11. Health Effects From Volcanic Eruptions

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11. Health Effects From Volcanic Eruptions
Kevin Friscia, Earth and Physical Sciences
Department, Western Oregon University, Monmouth,
Oregon, 97361 email
kfriscia05_at_wou.edu
ABSTRACT
Discussion of Case Studies
INTRODUCTION
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.
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.
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
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 1. Data from the deadliest historical
volcanoes
Geologic Processes
Volcanoes processes occur due to plate tectonics.
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 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
Figure 3. Common illnesses from case study.