Field Notes
Studies by Ruby and Sharkey in the United States, Sleivert in Canada, and Budd and Brotherhood in Australia confirm the high energy demands of wildland firefighting (7.5 kcal per minute, over 400 kcal per hour, up to 6000 kcal per day). Studies on military populations by Askew and Wood indicate the contribution of energy supplementation to immune function during periods of arduous work. Studies by Nieman support the value of liquid carbohydrate supplementation to immune function during prolonged work. Solid and liquid energy supplements provide energy and help to maintain the function of the immune system during periods of prolonged arduous work. A University of Montana study (Puchkoff and others 1998) indicates that carbohydrates also help maintain mental performance during prolonged periods of physical stress.
The use of between-meal energy supplements is recommended, including:
- Energy (or candy) bars.
- Carbohydrate and electrolyte (C/E) sports drinks.
Firefighters should consume at least two energy bars daily: one between breakfast and lunch, the other between lunch and dinner. Additional energy should be consumed during the lunch break and whenever meals are delayed. Further, it is recommended that firefighters be issued a powdered carbohydrate and electrolyte drink mix in sufficient quantity to provide for 25 to 50 percent of fluid needs. After work, the firefighter should be encouraged to rehydrate to replace fluid loss, and to immediately begin consuming carbohydrates to replace muscle carbohydrate stores.
Research has not indicated the superiority of a specific brand of energy bar. An energy or candy bar containing 200 to 250 kcal of energy, with at least 40 percent of the calories in the form of carbohydrate, will help sustain energy and immune function. Some energy bars include antioxidant supplements. Research on military populations suggests energy bars may help reduce muscle damage and subsequent fatigue. MTDC is studying the need for antioxidant supplementation in wildland firefighting.
No specific C/E sport drink has been proven more effective for firefighters. Regular use of C/E drinks will encourage fluid intake, provide energy, and diminish urinary water loss. The carbohydrate also helps to maintain immune function and mental performance during prolonged arduous work. Available products include between 200 and 400 kcal of energy per quart of liquid. Firefighters should be encouraged to provide 25 to 50 percent of fluid needs (2 to 4 quarts) with C/E drinks, mixed to suit their taste.
After work it is important to continue energy and fluid replacement. Ensure adequate carbohydrate intake in the first 2 hours after work to restore muscle glycogen levels. Rehydrate with a beverage containing some salt or eat foods containing salt to minimize urinary fluid loss. Continue energy and fluid replacement for several hours after the end of the work shift.
Information on dietary energy sources (carbohydrate, protein, and fat), vitamins, and minerals can be found in Fitness and Work Capacity (9751-2814-MTDC), along with information on nutrition and the immune function, oxidative stress, and dietary recommendations. USDA dietary recommendations suggest three to five servings of vegetables and three to four servings of fruit daily. Most firefighters get fewer servings than recommended even though they need more servings to maintain health and sustain performance.
MTDC is planning field studies to document the dietary intake and nutritional needs of firefighters, and to determine the effects of energy and nutrition on immune function and antioxidant status in wildland firefighting. The results of these studies and related work will be disseminated in future editions of Wildland Firefighter Health and Safety Report.
Recommendations
To meet energy and fluid needs and to maintain immune system and cognitive function, firefighters should:
- Eat two to three energy (or candy) bars daily (between meals).
- Drink carbohydrate and electrolyte (sport) drinks to provide up to 50 percent of fluid replacement needs.
- Continue carbohydrate and fluid replacement after work to ensure energy and fluid needs are met.
Medical Standards for Wildland Firefighters
The Federal Fire and Aviation Leadership Council (FFALC) accepted draft medical standards at its January meeting in San Diego. After followup work to fine-tune the standards, the forms, and the process, the medical standards will undergo pilot testing in Fiscal Year 2001.
The medical standards are intended to help the examining physician, the agency personnel officer, and the medical review officer determine whether medical conditions may hinder an individual's ability to safely and efficiently perform the arduous work requirements of wildland firefighting without undue risk. They are also intended to ensure consistency and uniformity in the medical evaluation of applicants and incumbents. Each of the standards is subject to clinical interpretation by a medical review officer (MRO) who will incorporate knowledge of the job requirements and environmental conditions in which employees must work.
The medical standards were developed to address health and safety issues, to improve medical surveillance, and to reduce job-related injuries. The initial medical exam includes a medical history, physical examination, and tests of vision, hearing, and blood. Subsequent examinations will be administered every 5 years until the age of 45, then every 3 years thereafter. A medical history and medical screen will be employed in the years between medical examinations. Future issues of this report will provide details of the program as they become available.
According to the National Institute for Occupational Safety and Health's (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 died from heart disease at a rate similar to the population at large. Data for wildland firefighting indicates 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 employed by States (Mangan 1999). The National Fire Protection Association (NFPA) has a standard on medical requirements for firefighters, (NFPA 1582).
Late summer wildfires on the Shasta Trinity National Forest, combined with stagnant meteorological conditions, culminated in the first declared state of emergency in a California county due to air pollution, and the first-known evacuation based on hazardous air pollution levels. Hourly average particulate values (PM10) at the Hoopa monitoring station ranged up to 1000 ug/m3, and area stations recorded several days of 24-hour average PM10 levels in excess of 400 ug/m3. On October 22, 1999, the County Emergency Services Office prepared the following notice:
The Humboldt County Sheriff's Department Office of Emergency Services is strongly recommending evacuation of the Hoopa, Willow Creek and all smoke affected areas due to serious health risks caused by hazardous air quality.
The conditions were reminiscent of those recorded in 1987, the year that led to the National Wildfire Coordinating Group's study of the effects of smoke exposure on wildland firefighters. For information on that project, contact MTDC for Health Hazards of Smoke: Recommendations of the April 1997 Consensus Conference (9751-2836-MTDC).
