This conclusion, however, has not been universally accepted by the scientific community. A recent and thorough discussion of these ongoing issues can be found in Nolan, et al. (2001). q Results of our mineralogical characterization studies, chemical leach tests, and AVIRIS mapping provide further support for the EPA and New York Department of Public Health recommendations that cleanup of dusts and the WTC debris should be done with appropriate respiratory protection and dust control measures. These results include: the presence of up to 20 volume % chrysotile in material coating steel beams in the WTC debris (which could be unintentionally released into the air as dust during cleanup); the small areas in the AVIRIS mineral maps indicating that asbestos might be found in localized concentrations in the dusts; the highly alkaline nature of the dusts; and, the presence of potentially bioavailable metals in the dusts.

No abstract

We report progress on the task "Processes in Organic-Rich Sediments of South Florida Mercury and Metals", part of the USGS-cooperative "Aquatic Cycling of Mercury in the Everglades" (ACME) project. Objectives of the task include: (1) definition of mercury and other element spatial concentration patterns and baselines, (2) definition of historical Hg and other element concentration trends in organic-rich sediments, and (3) development of an understanding of element uptake in sawgrass as it relates to element bioavailability in organic-rich sediments. The report focuses on work in Taylor Slough, Everglades National Park, because it is both the terminus of surface water flow for the eastern side of the Everglades and the main source of fresh water to the hyposaline eastern Florida Bay. Surface water, sawgrass leaf and root material, and cores of organic-rich sediments were collected in 1996 at eight sites within Taylor Slough along a predominantly north/south trend. The uppermost site was near the canal water discharge gate to the Slough and the lower two sites were within several km of Florida Bay. All samples were collected, preserved, transported and analyzed for mercury and other elements using accepted USGS QA/QC procedures and protocols. We present element concentration data for over thirty elements in the water, plant, and sediment samples collected. In addition to the cores used for element analysis, additional cores were collected at each site and used for nutrient and sulfur species studies, peat diagenesis studies, and geochronology (dating) determinations using 210Pb. The core dates and dry bulk density data were used to calculate sediment accumulation rates which were in turn used, in conjunction with the element concentration data, to calculate element accumulation rates (EAR). Very little variation in element concentration among cores was noted for the major elements. Several cores had higher Ca

Abstract.Weathering is important in the development of rock fabrics that control porosity in mine-waste materials, and in turn, porosity affects metal transport through and from mine-waste piles into watersheds. Mine-waste piles are dynamic physical and chemical systems as evidenced by remnant Fe-oxide boxwork structures after sulfide minerals, development of alteration rinds and etch pits on grains, and precipitation of secondary minerals under low temperature conditions. These microscale changes in the mine-waste materials are the result of partial to total dissolution of sulfide and other minerals.Mine-waste materials from the Dinero, Lower Chatauqua, and Saints John sites, Leadville and Montezuma mining districts, Colorado, exhibit rock fabrics that indicate that weathering products, e.g., Fe oxyhydroxides, jarosite, and clays, have been transported in suspension through the waste piles and deposited in voids and as coatings on rock fragments. Microscale characterization of weathered, partially dissolved minerals lends insight into the source of leachable metals in these mine-waste sites. Mineralogic studies show that galena in the Lower Chatauqua waste is enriched in Ag. Qualitative and semiquantitative microanalysis of weathered, altered galena grains from all three sites show that the Ag-bearing galena is more susceptible to dissolution. It is not surprising, then, that solutions experimentally leached from Lower Chatauqua waste are higher in Pb (2310 ppb) compared to leachates from the Dinero (31 ppb) and Saints John (1360 ppb) wastes.The mobility of metals is increased at acidic pH. Using the USGS Field Leach Test protocol, leachate derived from the Dinero waste has a pH of 3 and high concentrations of Al (443 ppb), Fe (441 ppb), and Zn (7970 ppb). Leachate from Sts. John tailings has a pH about 4 and high concentrations of Mn (1520 ppb), Zn (2240 ppb), and Pb (1360 ppb). Leachate from the Lower Chatauqua waste has an intermediate pH of 5, but in addition to the high Pb level already mentioned, it contains high levels of K (1.9 ppm), Mn (6720 ppb), and Zn (1550 ppb). The high concentration of metals, despite the intermediate pH of the leachate, may be explained by acidic microenvironments that exist at the surfaces of sulfide minerals, where sulfur-and iron-oxidizing microbes may flourish. It is at the reactive mineral-oxygen-water interface where metals are released and low-pH sulfate precipitates such as jarosite-beudantite form. Additional

Investigations in and near Denali National Park and Preserve (DENA), Alaska, had as their major objectives: (1) establishment of baseline information on selected native vegetation and the organic-rich Oa soil horizon of the study area; and, (2) definition of current element areal trends, if any, of the area, possibly resulting from anthropogenic influences such as power-plant emissions. These objectives were accomplished by establishing two generally east-to-west traverses (The Control and Stampede Traverses), one north-to-south Traverse (the Nenana River Traverse), and twelve additional sites at various strategic places in or near DENA. Traverse sample localities were positioned at geometric intervals starting near the existing Golden Valley Electric Association (GVEA) power-plant located in Healy. At each locality, samples were collected of Hvlocomium splendens (Hedw.) BSG (feather moss, whole plant, including rhizoids), Peltiaera aphthosa (L.) Willd. (lichen, whole plant), and the Oa soil horizon. Picea glauca (Moench) Voss. (white spruce, twigs and needles), was also collected at selected sites. All materials were analyzed for their major and trace total element concentrations. This report is the result of a cooperative study between the National Park Service (NPS) and the U. S. Geological Survey (USGS). A product of this study will be providing the information so that an assessment of the potential for any effects to the biological resources of DENA from air pollutants to be emitted from the proposed Healy Clean Coal Project (HCCP) power-plant can be made.1. Biogeochemical baseline and areal trends were assessed using an ANOVA/traverse study design. Baseline information was calculated as the observed range using the collective values for each of the three sampled media for sites beyond 6 km from the GVEA.2. Moss samples possessed a higher and more variable ash yield than lichen samples. Samples of both moss and lichen had higher and more variable ash yield along the Stampede and Nenana traverses than along the Control Traverse. All samples were washed, and loose, extraneous dust was removed. Very little overt contamination was observed; however, ash yield versus concentrations of Ti, Sc, and Al indicate that deeply imbedded, difficult to remove, dust contamination was present. We conclude, however, that the contamination would only dilute the relative concentration of environmentally important metals, not enhance their concentrations. In addition, important inverse ash yield versus distance trends occur for moss, lichen and soil on nearly all traverses, the only exception being for soil along the Control Traverse.3. Among-site variability for element concentrations in moss and soil is large, and is small for lichen, for nearly every element along every Traverse.4. Among-sample, within-site element concentration variability also appears large for moss and small for lichen (soil within-site variability was not measured). This is particularly true for samples collected within 6 km of GVEA. 5. In general, elemen...