USGS identifier

Science Goals

Goal 6--Interpret the links between human health and geologic processes

It is widely recognized that some aspects of human health can be affected by geologic materials and processes. Once released, toxic substances can be circulated and concentrated by geologic processes through a range of sensitive environments and are commonly incorporated into food chains, increasing the risks to human health. GD studies in cooperation with health experts have already contributed to the understanding of these effects and demonstrate the need for expanded research efforts in this area. For example, GD scientists were among the first to recognize that not all mineralogical forms of asbestos lead to increased incidences of cancer in humans, and GD scientists are currently helping to understand the origin of acidic volcanic fog in Hawaii (see Highlight 13). Earth science research can also identify how geologic processes transport and store substances that are toxic to humans (see Highlight 14), including both naturally occurring materials and those produced by human activities. By understanding these processes, improved strategies for pollution prevention, mitigation, and remediation can be developed.

Research linking geologic processes to human health and environmental pollution will continue to grow in scope and societal impact. Interpreting the links between geology and human health will provide major research opportunities and challenges for GD scientists and their cooperators. Research will continue in traditional earth science areas, such as examining geologic and geochemical processes that control contaminant source, transport, and fate in the environment and establishing natural baseline concentrations of potential toxins in soils, sediments, rocks, and plants. Significant scientific advancements will also result from increased collaboration between GD scientists and specialists from the medical and biological communities, such as other Federal agencies (EPA, the National Institutes of Health, and the Agency for Toxic Substances and Disease Registry), State health agencies, medical societies, and other USGS divisions. Earth scientists can provide crucial geological and geochemical insights into epidemiological studies examining the elevated regional occurrences of some diseases. For example, outbreaks of valley fever in the Los Angeles area resulting from earthquake-generated dust clouds underscore the need for input from earth scientists in understanding the potential controls of soil and rock type on some pathogenic illnesses.


Lay-oriented and publicly accessible summaries of the geology, geochemistry, and health effects of selected potentially toxic elements, mineral phases, and organic compounds.
In cooperation with appropriate health experts and agencies, GD scientists will prepare these summaries of potentially toxic substances, which can include data on their distribution in the environment as a function of geology, climate, and ecosystem; their natural concentration ranges in rocks, soils, sediments, ground and surface waters, and plants; their geoavailability (the ease with which they are liberated into the environment from earth materials); important geochemical and sedimentological processes that control their environmental mobility and degradation; and their potential health effects on humans, animals, aquatic species, and plants.

Nationally consistent, regional-scale environmental geology and geochemistry data bases and maps.
GD scientists will produce environmental geology maps depicting the distribution of rock types likely to produce, through natural weathering or anthropogenic enhancement of weathering, elevated levels of potentially toxic elements such as selenium, arsenic, and uranium. The GD will also prepare geochemical maps delineating, as a function of geologic terrane and climate, the measured or inferred natural baseline concentrations (and, where possible, the environmental availability) of selected toxic elements in rocks, soils, sediments, and plants. These maps will be based upon data included in a variety of data bases such as the USGS national geochemical data base and the coastal contaminated sediment data base for Atlantic and Gulf coasts, prepared in cooperation with the EPA.

Integrated geological, geochemical, and biological assessments of regions where contaminated sediments may accumulate.
These regions include selected lacustrine, estuarine, and coastal areas (for example, Massachusetts Bay). In making these assessments, GD scientists will collect and interpret data and develop models that can predict, for a variety of environments and contaminants, the physical transport and deposition of contaminated sediments, the potential release of contaminants from sediments to the water column, and the incorporation of contaminants from sediments and the water column into the food chain.

National and (or) regional, geology-based health assessments.
Similar to past GD assessments of radon, these assessments should evaluate the potential for a variety of health effects tied to geologic factors, such as the health effects of naturally elevated concentrations of heavy metals in certain rock terranes. The assessments can also evaluate the potential for various rock and soil types to foster pathogen colonies, as well as the potential for various earth processes such as landslides and earthquakes to release the pathogens into the environment.

Strategic Actions

Increase cooperative research efforts with specialists in human health, toxicity, epidemiology, and other life sciences.
GD scientists will collaborate with these specialists to examine the integrated role of geochemical and biological processes in controlling contaminant transport, fate, uptake, and health effects.

Continue research on the geologic occurrence, geoavailability, environmental mobility and degradation, and health effects of potential toxins.
GD scientists will conduct process-oriented studies on these factors for potentially toxic elements, minerals, and naturally occurring organic compounds.

Determine the transport mechanisms and ultimate fate of sediment-associated contaminants.
The GD will study sediment-associated contaminants that are transported through rivers to estuaries and coastlines and will establish sediment distribution and transport directions for selected offshore coastal waters of the United States

Understand the role of geology and geologic processes in the development and release of potential pathogens.
GD scientists will evaluate the role of factors such as parent rock composition, mineralogy, and soil type in fostering pathogen development and will examine the potential for various geologic processes, such as earthquakes and landslides, to release pathogenic material into the environment.

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Last updated 04.08.98