HISTORY
A Special Initiative on Medical Geology within the IUGS . Formerly the Internation Working Group on Medical Geology on the Commission on Geological Sciences for Environmental Planning (COGEOENVIRONMENT) (from 1998).
From January 2006 The International Medical Geology Association, IMGA
TERMS OF REFERENCE OF THE FORMER WORKING GROUP
ORGANISATION
(FORMER WORKING GROUP)
"Medical
Geology" is defined as the science dealing with the relationship between
natural geological factors and health in man and animals, and understanding
the influence of ordinary environmental factors on the geographical distribution
of such health problems. Medical Geology is therefore a broad and complicated
subject which requires interdisciplinary contributions from different scientific
fields if the problems are to be understood, mitigated or resolved.
Naturally occurring
metals and non-metals
can have detrimental effects on health when ingested in abnormal quantities.
Metals have always existed and will forever exist,
but we cannot avoid the fact that all humans and animals are affected by metals
in the environment. Some metals are necessary for our wellbeing and others are
detrimental to our health. Human activities of all kinds have led to metals
being redistributed from sites where they are fairly harmless to places where
they affect humans and animals in a negative way. This serious problem is beig
intensified in locations where acid rain and associated acidification accelerates
this process to make some heavy metals
(such as mercury), more easily accessible and thus absorbed in the nutritional
chain. Another consequence of acidification is that some essential trace elements,
such as selenium, become unavailable to living organism.
The presence
of toxic elements in soil or rocks, whether due
to natural geochemistry or human activities, including pollution, usually influences
human health indirectly ingested via food or drinking water. Although many places
in the world rely solely on locally produced food, food consumption in modern
industrialized societies is much more diverse, including food produced in different
geographical areas. Drinking water, however, is usually obtained locally and
therefore strongly related to local geochemistry. Problems of excess intake
from drinking water have been encountered for several inorganic compounds, including
fluoride in Africa and India; arsenic in certain areas of Argentina, Chile,
and Taiwan; selenium in seleniferous areas in the U.S., Venezuela, and China;
and nitrate in agricultural areas with heavy use of fertilizers.
Heavy metals
are not the only elements that are addressed by the subject of medical geology.
Classic internationally recognized examples of diseases related to geological
factors are goitre (which is due to iodine deficiency), and those diseases caused
by excess or deficiency of certain elements such as fluorine or selenium. Cardiovascular
mortality and morbidity in relation to water hardness which is controlled by
its geological settings is also one potential subject of research.
Many types
of rock have elevated uranium contents. These include for example alum shales,
certain granites, and pegmatites. Breathing or ingestion of abnormal levels
of the radioactive gas radon, derived from natural
radioactive sources in such rocks, has in recent years also been acknowledged
as a public health hazard. The number of radon-related cases of lung cancer
is increasing and qualifying radon to be the major radiation problem with respect
to health in several countries. Some current building traditions, such as the
use of light concrete made from uranium-rich alum shale, and a reduction in
building air circulation (justified from energy conservation aspects)
have in many cases aggravated the problem. More recently, focus has been put
on radon in domestic water as a potential radiation protection problem. Previous
risk assessments have focused on radon emanating from the domestic use of water
as an additional source of radon in indoor air. Recent studies suggest that
the intake of radon-rich water should be considered a risk as such, especially
for critical groups such as infants. The radon content of water is directly
related to local geological conditions.
Because of
the importance of geological factors on health, and the general lack of appreciation
an understanding of the importance of geology in such relationships, COGEOENVIRONMENT
decided in 1996 to establish an international Working Group on Medical Geology
with the primary aim of increasing awareness of this issue among scientists,
medical specialists, and the general public.
SPECIAL STATUS FOR THE INTERNATIONAL WORKING GROUP ON MEDICAL GEOLOGY
To address issues in geoscience which are emerging as important, and which have not received due consideration to date, the Commission COGEOENVIRONMENT establishes specialist International Working Groups to investigate and promote the issues to the international community. Working Groups are established for a defined lifetime (in the order of 1 or 2 four-year terms). Each Working Group is overseen by an elected Officer of COGEOENVIRONMENT who has freedom to approach experts worldwide for their input to the objectives of the Working Group. A primary aim of each Working Group has been the production and publication of monographs or textbooks on their subject of investigation. To assist with information dissemination Working Groups aim to develop websites, and to present specific workshops/training courses on their specific topic in different countries of the world.
As a result of their significant achievements to date two of the Commission's Working Groups have been given Special Project status by the IUGS. In March 2002 the IUGS announced that the International Working Group on Environmental Geoindicators, and the International Working Group on Medical Geology would be assigned Special Project status and will now operate directly under the IUGS. The Commission is proud of the very significant achievements of these Working Groups and will continue to assist the IUGS with these Special Project activities as required
INTERNATIONAL MEDICAL GEOLOGY ASSOCIATION
In January IMGA was established. For further information see other pages on this website