L. Hasselbach, J. M. Ver Hoef, J. Ford, P. Neitlich, E. Crecelius, S. Berryman, B. Wolk and T. Bohle Spatial patterns of cadmium and lead deposition on National Park Service lands near Red Dog Mine

Study Area

Objectives 1.Determine the spatial patterns and distribution of airborne heavy metal deposition on Monument lands (= this presentation) 2.Identify potential sources of these airborne heavy metals (see manuscript)

Study Design Collected Moss Hylocomium splendens Unwashed Analyzed for heavy metals & crustal elements (Al, Fe) Collected Soil Subsurface (depth 30”) Unaffected by surface activities

Study Design Centered on haul road 45 mi (70 km) north and south of road Intensified sampling near road & port 155 grid cells 226 moss samples

Sources Moss versus Soil Moss patterns are not due to subsurface geology 45 mi

( NOTE: 20 km = 12 miles ) Lead (Pb) Road and port gradient Lowest in southern portion of Monument Northern areas higher than southern areas Entire northern portion of Monument affected Mine-related deposition 15 miles north of road Depositional Patterns

Lead (Pb) Metals decrease with distance from haul road Metals decrease with distance from port site NOTE: 6 km = 3.5 miles

Context Regional moss sampling locations Study Area Data Comparison Elemental data in ppm (= mg/kg dw)

Topography as related to depositional patterns

as related to depositional patterns Wind Bulge = Fallout zone

Deposition in Outlying Areas South of Haul Road Least affected portion of study area Equal to regional background levels* by Igichuck Hills ( NOTE: 20 km = 12 miles ) * Ford et al. (1995) arctic Alaska maximum = 2.3 mg/kg dw Pb

Deposition in Outlying Areas North of Haul Road Fallout zone/bulge Mine-related versus natural sources (or both) Background level comparison (2 ppm Pb) Actual Pb concentrations in stratum 8 Surface or near-surface lead sulfide deposits

Summary 1.Very high heavy metal levels along haul road 2.Decrease with distance from road and port 3.Mine-related deposition occurs throughout the northern half of the Monument 4.Moss patterns not attributable to subsurface geology at sample points

Summary 5.SOUTH of road Constrained by topography Lowest levels at Igichuck Hills –Deposition unlikely to occur in Kotzebue and south 6.NORTH of road Deposition extends 15 miles or more Levels not high in far north (e.g., 7-15 ppm Pb) Beyond 15 miles, source = mine-related or natural, or both

Summary Future NPS Studies (NRPP) 2005: Risk Assessment review : Small mammals along haul road Full Report Available On-line: www/nps.gov/AKSO In Press: Science of the Total Env’t Hard Copies from NPS in Kotzebue

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