In June-July 2001 we had a workshop in Zambia as a part of the IGCP project 454 on Medical Geology. 

GEOMED 2001, & WORKSHOP, METALS, HEALTH AND THE ENVIRONMENT

GEOMED 2001: Second East and Southern Africa Regional Workshop in Geomedicine

Short Course: Metals, health, and the environment

June 28- July 1, 2001, Lusaka, Zambia

The participants

Short course leaders Jose Centeno and Bob Finkelman

MEDICAL GEOLOGY – The African Perspective

A report on a Short Course on Metals, Health and the Environment

and a summary of proceedings from GEOMED 2001, the Second East and Southern Africa Regional Workshop on Geomedicine, Lusaka, Zambia, 27 June – 1 July 2001

The recent medical geology meeting in Zambia confirmed previous articles and reports on the burgeoning interest and research in the relatively new field of medical geology. Organized by the School of Mines, University of Zambia and under the auspices of the International Union of Geological Sciences (IUGS), IGCP #454, UNESCO, UNEP, United States Armed Forces Institute of Pathology, United States Geological Survey, and the Geological Survey of Sweden, GEOMED 2001 brought together more than 50 geoscientists and medical scientists from around the world. Africa was of course especially well represented with participants from 9 countries including Angola, Kenya, Malawi, Niger, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe, with 12 overseas delegates from Australia, Canada, England, Germany, Japan, Lithuania, Norway, Poland, Romania, Russia, Sweden, and the United States of America. The inter- and multi-disciplinary experts comprised geoscientists, medical practitioners, veterinarians, environmental economists and engineers, and social scientists.

After a warm welcome by the local chairperson, Dr. Daniel Nkhuwa (University of Zambia, Lusaka, Zambia), the meeting was officially opened by Dr. Thomas Schlüter (UNESCO, Nairobi, Kenya), who emphasized the aim of the IGCP #454 project on Medical Geology to become an internationally well known project reaching more developing countries. Representing the Geological Society of Africa and secretariat for GEOMED 2001, Dr. Imasiku Nyambe (University of Zambia, Lusaka, Zambia) emphasized the importance of sharing knowledge between eastern and southern Africa.

Metals, Health and the Environment Short Course

A main part of the meeting in Lusaka was a short course and seminar under the auspicies of IGCP #454, "Metals, health and the environment". An extensive syllabus was produced, about 300 pages, covering many aspects on Medical Geology. This syllabus was handed over to all 50 participants.

Scope and Purpose:

Metal ions occur naturally in rocks, soils, gases, and waters in both harmless and harmful forms and concentrations. Natural concentrations can be extraordinarily high and have caused serious health problems. Metals are important in environmental health and on the study of human diseases (pathology) because of their potential toxic effects to one or more organs. Exposure to toxic metal ions may occur via three principle routes: percutaneous absorption, ingestion, or inhalation. Dermal toxicity results from local tissue responses through direct contact of the metal with skin, or alternatively, may represent a manifestation of systemic toxicity following ingestion or inhalation. Allergic contact dermatitis induced by nickel is an example of a local tissue response. The adverse cutaneous reactions resulting from chronic ingestion or inhalation of arsenical compounds exemplify systemic toxicity. A variety of toxic pathology responses in human tissues and organs (i.e., skin, liver, heart, kidney) associated with both acute and chronic exposures to metals have been described. The aim of the Seminar was to provide examples where both deficiencies of trace elements as well as toxic exposures of metals may be involved in physiologic changes and the development of human diseases. We discussed the impacts of metal ions and trace elements on human health as illustrated with examples of arsenic poisoning from contaminated water in the Bengal Delta (India and Bangladesh) and Taiwan, as well from coal combustion in southwest China. Studies associated with lung cancer risk in an occupational cohort of chromate production workers were described. An overview of clinical aspects of toxic metal exposures including discussions of essentiality and clinical manifestations were be presented. 

Short Course Leaders were Dr. José A. Centeno, Chief, Biophysical Toxicology Division, United States Armed Forces Institute of Pathology , Washington DC and Dr. Robert B. Finkelman, Coal Quality Coordinator, Research Scientist, United States Geological Survey, Reston, VA, USA. On the opening day, Dr. José Centeno and Dr. Robert Finkelman joined forces to share their expertise through a course devised to illustrate the breadth of geological and medical considerations involved in studying diseases caused by toxicity or deficiency of trace elements or metals.

The Seminar was intended for geologists, ecologists, chemists, biologists, occupational and environmental scientists, medical professionals, toxicologists, epidemiologists, pathologists and any other health, environmental and geo-sciences professional with interest on the effect of toxic metal ion species on environmental and human health. An important aim of the Seminar was to provide the opportunity for forming contacts and networks between professionals working in different areas of the field. 

The aim of the short course and seminar was to share the most recent information on the relationship between toxic metal ions, trace elements, and their impact on the environmental and public health issues. The scientific topics of the Seminar included environmental toxicology, environmental pathology, geochemistry, geoenvironmental epidemiology, extent, patterns and consequences of exposures to toxic metal ions, and analysis. Areas of interest included metal ions in the general environment, biological risk assessment studies, modern trends in metal analysis, and updates on the geology, toxicology and pathology of metal ion exposures.

Themes covered included an overview of essential elements and metals, potential toxicities and known disease associations, as well as clinical features of diseases and theories on mechanisms of toxicities, followed by sources of trace elements and pathways of potential impact. Considerations of anthropogenic sources and human activities that enhance or change trace elements concentrations and availability were illustrated. Standard methods of epidemiological studies and approaches to characterizing metal exposure were also described.

Two case studies were introduced, the first As and F poisoning through food drying processes in China, which affect around 10,000 and 10 million people, respectively. This is a relatively recent phenomenon due to forest denudation in the early 1900s and the subsequent necessity of a new fuel source, which came in the form of fuel briquettes composed of a mixture of As-rich coal and F-rich clay that, when burned, coat food dried over an open fire with As and F, or result in direct inhalation. This was elaborated on with an overview of clinical features of chronic As poisoning. Calin Tatu (Country Hospital, Timisoara, Romania) spoke on the elusive etiology of Balkan endemic nephropathy (BEN), that occurs in Romania, Bulgaria, Serbia, Croatia, Bosnia, and Kosovo and affects over 100,000 people. Through geological and disease prevalence maps BEN is known to occur in areas where people derive their groundwater from layers of lignite, and current research is focusing on organic contaminants as a possible causative factor.

The second day started with the importance of speciation (bio-availability, mobility, and toxicity) and the appropriate methods for determining them. Analytical methods to determine trace elements in geological material, especially for extremely low concentrations were then described, followed by methods and procedures used for the determination of trace elements in biological samples. Current topics with regard to trace elements, environmental legislation, and various approaches to regulation were also covered.

Olle Selinus (Chairman of IGCP #454, Geological Survey of Sweden) gave an overview of the emerging discipline of medical geology, including an historic perspective. He highlighted the multidisciplinary approach in Sweden at the Centre for Metal Biology in Uppsala, made up of members from various scientific organizations who come together monthly to discuss relevant issues, and encouraged this collaborative type of approach. He illustrated a positive outcome with the solution to the mysterious moose disease in Sweden, originally attributed to a virus but later diagnosed as diabetes due to molybdenosis and copper deficiency, caused by liming in acidified regions where there are high contents of natural molybdenum in bedrock and soils. In the African context, Theo Davies (Moi University, Eldoret, Kenya) presented an overview of medical geology research in east and southern Africa, in which he stressed the important role of earth scientists in helping to isolate causative factors, the need for baseline data, and correct diagnosis of diseases. He discussed a variety of issues including I, F, endomycardial fibrosis and Ce, asbestosis, Hg exposure, geophagia, Kaposi's sarcoma, radiation and radon gas, trace element deficiency studies on soils and plants, and the need to study health impacts of mine and waste dumps.

Imasiku Nyambe ended with an emphasis on the importance of the transfer of our geological and biochemical knowledge once we have obtained it, especially to policy makers. He pointed out that policy is donor driven in Africa with standards often set by foreign countries.

As a summary, following topics were covered:

• Environmental Health : Sources of Exposure and Effects of Toxic Metal Ions
• The Diversity of Trace Elements and Toxic Metal Ions in Environmental Health and Human Diseases:
• Essentiality, Toxicity and Carcinogenesis
• A Process-oriented Approach to Understanding Natural and Anthropogenic Sources, Transport and Fate of Toxic Metal Ions in the Environment
• Environmental Toxicology Studies and Considerations
• Considerations for the Design of Environmental Health Studies Associated with Effects of Toxic Metal
• Environmental Pathology, Geochemical Studies and Health Effects
• Environmental and Toxicologic Pathology of Metal Ion Exposures: An Overview of Selected Toxic Lesions
• Chronic Arsenic Poisoning: An Introduction and Overview
• An Overview of Health Impacts of Coal and Coal Use: Arsenicosis and Fluorosis
• Analytical Toxicology: Trace Element Speciation, Detection and Quantification Methods
• "Speciation" of Trace Elements and Toxic Metal Ion Species
• Analytical Methods for the Study of Trace Elements and Toxic Metal Ions in Geological and Environmental Samples
• Analytical Methods for the Study of Metal Ions in Biological and Tissue Samples
• Special Topics on Environmental Toxicology and Human Health Research on Metal Ions
• Current Topics on Trace Elements and Toxic Metal Ion Studies: Environmental Legislation, Management and Use of Some Waste Products Containing Toxic Metals
• Medical Geology: An Emerging Discipline in Environmental and Human Health

At the completion of the Seminar, the attendees were able to:

• Know and gain information on the type of evidence available about geological sources and processes, environmental health, toxicology, and pathological manifestations of exposures of toxic metal species.
• Know and gain information about geochemical processes, natural and anthropogenic sources, speciation, modes of occurrence; to assess the impact of trace elements and toxic metal ion species on human and environmental health.
• Have an elementary understanding of environmental toxicology, epidemiology, medical geology and issues associated with assessment, regulations and legislation as applied to the study of toxic metal species and trace elements.

Medical Geology Workshop, GEOMED 2001

Following the successful short course, and with the theme "The Role of Geomedicine in the 21st Century", the one-day workshop presenting medical geology work in eastern and southern Africa was opened by Bjørn Bølviken (Geological Survey of Norway, Trondheim, Norway) with an overview of associations between human disease and the environment. Nasopharynx occurs in the south-east of China and is known to have genetic and suspected viral components, but also only occurs in areas of low soil Mg and high Th. Likewise, multiple sclerosis in Norway seems to have a series of complicating factors, of which genetics is suspected to play a role, as well as viral and environmental factors. Studies have shown a positive correlation between multiple sclerosis and Rn, and he speculated on the possibility of an antagonistic synergy.

The first session of the workshop focused on fluorine and Adebayo Oladimeji (National University of Science and Technology, Bulawayo, Zimbabwe) presented a summary of F distribution in a variety of drinking water sources in populated areas of western Zimbabwe. Examination of the variation in mean concentrations over a thirty year period found the average F concentration to be within acceptable limits, although quite a few sites in the west had very high levels, which exceeded acceptable guidelines. Fluoride levels were found to be inversely correlated with rainfall. Edda Vuhahula (University of Dar es Salaam, Tanzania) presented work on the severe endemic dental fluorosis in Tanzania in communities exposed to low levels of F in drinking water, although some areas with dental fluorosis could not be explained by F levels in drinking water, and seem to be associated with magadi, a commonly-used salt composed of sodium carbonate or bicarbonate mined from saline lakes. Regional variations in diet with coastal people consuming mainly fish and tea, and higher altitude communities consuming more milk and magadi, were related to variations of F in urine samples.

Donnati Mosha (University of Dar es Salaam, Tanzania) described the problems of analysis of F in Tanzanian salt lakes, which are a potentially valuable local resource, subject to little research or exploitation, although the extremely high F concentrations could pose a health risk. He noted some of the complications that can arise during analysis such as etching of glass at low pH, the problem of molecular F not being detected, the fact that many of the multiple species in solution are not well known, and, lastly, the critical factor of maintaining the correct ionic strength. In another study, Patrick Hayumbu (University of Zambia, Lusaka, Zambia) reported on nuclear analytical techniques used to analyze a variety of geological, waste, and building materials to determine occupational exposure to radioactivity in Zambia, where about 30% of underground mines were found to have very high levels of radioactivity.

Trace and major element deficiencies of soils in relation to an endemic osteoarthritis, Mseleni Joint Disease (MJD), and dwarfism in Maputaland, South Africa were explained by Portia Ceruti (University of Stellenbosch, South Africa), who is looking at the spatial pattern of nutrient heterogeneity in relation to the prevalence of MJD. This work for her doctoral studies has shown multiple soil deficiencies of P, Cu, Zn, and Se that vary across the landscape. Health implications of geophagy were illustrated by Mr. Shitumbanuma (University of Zambia, Lusaka, Zambia) in a study of the textural and chemical composition of soils, as well as termite material deposited on tree bark, consumed by women in Lusaka. The materials were found to be acidic and clayey, with high Mg and Mn concentrations in soil from the Kafue region of Zambia versus soil from the Democratic Republic of Congo, while in the termite material Mg and Mn levels were also quite high.

The major theme of the workshop concentrated on pollution of soil and water, and ultimately impacts on ecosystems and humans, through a common activity in east and southern Africa: mining. Small-scale mining was considered by Benjamin Mapani (University of Zimbabwe, Mount Pleasant, Zimbabwe) who spoke on the importance of social as well as economic considerations in the search for a solution for a river system of northern Zimbabwe where small-scale Au mining has led to the destruction of the river. Jason Ogola (University of Venda, Thohoyandou, South Africa) stressed the necessity of public awareness in putting pressure on pollution and waste management policy makers with respect to environmental impacts of operational and abandoned mines in South Africa, such as the use of asbestos tailings as road material and to fill school playgrounds.

The influence of mining on water resources was discussed by James Kahatano (University of Dar es Salaam,Tanzania) with work on heavy metal proliferation in the environment of Mpanda mineral field in western Tanzania, where maximum allowable levels in the water and soil are often exceeded due to atmospheric fall out. Monique Omulo (Maseno University, Kenya) introduced preliminary results from her doctoral work on heavy metal contamination and health problems in western Kenya, where artisanal Au mining has polluted tributaries to Lake Victoria. Callist Tindimugaya (Directorate of Water Development, Entebbe, Uganda) reported on groundwater pollution in Uganda where reprocessing of stockpiles has caused widespread contamination by heavy metals, especially Mn, Cd, and Cr, through varied pathways.

Staying with the theme of groundwater, Samuel Mtetwa (University of Zimbabwe, Mount Pleasant, Zimbabwe) presented a spatial distribution map of nitrate, phosphates, and suspended and dissolved solids as a tool for water quality management, to control the particularly diffuse pollution sources in an agro-rural watershed in Zimbabwe. Daniel Nkhuwa (University of Zambia, Lusaka, Zambia) discussed a local problem in the karst landscape of Lusaka where natural holes in the ground are used for the disposal of liquid and solid waste, and the high watertable is easily contaminated. More data is needed to determine the association of pit latrines that intersect the watertable with outbreaks of cholera, as well as the impacts of open pit waste dumps on groundwater quality.

Imasiku Nyambe gave a review of the history of mining and the impact of tailings dams on the Kafue River in Zambia, which has elevated concentrations of Ca, Mg, Cu, and Co, and highlighted problems associated with atmospheric impacts, such as the high S emissions from the Nkana smelter. Maxwell Mwase (University of Zambia, Lusaka, Zambia) then introduced the topic of bioindicators in an ongoing study looking at chemical and morphological features of tropical fish species in the Kafue River in Zambia. He has found evidence of parasite infection and liver histological abnormalities in fish, as well as extremely high Cu concentrations in fish liver. Noma Ndiweni (University of Zimbabwe, Mount Pleasant, Zimbabwe) introduced work done on Se-dependent enzymes of crocodiles as a possible new Se indices for biochemical and xenobiotic metabolism, as a precursor to addressing nutritional and prophylactic remedies for skin diseases in crocodiles. Steve Mogere (Moi University, Eldoret, Kenya) presented findings of the first benthic study on Chironomous larva as an indicator of temporal changes along the River Nzoia in Kenya due to pesticide pollution. Beneah Odhiambo (Moi University, Eldoret, Kenya) discussed a study along the Rift Valley in West Pohot District, Kenya to determine background concentrations of Ni, Co, and Mn in mineralized soil, where specific plant species are used as indicators of high Cr accumulation associated with serpentine deposits. Soil concentrations of Ni and Mn were found to be elevated with respect to background levels and there is concern of toxic human and animal consumption.

At the end of the day, a medical geology overview was given by Theo Davies on the effects of metal and toxic ions on environmental health, with specific reference to toxicology and metal pathology.

Discussion

A panel discussion of several key issues raised in both the short course and workshop led to the following statements:

Preamble:

To bring awareness of medical geology to multiple disciplines and the public, specifically the importance of environmental factors in disease causation and prevention, which will decrease health costs and increase quality of life.

Resolutions:

• To encourage improved medical diagnosis and reporting of disorders that have a geological or environmental basis. In order to achieve this, there is a need to engage the participation of medical practitioners in medical geology meetings as well as in collaborative research.
• To increase the geoscientific considerations in political decision-making, the transfer of data from the geosciences and the biomedical sciences to policy makers and the public. This will require repackaging of the scientific information for public and layperson consumption, thus effectively communicating the value of our contribution to the public, public health practitioners, and to politicians.
• To generate or acquire the best quality analytical data feasible. This may involve collaboration with experts in analytical chemistry, and the correct use of reference standard and reference materials. There is a need to strengthen efforts on research on speciation and bioavailability of elements.
• To advocate for the incorporation of medical geology into the geo-curricula of institutes of higher learning.
• To sensitize the public and policy makers on safe waste disposal practices, especially in cities and municipalities.
• To abide by the Uppsala decision to use the term "Medical Geology" rather than "Geomedicine". This refers to the previous IGCP meeting for IGCP #464 Medical Geology in Uppsala Sweden in September 2000.
• To increase research on and strive to inform the public of the potentially harmful effects of using natural materials as dietary supplements and as cosmetics.
• To increase and improve communication and networking by posting, as well as by the effective use of, relevant web pages, and to provide material for the biannual Medical Geology Newsletter.
• To advocate for the revival of the Global Geochemical Baseline Project 259 IGCP since Africa was poorly studied. This initiative will increase the use of multi-elemental analysis for medical geology.

The Third East and Southern Africa Regional Workshop on Medical Geology was also discussed.

The venue of the next meeting will be Dar es Salaam, Tanzania, the convener is Dr. Edda Vuhahula. The meeting will be held in 2004 so as to avoid coinciding with the 6th International Symposium on Environmental Geochemistry meeting in Edinburgh, June 2003 (where IGCP #454 also will be involved). Publication of workshop papers will be either in African Geoscience Reviews or the Journal of Zambian Applied Earth Sciences. Concern was expressed about the more than two-year delay in publishing papers presented at the first workshop in Nairobi. Correspondence should be directed to the convener, Dr. Daniel Nkhuwa (Dnkhuwa@mines.unza.zm or dcwnkhuwa@yahoo.com).

It was also decided at the meeting to form an East and Southern Africa Association of Medical Geology (ESAAMG). Members of an Executive Committee were chosen to represent several countries as follows:

Angola – Dr. Suzanet Nunes da Costa (jacuan@netangola.com)

Kenya – Ms. Monique Omulo (Monicaomulo@hotmail.com)

Tanzania – Dr. Edda Vuhahula (evuhahula@muchs.ac.tz)

South Africa – Ms. Portia O. Ceruti (poceruti@maties.sun.ac.za)

Zimbabwe – Dr. Noma Ndiweni (ndiweni@vet.uz.ac.w)

The meeting was officially closed by the Vice Chancellor of the University of Zambia, Prof. Mutale Chanda, and delegates left on an engaging two-day excursion to sites of medical geology and environmental significance.

P. O. Ceruti, T. Davies, O. Selinus

Detailed program for the short course: