Medicine and Myth to Modern:

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Medicine and Myth to Modern Thoughts on
Connections Between Geology and Human Health
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Hippocrates (460-377 BC)
Whoever wishes to investigate medicine properly
should proceed thusWe must also consider the
qualities of the waters, for they differ from one
another in taste and weight, so also do they
differ much in their quality
So Hippocrates appreciated the significance of
human health in context of the characteristics of
the natural environment
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Marco Polo (1254-1324)
Su-chau
During his travels to China, Marco Polo noted a
curious affliction in imported European horses
that grazed on vegetation in Su-chau symptoms
only showed up in imported horses and were absent
among horses that were raised in the area.
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Observations Made by Marco Polo in Su-chau
Travellers passing this way do not venture to go
among these mountains with any beast except those
of the country, because a poisonous herb grows
here, which makes beasts that feed on it lose
their hoofs but beasts born in the country
recognize this herb and avoid it.
Geological investigations made much later
indicated high concentrations of selenium in the
soil of the Su-chau regions. Certain varieties
of plants (including grasses) concentrate
selenium in their tissues without ill effect.
Butherbivores cannot cope with very high
concentrations of selenium
Common symptoms of selenium poisoning Weakening
of hoofs/nails and hair (plus others that we will
look at later on in course). So Marco Polos
observations (together with geological evidence)
suggest selenium poisoning.
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Curative Properties of Minerals
Egyptians are known to have used Copper salts,
wine and frankincense were used to wounds. For
many centuries after the fall of the Roman
Empire, the Arabic world was the centre of
scientific and medical knowledge (700 - 1500 AD)
. Arabic pharmacists became skilled in the
formulation of medicines from plants and
minerals. In the Medieval and Renaissance
periods, use of mineral materials for the
treatment of ailments was widespread. But many
of the curative properties of minerals were
attributed to supernatural factors.
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Curative Properties of Minerals
The purported curative properties of minerals are
not completely unfounded Some minerals do have
antibacterial properties (e.g. Halite-regular
table salt) Other minerals provide important
elements for normal functioning of the human body
(hence the use of minerals for the manufacture of
dietary supplements).
Other curative properties are a bit more
dubious (even now !)
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By mid- to late- 20th century, people started to
recognize links between disease and environmental
factors Examples Incidence of widespread
common ailments such as goiter Concentration
of trace metals in food Occurrence of unusual
diseases associated with uses of common geologic
materials
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Goiter
Goiter (Latin guttur for "throat) is an
enlargement of the thyroid gland. Although
generally not uncomfortable, goiter may interfere
with swallowing or breathing.
Before the early part of the 20th century, goiter
was very common in the developed world, but was
especially prevalent in areas distant from water
bodies. Adolescent goiter was once considered
normal ! It is still common in developing nations
!
In North America, once very prevalent in Midwest
and Northwest U.S. (most common cause of draft
rejection in Michigan, during WW I) The Great
Lakes, Midwest, and Intermountain regions became
known as the "goiter belt".
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As early as 1833, Jean Baptiste Boussingnault
recommended the use of iodized salt to cure
goiter. By the early 1900s, it became widely
apparent that a common cause of goiter was iodine
deficiency (without enough dietary iodine, the
thyroid gland can't make and release enough
iodine-containing hormones). Food grown on
iodine-depleted soils of interior of North
America are very poor in iodine. Butseafood and
crops grown in coastal areas generally to contain
sufficient iodine for normal thyroid
functioning. Goiter became rare in the North
America after iodized salt was introduced in the
1920s.
Yay ! Im goiter-free !
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Minamata Disease
In 1956, in Minamata City located on the
Yatsushiro Sea coast in Kumamoto Prefecture, the
first Minamata Disease patient was reported as a
patient suffering from neurological symptoms of
unknown cause. In 1965, Minamata Disease
patients were also reported in the Agano River
basin in Niigata Prefecture.
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Minamata Disease Symptoms

• The initial symptoms included
• numbness of limbs area around mouth
• sensory disturbance
• difficulty with everyday hand movements
• lack of coordination
• weakness
• tremor
• slowed and slurred speech
• altered vision and hearing
• These symptoms worsened and led to general
  paralysis, involuntary movements, difficulty in
  swallowing, convulsions, brain damage, and death.

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The Aftermath of Minimata Outbreak
In 1968, the Japanese government sorted out
knowledge related to Minamata Disease and
announced its opinion. Minamata Disease was
determined to be a poisoning disease of central
nervous system caused by methylmercury compound
produced as by-product in the process of
manufacturing acetaldehyde near Minamata City and
upstream of Agano River Methylmercury compound
was discharged with the factory effluent and
polluted the environment, and then, through the
food chain, accumulated in fish and shellfish.
Consequently Minamata Disease occurred when the
inhabitants ate high amount of these seafoods.
2,265 persons affected by Minamata Disease on
the Yatsushiro Sea coast and 690 persons in the
Agano River basin
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Recent Minimata Outbreaks ?
In addition to being used in industrial
applications, mercury is also used in large
quantities in gold mining (used to separate gold
from crushed ore) and is readily washed from
soils in deforested areas. Miners release about
250 tonnes of mercury into the Amazon region each
year, most ending up in rivers- some forms of
bacteria can convert inorganic mercury to the
dangerous methylated form Minamata-type symptoms
have recently been documented in fishing
communities of the Amazon Basin where mining and
deforestation has been severe.
Determination of nature and extent of this
outbreak relies on a broad knowledge base with a
focus on interactions between physical, chemical,
and biological systems geologists are trained
to understand these interactions.
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Relevance of geological principles to current
health concerns
Bone diseases (with a recent focus on
osteoporosis) -related to bodys ability to
maintain healthy bone growth (obviously, in order
to understanding the dynamics of bone
mineralization, one must understand the manner in
which the minerals form) -recent studies have
demonstrated that substitution of calcium by
other ions (e.g. magnesium, strontium) may be
more significant to bone health than previously
thought
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Relevance of geological principles to current
health concerns, contd
Health concerns related to dust (with recent
focus on asbestos) -different forms of asbestos
(each with different mineral properties) have
been shown to pose very different health risks
-geomedical studies on asbestos and other
particulate mineral substances are currently
investigated -better understanding of effects of
minerals on human health will impact public
policies on the management of particulate
substances
Asbestosis scarring of lung tissue due to
inhalation of asbestos fibres
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Relevance of geological principles to current
health concerns, contd
Outbreaks of respiratory disease (e.g.
asthma) -recent cases have shown links between
respiratory disease and certain soil
fungi -geomedical studies are currently being
conducted to see how factors such as soil-forming
processes, climate, and the geochemical
characteristics and parental rock materials of
soils influence the proliferation of certain soil
fungi
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Relevance of geological principles to current
health concerns, contd
Trace element poisoning (due to high
concentrations of arsenic, fluoride, lead, and
other trace elements
e.g. Guizhou Province, China
Burning of low-grade coal (which has replaced
now-scarce wood as fuel) releases high
concentrations of arsenic (people ingest arsenic
via chili peppers dried over unvented stoves
Clay used as binder for coal briquettes -releases
high concentrations of fluorine when burned,
leading to fluorosis
Reduction of effects of trace metal poisoning
here will require knowledge of the distribution
of trace elements within fuel and clay deposits
and the development of inexpensive field tests
that can be used to determine trace element metal
toxicity.
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So how do geologists fit into the health equation
?
Geologists, being interdisciplinary scientists,
must have a good understanding many aspects of
Earths materials their composition, physical
and chemical properties, distribution, and the
manner in which they interact. The geologists
understanding of the complex interface and
interaction of substances in the natural
environment, in both time and space, is essential
to getting to the root of medical issues that
relate to processes inherent to the Earth System.
Awareness of the big picture enhances the
utility of information gleaned from more specific
biological, chemical and physical studies.
Geology serves as the glue for all Earth-based
science.
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End of Lecture