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Medical GeologyImpact of the Natural Environment
on Public HealthJose A. CentenoEmail: [email protected]
Dept. of Environmental and Infectious Disease SciencesArmed Forces Institute of Pathology, Washington, DC, USA
Medical GeologyAn Outline of this Presentation
• A Definition
• A Range of Issues
• Examples of Current Research Areas
• Milestones and Future Directions
Our Natural Environment and Health
“High levels of arsenic in drinking water has caused Severe health problems in many countries. In West Bengal alone, over 50 million people are at risk of developing arsenic poisoning”
Lake Nyos, CameroonEnvironmental
Tragedy
Our Natural Environment and Health
Impact of Geologic Events on Human and Environmental Health
TsunamiDecember 2004
Photos: Associated Press
Courtesy of Dr. Dale Griffin, USGS
Animation – NASA.JSC
Global Dust Storm Mobilization
Medical Geology: is defined as the science dealing with the relationship between geological materials and geologic processesand their impacts on health problems in man and animals.
Medical GeologyA Working Definition
The scope and range of Medical Geology include:
identifying and characterizing natural sources of harmful materials in the environment;
learning how to predict the movement and alteration of chemical, infectious, and other disease-causing agents;
and understanding how people may be exposed to such materials.
MEDICAL GEOLOGY
GeographySpatial analysis
Distribution
MedicineExposureHealth effects
GeologyRocks, soils, waterMinerals, Dust, volcanic emissionsEarthquakes
A Multidisciplinary Discipline
• Trace Element Exposure - As, Hg, F, Se, Zn, Al• Dust - Asbestos, African, Valley Fever, Silicosis • Organics - VOCs, PAHs, Antibiotics, Pesticides• Radionuclides - Radon, Radium, Uranium• Microbes, Pathogens - West Nile Encephalitis,
LaCrosse Encephalitis, Plague, Hantavirus, Rift Valley Fever, Lyme disease, etc.
• Global Climate Change
Medical GeologyRange of Issues
Medical Geology and the Natural Environment
Medical Geology and
Diseases Developed from Trace Element
Deficiency and Excess
All rights reserved/JACenteno/AFIP
Global Prevalence of I Deficiency Diseases
0123456789
%
Afr Med LAm Asia Pac
• >2 B at risk• 740 M with goiter• 20 M mentally
retarded• 6 M infants with
cretinism (half in SE Asia) each yr
All rights reserved/JACenteno/AFIP
Medical Geology and Trace Elements
ARSENIC EXPOSURE : GLOBAL IMPACT
PEOPLE AFFECTED BY NATURALLY
CONTAMINATED WATER AND SOILS
Selinus O, Alloway B, Centeno JA et al. “Essentials of Medical Geology” (Elsevier-AcademicPress, 2005)
LaguneraLagunera, , MexicoMexico, 30,000 , 30,000 affectedaffected; 0.5 ; 0.5 millonmillon atat riskrisk
Antofagasta, Chile 0.8 mg/L in water, 20,000 affected
Cordoba, Argentina 10,000 contaminated
Bangladesh Bangladesh upup to 2.0 to 2.0 mgmg/L, 200,000 /L, 200,000 affectedaffected; 50 ; 50 millionmillionatat riskrisk
Taiwan Taiwan upup to 0.6 to 0.6 mgmg//20,000 20,000 contaminatedcontaminated
MongoliaMongolia50,000 50,000 contaminatedcontaminatedCornwal, England up
to 2% As in soil
All rights reserved/JACenteno/AFIP
Arsenic Contamination of Groundwater in India and Bangladesh
First reported in mid-1980’sTube wells screened (~3000) in West BengalOf 18 state districts, 9 are affectedIn Bangladesh, 50 of 64 districts are affected (As levels <10 - > 10,000 µg/L)150 million people may be at risk in Bangladesh and in West Bengal alone
All rights reserved/JACenteno/AFIP
Health Effects Associated with Arsenic Exposure
• Cancer: skin, lung, bladder, liver, kidney• Cardiovascular disease• Peripheral vascular disease• Developmental effects• Neurologic & neurobehavioral effects• Diabetes Mellitus• Hearing loss• Portal fibrosis of the liver• Lung fibrosis• Hematological effects (e.g., anemia)
Tchounwou PB, Patlolla AK, Centeno JA. ToxicologicPathology 31:575-588 (2003).
All rights reserved/JACenteno/AFIP
Medical GeologyOther Geologic Links to
Human Diseases
Natural and Mineral Dust
Water-Borne Diseases
Emerging Infectious Diseases
Volcanic Emissions
All rights reserved/JACenteno/AFIP
The Health Effects of Dusts• Some aspects have been well known for decades• General effects of industrial
/ commercial asbestos• Silicosis (hard rock mining)• Black lung (coal mining)
• New issues and problems are arising• Effects of mineral dust (ie,
trace asbestos)• Valley fever• Trans-oceanic dust
transport
Intercontinental dust transport• Increasing evidence from satellite imagery and other means that significant dust
transport can occur between continents across large expanses of oceans• This exotic dust is increasingly viewed as a key component of some terrestrial
and marine ecosystems, as well as a potentially significant source of pathogens and environmental contaminants
• For example, atmospheric transport of dust from North Africa to the western Atlantic Ocean region has increased substantially in recent decades due to desertification of grasslands in the Sahara region
• 100’s of millions of tons annually
A huge cloud of African dust covers the Caribbean
Wind-lain quartz particles - ChinaSilicon (Si) makes up
more than one quarter of the element composition of the earth’s crust. It is highly reactive, readily combining with oxygen to form free silica (SiO2), the commonest form of which is quartz.
Silica is the most significant cause of dust-associated morbidity and mortality
Asian Dust Storm – April 2001
African Dust-Event – St. Thomas, USVI, August 8, 2001Atmospheric dust - Human and ecosystem health
• Dust as a trigger for harmful algae blooms
• Death of marine organisms
• Human illness – respiratory stress, skin rash, paralysis and memory loss from consumption of contaminated seafood
• Dust as a carrier of toxins
• pesticides, herbicides, hydrocarbons, metals, industrial emissions…
• implications – direct (exposure = death/acute illness) or indirect (exposure = immune suppression)
• Dust as a carrier of microorganisms
•Pathogenic = disease outbreaks
• Non–pathogenic = ecological change
•Respiratory stress from inhalation of soil particles
Dusts and the origin of Valley Fever (Coccidioidomycosis)
• Coccidiomycosis is a reemerging infectious disease
• C. immitis is the etiological agent of coccidioidomycosis
• C. immitis is a soil inhabiting fungus found in North, Central, and South America. • Given proper conditions, infectious spores
are released when soil is disturbed• ie, storms, construction, earthquakes
• Acknowledgments to • Mark Bultman ([email protected]); Randy
Jibson ([email protected]), Robert B. Finkelman (UTexas-Dallas)Geoffrey Plumlee, USGS
Dominant dust source regions around the world (in brown)
Natural dusts provide a striking example of the global paradigms required to understand many current environmental health issues.
Medical Geology Tools and Solutions to
Environmental Health Problems
Integrating earth and health sciencesTools of the trail
• Mineralogical, chemical characterization of earth materials (EM), pathological samples (SEM, TEM, XRD, ICP-MS, XAAFS, etc.)
• Techniques to characterize particle surface chemistry, morphology, redox state of elements
• Techniques to measure generation of reactive oxygen species
Integrating earth and health sciences Toxicological/geochemistry/clinical
• Chemical speciation and reaction-path modeling of EM - body fluid interactions
• In vitro physiologically-based extraction tests of well-characterized EM
• In vitro toxicity tests• In vivo toxicity tests• Biomonitoring (Blood, urine, tissues)
of human populations exposed to potential toxicants in EM
• Epidemiological studies of disease occurrence in human populations exposed to potential toxicants in EM
Geographic Information System (GIS)
Analysis of Disease Risk:
Where are the potential areasof disease?;
Who are the populations at riskNow and in the future?;
When might an outbreak occur?
How can outbreaks be mitigated?
National age-adjusted rates of asbestosis-related mortality by county for U.S. residents age 15 and over, 1970-1999. Reproduced from
NIOSH (2006)
What Occupations Can Medical Geology Benefit?
OCCUPATION HEALTH ISSUES
• Mining- Hard Rock Silicosis- Coal CWP, Silicosis,- Asbestos Asbestosis, Mesothelioma- Uranium Lung cancer (radon)
• Utility plants Coal dust and fly ash
• Ore processing plants Metal exposure
• Cement plants Mineral dusts
• Construction Mineral dust
• Farming Dust
• Sanitary and Env. Eng. Metals, water-borne diseases
Medical Geology Milestones and Future Activities
• International Medical Geology Association (www.medicalgeology.org)
• Conferences, symposia,
workshops, technical sessions
• Worldwide Short Courses
• Associate degree (GWU,WAU, etc.)
• Book (“Essentials of Medical
Geology”, Elsevier & Academic Press, 2005)
• Medical Geology Registry (AFIP)
• Centers of Excellence on Medical Geology
• National Academy of Sciences-NRC
(Committee on Earth Science and Public Health)
• United Nations – Planet Earth 2006-2007
SummaryIntegration among Earth Sciences and Public Health is a multidisciplinary approach able to span the breadth of geological (basic, applied, environmental), medical (clinical, epidemiological, toxicology, sociological), and political sciences.
Geoscientists have unique training and perspective about the magnitude and nature of natural environmental problems.
The present public interest in natural and climate changes therefore offers the environmental geoscientist extraordinary opportunity for technical investigation and for direct communication with the community and local environmental and public health managers.
An Invitation
We welcome the opportunity to explore with Convención Minera
and EXTEMIN 2007, with the Institute of Mining Engineers of
Peru and you, possible collaborative ventures in Medical
GeologyIMGA Website: http://www.medicalgeology.org
Thank You!