Medical geology looks at (1) the geological factors that affect human, animal and plant health and (2) how we can use natural resources for modern medicine and diagnostics.
1. By studying the geology of an area the relationship between disease and the geochemical properties can be determined. These geochemical properties can relate to deficiencies or excesses of certain elements and minerals. The GSI Tellus programme collects data on a wide range of elements in our sediments, stream water and soils.
Trace elements are those which occur in small amount but have significant impact on the food chain. Three well studied trace elements are Iodine, Fluorine and Selenium. By studying their occurrence in different regions medical geologists can predict possible deficiency diseases. For example Iodine is found naturally in seaweed, kelp and seafood, it helps maintain a healthy thyroid gland and regulate fat metabolism. A deficiency in iodine can lead to hypothyroidism which can cause weight gain, lack of energy and reduced mental focus. By studying an area and knowing if the population is at risk of developing this deficiency disease an iodine supplement can be given.
Sulphur fumeroles near a volcano
Geological events such as earthquakes and volcanic activity can also affect the health of a population. Volcanic emissions can contain naturally elevated levels of different minerals, elements and other compounds. By studying these emissions possible health risks can be determined.
Earthquakes can also be a cause of knock on effects on our health, as the earthquake shakes the ground it raises dust that may contain harmful components that are released into the air and breathed in by the population. An example of this was the 1994 earthquake in Los Angeles, the dust raised contained fungal spores that cause Valley Fever. The month following the earthquake saw a large increase in the number of cases of Valley Fever.
Similarly, and in particular if not monitored sufficiantly, activities such as mining can have devastating effects on human and animl health.
2. However, geology has also brought us some essential treatments for difficiencies, diseases and skin treatments. For example, substances such as tungsten, molybdenum, copper, cobalt and iron are all used in various forms of x-ray analysis and scanning.
Other minerals and are extracted from rock and soils for use in food supplements. Kaolinite, Bentonite and Barium are used for the treatment and disgnosis gastric problems. Pumice (a lightweight volcanic rock), clays and minerals are used widely in the beauty industry!