This study compares select dust sampling apparatuses and monitoring methods by investigating fugitive tailings dust transport and deposition at an abandoned Zn-Pb-Cu mine located in eastern, Canada. ...The sampling apparatuses and monitoring methods are compared in terms of capturing seasonal trends and spatial extent, as well as the ability to evaluate impacts to aquatic ecosystems. Methods evaluated include satellite imagery, lichen tissue analysis, passive dry deposition collectors (Pas-DDs) with two different configurations, dust deposition gauges (DDGs) and a high volume total suspended particulate (Hi-Vol TSP) sampler. All methods utilized demonstrated benefits and challenges in relation to seasonal sampling and determining spatial extent of dust deposition. Results indicate that the polyurethane foam disk configuration of the Pas-DD sampler efficiently accumulates dust in comparison to the glass fiber filter configuration and DDGs which both likely underestimate dust deposition. Lichen and satellite imagery were shown to be effective tools for identifying areas of interest and extent of contamination. At the study site, it was observed that dust deposition was highest in the winter months and lowest in the summer months, likely due to increased erosion in winter weather conditions (higher wind speeds and/or freeze drying effect).
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•Passive and active dust sampling methods, lichen and remote sensing are compared.•Satellite imagery can be used to guide field investigations of dust deposition.•Methods utilized differ in quantification of dust deposition, yet similar trends were observed.•Polyurethane foam was successful at entraining particles when used with a Pas-DD.•Robust data sets can be created by comparing dust monitoring methods simultaneously.
Biodiversity indicators used by policy-makers are underdeveloped and underinvested.
In response to global declines in biodiversity, some 190 countries have pledged, under the Convention on Biological ...Diversity (CBD), to reduce the rate of biodiversity loss by 2010 (
1
,
2
). Moreover, this target has recently been incorporated into the Millennium Development Goals in recognition of the impact of biodiversity loss on human well-being (
3
). Timely information on where and in what ways the target has or has not been met, as well as the likely direction of future trends, depends on a rigorous, relevant, and comprehensive suite of biodiversity indicators with which to track changes over time, to assess the impacts of policy and management responses, and to identify priorities for action. How far have we come in meeting these needs, and is it sufficient?
The inhibition of acetylcholinesterase (AChE) activity has been used widely as a biomarker of exposure to organophosphorous pesticides (OPs). However, scientific uncertainty about the risk assessment ...implications of data describing inhibition of cholinesterases in diverse species and tissues has hampered the use of AChE activity as a biomarker of adverse effect. Here, haemolymph AChE activity was combined with biomarkers of cellular integrity, immunotoxicity and physiological status in order to measure exposure to and the effects of the priority pollutant chlorfenvinphos. Laboratory exposures of the blue mussel
Mytilus edulis to commercial grade chlorfenvinphos (Sapecron
®) were conducted over 24, 48 and 96
h. AChE activity in haemolymph of
M. edulis was highly variable and bore no relationship to either sublethal effects or lethality over the range 0.003–0.03
mg/l chlorfenvinphos. In comparison, concentration dependent inhibition was evident for each of the remaining biomarkers (phagocytic activity, spontaneous cytotoxicity, neutral red retention time, total haemolymph protein). Mussels at the highest exposure concentration showed visual signs of neurotoxicity (impaired neuromuscular control). Haemocyte phagocytic activity and spontaneous cytotoxicity responses were highly sensitive to chlorfenvinphos with significant modulation evident after 24
h exposure to environmentally realistic concentrations of 0.007
mg/l (
P=0.0003). Thus the immune function and well being of the mussels was significantly impacted in the absence of measurable inhibition of haemolymph AChE.
The increased potential for dust mobilization as a result of climate change indicates a need to better understand interactions between dust and water. This research investigates the geochemical ...effects of tailings dust on surface waters near Stirling mine, Nova Scotia. Tailings were sieved to <63 μm as a proxy for dust and analyzed geochemically and mineralogically for the identification of primary and secondary metal-bearing phases using a scanning electron microscope with automated mineralogy, electron microprobe analysis and synchrotron-based microanalysis. Metal-hosting phases identified include in order of abundance; sphalerite (ZnS), cerussite (PbCO3), chalcopyrite (CuFeS2), Pb–Mn phases (possibly cesàrolite (PbMn3O6(OH)2)), smithsonite (ZnCO3), goethite (FeO(OH), aurichalcite ((Zn,Cu)5(CO3)2(OH)6), hydrohetaerolite (ZnMn2O4·H2O), tennantite (Cu6(Cu4Zn2)As4S12S), and galena (PbS). Shake flask tests were conducted in simulated stream waters (pH = 7) using sieved tailings and passive dry deposition collector filters to investigate the solubility of metal-hosting mineral phases within dust. Results indicate metal leaching at near neutral pH conditions. Sphalerite, cerussite and chalcopyrite are likely the main sources of Zn, Pb, and Cu in the shake flask leachate, based on calculated saturated indices and mass balance. Analyses of stream waters indicate similar conditions (pH, ORP, saturation indices, etc.) compared to the results of the shake flask tests, suggesting they provide reasonable insight about processes occurring in the field. Tailings dust generated at the site is therefore a potential source of metals to surface waters.
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•Dust from weathered tailings contains primary and secondary metal hosting minerals.•Most minerals of interest are undersaturated in pH-neutral simulated surface waters.•Sphalerite, chalcopyrite and cerussite are likely the main sources of Zn, Cu and Pb.
This study illustrates the use of a mesocosm approach for assessing the independent effects of three treated metal mine effluents (MME) discharging into a common receiving environment and regulated ...under the same regulation. A field-based, multi-trophic artificial stream study was conducted in August 2008 to assess the effects of three metal mining effluents on fathead minnow (
Pimephales promelas) in a 21-day reproduction bioassay. The nature of the approach allowed for assessment of both dietary and waterborne exposure pathways. Elements (e.g. Se, Co, Cl, Cu, Fe) were analyzed in several media (water, sediments) and tissues (biofilm,
Chironomus dilutus, female fathead minnow (FHM) body, ovary, liver, gills). Significant increases in metal and micronutrient concentrations were observed in the water and biofilm tissues in all MME treatments 20% surface water effluent (SWE), 30% mine water effluent (MWE), and 45% process water effluent (PWE), compared to reference. However, copper was the only element to significantly increase in the sediments when exposed to PWE. Co and Ni increased significantly in
C. dilutus tissues in SWE (1.4- and 1.5-fold, respectively), Cu and Se also increased in chironomid tissues in PWE (5.2- and 3.3-fold, respectively); however, no significant increases in metals or micronutrients occurred in chironomid tissues when exposed to MWE compared to reference. There were no significant increases in metal concentrations in female FHM tissues (body, liver, gonads, gills) in any of the treatments suggesting that metals were either not bioavailable, lost from the females via the eggs, or naturally regulated through homeostatic mechanisms. Cumulative number of eggs per female per day increased significantly (∼127%) after exposure to SWE and decreased significantly (∼33%) after exposure to PWE when compared to reference. Mean total number of days to hatch was reduced in PWE compared to reference. This study shows the importance of isolating treatment streams in cumulative discharge environments to assess aquatic effects due to the different nature of the effluents.
The winter stress syndrome hypothesis proposes that the combination of winter conditions and contaminant exposure reduces overwinter survival in juvenile fishes, mainly due to increased depletion of ...stored energy (lipids). To test this hypothesis in the field, juvenile fathead minnows (Pimephales promelas), creek chub (Semotilus atromaculatus), and white sucker (Catostomus commersoni) were collected from three exposure sites along Junction Creek, Sudbury, Ontario, Canada, representing cumulative inputs from metal mining and municipal wastewater. Overwinter survival potential was determined through measurements of growth (length, weight, muscle RNA/DNA ratio, muscle proteins) and energy stores (whole body triglycerides) in fish collected just prior to and following the overwinter period. We hypothesized that fish collected from exposure sites would exhibit reduced growth and energy storage compared to reference fish in both fall and spring, and that fish from all sites would exhibit reduced energy storage in spring compared to the previous fall. Whole body Se concentrations were elevated (11-42 μg/g dry wt) in juvenile fathead minnows and white sucker collected at two exposure sites in comparison to fish collected from the reference site (3-6 μg/g dry wt). In contrast to our hypothesis, fathead minnows were larger with greater triglyceride stores at exposure sites compared to the reference site. White suckers were smaller at exposure sites but did not differ in triglycerides among sites. Overall, the results in these fish species exposed to metal mining and municipal wastewaters do not support the winter stress syndrome hypothesis. It is recommended that future studies focus on relating growth and energy storage with other environmental factors such as habitat and food availability in addition to anthropogenic contamination.
Junction Creek in Sudbury, Ontario, Canada receives effluent from three metal mining effluents (MMEs), as well as urban run-off and municipal sewage treatment plant (STP) discharges. The present ...study examined organismal and sub-organismal end-points in prespawning fathead minnow (FHM;
Pimephales promelas) and creek chub (CC;
Semotilus atromaculatus) collected in May 2004 from Junction Creek. Metal body burdens of Cd, Cu, Rb, Se, and Sr increased in a gradient down Junction Creek in both species. In general, male fish had lower body weights downstream of effluents, while females were unchanged or larger compared to reference fish. Livers were larger in FHM of both sexes downstream of STP and in CC downstream of two MMEs compared to reference fish, while gonad weight was unchanged. The most consistent finding was delayed development, increased cell death and increased eosinophilia in FHM testes collected downstream of all effluents, while female FHM and both sexes of CC gonads were relatively unaffected. In conclusion, the results of the current study in Junction Creek suggest that male FHM reproduction may be sensitive to multiple effluents, but failed to clearly establish whether MME or STP effluents were causative agents over urban inputs or historical contamination.
The UNEP GEMS/Water Programme is the leading international agency responsible for the development of water quality indicators and maintains the only global database of water quality for inland waters ...(GEMStat). The protection of source water quality for domestic use (drinking water, abstraction etc) was identified by GEMS/Water as a priority for assessment. A composite index was developed to assess source water quality across a range of inland water types, globally, and over time. The approach for development was three-fold: (1) Select guidelines from the World Health Organisation that are appropriate in assessing global water quality for human health, (2) Select variables from GEMStat that have an appropriate guideline and reasonable global coverage, and (3) determine, on an annual basis, an overall index rating for each station using the water quality index equation endorsed by the Canadian Council of Ministers of the Environment. The index allowed measurements of the frequency and extent to which variables exceeded their respective WHO guidelines, at each individual monitoring station included within GEMStat, allowing both spatial and temporal assessment of global water quality. Development of the index was followed by preliminary sensitivity analysis and verification of the index against real water quality data.
Juvenile fathead minnows (
Pimephales promelas) were exposed from 10 to 100 days post-hatch (dph) to metal mining effluent under simulated summer (20
°C and 16/8 light/dark) or winter (4
°C and 8/16 ...light/dark) conditions in order to test the winter stress syndrome hypothesis. The condition factor of fish at 100
dph was similar between seasons, and was greater in the summer effluent exposure group compared to the summer control. Whole body triglycerides were lower in the effluent exposure group compared to control under winter conditions, but not summer. Whole body burdens of several trace metals, notably Cu, Rb and Se, were greater in the effluent exposed fish at 100
dph and displayed seasonal differences in bioaccumulation. Fathead minnows were also exposed from 10 to 100
dph to graded concentrations of ammonia (0.02–0.40
mg unionized NH
3/L) under summer conditions in order to investigate potential effects of this component of the effluent. There was no effect of ammonia exposure on growth parameters, but an increase in whole body triglycerides was observed at the highest exposure. The seasonal differences in bioaccumulation and biological responses suggest that winter conditions may be an important modifying factor in aquatic toxicological studies.
