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Storm Decline Fatalities. A mine rescue trainer and co-trainer were fatally injured during exploration of an abandoned underground decline. Wearing approved self contained breathing apparatus, they collapsed while retreating up a 2000 foot slope with a 15 percent grade.
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Storm Decline Fatalities A mine rescue trainer and co-trainer were fatally injured during exploration of an abandoned underground decline. Wearing approved self contained breathing apparatus, they collapsed while retreating up a 2000 foot slope with a 15 percent grade. The cause of death was attributed to multiple organ failure from environmental exposure.
Causal Factors • A risk assessment to identify all possible hazards was not conducted prior to exploring the abandon decline • A protocol was not developed prior to the team’s exploration, nor were restricted activities defined. • Constant communication was not maintained between the surface and the team
Conclusion The fatalities resulted from a failure to accurately assess the risks from exposure to an environment with excessive heat and humidity.
Physical Environment • No air movement The decline had not been ventilated for more than two years • They expected the temperature to be 100 degrees Fahrenheit (38°C) with very high humidity • They knew the oxygen level may be low
Risk Factors for Heat Related Injuries • Dehydration • Salt depletion • Lack of heat acclimatization • Poor physical fitness • Excessive body weight • Medications • Inflammation, fever, gastroenteritis • Chronic disease • Alcohol use
Factors Controlling Body Heat • Heat stress is caused by high temperature, high humidity, radiation and low air movement • Heat exchange from skin is influenced by air temperature, air humidity, air movement, radiation and clothing • Heat loss occurs from convection when air temperature is below body temperature • Heat loss occurs from radiation when the temperature of surrounding objects is below body temperature
When surrounding temperatures are above skin temperature Evaporative heat loss accounts for all body cooling Body fluid is secreted onto skin to evaporate, fluid loss may be 2 Liters/Hour
When surrounding temperatures are above skin temperature Evaporation depends on air movement and the water vapor pressure gradient between the skin and the environment If sweat is not evaporated, sweating slows and body core temperature rises
Exertional Heat Stroke • During strenuous physical activity the body generates heat, causing core temperature to elevate. Blood flow to skin increases and sweating begins. • Cardiac output can not maintain blood flow to support to lower core temperature and can not provide adequate blood to support muscle activity • Victims suffer organ or tissue damage
Classical Heat Stroke • Hot dry skin with elevated body temperature, headache, confusion, dizziness, irrational behavior, convulsions or coma • High core body temperature (41.3 C) resulting in liver damage, or renal failure • Treatment – Rapid reduction of core body temperature
American Mining Regulations • Mandatory regulations in America do not address heat stress • Adoption of recommendations is voluntary on the part of the mine operator. • In the past 5yrs, 150 cases of heat related illnesses have been reported
Managing Heat Illnesses Develop a preventive program to identify risks related to heat Implement a policy to protect mine rescue personnel from heat stress
Prevention of injuries Management should establish standards, policies and administrative controls that implement Risk Assessment into the work cycle. No operating condition or urgency of service can ever justify endangering a person’s life.