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J.G. Crock

Publications and source records attributed to J.G. Crock.

At least 19 recordsLinked to original sources
USGS2022

Mercury methylation at mercury mines in the Humboldt River Basin, Nevada, USA

Total Hg and methylmercury concentrations were measured in mine-waste calcines (retorted ore), sediment, and water samples collected in and around abandoned mercury mines in western Nevada to evaluate Hg methylation at the mines and in the Humboldt River Basin. Mine-waste calcines contain total Hg concentrations as high as 14 000 ??g g-1. Stream-sediment samples collected within 1 km of the mercury mines contain total Hg concentrations as high as 170 ??g g-1, whereas stream sediments collected at a distance >5 km from the mines, and those collected from the Humboldt River and regional baseline sites, contain total Hg concentrations <0.5 ??g g-1. Similarly, methylmercury concentrations in mine-waste calcines are locally as high as 96 ng g-1, but methylmercury contents in stream sediments collected downstream from the mines and from the Humboldt River are lower, ranging from <0.05 to 0.95 ng g-1. Stream-water samples collected downstream from two mines studied contain total Hg concentrations ranging from 6 to 2000 ng 1-1, whereas total Hg in Humboldt River water was generally lower, ranging from 2.1 to 9.0 ng 1-1. Methylmercury concentrations in the Humboldt River water were the lowest in this study (<0.02-0.27 ng 1-1). Although total Hg and methylmercury concentrations are locally high in mine-waste calcines, there is significant dilution of Hg and there is also lower Hg methylation down gradient from the mines, especially in the sediments and water collected from the Humboldt River, which is >8 km from the nearest mercury mines. Our data indicate little transference of Hg and methylmercury from the sediment to the water column due to the lack of mine runoff in this desert climate.

Geochemistry: Exploration, Environment, Analysis↗
USGS2011

Inorganic chemical analysis of environmental materials&mdash;A lecture series

At the request of the faculty of the Colorado School of Mines, Golden, Colorado, the authors prepared and presented a lecture series to the students of a graduate level advanced instrumental analysis class. The slides and text presented in this report are a compilation and condensation of this series of lectures. The purpose of this report is to present the slides and notes and to emphasize the thought processes that should be used by a scientist submitting samples for analyses in order to procure analytical data to answer a research question. First and foremost, the analytical data generated can be no better than the samples submitted. The questions to be answered must first be well defined and the appropriate samples collected from the population that will answer the question. The proper methods of analysis, including proper sample preparation and digestion techniques, must then be applied. Care must be taken to achieve the required limits of detection of the critical analytes to yield detectable analyte concentration (above "action" levels) for the majority of the study's samples and to address what portion of those analytes answer the research question-total or partial concentrations. To guarantee a robust analytical result that answers the research question(s), a well-defined quality assurance and quality control (QA/QC) plan must be employed. This QA/QC plan must include the collection and analysis of field and laboratory blanks, sample duplicates, and matrix-matched standard reference materials (SRMs). The proper SRMs may include in-house materials and/or a selection of widely available commercial materials. A discussion of the preparation and applicability of in-house reference materials is also presented. Only when all these analytical issues are sufficiently addressed can the research questions be answered with known certainty.

Open-File Report↗
USGS2010

The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies

Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the purpose of a study. Our hypothesis is that the method of sample preparation is important for interpretation of the results. Here we compare the results of 36 element determinations performed by ICP-MS on ashed and on acid-digested (HNO 3 , H 2 O 2 ) samples of two moss species ( Hylocomium splendens and Pleurozium schreberi ) collected in Alaska and in south-central Poland. We found that dry ashing of the moss samples prior to analysis resulted in considerably lower detection limits of all the elements examined. We also show that this sample preparation technique facilitated the determination of interregional and interspecies differences in the chemistry of trace elements. Compared to the Polish mosses, the Alaskan mosses displayed more positive correlations of the major rock-forming elements with ash content, reflecting those elements’ geogenic origin. Of the two moss species, P. schreberi from both Alaska and Poland was also highlighted by a larger number of positive element pair correlations. The cluster analysis suggests that the more uniform element distribution pattern of the Polish mosses primarily reflects regional air pollution sources. Our study has shown that the method of sample preparation is an important factor in statistical interpretation of the results of trace element determinations.

Environmental Chemistry Letters↗
USGS2010

Analytical results for municipal biosolids samples from a monitoring program near Deer Trail, Colorado (U.S.A.), 2009

Since late 1993, Metro Wastewater Reclamation District of Denver, a large wastewater treatment plant in Denver, Colo., has applied Grade I, Class B biosolids to about 52,000 acres of nonirrigated farmland and rangeland near Deer Trail, Colo., U.S.A. In cooperation with the Metro District in 1993, the U.S. Geological Survey began monitoring groundwater at part of this site. In 1999, the Survey began a more comprehensive monitoring study of the entire site to address stakeholder concerns about the potential chemical effects of biosolids applications to water, soil, and vegetation. This more comprehensive monitoring program has recently been extended through the end of 2010. Monitoring components of the more comprehensive study include biosolids collected at the wastewater treatment plant, soil, crops, dust, alluvial and bedrock groundwater, and stream-bed sediment. Streams at the site are dry most of the year, so samples of stream-bed sediment deposited after rain were used to indicate surface-water effects. This report presents analytical results for the biosolids samples collected at the Metro District wastewater treatment plant in Denver and analyzed for 2009. In general, the objective of each component of the study was to determine whether concentrations of nine trace elements ('priority analytes') (1) were higher than regulatory limits, (2) were increasing with time, or (3) were significantly higher in biosolids-applied areas than in a similar farmed area where biosolids were not applied. Previous analytical results indicate that the elemental composition of biosolids from the Denver plant was consistent during 1999-2008, and this consistency continues with the samples for 2009. Total concentrations of regulated trace elements remain consistently lower than the regulatory limits for the entire monitoring period. Concentrations of none of the priority analytes appear to have increased during the 11 years of this study.

Open-File Report↗
USGS2009

Analytical Results for Municipal Biosolids Samples from a Monitoring Program Near Deer Trail, Colorado (U.S.A.), 2008

Since late 1993, Metro Wastewater Reclamation District of Denver (Metro District), a large wastewater treatment plant in Denver, Colo., has applied Grade I, Class B biosolids to about 52,000 acres of nonirrigated farmland and rangeland near Deer Trail, Colo. (U.S.A.). In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring groundwater at part of this site. In 1999, the USGS began a more comprehensive monitoring study of the entire site to address stakeholder concerns about the potential chemical effects of biosolids applications to water, soil, and vegetation. This more comprehensive monitoring program has recently been extended through 2010. Monitoring components of the more comprehensive study include biosolids collected at the wastewater treatment plant, soil, crops, dust, alluvial and bedrock groundwater, and stream-bed sediment. Streams at the site are dry most of the year, so samples of stream-bed sediment deposited after rain were used to indicate surface-water effects. This report will present only analytical results for the biosolids samples collected at the Metro District wastewater treatment plant in Denver and analyzed during 2008. Crock and others have presented earlier a compilation of analytical results for the biosolids samples collected and analyzed for 1999 thru 2006, and in a separate report, data for the 2007 biosolids are reported. More information about the other monitoring components is presented elsewhere in the literature. Priority parameters for biosolids identified by the stakeholders and also regulated by Colorado when used as an agricultural soil amendment include the total concentrations of nine trace elements (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc), plutonium isotopes, and gross alpha and beta activity. Nitrogen and chromium also were priority parameters for groundwater and sediment components.

Open-File Report↗
USGS2009

Analytical Results for Agricultural Soils Samples from a Monitoring Program Near Deer Trail, Colorado (USA)

Since late 1993, Metro Wastewater Reclamation District of Denver (Metro District, MWRD), a large wastewater treatment plant in Denver, Colorado, has applied Grade I, Class B biosolids to about 52,000 acres of nonirrigated farmland and rangeland near Deer Trail, Colorado, USA. In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring groundwater at part of this site. In 1999, the USGS began a more comprehensive monitoring study of the entire site to address stakeholder concerns about the potential chemical effects of biosolids applications to water, soil, and vegetation. This more comprehensive monitoring program has recently been extended through 2010. Monitoring components of the more comprehensive study include biosolids collected at the wastewater treatment plant, soil, crops, dust, alluvial and bedrock groundwater, and stream bed sediment. Soils for this study were defined as the plow zone of the dry land agricultural fields - the top twelve inches of the soil column. This report presents analytical results for the soil samples collected at the Metro District farm land near Deer Trail, Colorado, during three separate sampling events during 1999, 2000, and 2002. Soil samples taken in 1999 were to be a representation of the original baseline of the agricultural soils prior to any biosolids application. The soil samples taken in 2000 represent the soils after one application of biosolids to the middle field at each site and those taken in 2002 represent the soils after two applications. There have been no biosolids applied to any of the four control fields. The next soil sampling is scheduled for the spring of 2010. Priority parameters for biosolids identified by the stakeholders and also regulated by Colorado when used as an agricultural soil amendment include the total concentrations of nine trace elements (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc), plutonium isotopes, and gross alpha and beta activity (Colorado Department of Public Health and Environment, Hazardous Materials and Waste Management Division, 1997; Colorado Department of Public Health and Environment,1998; U.S. Environmental Protection Agency, 1993). Since these were the identified priority parameters for the biosolids, the soils have the same set of priority parameters. Although the composite soils' priority analytes have been reported earlier to Metro District, the remaining elemental datasets for both the composite soils samples and selected fields' individual subsamples' data are presented here for the first time. More information about the other monitoring components is presented elsewhere in the literature (http://co.water.usgs.gov/projects/CO406/CO406.html). In general, the objective of each component of the study was to determine whether concentrations of priority parameters (1) were higher than regulatory limits, (2) were increasing with time, and(or) (3) were significantly higher in biosolids-applied areas than in a similar farmed area where biosolids were not applied. The method chosen for sampling the soils proved to be an efficient and reliable representation of the average composition of each field. This was shown by analyzing individual subsamples, averaging the resulting values, and then comparing the values to the composited samples' values. The soil chemistry shows distinct differences between the two sites, most likely due to the different underlying parent material. Biosolids data were used to compile an inorganic-chemical biosolids signature that can be contrasted with the geochemical signature of the agricultural soils for this site. The biosolids signature and an understanding of the geology and hydrology of the site can be used to separate biosolids effects from natural geochemical effects. Elements of particular interest for a biosolids signature after application in the soils include bismuth, copper, silver, mercury, and phosphorus. This signat

Open-File Report↗
USGS2008

Analytical Results for Municipal Biosolids Samples from a Monitoring Program Near Deer Trail, Colorado (USA), 1999 through 2006

Since late 1993, Metro Wastewater Reclamation District of Denver (Metro District), a large wastewater treatment plant in Denver, Colorado, has applied Grade I, Class B biosolids to about 52,000 acres of non-irrigated farmland and rangeland near Deer Trail, Colorado. In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring ground water at part of this site (Yager and Arnold, 2003). In 1999, the USGS began a more comprehensive monitoring study of the entire site to address stakeholder concerns about the potential chemical effects of biosolids applications. This more comprehensive monitoring program has recently been extended through 2010. Monitoring components of the more comprehensive study include biosolids collected at the wastewater treatment plant, soil, crops, dust, alluvial and bedrock ground water, and stream bed sediment. Streams at the site are dry most of the year, so samples of stream bed sediment deposited after rain were used to indicate surface-water effects. This report will present only analytical results for the biosolids samples collected at the Metro District wastewater treatment plant in Denver and analyzed during 1999 through 2006. More information about the other monitoring components is presented elsewhere in the literature (e.g., Yager and others, 2004a, 2004b, 2004c, 2004d). Priority parameters for biosolids identified by the stakeholders and also regulated by Colorado when used as an agricultural soil amendment include the total concentrations of nine trace elements (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc), plutonium isotopes, and gross alpha and beta activity. Nitrogen and chromium also were priority parameters for ground water and sediment components. In general, the objective of each component of the study was to determine whether concentrations of priority parameters (1) were higher than regulatory limits, (2) were increasing with time, or (3) were significantly higher in biosolids-applied areas than in a similar farmed area where biosolids were not applied. Analytical results indicate that the elemental composition of the biosolids from the Denver plant was consistent during 1999-2006, and total concentrations of regulated trace elements were consistently lower than the regulatory limits. Plutonium isotopes were not detected in any of the biosolids samples for the entire sampling period. Analytical results for gross and were highly imprecise and erratic. As a result of the cancelation of regulation requiring their monitoring in biosolids, the determination of both was discontinued mid-study. Data from this study were used to compile an inorganic-chemical biosolids signature that can be contrasted with the geochemical signature for this site. The biosolids signature and an understanding of the geology and hydrology of the site can be used to separate biosolids effects from natural geochemical effects. Elements of particular interest for a biosolids signature include bismuth, copper, silver, mercury, and phosphorus.

Open-File Report↗
USGS2008

Analytical Results for Municipal Biosolids Samples from a Monitoring Program near Deer Trail, Colorado (U.S.A.), 2007

Since late 1993, the Metro Wastewater Reclamation District of Denver (Metro District), a large wastewater treatment plant in Denver, Colorado, has applied Grade I, Class B biosolids to about 52,000 acres of nonirrigated farmland and rangeland near Deer Trail, Colorado (U.S.A.). In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring ground water at part of this site. In 1999, the USGS began a more comprehensive monitoring study of the entire site to address stakeholder concerns about the potential chemical effects of biosolids applications to water, soil, and vegetation. This more comprehensive monitoring program recently has been extended through 2010. Monitoring components of the more comprehensive study include biosolids collected at the wastewater treatment plant, soil, crops, dust, alluvial and bedrock ground water, and streambed sediment. Streams at the site are dry most of the year, so samples of streambed sediment deposited after rain were used to indicate surface-water effects. This report will present only analytical results for the biosolids samples collected at the Metro District wastewater treatment plant in Denver and analyzed during 2007. We have presented earlier a compilation of analytical results for the biosolids samples collected and analyzed for 1999 through 2006. More information about the other monitoring components is presented elsewhere in the literature. Priority parameters for biosolids identified by the stakeholders and also regulated by Colorado when used as an agricultural soil amendment include the total concentrations of nine trace elements (arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc), plutonium isotopes, and gross alpha and beta activity. Nitrogen and chromium also were priority parameters for ground water and sediment components. In general, the objective of each component of the study was to determine whether concentrations of priority parameters (1) were higher than regulatory limits, (2) were increasing with time, or (3) were significantly higher in biosolids-applied areas than in a similar farmed area where biosolids were not applied. Previous analytical results indicate that the elemental composition of the biosolids from the Denver plant was consistent during 1999-2006 and this consistency continues with the samples for 2007; total concentrations of regulated trace elements remained consistently lower than the regulatory limits for the entire monitoring period. Our previously reported data (1999-2006) and data presented in this report were used to compile an inorganic-chemical biosolids signature that can be contrasted with the geochemical signature for this site. The biosolids signature and an understanding of the geology and hydrology of the site can be used to separate biosolids effects from natural geochemical effects. Elements of particular interest for a biosolids signature include bismuth, copper, silver, mercury, phosphorus, and silver. An alternative method of digestion of biosolids was also recently investigated, and the results are presented in this report. A microwave digestion using only nitric acid at controlled elevated temperature and pressure was tested to replace the much more time-consuming and labor-intensive, traditional four-acid, hotplate method for the preparation of solutions to be analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Elements of concern determined by ICP-MS following digestion include cadmium, copper, lead, molybdenum, nickel, and zinc. The microwave 'digestion' proved to be a strong acid leach, and it was less efficient at digesting the biosolids samples with consistently lower recoveries (compared to the four-acid digestion value) for most elements, but especially for the elements of concern - copper, nickel, and zinc. Other elements traditionally associated with the silicate or oxide minerals demonstrated low recoveries, especially titaniu

Open-File Report↗
USGS2008

Substrate Geochemistry and Soil Development in Boreal Forest and Tundra Ecosystems in the Yukon-Tanana Upland and Seward Peninsula, Alaska

We report on soil development as a function of bedrock type and the presence of loess in two high latitude ecosystems (boreal forest and tundra) and from two regions in Alaska?the Yukon-Tanana Upland (YTU, east-central Alaska) and the Seward Peninsula (SP, far-west coastal Alaska). This approach to the study of 'cold soils' is fundamental to the quantification of regional geochemical landscape patterns. Of the five state factors in this study, bedrock and biota (ecosystem; vegetation zone) vary whereas climate (within each area) and topography are controlled. The influence of time is assumed to be controlled, as these soils are thousands of years old (late Quaternary to Holocene). The primary minerals in soils from YTU, developed over loess and crystalline bedrock (metamorphic and intrusive), are quartz, plagioclase, and 2:1 clays; whereas in the SP, where loess and metasedimentary bedrock (schist and quartzite) predominate, they are quartz and muscovite. The A horizon of both regions is rich in peat. Examination of the ratio of mobile (K2O, CaO, and Fe2O3) to immobile (TiO2) major oxides, within each region, shows that very little difference exists in the chemical weathering of soils developed between the two ecosystems examined. Differences were observed between tundra soils developed in the two regions. These differences are most probably due to the dissimilarity in the geochemical importance of both loess and bedrock. A minimal loss of cadmium with soil depth is seen for soils developed over YTU crystalline bedrock in the boreal forest environments. This trend is related to the mobility of cadmium in these soils as well as to its biogenic cycling. Major differences were observed in the proportion of cadmium and zinc among the A, B, and C horizon material sequestered in various soil fractions as measured by sequential soil extractions. These trends followed such variables as the decrease with depth in organic matter, the change in clay minerals, and the change in the proportion of oxides/hydroxides. An analysis of the bulk soil mineralogy and the relation between CaO and MgO and Al2O3 and Fe2O3 indicates that the silty textured soils of the YTU are predominantly eolian (that is, of late Tertiary or Quaternary age) but not broad-regional in origin. Their composition instead is probably the result of locally derived dusts as well as input from long-term, in-place bedrock weathering.

Scientific Investigations Report↗
USGS2004

Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

Spawning cutthroat trout ( Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears ( Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized ( i ) the relatively high, naturally occurring concentration of mercury in Yellowstone Lake cutthroat trout (508 &plusmn; 93 ppb) and its virtual absence in all other bear foods ( 6 ppb), ( ii ) hair snares to remotely collect hair from bears visiting spawning cutthroat trout streams between 1997 and 2000, ( iii ) DNA analyses to identify the individual and sex of grizzly bears leaving a hair sample, ( iv ) feeding trials with captive bears to develop relationships between fish and mercury intake and hair mercury concentrations, and ( v ) mercury analyses of hair collected from wild bears to estimate the amount of trout consumed by each bear. Male grizzly bears consumed an average of 5 times more trout/kg bear than did female grizzly bears. Estimated cutthroat trout intake per year by the grizzly bear population was only a small fraction of that estimated by previous investigators, and males consumed 92% of all trout ingested by grizzly bears.

Wyoming, Montana, Idaho↗
USGS2003

Biosolids, soils, ground-water, and streambed-sediment data for a biosolids-application area near Deer Trail, Colorado, 1999

In January 1999, the U.S. Geological Survey began an expanded monitoring program near Deer Trail, Colorado, in cooperation with the Metro Wastewater Reclamation District and the North Kiowa Bijou Groundwater Management District. Monitoring components were biosolids, soils, crops, ground water, and streambed sediments. The monitoring program addresses concerns from the public about chemical effects from applications of biosolids to farmland in the Deer Trail, Colorado, area. Constituents of primary concern to the public are arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, zinc, plutonium, and gross alpha and beta activity and are included for all monitoring components. This report presents chemical data from the first year of the monitoring program, January?December 1999, for biosolids, soils, alluvial and bedrock ground water, and streambed sediments. The groundwater section of this report also includes climate data, lithologic descriptions, well-completion diagrams, water levels, summary statistics for the water-quality data, and results of statistical testing of selected data for trends and for exceedance of Colorado regulatory standards. Data in this report provide a geochemical baseline for each monitoring component prior to the planned water transfer in 2000 from the Lowry Landfill Superfund site to Metro Wastewater Reclamation District treatment facilities.

Open-File Report↗
USGS2003

Results of elemental and stable isotopic measurements, and dietary composition of Arctic grayling (Thymallus arcticus) collected in 2000 and 2001 from the Fortymile River Watershed, Alaska

We report the results of the elemental and stable isotopic analyses, as well as the composition of stomach contents, of Arctic grayling (Thymallus arcticus), an ecologically important resident freshwater sport and subsistence fish in the Fortymile River Mining District of the Interior Highlands Ecoregion in eastern Alaska. These data are presented here as a data compilation with minimal interpretation or discussion. Further analyses of the data will be presented elsewhere. The study area has been mined for placer gold for over a century and is currently experiencing renewed mineral exploration activity. The results for the analysis of 40 inorganic elements are reported for grayling muscle (fillet) tissue, liver tissue, and stomach contents from 34 individuals caught at 11 sites within the watershed. The 11 sites were classified as occurring within the following lithologies: metavolcanic (7 sites), metasedimentary (3 sites), and granitic intrusion (1 site). This information (along with fish tissue stable isotope data) is critical in the assessment of the influence of regional lithology on the fish chemical composition, especially the trace metal content. We report the nitrogen, carbon, and sulfur stable isotope composition of muscle samples. Nitrogen isotopes appear homogeneous (d15N = 7.6 to 9.7 permil) whereas carbon and sulfur isotope compositions of the same samples span a range from d 13C = ?33.1 to ?25.8 permil, and d 34S = ?8.4 to 8.2 permil. Stomach content material was examined for the occurrence and frequency of macroinvertebrate composition and diversity in three individual fish. Results showed a high degree of diversity with 9 to 15 invertebrate taxa; both aquatic and terrestrial forms were represented.

Open-File Report↗
USGS2002

Environmental geochemistry of abandoned mercury mines in West-Central Nevada, USA

The Humboldt River is a closed basin and is the longest river in Nevada. Numerous abandoned Hg mines are located within the basin, and because Hg is a toxic heavy metal, the potential transport of Hg from these mines into surrounding ecosystems, including the Humboldt River, is of environmental concern Samples of ore, sediment, water, calcines (roasted ore), and leachates of the calcines were analyzed for Hg and other heavy metals to evaluate geochemical dispersion from the mines. Cinnabar-bearing ore samples collected from the mines contain highly elevated Hg concentrations, up to 6.9 %, whereas calcines collected from the mines contain up to 2000 mg Hg/kg. Stream-sediment samples collected within 1 km of the mines contain as much as 170 mg Hg/kg, but those collected distal from the mines (> 5 km) contain < 1 mg Hg/kg, indicating significant geochemical dispersion of Hg downstream from the mines. Sediment samples collected from the Humboldt River basin contain ??? 0.28 mg Hg/kg. Leachate samples of the calcines obtained by using a synthetic water leaching technique contain as much as 1500 ??g Hg/l, suggesting that some calcines contain soluble Hg compounds. However, much lower Hg concentrations were found in water samples collected from the Humboldt River system, and these were below the 0.012 ??g/l Hg standard used to protect against chronic effects to aquatic wildlife. Mercury transference from these mines to the Humboldt River basin is generally minor because the mines are typically > 8 km from the Humboldt River, and Hg is transported and diluted through a large volume of pediment before it reaches the Humboldt River. ?? 2002 Elsevier Science Ltd. All rights reserved.

Conference Paper↗
USGS2000

Cadmium toxicity among wildlife in the Colorado Rocky Mountains

Cadmium is known to be both extremely toxic and ubiquitous in natural environments. It occurs in almost all soils, surface waters and plants, and it is readily mobilized by human activities such as mining. As a result, cadmium has been named as a potential health threat to wildlife species; however, because it exists most commonly in the environment as a trace constituent, reported incidences of cadmium toxicity are rare. Here we have measured trace metals in the food web and tissues of white-tailed ptarmigan (Lagopus leucurus) in Colorado. Our results suggest that cadmium toxicity may be more common among natural populations of vertebrates than has been appreciated to date and that cadmium toxicity may often go undetected or unrecognized. In addition, our research shows that ingestion of even trace quantities of cadmium can influence not only the physiology and health of individual organisms, but also the demographics and the distribution of species.

Nature↗