Since when the geography significantly and effectively contributed to medicine
and health, all of these three sciences benefited from the cooperation. Geography,
in terms of its function, implanted another seed, the yield of which was this
newly-emerged science. Taking advantages of this new science, medicine and health
reach wonderful explorations in the fields of the occurrence of pathogenic agents,
influence of geographic factors on the appearance of pathogenic agents and the
rate of their impact on disease spread (http://www.who.int/publications/en/).
The manner and the type of human predominance over the Earth and the methods he chooses to apply them as well as the natural richness or deficiency of the Earth and in general, natural susceptibilities of the region have deep effects on nutrition quality and quantity, health, hygiene, kind of disease and individuals life-span. If we think of the interactions between the aforesaid conditions and factors and would arrange to measure the relations in qualitative and quantitative respect, we will reach the concept of medical geography.
The old saying as To travel from one region which refers to getting
sick because of changes in settlement and climatic conditions is a proverb showing
the impact of geographical conditions on human body and its role in pathogenesis
Diseases and medical geographical insight aged several thousands of years.
According to Hippocrates (5th century B.C.), the father of medicine (Chaklin,
AEveryone who is in seek of the art of medicine, first of all should think
of seasonal influences and then, to gain knowledge on the effects of hot and
cold winds and water quality and at last he will have to examine about green
and lush spaces (Haddock, 1981). Though these
geographical insights have a very long record, the term of medical geography
aged less than a century. This branch of geography is very young and requires
more information be obtained.
DOMESTIC AND OVERSEAS COMMENTS ON MEDICAL GEOGRAPHY
In Iran, the first geographer paying attention to medical geography was Mr.
Hossein Shokouei, at the Department of Geography at Azarbadegan (Azerbaijan)
University. In 1975, he published a remarkable essay titled: Medical Geography
and its Methodology of Research in the press issued by the Faculty of
Literature and Humanities of the said university (Ganji, 2001).
The late Dr. Ahmad Mostofi, formerly professor of geography at Tehran University, in his book under the title of General Geography has described the function of the geography of diseases as follows:Different regions on the earth in accordance with natural conditions are appropriate to get some diseases and in the said regions the physician may specify the disease distribution location based on their full identification on climate, elevations, reliefs and people lifestyle.
And Dr. Zartosht Hoshour in his book titled: Introduction to the Medical Geography of Iran presents his view based on the opinions made by domestic and foreign advisors in this respect:
AMedical geography is a subdiscipline of human geography highly affected and constrained by natural geography (totally and generally) in all perspectives. This field of geography is dealt with the impact of natural factors (weather; intensity and direction of wind; sunshine; natural radioactive radiations; regional elevation; texture, quality, composites and components of soil, vegetation and various microorganism and macroorganism living things, water quality and quantity) on human body and this generality is a characteristic feature of geography.
Followed by his works, a retired assistant professor of Esfahan University, Dr. Mahmud Mohammadinejad, also make investigations on the impact of iodine deficiency in Sistan-va-Balouchestan Province of Iran.
Dr. Jack May considers medical geography as the study of relationships between pathological events and environmental factors.
And James Benta defined medical geography as:
“In geographical literature we encounter with different concepts on medical
geography including medical ecology, geographical pathology, planet epidemiology,
global epidemiology, ecology of diseases and sometimes human ecology.
Mack Gloshen syas: Medical geography discusses about the influences of different factors on health and disease.
According to Melvin Hue: Certain diseases are spread in certain geographical
areas and affected by geographical characteristics (Johannessen,
CLIMATES ROLE IN MEDICAL GEOGRAPHY
The term of Meteoropathologic referring to the effect of climatic factors on human body has an intertwined and extensive concept. Several factors make regional climate; whatever geographer states as weather, in fact, is a kind of climatic events e.g., wind, precipitation, cold and heat, moisture, air pressure, evaporation, thunder and lightning, climatic revolutions, sun shine and radiation, which is a wrong translation of Meteore, but since this term, though wrongly, is integrated in Farsi and even in scientific language and any one speaking on weather, depending on his/her familiarity with this knowledge, somehow means Meteore, it may be used considerately.
As we know, climatic factors are a product of interrelated effects of sun and atmosphere and the strength and weakness of climatic events in any geographical region is due to its latitude, elevation and distance from sea. In other words, sun is the main factor and the latitude, elevation and distance from sea
are intermediate factors and also, the climatic events are the effects resulted from this system.
There are many theories on the existence and/or non-existence of a relation
between climate and human physical, mental and living abilities. One of these
theories is about the energy discrepancy between races living in diverse climatic
conditions and regions. The followers of this theory believe that the people
living in tropical regions, compared to those living in temperate zones or cold
areas, use lesser oxygen, has a lower blood pressure and as a result, has a
lower susceptibility to resist events (Kearns and Moon,
2002). Even some psychologists believe that diverse climate may cause people
to grow with different moral and mental ability (Mathoulin
and Haerle, 2005).
Though the above theories are currently regarded extremist and false and are
not taken into account, it has been clear that the health is related with many
climatic events and geographical conditions and such a relation is so recognized
and sensible that a particular subdivision of medicine, namely Meteropathology
has been taken into consideration by researchers (Mathoulin
and Haerle, 2005). These relations are not a new finding and the climatic
conditions have been determined as factors effective on health or disease at
the time of Socrates. But, since long the main problem was the knowledge on
how and why these relations exist as well as on how to find ways to prevent
their adverse effects on human body (Prothero, 2006).
As an example, it is worth to name some diseases caused by climatic conditions as follows:
Respiratory diseases e.g., Asthma, bronchitis, skin cancer, rheumatism, cardiac diseases etc.
Now, it is necessary to deliberate the concept of climate somehow more accurately
(Mathoulin and Haerle, 2005).
Firstly, in definition of climate as token, climatology is a science seeking the expression and description on the nature of climate and also, on how it has been altered upon dispositions and also, how it links with human activities. This science is thoroughly and continuously associated with meteorology and discusses about climatic daily changes and the results thereof. It should not be neglected that at ancient times, climate was referred to continents and later, in next eras, to a quarter of the earth. and briefly, the general concept of climate means weather.
Since, climatic conditions are variable and discrepant in different regions, the elements of climate whether affect different conditions or take effect from different conditions, create abundant life layers which are the habitats of various living things, plants and even human that show consistency and or inconsistency against climatic conditions. Here if we have a look at the two definitions of climate below, that is:
Whether is the immediate and transient state of atmosphere at a specific spatial
location and climate is the mean atmosphere during a defined period of time,
it will be well demonstrated that different climatic conditions, in addition
to other elements effective on climate e.g., water, sometimes can make various
effects on living- and even non-living things like soil in the settlement so
that the action and reaction made against them may be variable and all above
mentioned as well as other issues, any of which being a portion for a huge entire,
are among those requirements that determine the role of medical geography on
the influence of all these factors which, as discussed above, are the life layers
endurable for living things. As we well know, equal to all climatic conditions
and situations there are life layers and each of these layers required its own
factors and conditions, which may result in its acceptance or non-acceptance
in the settlement and the survival of living things in the said environment.
A detailed description will be given under section Medical Geography
of this chapter (Moshiri, 2006).
PLANTS ROLE IN MEDICAL GEOGRAPHY
Plant geography is involved in plants distribution and the reason of its changes
over the world. This explains that biological and geographical aspects of distribution
in the world is not casual, rather the needs of any plant and the situations
provided for any plant in any region of the world is an effective factor in
its spread. There are other factors to be added to the above-mentioned ones,
including any plant susceptibility in struggle for survival (among the individuals
of the same species or other species) and their past history as well (Ghorbani,
Plant geography is a biological science. Plant geographer should be aware of biological information on physiological behavior and plants growth and reproduction mechanisms. This is closely related with geology, climatology, sedimentology, geomorphology, botany, zoology, plant physiology, ecology and genetics. Since, mobility in plants is not so much as in animals and as they have a more specified settlement, it is easier to make a study thereon and for the same reason, as well as other causes as mentioned below, plants and plant geography forms the main part of biological geography because plants are a better index to represent their environment and also, they reflect the environmental effects better than animals because of their relative non-mobility. Moreover, the more biomass in plants leads to their having more influence on physical environment so that they provide a unique biological environment for other living things and at last but not least, plants are a source of food and energy for other living things, including human beings.
It should be briefly noted that various determinant factors affect growth and/or
lack of growth in plants the most important of which are: physiographical factor
or the shape of ground surface, climatic agents, soil agents pertaining to soil
features and characteristic (Kardavani, 2006). They are
very variable because contains many factors like physical structure, chemical
composition, moisture, temperature and even living things present in soil, of
which only one factor can cause or prevent the settling of plant in the settlement.
Among other factors one can define whether the plant is in equilibrium with
environmental conditions or not and whether this equilibrium is based on parasitism,
commensal, symbiosis or competition (Asayesh and Moshiri,
Now it is necessary to have a brief summary on ecology to explain the effectiveness and efficiency of plants in the environment as one of effective factors in medical geography.
Plants are able to spread by means of their reproduction mechanisms and when
the environmental conditions are suitable for their living they will be able
to spread and dispense all over the earth. The extent of geographical zone of
one species in which it has been settled and the extent of areas where this
species have been settled in its own zone is associated with those physicochemical
and biological conditions which are in consistent with its settlement. To recognize
the relations between plants and their surrounding environment it is necessary
to firstly examine the features of the environment with which the plant encounters
and then, to study how plants react in this environment. The entire energetic,
physical, chemical and biological conditions dominant immediately adjacent to
plant or animal are consisted in their environment. The very environment on
a certain area is called settlement. The term of environment, in
fact, determines the nature of materials that compose the settlement e.g. aquatic,
sea and ground, underground and aerial environment. Settlement is a set of many
different features or factors or natures. The study on a number of factors is
a subject of different sciences such as climatology, atmosphere variation, pedology,
soil chemistry, hydrology and ocean logy (Ghorbani, 2002).
And finally, in view of the effective role of plants in the life of all living things and their settlement conditions, it is necessary to categorize the ecological factors in terms of two general concepts as follows:
based on environments where reactions result in basic distinguishing between
aquatic and terrestrial environments
Atmosphere and climatic factors, temperature, moisture,
precipitations, wind and gases existing in weather
Terrestrial factors, which is the base of plant such as
temperature, moisture and soil air, physical and chemical features of
Reliefs factors, concerning with the status of mountains
and earth shape which, particularly, affect terrestrial and climatic alterations
||Biological factors explaining the reactions between living
things and human interference
based on nature and function of physiological factors including:
||Energetic factors: radiation (light and heat)
||Aquatic factors: atmosphere water and soil water
Chemical factors: Free gases present in atmosphere and
soil, gas and soluble substances in water, minerals and organic substances
Mechanical factors: wind, erosion, snowfall, glacial and
The above factors whether adopt various effects or affect environment and its factors.
In contrary to what discussed above, plants and vegetation make productive
and positive effects on the living of human, animal and other living things
and in other situations, make undesirable effects on the same living things
system and organism and in other words, cause inconsistency and negative effect.
The interaction among human, animals and plants in existing environment result
in the generation of a life cycle, where all above living things are beneficial
and effective for each other and also, this effectiveness in medical geographical
perspective may inevitably result in health, balanced and normal behavior for
the members of this life cycle and ring and/or causes disease and deficiency
in systematic behavior of living things, in general. For instance, the existence
of different plants with pharmaceutical effect may vary with the man knowledge
on their organism and/or animals instinctive behavior for consuming them
may lead to various role-playings; for example, the direct role which honey
bees perceives from flower and plant, or the effects of pharmaceutical plants
such as eucalyptus, matricaria chamomilla, mint, celery and hundreds of other
types on humans and even animals, recovery and health and moreover,
the role the plants play in all living things, including human, dietary
and vice versa, the allergic and inflammatory effects of plants directly affect
immune system as well as so many other roles that plants play in human and living
things health and disease. The more the difference and variation of climatic
factors and conditions influencing plants the more effect the surrounding environment
and all therein will take. For instance, low rate of light, not suitable soil
and salinity have direct effect on plants growth and as a consequent, on the
organisms consuming them. There are so many examples to be given in this respect.
These may even make unfavorable effects on organisms genetic system in
long term and/or upon modifying climate in a certain region the plant and environmental
area will be improved, for example the influence of greenhouse gases or genetically
interbred plants identify the positive and negative effects of this influence
The role of plants and their activities in settling of settlements is apparent and evident during man civilization history; the relationship of human and animals and unfairly exploitation of animals, on one hand and human beings action for supplying primary needs, on the other hand. For instance, a condition showing the role and activities of plants in the settling of human settlements and their social, economic and cultural activities is nomadic life because:
Nomads rely on pasture and vegetation. This is both related with climatic system
and the quality of soil. Tundra, coniferous forests, steppes of arid zone, Mediterranean
zone, tropical and semitropical, savanna and tropic forests each have its own
certain faun and flora. Therefore, vegetation as well as faun and flora cause
nomads to be relied on a certain system (Moshiri, 2006).
And upon considering nomadism, followed by cave dwelling, as a thoughtful movement
in settling settlements, we will find that this role had been played by means
of a necessary and required movement having been established among the three
elements of plant, animal and man and in this respect, after transition to a
in-the-mass living and the shift from livestock farming-orientated lifestyle
to a agricultural-orientated one which demonstrates the influencing role of
plant in human life. This very role guides man to find areas to be settled,
to make this achievement easier and the settlement alongside aquatic resources,
plains; piedmonts and so on are based on this kind of planning and thinking.
For instance, civilized living of Elam tribes along Karun River, considering
Khuzestan plain, Moqan plain and the objective movements of nomads in Iran,
lifestyle of Buwaihids, Zyarids, Buyids, Alawides in Tabarestan and the forest
zone at the coast of old Gorgan (todays Mazandaran) Sea and so many domestic
and overseas examples are all taken as a confirmation on the history of plants
influencing in human thoughts whether in the field of economic, social, cultural
and even residential activities and this thought has been realized through plants
positive and negative influences in accordance with climatic conditions.
In addition to their role on human beings and animals health and diseases,
plants have other reciprocal influences on human economic and living activities
as well as their social and cultural behaviors. For instance; agriculture, farming,
horticulture and even silkworm breeding whether traditionally or at modern and
advanced level are very effective in economic activities and they are directly
related with other factors and activities which do not concern plants. Cattle
husbandry farming and honey bee breeding are included in this kind of economic
activates (Mahdavi, 2004).
Even the social and cultural traditions and celebrations the people of a region adopt vary for those living in a green space covered with various plants versus those living in arid areas. This effect is so remarkable that it has been integrated in Persian great poems, religious sayings (Ahadith), narratives and even in not-known movements entered into sociocultural movements of inhabitants. Existence of Myrtle in mourning ceremonies in Arab-residing areas of Khuzestan, existence of greenery at Haft-Seen table on Nowrouz (Iranian New Year traditional table with seven symbols), using plants and flowers at celebrations are some signs of the role plants play in cultural and social life of people and their traditional behaviors.
Disease caused by plants influence on living things organism, especially that of human, are different. But, in total, they mostly influence by pollination during certain seasons and months of each year and affect the living things immune system resulting in various allergies. Here we can refer to the allergic agent present in tomato, eggplant, cucumber and some melon-ground fruits such as oblong variety of melons, cantaloupe or deep-ribbed cantaloupe.
However, plant-borne agent having negative effect on living things can be dependent on the nature of the plant, itself, or any other factor affecting plants such as soil, weather, elevations and so on.
ROLE OF EARTH FORMING FACTORS IN MEDICAL GEOGRAPHY (MEDICAL GEOLOGY)
Mineral capabilities of Iran and accordingly, geological complicated mineral and industrial activities on one hand and development of urban planning and settlement regions and existence of diseases with an unknown cause, on the other hand, have necessitated the investigations on medical geology in Iran.
Suitable geological conditions are the requirements for the existence of living
at any region of the Earth. Of initial important are oxygen, water and the environment
in which the living things can live. These were obvious for human being from
the earliest time of his life on Earth and therefore, human societies have been
developed in regions with such conditions. But as time passed and as a result
mans need to natural resources, he was further exposed to environmental
factors. For the same reason, in historical references of many civilizations
the relationship of environment and human health has been taken into consideration.
But in some cases, the relationship with natural environment is also taken as
an origin for health problems. For example, in a Chinese medical book dating
back to two centuries B.C. there is a reference to the relationship between
environment and health and moreover, the existence of some respiratory diseases
caused by gravels, toxicity of lead in occupations and also, the poisoning characteristic
of silver, copper, antimvan and mercury have been demonstrated (Curtis
and Riva, 2010).
Currently with the available developed new sciences and making extensive investigations
associated with environmental effects on human health, a relationship between
geological conditions and health has been surprisingly indicated. In conclusion,
in view of the scientific proof on the relationship of many diseases with geology,
a new sub-discipline of science, namely Medical Geography has been founded.
This new science is, in fact, involved in the examination of the relationship
between geological factors, humans and animals health as well as the influence
of environmental effects on the geographical diffusion of related diseases (Ganji,
Poisoning elements present in soil and stone are formed by natural geochemical
activities and human actions and they usually entered human body through eating
and drinking and thereby, affect human health. Since, drinking water is supplied
in a natural manner and it is mainly affected by local conditions, the excess
amount of some non-organic compounds entering human body through drinking water
has caused problems in different areas (Kardavani, 2006).
An epidemic disease related with medical geography is Goiter (iodine deficiency) and other diseases associated with excess or lack of certain elements like fluorine and silicon. Cardiovascular diseases related with the physical hardness of water are subjects of medical geology in addition to other topics which will be discussed.
Medical geology, in general, is a science dealing with the examination of the
relationship between geological factors and humans and animals health as well
as the influence of environmental factors on the geographical diffusion of related
diseases. In view of the scientific proof on the relationship of many diseases
with geology, a new sub-discipline of science, namely Medical Geography has
been founded (Ramesh and Hyma, 2005).
There are several factors in the structure which forms earth crust, i.e., reliefs,
affected by earth internal layers as well as earth core and external factors
including light, weather and climate and so on. As a result of the existing
tectonic conditions and earth crust changes, the influence of geological factors
and geographical diffusion on diseases and health in here and especially in
Iran plateau, the 1996 Environmental Congress decided to organize an international
working team in the field of medical geology aiming at the promoted importance
of this subject among scientists, medical affairs specialists and the public
And finally, since the environment can be regarded as the origin of reciprocal
effects of geology and biology, there are many developing difficulties, challenges
and environmental problems. Main and secondary elements of bed rock or earth
may be turned to a direct treat for humans or animals health under certain conditions
and to a fundamental cause of organisms disorders and poisonings (Shokouhi,
In conclusion, medical geology, as a sub-discipline of medical geography provide an appropriate foundation to examine the influence of environmental factors that can reveal the role of other elements and factors in the establishment of human environments in a positive or negative manner and to identify the productive and/or destructive interactions in human decision making.
Obviously, it is necessary to consider the novel sub discipline of medical geography because it, as a base, may play a role as a determinant index in all principal and fundamental aspects. Medical geography can secure all human and environment planned infrastructures.
And medical geography is the basic principal and observer in politic-economical, social and even cultural development of a system. However, medical geography can reveal rather more effective role in a more strict manner and novel characteristics through a series of guidelines, the most important of which are as follows:
underlying rule of any planning should be based on environment and human,
i.e., it should have a fixed role in principles and structures
environmental identity book should be made for each geographical region
containing all its features such as water, quality of soil, climatic structure,
dispersion of planets and so on, enabling us to provide more time for
the requirements in future planning, that is, each region should be codified
to allow obtaining required sensitivities regarding environmental essence
before any decision is made
||The major of medical geography with the branches of Human
and Environment should be incorporated as a fundamental field of study in
university system of education
at last, medical geography philosophically has a historical role and medically
has a preventive role, respectively and every one, especially medical
scientists, believes that prevention is predominant to treatment