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At least 235 records · Page 13Linked to original sources

The world's largest floods, past and present: Their causes and magnitudes

Floods are among the most powerful forces on earth. Human societies worldwide have lived and died with floods from the very beginning, spawning a prominent role for floods within legends, religions, and history. Inspired by such accounts, geologists, hydrologists, and historians have studied the role of floods on humanity and its supporting ecosystems, resulting in new appreciation for the many-faceted role of floods in shaping our world. Part of this appreciation stems from ongoing analysis of long-term streamflow measurements, such as those recorded by the U.S. Geological Survey's (USGS) streamflow gaging network. But the recognition of the important role of flooding in shaping our cultural and physical landscape also owes to increased understanding of the variety of mechanisms that cause floods and how the types and magnitudes of floods can vary with time and space. The USGS has contributed to this understanding through more than a century of diverse research activities on many aspects of floods, including their causes, effects, and hazards. This Circular summarizes a facet of this research by describing the causes and magnitudes of the world's largest floods, including those measured and described by modern methods in historic times, as well as floods of prehistoric times, for which the only records are those left by the floods themselves.

Circular

Epistylis spp. infestation in two species of mud turtles (Kinosternon spp.) in the American Southwest

The protistan genus Epistylis contains freshwater colonial species that attach to aquatic organisms in an epibiotic or parasitic relationship. They are known to attach to the epidermis and shells of aquatic turtles, but have not been reported to cause heavy infestations or morbidity in turtles. We documented heavy infestations of Epistylis spp. in several populations of Sonoran mud turtles ( Kinosternon sonoriense ) inhabiting livestock ponds in Arizona, USA, and rough-footed mud turtles ( Kinosternon hirtipes ) from livestock ponds in Texas, USA, over the course of several years. Severe Epistylis spp. infestations on mud turtles appeared to alter diving and swimming behavior when compared to uninfested conspecifics. Infestations were cleared in captivity using tap water or a 10% salt solution, and the turtles had no permanent damage to their shell or epidermis upon clearing. While several of the mud turtles we observed had poor body condition, it is possible that the severe infestations we observed were caused by a comorbidity associated with a pathogen, parasite, or poor habitat quality that made the turtles more susceptible to the Epistylis spp. infestation. Further research on causes for these severe infestations are warranted because they contribute to changes in behavior of the heavily infested turtles and may contribute to morbidity in Kinosternon spp. when mud turtles inhabit extremely warm, shallow, eutrophic aquatic habitats, such as livestock ponds.

Arizona

An exploration of Bureau of Reclamation approaches for managing conflict over diverging science

As a major institutional agent supplying Western water resources, the Bureau of Reclamation (Reclamation) provides important leadership, technical, and financial resources in water management, serving as the West's "water broker" (Bowersox 2000; Pisani 2003). In recent years, growing numbers of constituencies using water and the over-allocation of water resources have contributed to conflict over the resource in the American West (National Research Council 2004). Although the conflicts arise from many sources, one common theme is that Reclamation managers often must make decisions about water use and allocation when scientific studies provide uncertain or competing recommendations. We conducted a preliminary study of Reclamation water managers and water scientists to try to understand the approaches or techniques they use or consider useful for dealing with scientific conflicts over water allocation and how these compare to techniques found in the relevant literature. We report the results of (1) an electronic survey of Reclamation senior managers and (2) a panel discussion amongst Reclamation senior managers as to the current institutional capabilities for managing diverging scientific findings in water dispute resolution processes. We conclude with a discussion of the strengths and weaknesses of the different tools and techniques managers reported in the survey and in the panel discussion.

Technical Memorandum

USGS supports ecosystem management in the San Francisco bay and delta

In the past several years, the Department of the Interior has ,l?laced particular emphasis on "ecosystem management" - the integration of scientific knowledge of ecological relationships with resource management practices to sustain ecological, cultural, and economic systems in broad habitat areas; eg., forest, desert, and aquatic habitats. The goal of ecosystem management is to understand the habitat requirements of many species and thereby assess the impact of a variety of human activities on regional biodiversity rather than to manage for individual species. In support of the management of the natural resources of San Francisco Bay and the delta, the USGS is augmenting its ongoing research program to provide additional research, monitoring, and assessment information and to improve the availability of that information. Following a workshop with resource and regulatory agency representatives, hosted by the USGS in early 1994, USGS researchers identified specific areas where existing and new scientific information could contribute to resolving some of the critical bay and delta land and aquatic management issues. The "ecosystems initiative" effort now underway addresses questions in three areas: Freshwater flow, including sediment and contaminant transport. Wetlands. Information and data access. Following is a brief description of activities being supported by this initiative.

Interagency Ecological Program Newsletter

Layered intrusions in the Precambrian: Observations and perspectives

Layered intrusions are plutonic bodies of cumulates that form by the crystallization of mantle-derived melts. These intrusions are characterized by igneous layering distinguishable by shifts in mineralogy, texture, or composition. Layered intrusions have been fundamental to our understanding of igneous petrology; however, it is their status as important repositories of critical metals – such as platinum-group elements, chromium, and vanadium – that has predominantly driven associated research in recent decades. Many layered intrusions were emplaced during the Precambrian, predominantly at the margins of ancient cratons during intervals of supercontinent accretion and destruction. It appears that large, layered intrusions require rigid crust to ensure their preservation, and their geometry and layering is primarily controlled by the nature of melt emplacement. Layered intrusions are best investigated by integrating observations from various length-scales. At the macroscale, intrusion geometries can be discerned, and their presence understood in the context of the regional geology. At the mesoscale, the layering of an intrusion may be characterized, intrusion-host rock contact relationships studied, and the nature of stratiform mineral occurrences described. At the microscale, the mineralogy and texture of cumulate rocks and any mineralization are elucidated, particularly when novel microtextural and mineral chemical datasets are integrated. For example, here we demonstrate how mesoscale observations and microscale datasets can be combined to understand the petrogenesis of the perplexing snowball oiks outcrop located in the Upper Banded Series of the Stillwater Complex. Our data suggest that the orthopyroxene oikocrysts did not form in their present location, but rather formed in a dynamic magma chamber where crystals were transported either by convective currents or within crystal-rich slurries. Critical metals may be transported to the level of a nascent intrusion as dissolved components in the melt. Alternatively, ore minerals are entrained from elsewhere in a plumbing system, potentially facilitated by volatile-rich phases. There are many ore-forming processes propounded by researchers to occur at the level of emplacement; however, each must address the arrival of the ore mineral, its concentration of metals, and its accumulation into orebodies. In this contribution, several of these processes are described as well as our perspectives on the future of layered intrusion research.

Precambrian Research

Ungulate personality and the human shield contribute to long-distance migration loss

Long-distance ungulate migrations are declining and past research has focused on preserving migration paths where habitat fragmentation and loss disrupts movement corridors. However, changing residency-migration tradeoffs are the stronger driver of long-distance migration loss in some populations. The human shield effect relative to predation risk and anthropogenic food resources likely shapes these tradeoffs, but individual animals also vary in their propensity to tolerate proximity to humans and developed areas. We investigated how personality relative to human-habituation affects migration behavior. We categorized elk as bold or shy based on use of anthropogenic food resources identified through a clustering algorithm applied to GPS collar data. Bold elk were 4 times more likely to select wintering areas close to human activity and migrated 60% shorter distances compared to shy elk. As a result, elk wintering grounds were spatially structured such that conflict- and disease-prone individuals selected areas adjacent to human activity. Our results suggest that bold personality traits act as a precursor to human-habituation, which permits bold elk to reap the forage and predation rewards that occur in suburban landscapes. A multi-pronged approach beyond just maintaining habitat corridors may be necessary to conserve long-distance migrations for species that can become human-habituated.

BioRxiv

Integrating hydrology and biogeochemistry across frozen landscapes

Research has traditionally focused on atmospheric release of carbon from thawing permafrost, yet overlooked waterborne release pathways likely contribute significantly, especially in a warming Arctic. To address this knowledge gap and better constrain the fate of carbon in the North, we recommend inter-disciplinary efforts bridging physical, chemical and computational research.

Nature Communications

Population-specific life histories contribute to metapopulation viability

Restoration efforts can be improved by understanding how variations in life-history traits occur within populations of the same species living in different environments. This can be done by first understanding the demographic responses of natural occurring populations. Population viability analysis continues to be useful to species management and conservation with sensitivity analysis aiding in the understanding of population dynamics. In this study, using life-table response experiments and elasticity analyses, we investigated how population-specific life-history demographic responses contributed to the metapopulation viability of the Federally threatened Pitcher's thistle ( Cirsium pitcheri ). Specifically, we tested the following hypotheses: (1) Subpopulations occupying different environments within a metapopulation have independent demographic responses and (2) advancing succession results in a shift from a demographic response focused on growth and fecundity to one dominated by stasis. Our results showed that reintroductions had a positive contribution to the metapopulation growth rate as compared to native populations which had a negative contribution. We found no difference in succession on the contribution to metapopulation viability. In addition, we identified distinct population-specific contributions to metapopulation viability and were able to associate specific life-history demographic responses. For example, the positive impact of Miller High Dunes population on the metapopulation growth rate resulted from high growth contributions, whereas increased time of plant in stasis for the State Park Big Blowout population resulted in negative contributions. A greater understanding of how separate populations respond in their corresponding environment may ultimately lead to more effective management strategies aimed at reducing extinction risk. We propose the continued use of sensitivity analyses to evaluate population-specific demographic influences on metapopulation viability. In understanding the underlying causes of the projected extinction probabilities of each population and identifying broad-scale contributions of different populations to the metapopulation, the process of pinpointing target populations is simplified. More detailed analyses can then be applied to the target populations to increase population viability and consequently metapopulation viability. Based on our research, we suggest that the best approach to improve the overall metapopulation viability is to manage the contributions to population growth for each population separately.

Ecosphere

Species management research program [postcard]

Executive Summary Our nation’s fish and wildlife species face increasingly complex threats and challenges. Ensuring a healthy future for these species benefits all Americans, contributing to the abundance of our food supply, the well-being of diverse cultures and communities, and the future of biodiverse ecosystems. The U.S. Geological Survey Species Management Research Program (SMRP) plays a critical role in achieving that future by delivering targeted research and foundational scientific services needed to conserve fish and wildlife in a changing world.

General Information Product

Young (<7 Ma) gold deposits and active geothermal systems of the Great Basin: Enigmas, questions, and exploration potential

Young gold systems in the Great Basin (£ 7 Ma), though not as well studied as their older counterparts, comprise a rapidly growing and in some ways controversial group. The gold inventory for these systems has more than doubled in the last 5 years from roughly 370 tonnes (12 Moz) to 890 tonnes (29 Moz). Although these deposits are characterized by low grades, tonnages can be high and stripping ratios low, and they have been mined profitably, as exemplified by Florida Canyon and Hycroft. Active geothermal systems in the Great Basin also comprise a rapidly growing group, as evidenced by a number of recent discoveries of geothermal groundwater and a more than 50% increase in electricity production capacity from these systems in the last 5 years. Many young gold deposits are closely associated with active geothermal systems, suggesting that gold deposits may be forming today in the Great Basin. Measured or estimated geothermal reservoir temperatures commonly approach or exceed 200∞C, and other characteristics and processes (advanced argillic caps, hydrothermal eruption breccias) of these young deposits resemble those of nearby Tertiary precious metal deposits. Nonetheless, many young gold systems, especially in Nevada, are not associated with coeval igneous rocks. Similarly, almost all electricity-grade geothermal systems in Nevada are not associated with Quaternary silicic volcanic rocks, and have lower temperature gradients, lower 3He/4He ratios, and lower dissolved trace element concentrations than most magmatic-heated geothermal systems elsewhere in the world. The increasing economic significance of young gold deposits and active geothermal systems justifies more research to better understand their origins, particularly because in some aspects they remain enigmatic and controversial. Are young gold deposits in Nevada truly amagmatic, or have they received metal and fluid contributions from magmas deeper within the crust? Has gold in these deposits been remobilized from older gold mineralization? Current research is investigating these and other questions to improve our genetic understanding of these young gold systems, which in turn can lead to improved exploration targeting. The recent rapid growth in resources for both young gold deposits and geothermal systems underscores their underdeveloped exploration potential. Even though many young gold deposits exhibit relatively shallow hot-springs-style mineralization, their young age may preclude exposure by erosion. Uplift along active normal faults has exposed some deposits (e.g., Florida Canyon, Dixie Comstock, Wind Mountain), but in other areas, such as the Walker Lane, where strike-slip faulting is prevalent, the opportunities for exposure can be limited. Many active geothermal systems are also concealed below the surface in that hot springs or steam vents may be absent above areas of thermal groundwater. With sources of energy to support mine production becoming more problematic, the potential advantages of simultaneously exploring for young gold deposits and spatially associated geothermal systems are becoming more apparent. Exploration methods recently proven effective in geothermal exploration that can be adapted to gold exploration include temperature surveys, hyperspectral remote sensing, geophysical surveys, water analyses, and detailed mapping of geothermal-related features and related fault systems.

Conference Paper

Scientific integrity issues in environmental toxicology and chemistry: Improving research transparency, reproducibility, and credibility

High‐profile reports of detrimental scientific practices leading to retractions in the scientific literature contribute to lack of trust in scientific experts. Although the bulk of these have been in the literature of other disciplines, environmental toxicology and chemistry are not free from problems. While we believe that egregious misconduct such as fraud, fabrication of data, or plagiarism is rare, scientific integrity is much broader than the absence of misconduct. We are more concerned with more commonly encountered and nuanced issues such as poor reliability and bias. We review a range of topics including conflicts of interests, competing interests, some particularly challenging situations, reproducibility, bias, and other attributes of ecotoxicological studies that enhance or detract from scientific credibility. Our vision of scientific integrity encourages a self‐correcting culture that promotes scientific rigor, relevant reproducible research, transparency in competing interests, methods and results, and education.

Integrated Environmental Assessment and Management

Southern California and range‐wide raccoon gastrointestinal helminth database

Local and global measurements of parasite prevalence and abundance are critical for understanding the dynamics that underlie the diversity, distribution, and evolution of infectious diseases. Here, we present a data set of gut helminths found in (1) raccoons throughout their range, based on primary literature from 1925–2017 and (2) raccoons in Santa Barbara County, California, USA surveyed from 2012 to 2015. The range‐wide data set has 1,256 parasite entries from 217 literature sources across three continents and 32 states in the USA. This data set includes a list of all recorded raccoon gut helminths (n = 100) and their presence and prevalence in surveyed raccoon populations. The Santa Barbara data set includes gut helminth data from 182 raccoons from one Southern California County. In addition to the presence and abundance data for 13 parasite species, this data set includes measurements of 7,465 individual raccoon roundworms (Baylisascaris procyonis). For both range‐wide and Santa Barbara data sets, we include information on parasite site of infection in host, sampling method, and sample size. We also provide geographic coordinates for infected raccoon populations (range‐wide database) and individuals (Santa Barbara). In the associated metadata, we include sampling methods and summary figures for both the range‐wide and Santa Barbara raccoon gut helminth records. There are no copyright or proprietary restrictions for research and/or teaching purposes. S. B. Weinstein and J. C. Van Wert contributed equally to this manuscript and are shared first authors.

California

Physiological tolerances of juvenile robust redhorse, Moxostoma robustum: Conservation implications for an imperiled species

The robust redhorse, Moxostoma robustum (Teleostei: Catostomidae), is an imperiled sucker native to large rivers of the Atlantic slope of the southeastern United States. Juvenile M. robustum were tested for tolerances to temperature, salinity, pH, and hypoxia in order to evaluate basic early life-history requirements. Static (acute) tests resulted in estimates of mean lower temperature tolerances (5.3-19.4 ??C) that varied with prior thermal acclimation and indicated no apparent difference in tolerance among fish 30, 60, and 90 days old. Fish acclimated to 20 ??C and 30 ??C had significantly different mean critical thermal maxima (34.9 ??C and 37.2 ??C, respectively) and exhibited pronounced increased opercular ventilation rates with elevated temperatures. Fish exposed to acute and chronic increases in salinity showed unusual patterns of mortality above the isosmotic point (9 ppt) that reflected possible differences in body mass and prior acclimation conditions (i.e., water ionic composition); small fish and those held in soft water were the least tolerant of increased salinity. Abrupt exposure to extreme pH values resulted in greater than 50% mortality at pH values below 4.3 and above 9.5 within a 96-hour period. Fish exposed to progressive hypoxia utilized aquatic surface respiration at a mean oxygen concentration of 0.72-0.80 mg O2 l-1 (20 ??C and 30 ??C acclimated fish, respectively), and lost equilibrium at 0.54-.57 mg O2 l-1. Juvenile M. robustum are moderately tolerant of a wide range of ambient physicochemical parameters, but further research is needed to determine how both abiotic and biotic factors have contributed to population decline and extirpation of this species.

Environmental Biology of Fishes

North American wintering mallards infected with highly pathogenic avian influenza show few signs of altered local or migratory movements

Avian influenza viruses pose a threat to wildlife and livestock health. The emergence of highly pathogenic avian influenza (HPAI) in wild birds and poultry in North America in late 2021 was the first such outbreak since 2015 and the largest outbreak in North America to date. Despite its prominence and economic impacts, we know relatively little about how HPAI spreads in wild bird populations. In January 2022, we captured 43 mallards ( Anas platyrhynchos ) in Tennessee, USA, 11 of which were actively infected with HPAI. These were the first confirmed detections of HPAI H5N1 clade 2.3.4.4b in the Mississippi Flyway. We compared movement patterns of infected and uninfected birds and found no clear differences; infected birds moved just as much during winter, migrated slightly earlier, and migrated similar distances as uninfected birds. Infected mallards also contacted and shared space with uninfected birds while on their wintering grounds, suggesting ongoing transmission of the virus. We found no differences in body condition or survival rates between infected and uninfected birds. Together, these results show that HPAI H5N1 clade 2.3.4.4b infection was unrelated to body condition or movement behavior in mallards infected at this location during winter; if these results are confirmed in other seasons and as HPAI H5N1 continues to evolve, they suggest that these birds could contribute to the maintenance and dispersal of HPAI in North America. Further research on more species across larger geographic areas and multiple seasons would help clarify potential impacts of HPAI on waterfowl and how this emerging disease spreads at continental scales, across species, and potentially between wildlife and domestic animals.

Tennessee

Worldwide Asbestos Supply and Consumption Trends from 1900 through 2003

This Circular updates and supersedes U.S. Geological Survey (USGS) Open-File Report 03–083, "Worldwide Asbestos Supply and Consumption Trends from 1900 to 2000," with the addition of supply and consumption estimates and analysis from 2001 through 2003 and revisions to the consumption estimates for 1998 through 2000. The text from Open-File Report 03–083 also has been updated in this Circular to include revisions to and expansion of the time-series coverage. The use of asbestos is one of the most controversial issues surrounding the industrial minerals industry. Its carcinogenic nature, an overall lack of knowledge of minimum safe exposure levels, its widespread use for more than 100 years, and the long latency for the development of lung cancer and mesothelioma are the main contributing factors to these controversies. Another factor is that, despite decades of research, the mechanisms responsible for its carcinogenic properties are still largely unknown. The United States produced about 3.29 million metric tons (Mt) of asbestos and used approximately 31.5 Mt between 1900 and 2003. About half of this amount was used after 1960. In 2002, the last asbestos mine in the United States closed, marking the end of more than 110 years of U.S. asbestos production. Cumulative world production from 1900 through 2003 was about 181 Mt. If one assumes that unusually large stocks were not maintained and that world consumption roughly equaled production, then about half of the world production and consumption occurred between the end of 1976 and the end of 2003. The United States and Western European nations were the largest consumers of asbestos during the first two-thirds of the 20th century. They were surpassed by the collective production and consumption of Kazakhstan and Russia by the 1970s. After the onset of the health issues concerning asbestos in the late 1960s and early 1970s, the decline in world production and consumption began to be evident in the late 1970s and early 1980s. The 1991 breakup of the Soviet Union, a major user of asbestos, resulted in a significant decline in asbestos consumption and production in former Soviet-bloc countries. Consumption and production in Kazakhstan and Russia increased through 2003 from 2001, albeit to a much lower level than in the 1980s. In 2003, world consumption was estimated to be 2.11 Mt, about 45 percent that of 1980. Relatively few countries in Asia, the Middle East, South America, and the former Soviet Union remained as the leading users of asbestos. China was the leading consuming nation, using an estimated 492,000 metric tons (t) in 2003. China was followed, in decreasing order of consumption, by Russia (429,000 t), India (192,000 t), Kazakhstan (174,000 t), Ukraine (156,000 t), Thailand (133,000 t), Brazil (78,400 t), and Iran (75,800 t). These eight countries accounted for 82 percent of the world's apparent consumption in 2003. Following Iran, in decreasing order of consumption by tonnage, were Uzbekistan (42,400 t), Vietnam (39,400 t), Indonesia (32,300 t), the Republic of Korea (23,800 t), Kyrgyzstan (23,700 t), Japan (23,400 t), and Mexico (20,100 t). Consumption in all other countries was estimated to be less than 15,000 t each in 2003. Sizable consumption increases occurred in Azerbaijan, China, India, Iran, Kazakhstan, Thailand, and Ukraine between 2000 and the end of 2003. Consumption patterns in countries using less than 5,000 t per year were too erratic to ascertain any trends in their use of asbestos.

Circular

Summary of selenium in the lower Gunnison River Basin, Colorado—Information and data gaps

The Cretaceous Mancos Shale is a geologic source of selenium in the lower Gunnison River Basin. Natural weathering processes and human activity mobilize selenium from the Mancos Shale and derived materials, and surface water, groundwater, and sediment all affect the transport of selenium from source areas to receiving streams and biota. Selenium accumulates through the aquatic food chain, and its toxic effects can result in invertebrate mortality and mortality, decreased reproduction, and deformities to fish and birds. The Bureau of Reclamation, in cooperation with the State of Colorado and Gunnison River Basin water users, is implementing a Selenium Management Program to reduce selenium concentrations in the lower Gunnison River Basin of Colorado. Goals of the Selenium Management Program are to (1) achieve compliance with the State of Colorado chronic aquatic-life standard for dissolved selenium (4.6 micrograms per liter) in the Gunnison River near Grand Junction, Colorado; (2) sufficiently improve water-quality conditions to assist in the recovery of endangered species in the Gunnison and Colorado Rivers by reducing selenium concentrations; and (3) support continued water uses in the basin. Many previous studies have contributed to the understanding of selenium in the environment; however, monitoring and research data gaps exist in the lower Gunnison River Basin. The purpose of this report is to summarize information regarding selenium in the lower Gunnison River Basin and describe strategies for scientific research and monitoring to potentially improve understanding of selenium sources; processes affecting the mobilization, transport, and fate of selenium; and the effects of selenium-mitigation projects in the lower Gunnison River Basin. Monitoring and research data gaps discussed in this report include geologic mapping and geochemical source characterization, long-term and ongoing monitoring of the surface-water and groundwater networks, developing and refining statistical models, characterizing selenium on suspended sediment, modeling selenium in the food web, evaluating best management practices, and more.

Colorado

Chinese tallow: Invading the southeastern Coastal Plain

Chinese tallow is an ornamental tree with colorful autumn foliage that can survive full sunlight and shade, flooding, drought, and in some cases fire. To horticulturists this kind of tree sounds like a dream, but to ecologists, land managers, and land owners this kind of tree can be a nightmare, especially when it invades an area and takes over native vegetation. Chinese tallow ( Triadica sebifera ), a nonnative tree from China, is currently transforming the southeastern Coastal Plain. Over the last 30 years, Chinese tallow has become a common tree in old fields and bottomland swamps of coastal Louisiana. Several studies at the U.S. Geological Survey's National Wetlands Research Center (NWRC), Lafayette, Louisiana, are aimed at understanding the factors that contribute to Chinese tallow growth, spread, and management. When tallow invades, it eventually monopolizes an area, creating a forest without native animal or plant species. This tree exhibits classic traits of most nonnative invaders: it is attractive so people want to distribute it, it has incredible resiliency, it grows quickly and in a variety of soils, and it is resistant to pests. In the coastal prairie of Louisiana and Texas, Chinese tallow can grow up to 30 feet and shade out native sun-loving prairie species. The disappearing of prairie species is troublesome because less than 1% of original coastal prairie remains, and in Louisiana, less than 500 of the original 2.2 million acres still exist. Tallow reproduces and grows quickly and can cause large-scale ecosystem modification (fig. 1). For example, when it completely replaces native vegetation, it has a negative effect on birds by degrading the habitat. Besides shading out grasses that cattle like to eat, it can also be potentially harmful to humans and animals because of its berries (fig. 2) and plant sap that contain toxins. There is some concern its leaves may shed toxins that change the soil chemistry and make it difficult for other plants to grow.

Fact Sheet

Navajo coal and air quality in Shiprock, New Mexico

Among the Navajo people, high levels of respiratory disease, such as asthma, exist in a population with low rates of cigarette smoking. Air quality outdoors and indoors affects respiratory health. Many Navajo Nation residents burn locally mined coal in their homes for heat, as coal is the most economical energy source. The U.S. Geological Survey and Dine College, in cooperation with the Navajo Division of Health, are conducting a study in the Shiprock, New Mexico, area to determine if indoor use of this coal might be contributing to some of the respiratory health problems experienced by the residents. Researchers in this study will (1) examine respiratory health data, (2) identify stove type and use, (3) analyze samples of coal that are used locally, and (4) measure and characterize air quality inside selected homes. This Fact Sheet summarizes the interim results of the study in both English and Navajo.

Fact Sheet