Altitude

1
Altitude

• BCN 3735 Construction Safety

2
Agenda

• Introduction
• Construction at high Altitudes
• Effects of high altitude
• Precautions
• Conclusion

3
Introduction

• 40 Million people live at altitudes over 3000 m
• Impossible to live at altitudes over 5500 m for
  more than a few months.
• Improvements in technology are allowing for new
  construction in more difficult and dangerous
  areas.
• Safety concerns include tight working spaces
  ,maintenance of mechanical equipment and worker
  safety.
• Medical concerns are very serious and attended to
  with every precaution.

4
Construction at High Altitudes

• China Tibet Train
• Qinghai to Tibet
• 30 kilometers of tunnels and 286 bridges
• Line lies between 4000 and 5000 meters
• Asphalt Paving in the Rocky Mountains
• Trail Ridge Road in Rocky Mountain National Park,
  12,183 feet
• Pikes Peak Toll Road
• Telescopes
• Mauna Kea, Hawaii (altitude 4200 m)
• Chajnantor plateau in north Chile at an altitude
  of 5050 m.

5
Why does high altitude affect us?

• All the medical effects of high altitude are
  caused by oxygen deprivation.
• The reduction in oxygen is best described by the
  fall in inspired partial pressure of oxygen
• These altitudes can have serious physical effects
  on humans.
• The three major areas that are affected are
• mental performance
• physical performance
• quality of sleep

6
High Altitude Diseases

• Altitude Sickness- Hypoxia
• Low oxygen pressure
• Ambient pressure and partial pressure of oxygen
  decrease with altitude.
• AMS- Acute Mountain Sickness
• Monges Disease
• Rarely occurs below 2500 m
• Headache, drowsiness, general fatigue, difficulty
  breathing during physical exertion, nausea, loss
  of appetite.

7
High Altitude Diseases

• High Altitude Pulmonary Edema- HAPE
• May when ascending rapidly from sea level to
  altitudes over 2500 m.
• Symptoms such as coughing, fatigue and breathing
  difficulties usually appear 2 to 7 days after
  arrival.
• High blood pressure in the lungs forces fluid
  into the lung tissue, possibly impeding oxygen
  from moving through the alveoli to the blood.
• Woman are at less risk teenagers and children at
  higher risk.

8
High Altitude Diseases

• High Altitude Cerebral Edema- HACE
• serious, but rare condition where fluid leaks
  out of capillaries into the brain tissue.
• Begins like acute mountain sickness but
  progresses to loss of balance, difficulties with
  walking, clouding of consciousness, irrational
  behavior and coma.

9
Effects of High Altitude

• Mental Performance
• arithmetical errors
• reduced attention span
• increased fatigue
• impaired short-term memory
• increased difficulty in making decisions.
• Conditions improved after acclimatization.

10
Effects of High Altitude

• Physical Performance
• physical work performance (power output) depends
  on the
• amount of oxygen available to the body.
• As altitude increases, maximal oxygen uptake
  falls.
• At 4200 m, power output of the body is reduced to
  about 70 of its sea level value.
• Muscular exertion
• Fatigue and Panting
• Difficult to recover from full days work

11
Effects of High Altitude

• Quality of Sleep
• Difficulties sleeping noticeable at 2500 to 3000
  m (like at ski resorts)
• wake frequently, have unpleasant dreams, and do
  not feel
• refreshed in the morning
• Caused by periodic breathing, waxes and wanes of
  breath with typical cycles of ten to fifteen
  seconds
• Apnea, no breathing at all, may occur for five to
  ten seconds.

12
Precautions and Prevention

• Acclimatization- adapting to the oxygen
  deprivation of high altitude to some extent
• Hyperventilation
• Polycythemia
• Increased concentration of capillaries in some
  body tissues
• changes of oxidative enzymes in the cells
• full acclimatization requires continuous
  residence at
• the altitude for about ten days.

13
Precautions and Prevention

• Acclimatization- adapting to the oxygen
  deprivation of high altitude to some extent
• Although acclimatization ameliorates the hypoxia
  of high altitude to some extent, professionals
  still recommend supplementary oxygen.

14
Precautions and Prevention

• Plenty of rest
• Avoid alcohol
• Avoid tobacco
• Avoid marijuana
• Stay hydrated
• Avoid heavy meals

15
Conclusion

• Today there are many reasons for working at high
  altitudes, but these altitudes can seriously
  impair human mental and physical performance and
  quality of sleep.
• Acclimatization is crucial to high altitude work,
  but it not always sufficient.
• The introduction of supplemental oxygen , or
  concentrated oxygen where workers sleep,
  dramatically improves conditions.