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Earth Materials and Human Health

Project Highlights



Hurricane Katrina response

Contact — Geoff Plumlee

The flooding in the greater New Orleans area that resulted from Hurricanes Katrina and Rita in September, 2005, left behind accumulations of sediments up to many centimeters thick on streets, lawns, parking lots, and other flat surfaces. These sediments have been of concern due to their potential to contain a variety of pathogens and inorganic and organic contaminants.

EMHH project scientists proposed and have helped carry out a study that characterizes the potential environmental and health hazards of flood sediment samples from the New Orleans area. This has been a truly interdisciplinary effort with key contributions from scientists in all the USGS disciplines and regions. Samples were collected in September and October, 2005, from 25 localities in the greater New Orleans and Slidell area by colleagues from the USGS Louisiana Water Science Center. A wide variety of physical, inorganic, organic, and microbial characterization methods are being applied to the samples, with appropriate splits of the samples sent to USGS analytical facilities in Denver, CO, Reston, VA, St. Petersburg, FL, Columbia, MO, and Menlo Park, CA. Additional characterization studies are being performed on splits of the same samples by external collaborators at the Colorado School of Mines (Golden, CO), EPA National Enforcement Investigations Center (Denver), University of California—Davis, and SUNY Stony Brook, NY. The USGS characterization studies of the flood sediments are designed to produce data and interpretations to help understand how the sediments and any contained contaminants may respond to environmental processes, and to help identify potential sediment characteristics of potential concern from a health standpoint. This information will be of use to cleanup managers and DoI/USGS scientists assessing environmental impacts of the hurricanes and subsequent cleanup activities. This study's results are also being integrated with those from other ongoing USGS efforts examining water quality and the makeup of suspended sediment and bed sediment in areas of Lake Pontchartrain affected by floodwaters pumped from New Orleans.

The USGS flood sediment studies to date indicate that the sediments were derived from several different sources, and that large-scale spatial variations in sediment makeup and chemical composition across the New Orleans area reflect variable contributions from these different sources. Flood sediments in areas near marshes (Chalmette, Violet) have a high component of marsh muds with clays, 5-10 % framboidal pyrite, and siliceous diatoms. Sediments from areas close to the breached canals or lakes such as Lake Pontchartrain (Lakeview, Rigolets, nearshore Slidell) have abundant clays, diatoms, and sandy material, but generally smaller amounts of pyrite, indicating they were derived from remobilized lake-bottom sediments and materials eroded from the levees. In contrast, samples from downtown New Orleans are composed of mud and sand-sized material with no pyrite but more abundant particles of urban construction and commercial materials such as soda lime glass, glass fibers, concrete, nails, and glass jewelry beads. The downtown New Orleans samples typically have substantially higher levels of metals such as lead, zinc, mercury, copper, arsenic, and cadmium than the samples dominated by lake-bottom or marsh mud. For many of these elements, concentrations at some sites can exceed EPA or soil quality criteria. Lead concentrations, for example, range from 95 to 2160 parts per million (ppm) in the downtown samples, with most having levels above 500 ppm; simulated gastric fluid leaches of these samples indicate that the lead can be quite bioaccessible. Downtown New Orleans flood sediment samples are also enriched in a variety of organic chemicals (such as polycyclic aromatic hydrocarbons, PAH) compared to the flood sediments dominated by lake-bottom or marsh muds. Similar spatial patterns of lead and PAH enrichments between the Katrina flood sediment samples and urban New Orleans soil samples collected and analyzed in the late 1990's and early 2000's by H.W. Mielke, Xavier University, suggest that the Katrina flood sediments in the downtown New Orleans area are likely dominated by reworked local soil material having pre-existing elevated metal and organic concentrations. There are localized areas of metal or organic contamination in flood sediments outside the downtown area, such as near an oil refinery that had a hurricane-related spill; however, these areas appear to be rather restricted in occurrence and extent.

USGS tests indicate that flood sediments dominated by pyrite-rich marsh mud have a substantial potential to generate acid drainage as the contained pyrite weathers. Therefore, flood sediments containing high levels of iron sulfides and low levels of carbonate minerals might best be considered as candidates for disposal into water-covered disposal areas or disposal facilities isolated from the atmosphere and rainfall.

USGS study results have been and will continue to be transmitted by the LA Water Science Center Director (Charlie Demas) to on-scene cleanup managers with the EPA and LA Dept. of Environmental Quality (LDEQ). Initial results were released to EPA Region VI and the LDEQ in November. A progress report for the effort was released as USGS Open-File Report 2006-1023 (http://pubs.usgs.gov/of/2006/1023/).


Report released on naturally occurring asbestos in the Eastern United States

Contact — Brad Van Gosen

In the past, most asbestos-related medical research and regulatory focus has been on the health effects of asbestos used industrially or commercially. However, there have been increasing concerns recently regarding the potential health effects of naturally-occurring asbestos (NOA), which occurs as an accessory mineral in some rocks (for example, tremolite in metamorphosed magnesium-rich carbonate rocks, chrysotile and amphibole asbestos in ultramafic rocks), or as an impurity in some other industrial minerals (for example, amphibole asbestos intergrown with vermiculite mined at Libby, Montana). For example, a recently released study in the American Journal of Respiratory Medicine found a significant statistical correlation between mesothelioma occurrences in California residents living in proximity to ultramafic rock bodies.

As part of the project's ongoing effort to update existing national-scale databases on asbestos occurrences, USGS Open-File Report 2005-1189 was released on July 1, 2005. The report contains a map and accompanying database that provide information for 324 natural asbestos occurrences of many sizes in the Eastern United States (U.S.), using descriptions found in the geologic literature. These asbestos occurrences range in size from small veins to large ore bodies once mined for commercial and industrial uses. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided in the database. Using the map and digital data in the report, the user can examine the distribution of previously reported asbestos occurrences and their characteristics in the Eastern U.S. This report is intended to provide geologic information that can be used by State and local officials and other stakeholders as the first step of the multi-step processes required to evaluate possible environmental exposures to natural occurrences of asbestos. The report also provides public health specialists with improved geological information that may be used in the interpretation of regional and national scale epidemiological data on the occurrences of asbestos-related diseases.

The following web sites provide excellent information on asbestos health effects and ways to reduce exposure to naturally occurring asbestos:


Report released on remote sensing identification and mapping of potential asbestos-forming minerals in serpentite-bearing rocks of El Dorado and Plumas Counties, California

Contact — Gregg Swayze

Project scientists have been working in collaboration with geologists from the California Geological Survey to determine if remote sensing techniques can be used to identify and map the distribution of potentially asbestos-forming minerals in rocks in El Dorado and Plumas Counties, California. Airborne Visible/InfraRed Imaging Spectrometer (AVIRIS) data were collected in approximately 3-kilometer-wide swaths over selected areas of the counties that are underlain by serpentinite and ultramafic rocks. Mineral maps created from the AVIRIS data were used successfully (as shown by extensive field checking) to delineate exposures of serpentine and tremolite-actinolite/talc in areas with up to 70 percent vegetation cover in some cases. The maps also delineated serpentine rocks on roads surfaced with serpentinite aggregate that are well outside areas of serpentinite rock outcrops.

Results of the study were released in late 2004 as USGS Open-File Report 2004-1304 and California Geological Survey Geologic Hazards Investigation 2004-01.


USGS activities tied to the EPA World Trade Center Technical Expert Review Panel

Contact — Greg Meeker

As a result of the USGS work on the World Trade Center dusts, and as a result of his expertise in asbestos analytical methodologies, EMHHP scientist and co-chief, Greg Meeker was invited to participate in 2003 in the US EPA's World Trade Center Technical Expert Review Panel. This panel is addressing concerns of local stakeholders regarding the assessment of potential dusts remaining in lower Manhattan buildings from the 2001 WTC collapse. As part of this work, the USGS was asked to take the lead in helping to develop analytical methods and standards that would enable the detection and measurement of trace levels of WTC dusts that may remain in lower Manhattan buildings. The results to date have been summarized in two USGS Open-File Reports, available at http://pubs.usgs.gov/of/2005/1165/ and http://pubs.usgs.gov/of/2005/1031/.


Four papers published in the American Chemical Society Special Volume on the World Trade Center collapse

Contact — Greg Meeker

Results of interdisciplinary USGS studies of the World Trade Center area after 9-11-2001 are currently being published as 4 papers in a special volume by the American Chemical Society: Gaffney, J.S., and Marley, N.A., eds., Urban Aerosols and Their Impacts: Lessons Learned from the World Trade Center Tragedy, American Chemical Society Book Series 919, Oxford University Press. The 4 USGS papers cover: environmental mapping of the WTC area; spectroscopic and x-ray diffraction analysis of asbestos in the WTC dust; materials characterization of the WTC dusts; and, the inorganic chemical composition and chemical reactivity of the WTC dusts.


Rapid response characterization of ash and other eruptive products from the 2004-2005 Mount St. Helens eruptions

Contacts — Geoff Plumlee and Greg Meeker

The EMHH project has worked with USGS volcanologists at the Cascades Volcano Observatory to provide extensive rapid characterization of volcanic ash and other eruptive products from the recent 2004 and 2005 Mt. St. Helens eruptions. Analyses include: extensive Scanning Electron Microscope (SEM) and Electron Probe Microanalysis (EPMA) of the materials; particle size analysis of ash; characterization of ash from a human health perspective; water leach tests to determine amounts of volcanic gas species adsorbed onto the ash; and (in cooperation with the Hydrothermal Alteration on Cascades Volcanoes project) identification of hydrothermal alteration in the rocks of the new dome forming in the Mt. St. Helens crater. In part as a result of this work, project scientist Geoff Plumlee was invited to give a talk as part of a panel discussion at the American College of Chest Physicians annual meeting in November on Health Impacts of Volcanic Ash.

For further information on the Mt. St. Helens 2004-2005 eruptions, see the Cascades Volcano Observatory Mt. St. Helens web site.


Characterization of lead-bearing mine wastes and edible soils from Kabwe, Zambia

Contact — Geoff Plumlee

In late May, 2005, the USGS and EPA (National Enforcement Investigations Center - NEIC) hosted in their Denver lab facilities a delegation of environmental scientists from the Zambian Copperbelt Environment Project (ZCEP) and World Bank. EMHH project scientists presented preliminary results of USGS characterization studies of mine wastes, mining-affected soils and edible soils from Kabwe, Zambia. Kabwe was one of southern Africa's dominant producers of lead and zinc for nearly a century until the mines closed in 1994. Concerns have developed since the mines' closure regarding blood lead poisoning and other health effects resulting from exposure to mining and mineral processing wastes, and soils affected by these wastes (UN-IRIN, 2005). An assessment of the potential health and environmental issues at Kabwe is currently being overseen by the ZCEP) and World Bank. ZCEP and funded by the World Bank. To complement the ongoing assessment, EMHHP scientists were asked to characterize a limited number of samples of mining and mineral processing wastes, soils, and other materials from Kabwe to understand their mineralogical makeup, chemical reactivity, and metal bioaccessibility. Included in the materials analyzed was a set of edible soils purchased by a World Bank contractor from the local Kabwe market; these soils are sold for consumption, primarily by pregnant women following the custom of geophagia. Apparently, some of the edible soil products are obtained from soils local to the Kabwe area.

USGS results found that many of the mine waste samples and mining-affected soil samples analyzed contained very high levels of lead (nearly all greater than 1100 ppm, and one sample as high as 18 % lead). Other heavy metals or metalloids were also found in high levels in some or most of the samples, including cadmium, zinc, copper, vanadium, arsenic and mercury. Analyses of the edible soils indicated lead levels in several reach as high as 1500 ppm. Geochemical leach tests, using simulated gastric fluids, show that the lead in general is highly soluble, both in the mining-related samples and in the edible soils with high total lead concentrations. Leach tests indicate that, in addition to lead, metals such as cadmium, vanadium, manganese, and aluminum can also be quite soluble in water, simulated lung fluids, and simulated gastric fluids. Lead is highly bioaccessible in the Kabwe samples because it is hosted mineralogically by lead carbonates and iron oxides that are highly soluble in simulated gastric fluids.

The USGS results indicate that lead and a variety of other potentially toxic elements should continue to be evaluated as part of biomonitoring and health assessment programs at Kabwe. The results also indicate that at least some edible soils consumed by local residents may be a potential source of lead exposure.

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