Arduous Work

The pack test is based on the demands of wildland firefighting. It was developed to test the ability to perform prolonged arduous work under difficult environmental conditions, with a reserve to carry out emergency responses. The test includes elements of aerobic and muscular fitness that are related to the performance of firefighting tasks. While the pack test was developed to screen firefighters, the arduous category has been extended to cover 20 additional positions (NWCG 310-1). Several test-related fatalities raise questions regarding application of the test to these positions. Positions that do not fit the arduous category and are not required to perform the tasks of wildland firefighting may be better served by the moderate or light categories.

The Safety and Health Working Team (SHWT) has requested a review of the work capacity requirements for all line positions. MTDC has begun a review and will report recommendations for further study. Recommendations will be considered by the National Wildfire Coordinating Group. In the meantime, test admin-istrators should conduct health screening for all work capacity tests. Candidates should engage in training appropriate for the test and the job.

According to the National Institute for Occupational Safety and Health (NIOSH) Fire Fatality Investigation and Prevention Program, 49 percent of deaths among municipal (structural) firefighters are from heart disease. The largest firefighter mortality study ever conducted confirms that municipal firefighters die from heart disease at a rate similar to the population at large (Baris et al. 2000). Data for wildland firefighting indicate 42 percent of volunteer firefighter deaths were due to heart disease, compared to 15 percent for firefighters associated with Federal agencies and 11 percent for those associated with State agencies (Mangan 1999). The vast majority of deaths occur in firefighters who are more than 45 years old. Demographics (the number of firefighters older than 45) and annual work capacity requirements explain some of the differences between municipal, volunteer, and wildland firefighter fatality rates.

On wildland fires, heart attacks constituted 21 percent of all fatalities from 1990 to 1998, while entrapments were associated with 29 percent, aircraft 23 percent, and vehicles 19 percent of all fatalities. Studies show that active and fit individuals have less than half the heart disease risk of the sedentary population. During strenuous exercise, the risk of heart attack for habitually active individuals rises to a level slightly above the risk of sedentary living, but only during the period of exertion. The risk for sedentary individuals rises dramatically during strenuous effort.

Heart disease is the major cause of death for men and women. It begins early in life and develops at a rate that depends on the influences of heredity and lifestyle (diet, physical activity, smoking, body weight). While exertion may trigger a heart attack in a susceptible individual (a person with preexisting disease), it does not cause the disease. Regular activity has been proven to substantially reduce the risk of heart disease and cardiac death. The reduction in risk ranges from 30 percent for moderately active individuals to 70 percent for those habitually engaged in vigorous activity. The American Heart Association considers physical inactivity a major risk factor for heart disease.

Risks of Exertion

Unstable Plaque—As people age, their coronary arteries are gradually narrowed by the deposition of plaque, a scale consisting of cholesterol and other debris. Some plaque is soft and easily dislodged, capable of causing a clot that interrupts the flow of blood to the heart. Heavy physical exertion, along with increased heart rate, blood pressure, and hormones (such as epinephrine), may disrupt vulnerable plaque and trigger an acute myocardial infarction (heart attack). At present, no readily available test can identify persons with vulnerable plaque.

Blood Pressure—Individuals with elevated blood pressure (hypertension) may exhibit an exaggerated blood pressure response to exertion, increasing the risk of a heart problem. The exaggerated increase in blood pressure, along with the elevated heart rate associated with a low level of fitness, increase the work and oxygen needs of the heart muscle. If the coronary arteries are narrowed, the muscle may experience the pain of ischemia or lack of oxygen. The Centers for Disease Control report that 61 percent of the population is overweight or obese. Excess weight is associated with elevated blood pressure and low fitness.

Fire Storm 2000—During the 2000 fire season, the worst in 50 years, over 25,000 fire personnel were deployed. Fatality data for the year indicated one heart death related to firefighting and one heart death related to training for the pack test. The fatality incidence was consistent with historic trends that included three fatalities in 1994 and four fatalities in 1996. The small number of fatalities is remarkable considering the number of personnel deployed, the length and severity of the season, and the advanced age of returning retirees (the risk of heart-related deaths increases after age 45 for men and 55 for women).

To Reduce Risk:

• Screen all candidates for wildland firefighting with a health screening questionnaire.
  
• Provide a medical examination for those individuals over 45 years of age and those identified by the health questionnaire.
  
• Train at a moderate intensity for several weeks before engaging in vigorous training or work, particularly if you have been inactive.
  
• Encourage a year-round fitness program for those required to pass at the arduous level (pack test).
  
• Provide an employee health (wellness) program to help reduce cardiovascular risk.
  
• Review the Incident Command System positions that require the pack test.