Learning Outcomes:
The learning outcomes of this elective module are to provide undergraduate students who have an interest in Health Science and Medicine with: (i) an improved knowledge of how naturally occurring Earth materials (e.g. carcinogenic minerals, geogenic contaminants in groundwater, bedrocks and soils) can impact on human health and disease, (ii) a better appreciation of the complex pathways through which humans can be exposed to both excesses and deficiencies of essential and trace elements via multiple processes involving the food-soil-rock nexus and water-rock interactions, (iii) the variety of potential exposure pathways including direct and indirect ingestion of geological contaminants, inhalation of airborne dusts and harmful but naturally occurring gases (e.g. radon), (iv) an understanding of how the speciation and therefore the bioavailability of certain heavy metals varies in a range of geological and geochemical environments and finally (v) how methods that were originally developed in the field of geochemistry (e.g. Fe and Cu heavy metal isotope geochemistry) are finding novel applications in the diagnosis of certain pathologies.
Indicative Module Content:
Section 1: Introduction to Medical Geology, Minerals and Health
Lecture 1 (FMcD)
PART 1: Brief definition/discussion of the scope of Medical Geology as a field. Definitions of minerals (geological) and meaning sensu-lato.
PART 2: Major, essential and trace elements for the human body. Toxicity effects of selected elements.
PART 3: The food-soil-rock connection – deficiencies and excesses.
Lecture 2 (FMcD)
High level general introduction to exposure pathways for humans
PART 1: Exposure via drinking water.
PART 2: Exposure via soils, food crops and seafood.
PART 3: Exposure via direct inhalation and ingestion of soils and dusts.
Lecture 3 (FMcD)
Specific biological and health functions of the essential elements such as Ca, Mg, K, Fe, Cr, Co, Cu, I, P, S, Se, Zn, Mo, F, Si.
PART 1: The major elements (O, C, H, N)
PART 2: The minor elements (Ca, P, Mg, Na, K, S, Cl)
PART 3: The essential trace elements (F, Si, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Mo, I, W)
Lecture 4 (FMcD): Specific biological and health functions – detailed case studies.
PART 1: Selenium
PART2: Cobalt
PART 3: Iodine (Goitre)
Section 2: Ingestion Pathways; Water and Food
Lecture 5 (FMcD)
Common geogenic and anthropogenic contaminants. Effects of exposure to toxic levels of some trace elements such as arsenic, uranium, chromium, cadmium, lead. Health implications of nitrate pollution in groundwater. WHO guidelines, baseline thresholds and multivariate compositional analysis to discern synergistic effects between contaminants.
PART 1: Arsenic and Chromium
PART2: Cadmium and Lead
PART 3: Nitrates and other nitrogenous compounds
Lecture 6 (FMcD)
Bioavailability and uptake of elements. Some general information on factors affecting bioavailability. Organometallic forms. Methylation and other bio-transformations that influence metal speciation, bioavailability and uptake by organisms with a focus on Hg and As. Bioaccumulation and biomagnification effects with particular reference to fish- and shellfish-rich diets. Emerging contaminants in groundwater and their biogeochemistry.
PART 1: Mercury – organometallic forms including methyl Hg
PART2: Role of organics in lead bioavailability and toxicity
PART 3: Role of organics in arsenic bioavailability and toxicity
Lecture 7 (FMcD)
‘Mineral’ deficiencies. Geological impacts on nutrition with a focus on the impact of rocks and soils on soil water chemistry and therefore uptake by plants/animals/food. Effects of deficiencies of certain elements such as iodine, calcium, magnesium, potassium, sodium, iron, zinc, copper, fluorine and selenium and how these are transmitted to humans. Health effects of lithium in groundwater.
PART 1: The chemistry of rocks, soils and soil solutions
PART2: Role of soil pH and carbonates in causing deficiencies
PART 3: Role of soil organics in causing deficiencies
Lecture 8 (FMcD)
‘Mineral’ excesses. Geological impacts on nutrition with a focus on the impact of rocks and soils. Links to geology and soil geochemistry. Soil solutions. Health effects of lithium in groundwater. Effects of excesses of certain elements such as iodine, calcium, magnesium, potassium, sodium, iron, zinc, copper, fluorine and selenium in soils and soil solutions and how these are transmitted to humans.
Section 3: Inhalation pathways, airborne minerals and other particulates
Lectures 9 and 10 (JFM): Mineral types (brief introduction), sizes, shapes and typical specific surface areas. Size range of atmospheric particulates from different sources. Naturally occurring mineral dust sources (e.g. desert dusts, soil erosion, wildfires and volcanoes). Mechanics of mineral dust inhalation, nanominerals and other nanoparticles in the human respiratory system. Volcanic gases.
Lectures 11 and 12 (JFM) : Anthropogenic dust sources. Quarrying and mining. Asbestos and other fibrous mineral dusts, erionite, silicosis, black lung, airborne heavy metals (e.g. Pb, As) around some extractive and other industries (e.g. glass), airborne nanoparticles. Effect of hydrocarbon extraction, especially fracking on mobilisation of geogenic contaminants.
Section 4: Radioactivity and radioactive minerals
Lecture 13 (JFM): Radon. Sources and pathways into buildings. Health effects and links to smoking. Other naturally occurring radioactive elements and their biological/medical effects such as uranium, thorium, radium etc.
Lectures 14 (JFM): Artificially produced radioisotopes from nuclear facilities. The ‘bomb spike’ in 14C. Health impacts of depleted uranium (DU) from munitions. Fallout from nuclear accidents such as Chernobyl and Fuchishima. Occurrence and biological uptake behaviour of radioactive strontium, caesium, plutonium, americium etc. Particle reactivity and plutonium in Irish Sea.
Section 5: Biomineralization in the human body as affected and inspired by Earth materials (FMcD)
Lecture 15 (FMcD): Pathological and other detrimental biomineralization effects in the human body (e.g. plaque, kidney and gall stones, gout etc). Health effects of water hardness. Effect of water hardness on coronary health.
Lecture 16 (FMcD): Mineralisation of bones and teeth. Intentional addition of some elements to water sources to influence biomineralisation (e.g. fluoridation of drinking water). Fluorosis. Synergistic interactions between elements (e.g. F in bone building). Bioengineered and bioactive glass and mineral-inspired scaffolds for bone regeneration and reconstruction.
Section 6: Geochemistry and Minerals in medicine (FMcD and JFM)
Lecture 17 (FMcD): History of geophagy. Effects of unintended ingestion of minerals by children. Use of industrial minerals in pharmaceutical and skin cosmetic formulations. Soil minerals as vectors for pathogens.
Lecture 18 (FMcD): Microbes and minerals. Mineral selection of microbial populations in nature. Current research on the antimicrobial properties of minerals.
Lecture 19 (JFM): Use of geochemistry tools (e.g. stable isotopes of Fe and Cu) in medical research and in understanding hemochromatosis and cancer progression.