Transcript Research poster 36 x 48 - D

11. Health Effects From Volcanic Eruptions
Kevin Friscia, Earth and Physical Sciences Department, Western Oregon
University, Monmouth, Oregon, 97361
email: [email protected]
ABSTRACT
Volcanic processes operated on
Earth long before the onset of
planetary
life
and
biological
evolution. Humans have long lived in
the shadows of active volcanoes,
with catastrophic deaths in proximal
eruptive zones the most obvious
hazard. Only in the past several
decades have geoscientists begun
monitoring the long term effects that
volcanic emissions have on human
health. Living near vents causes
hazards associated with pyroclastic
and lava flows, while farther away,
fine atmospheric tephra pose other
health problems. This study focuses
on the long-term health effects from
volcanic eruptions. Ejecta containing
hot ash, gases and dust commonly
result in inhalation, short-term
respiratory stress, skin and ocular
irritation. Inhalation of volcanic
gases (e.g. SO2, H2S, SO3, H2SO4)
can lead to chronic respiratory
disease and death. Understanding
of the long- and short-term effects
associated with volcanic eruptions is
essential for developing public heath
strategies and hazards mitigation
plans in tectonically active regions.
Both regional and global case
studies
are
presented
to
demonstrate the relevance of
medical geology with respect to
applied practice.
Discussion of Case Studies
INTRODUCTION
Volcanic eruptions have occurred since before
human have inhabited the earth. Though the most
notable eruptions are from specific events that have
been recorded. (Fig 1.) Gives a list of specific
eruptions that have made a detrimental impact on
landscapes and human health. Over the past 500
years as many as 250,000 death have been
recorded (Weinsten 2005). Though medical geology
is a relatively new topic of research, it has been
observed for centuries. The history of heath effects
are observed from old data with symptoms
depending on the specific type of gas.
Figure 2. Basic Diagram of Plate Tectonics
Health Connection
My discussion is mainly based on long term effects of
volcanic eruptions. Apart from thermal and physical
injuries from an eruption, ejecta may also contain toxic
elements that can cause long term damage (Weinstein
2005). Emissions from volcanic eruptions cause the
most harmful effects, which include hot ash, gases and
dust. Hot ash can cause irritation of the skin causing a
rash from contact. Eye damage is cause by fine
tephra particles that make contact with the cornea.
Most irritation of the eye is from people with eye
contacts. Nasal irritation mainly involves stuffiness
after an eruption, along with throat irritation that
contains sore throat issues. Short term death from
gases when inhaled can cause asphyxiation, though
long term damage from inhalation of gases include
SO2 that can cause prolonged respiratory disease.
Figure 1. Data from the deadliest historical
Fluoride from skin irritation and inhalation can cause
volcanoes
permanent lung injury and osteoporosis of ligaments.
Volcanic material also can enter the human body by
Geologic Processes
ingestion from foods or soil, most commonly exposure
Volcanoes processes occur due to plate tectonics. of selenium.
The Earths lithosphere is broken into several tectonic
plates which ride on the asthenosphere. The plates
are either converging, diverging or sliding past each
other. (Fig 2.) shows the three types of plate
boundaries. Most commonly volcanoes form from
convergent and divergent plate boundries. When a
plate subducts under another plate, the subducting
plate melts and magma rises creating volcanoes.
During volcanic eruption, debris and gases are
emmited. Debris can include pyroclastic flows, lahars,
lava and ash. Pyroclastic flows and lahars can be the
most deadly ejecta from a volcanic eruption causing
incredible damage within 100km from the volcano.
Gas emission, though very deadly, causes long term
damage that can disrupt biological systems.
Figure 3. Common illnesses from case study.
During an Iceland eruption from the Laki fissure,
studies were done from the air pollutants (gases and
aerosols) in the troposphere in 1783 (Fig 3). High gas
contents flowed to Europe through a volcanogenic dry
fog. Respiratory problems were noted with an extreme
increase in asthma related dysfunctions. Eye irritation
also increased with reports of tiring, stinging and
tingling which was cause by sulfur dioxide(SO2).
Headaches and loss of appetite were also noted by
the intake of fluorine and H2S. Overall, Europe was
affected greatly due to the westerly wind that carried
the pollutants, creating the widespread episodes of
respiratory illnesses (Gratten 1999). The dry fog did
contain sulfur, chlorine and fluorine which caused the
reported symptoms from prolonged breathing.
Summary
Short term and long term deaths caused by volcanic
eruptions is still a very common today. Understanding
the warning signs of a volcano, using public strategies
and mitigation plans to stay away from danger of a
potential eruption is the best way to stay safe. The
use of medical geology has made way to gather
information of volcanoes and past health problems
and give better insight on what to do to reduce
volcano-related deaths.
Figure 4. Health effects of Mt. Vesuvius eruption.
REFERENCES
Weinstein and Cook, 2005, Volcanic Emissions and
Health, in Selinus, 2005
Durand and Grattan, 1999, Extensive Respiratory
Health Effects of Volcanogenic Dry Fog 1783 Inferred
From European Documentary Sources