1. Why Care About Air Toxics in the NPS? • Toxic deposition from Asian sources is occurring • Degree of risk is undetermined • Toxic re-deposition with elevation is very likely • Snow is an efficient pathway for toxic deposition • Snow is the primary alpine precipitation source • Bioaccumulation through food webs will occur • Multiple stressors and sources (local, region, hemisphere) • High elevation sites could be “sinks” for toxics • Early warning sites for the rest of the continent
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1. Why Care About Air Toxics in the NPS? Toxic deposition from Asian sources is occurring Degree of risk is undetermined Toxic re-deposition with elevation.
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1. Why Care About Air Toxics in the NPS?
• Toxic deposition from Asian sources is occurring
• Degree of risk is undetermined
• Toxic re-deposition with elevation is very likely
• Snow is an efficient pathway for toxic deposition
• Snow is the primary alpine precipitation source
• Bioaccumulation through food webs will occur
• Multiple stressors and sources (local, region, hemisphere)
• High elevation sites could be “sinks” for toxics
• Early warning sites for the rest of the continent
2. Where have we seen effects?What concentrations?
• Effects seen in Arctic
• Food web dependent (marine, fw, terrestrial)
• Fish
• Piciverous birds (eagles, falcons)
• Waterfowl (green-winged teal/Hg & PCB)
• Cause/effect relationships are poorly studied; non-lethal effects on immune system and reproduction probable
• http://www.amap.no/
3. Toxic Distribution and Effects in Western United States?
• Trans-Pacific toxics are poorly characterized• Distribution of toxics in general is very poorly
understood both spatially, vertically and temporally!
• Investigations at a few sites are beginning: amphibians in Southern Sierra; Denali NP; others?
4. Recommendations to NPS
• Develop clear objectives • Consider a robust spatial design• Sediments - history of exposure, system flux• Snow - annual and spatial loading variability• Biota - select meaningful biological indicators:
wide distribution, relatively abundant, easy to sample, known food web position
5. Advance Work
• Develop clear objectives • Consider a robust spatial (geographic) design• Integrate effort with atmospheric monitoring efforts (analyte selection)• Combine exposure and effects monitoring (snow, sediment, biota)• Create a Research Plan• Obtain very high quality analytical support• Create a Scientific Advisory Board to guide effort• Factor in adequate peer review• Strive to collaborate with Canada, Mexico?• Get more money (POP analyses are @~$500, logistics may involve
aircraft, interdisciplinary investigation team, many parks, multiyear effort)
6. What trends are predicted for toxic emissions, deposition and impacts?
• Regulations have reduced many POPs and declines in emission, deposition and impacts have been observed (DDT, Pb, HCH)
• Arctic and high latitudes may lag behind since they may function as environmental “sinks”
• Mercury is just beginning to be regulated - anthropogenic sources abound
• New Generation Pesticides (NGP)???• Impacts need much greater study to link
contaminants with effects
7. Research Gaps
• Effects are difficult - outside normal monitoring program - establish bioaccumulation
• 1o Production: Not where the wise would look for effects! But if you MUST investigate effects (get more money):
• Link effects at the individual and population level• Determine contaminant effects on eggs and larvae of
invertebrates• Investigate cumulative effects. Investigate non-lethal effects• Urgent: develop methods to assess the individual health of
zooplankton and fish larvae, mainly to establish causality between effects and environmental factors.
(emphasis on 1o Production - Aquatic?)
Problem: Possible deposition oftrans-pacific air toxics to highelevation ecosystems in N. America
Toxic substances of concernare not well established
Identify most likelytoxics substances transported to and
accumulated in N. A.Ecosystems
Probable materials Are: HCH, DDT,
PCB, & Hg
Collaboration withAtmospheric Scientists
Final List of Toxic Materials
To Evaluate• long lived• toxic
• unique origin
Probability based spatial Design - High elevation Western N. America
EffectsExposure
Biological indicator
of Bioaaccumulation
(Gammarus spp.?)
Historic LoadingLake Sediments
Annual VariabilitySnowpack
QuantitativeRegional Scale
Risk Assessment
Sediment Sampling:Sediment Sampling:• • Design matches objectivesDesign matches objectives• • Bathymetry screeningBathymetry screening• • Gradients (elev./ Lat.)Gradients (elev./ Lat.)• • Watershed type/sizeWatershed type/size• • Inflows/glaciersInflows/glaciers• • Nice to have p-chem,Nice to have p-chem,
• • Importance of coresurfaceImportance of coresurface
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Coring set up for large diameter, heavy corer in remote locationIce thickness - 2 m
Core head - 50-100 kgHole diameter - 30 cm
“Lightweight” mobile coring operation21.5 diameter corerIce thickness - 1 m
83 mm ID corerCorer weight - ~15 kg max
Corer in core rack
Winch
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Key References
Macdonald, R. W., L. A. Barrie, et al. (2000). Contaminants in the Canadian arctic: 5 years of progress in understanding sources, occurrence and pathways.
The Science of the Total Environment 254: 93-234.
Carrera, G., P. Fernandez, et al. (2001). Persistent organic pollutants in snow
from European high mountain areas. Atmospheric Environment 35: 245-254.
Landers, D. H., C. Gubala, et al. (1998). Using lake sediment mercury flux ratios toevaluate the regional and continental dimensions of mercury deposition in arctic and boreal ecosystems. Atmospheric Environment 32(5): 919-928.
Muir, D. C. G., A. Omelchenko, et al. (1996). Spatial trends and historical deposition of polychlorinated biphenyls in Canadian mid-latitude and arctic lake sediments. Environ. Sci. Technol.(30): 3609-3617.
http://grida.no/amap/ [Arctic Monitoring and Assessment Program web site]