20.2 and 15.2 mBq g(-1) dry weight, respectively, using pooled equal portions of all plant parts, n = 3 in both cases). Muskrats from waters with mean total (226)Ra levels in the period, 1984-1987 greater than 75.0 mBq litre(-1) ('study-high' sites), near U tailings within 10 km of Quirke Lake, had a mean (geometric) bone level of (226)Ra of 344.9 mBq g(-1) (dry-weight basis, n = 36); those from nearby waters, containing < 75.0 mBq litre(-1) of (226)Ra ('study-low' sites), had a mean bone level (80.3 mBq g(-1), n = 9) similar to animals taken in unaffected local control areas 20 km from the tailings (79.1 mBq g(-1), n = 12); animals from the distant control area, near Sudbury, Ontario, had the lowest mean burden (11.5 mBq g(-1), n = 24). Levels were unrelated to age or sex of the animals. Dry-weight based (226)Ra concentration ratios (bone concentration/plant tissue concentration) were calculated to range from 0.3-1.4 in the study-high area to 2.4-6.3 in the local control area. Wet-weight based concentration ratios were about 4.3 times higher. Concentration ratios were similar to values calculated for other species and in general agreement with values calculated for humans. The muskrat is judged to be a useful indicator (biomonitor) of environmental (226)Ra levels as there is a highly significant positive correlation coefficient (r = 0.74) between bone and ambient (water) concentrations of the radionuclide (F79 = 95.04, P < 0.0001) Estimated yearly (226)Ra intake by people eating muskrats was calculated to be below the current allowable level set by Canadian regulatory authorities.

Nickel in the terrestrial environment

This paper provides an overview of nickel concentrations in the terrestrial environment especially as it relates to exposure of the metal to humans and animals through food. The information includes a review of reports published in the scientific literature substantially supplemented with data obtained across the province of Ontario, Canada. The topics covered include background levels and levels of nickel measured in a number of different types of biota exposed to environmental contamination. These include plants of different types (higher plants, mosses), fungi and lichens and animals (birds, mammals, invertebrates). The information covers accumulation of nickel in plants with time and distribution of nickel among tissues of individual plants. Information on phytotoxicity and environmental guidelines are reviewed.

Accumulation of heavy metals in the mole in Finland

Metal concentrations (Cu, Ni, Zn, Cd, Cr, Hg, Pb and Mo) were analysed from the liver and kidneys of moles, Talpa europaea L. (Insectivora), trapped in southern Finland on both contaminated and rural areas. In rural areas the concentrations of Cd, Cu, Zn, Pb and Mo were lower in juveniles (individuals in their first summer), except for Zn in the liver, which was lower in adults. When the animals were divided into annual classes (0-6 years), Cd and Mo concentrations in the liver increased significantly with age, while concentrations of Cu, Zn and Cr tended to decrease. Female moles had higher Pb concentrations than males, especially adult females, which also had lower levels of Cu in the liver than adult males. Moles in the metropolitan area of Helsinki clearly differed from those in rural areas in that the concentrations of heavy metals in these moles were higher (especially for the most toxic metals: Cd, Pb and Hg), and their body weight was lower. The renal concentrations of Cd in most of the moles in Helsinki exceeded the threshold that has been shown to have a nephrotoxic effect in mammals. In one subsample from Helsinki, Pb and Zn concentrations in the mole liver decreased as the distance from the highway increased. Concentrations of Pb in earthworms and several heavy metals in soil also decreased similarly in the same area. Our data indicate that Pb accumulates in moles through their diet of earthworms.

Radium-226 levels and concentration ratios between water, vegetation, and tissues of ruffed grouse (Bonasa umbellus) from a watershed with uranium tailings near Elliot Lake, Canada

Radionuclide levels measured in bone, muscle, kidney and liver tissues, gut contents and diet items of 47 grouse from the Serpent River drainage basin, containing uranium (U) tailings at Elliot Lake, and from control areas in Ontario, showed variation by site and tissue. The mean level of 226radium (Ra) in bones of grouse sampled from Elliot Lake (28.5 mBq g(-1)) was higher than that in bones of birds from a distant control site near Sudbury, Ontario (8.0 mBq g(-1)) but similar to the value in a local control population (28.1 mBq g(-1)). Birds from Mid- and Low-Serpent River basin populations (with 17.1 and 17.7 mBw g(-1), respectively) did not differ from local or distant control populations; muscle, liver and kidney had lower 226Ra concentrations, which did not differ significantly among populations. Levels of 226Ra in the crop contents and intestine did not differ significantly by site and were similar to those of food items consumed by the birds. Stomach content values were higher in birds sampled in Elliot Lake and at the local control site than in those taken at the distant control site; birds sampled downstream from Elliot Lake did not differ from distant controls in this regard. Levels of 232thorium (Th) and 230Th were below detection limits (0.1 microg g(-1) and 5.0 mBq g(-1), respectively) in bone, muscle and liver tissue in two grouse with elevated levels of 226Ra. Other radionuclides were measurable in some tissues: 238U in bone at 0.4 microg g(-1), in muscle to 0.2 microg g(-1), in liver to 1.0 gmg g(-1.), 228Th was found only in muscle (8.0 mBq g(-1)), 210poloniuim (Po) was found in bone, muscle and liver (maxima: 24.0, 7.0, 16.0 mBq g(-1)) with the exception of one muscle sample; 210lead (Pb) was detected in only one liver sample (50.0 mBq g(-1)). Environmental levels fell within ranges previously reported at the sites, or at similar locations elsewhere. Leaves of trembling and largetooth aspen growing in the basin had mean 226Ra levels of 14.8 and 52.7 mBq g(-1) (dry weight) respectively, and fungal material carried up to 215.4 mBq g(-1) (air-dried), with some variation by site. River and lake waters sampled near the U tailings had 118.1 mBq litre(-1) of dissolved 226Ra; at the distant control site the value was 12.1 mBq litre(-1). The concentration ratios (CR) between bone of grouse collected at the Elliot Lake sites and trembling and largetooth aspen leaves were 1.38 and 1.09 (fresh weight basis); from other diet items and to other tissues the values were less than unity. Bone tissue: water ratios, based on dissolved 226Ra levels, ranged to 30.89. People eating grouse from the study area are unlikely to consume radionuclides in excess of limits currently established by Canadian regulatory authorities.

226Ra and other radionuclides in water, vegetation, and tissues of beavers (Castor canadensis) from a watershed containing U tailings near Elliot Lake, Canada

Radionuclide levels were measured in tissues, gut contents, diet items, and water at site of capture, of adult beavers from the Serpent River drainage basin which contains U tailings at Elliot Lake, Ontario, and from nearby control sites. Levels of (226)Ra in beaver bone, muscle and kidney were highest in animals from locations close to U tailings; liver levels did not vary by site. Environmental (226)Ra levels were within ranges previously reported at these or similar locations elsewhere; levels in beaver gut contents reflected levels in diet items. Concentration ratios exceeded unity only between some vegetation items and beaver bone at the Elliot Lake site and were less than 0.19 between vegetation and other tissues. In two beavers with tissue levels of (226)Ra higher than other sampled, neither (232)Th nor (230)Th were detected in bone, muscle or liver tissues. U-238 was measurable in bone, muscle and liver, (228)Th in bone, (210)Po bone, muscle and liver; and (210)Pb was measurable only in bone. Estimated yearly intakes of radionuclides by people eating beavers were calculated to be below current allowable levels set by the Canadian regulatory authorities.

Bank voles as monitors of environmental contamination by heavy metals. A remote wilderness area in Poland imperiled

Concentrations of heavy metals (Cd, Pb, Cu, Zn, Fe) were determined in the tissues of bank voles collected in polluted forest sites in southern Poland and in Białowieza National Park. The highest cadmium concentrations were found in livers (0.9-12.8 microg g(-1)) and kidneys (3.2-29.6 microg g(-1)), whereas the lowest were in bones (0.2-0.9 microg g(-1)). The lead concentrations found in kidneys and bones ranged from 9.5 to 40.0 microg g(-1). The ranges of zinc, iron and copper concentrations in the tissues of animals were: 137-343 microg g(-1), 206-1017 microg(-1) and 12.0-73.8 microg(-1), respectively. Some of the differences between the levels found in various sites were statistically significant.

Ecosystem health. IV. The National Animal Poison Information Network database as a tool for ecological risk assessment

Toxicology is a unique discipline in human and veterinary medicine because there are orders of magnitude more toxicants available to man and animals than all known pathogenic microorganisms and parasites. The study of toxicologic responses of ecosystems to contaminants, ecoepidemiology, and the specific study of animal populations in this context, epizootiologic ecotoxicology, are concerned with identifying chemically induced causes and determining effects on and links among populations, communities, and ecosystems. Necessary activities implied by the term "epizootiologic ecotoxicology" are the systematic compilation and analysis of "health" data for ecosystem components. This concept paper describes the value and limitations of adapting methods used by the National Animal Poison Information Network (NAPINet) for epizootiologic ecotoxicology studies. It is concluded that NAPINet methodology, as part of an innovative use of population statistics and clinical measurements, could eventually be adapted into a valuable component of a standardized approach to epizootiologic ecotoxicology.