Preventing and Managing Wildfire Smoke Inhalation

Wildfire smoke inhalation poses a serious health risk for outdoor workers and vulnerable populations such as older adults, children, and individuals with respiratory conditions. Exposure to smoke and ash can significantly impact air quality and trigger or worsen breathing issues. This fact sheet outlines key prevention strategies, the proper use of N95 masks, and steps to take at the first sign of symptoms. It is intended for the general workforce and public not trained firefighters or first responders who use specialized respiratory protection.

Wearing a Mask

When exposed to smoke, ash and other particulate matter, public health officials recommend wearing a properly fitted N95 dust mask with two elastic straps. When there is a seal around the nose and mouth, masks with an N95 rating (N=not oil resistant) filter out 95 percent of particles that are at least 0.3 microns in diameter. While masks with an N95 rating offer some protection from fine particles in smoke, they do not block exposure to toxic gases. Dust masks worn when cleaning house or gardening, and surgical masks used in dental and medical offices, do not provide adequate protection in smoky environments.

Masks reduce air flow. People with asthma and other types of chronic health conditions should consult their physician.

Occupational Exposure Risks

With advances in fire protection, construction techniques and product manufacturing, fire-related mass casualties in the U.S. are relatively infrequent. The vast majority of fire-related deaths and injuries occur to individuals in their homes. In the U.S., fire-related deaths decreased 21.6 percent from 2006 to 2015 (U.S. Fire Administration statistics).

However, wildfire-related exposure risk appears to be increasing. In 2016, more than 67,000 wildfires burned over 5.5 million acres. National statistics for 2017 will be considerably impacted by wildfires in Northern and Southern California. The National Interagency Fire Center estimates more than 72,000 U.S. communities are at risk from wildfires.

Most injuries and deaths directly linked to exposure are not caused by burns but by smoke inhalation, lack of oxygen and toxic fumes from burning materials such as plastic and vinyl. Smoke can contain potentially lethal components such as:

• Particles that can lodge in the lungs, irritate eyes, and affect respiratory and digestive systems
• Toxic liquids, gases and vapors that can be inhaled or absorbed through the skin

Chemical irritants found in smoke include ammonia, carbon monoxide, chlorine, hydrogen chloride, hydrogen cyanide, phosgene and sulfur dioxide. Carbon monoxide, hydrogen cyanide and hydrogen sulfide are examples of chemicals produced in fires that interfere with the body’s use of oxygen at the cellular level.

Carbon monoxide, an odorless, colorless gas, is the leading cause of smoke inhalation incapacitation and death. Sources of carbon monoxide include cars, stoves, heaters, generators, and burning charcoal and wood. (As of January 2017, 32 states had statutes requiring use of carbon monoxide detectors; another 11 have promulgated regulations, according to the National Conference of State Legislatures.)

Fire can also cause incapacitation by reducing oxygen levels, either by consuming oxygen or by displacing it with other gases. Heat is also a respiratory hazard. Superheated gases burn the respiratory tract and can be fatal.

Inversion

Outdoor exposure risk increases when a temperature inversion traps smoke, other pollutants and fog (smog) close to the ground. For example, an inversion can occur when a warmer, less-dense air mass moves over a cooler, denser air mass. Local geography and climate, such as coastal communities in fog belts or urban areas located in valleys or basins surrounded by mountains, are contributing factors.

An inversion is also produced when radiation from the surface of the earth exceeds the amount of radiation received from the sun, which commonly occurs at night or during the winter when the sun is low in the sky. Temperature inversions are also associated with severe thunderstorms and freezing rain.

Symptoms and Assessment

Airway, breathing and circulation – the ABCs – apply when evaluating signs and symptoms of smoke inhalation. Watch for the following:

• Loss of consciousness (medical emergency)
• Nausea/vomiting
• Shortness of breath
• Chest tightness
• Coughing with or without mucus
• Burning sensation in the throat and/or lungs
• Voice changes/hoarseness
• Tingling sensations (may be related to oxygen deficiency)
• Headache, dizziness, lightheadedness
• Confusion or irritability
• Burning sensation to the eyes, blurry vision, watery eyes

Questions that may apply during a medical assessment include:

1. What was the source and duration of exposure to smoke?
2. Is there a likelihood of exposure to burning plants such as poison oak or poison ivy? (Inhalation of plant toxins may constitute a medical emergency.)
3. Does the person with suspected exposure have a history of asthma or other respiratory disease?

Recommendations

In a medical emergency, follow your company’s emergency assistance protocol or call 911. If you observe or experience non-emergency signs and symptoms of smoke inhalation, move to an area with clean air and seek medical advice. In addition to wearing a mask, here are some ways to prevent or reduce smoke inhalation symptoms:

1. As feasible, work indoors or limit outdoor exposure.
2. Avoid strenuous activity and outdoor exercise.
3. Keep windows and doors closed, and use the air recirculation option in vehicles.
4. If you run an air conditioner, keep the fresh-air intake closed and ensure the filter is clean.
5. Do not burn candles or light a fire in a fireplace or wood-burning stove.
6. Increase fluid intake to the extent your personal health allows.
7. Use over-the-counter natural tears or eye drops for burning or watery eyes.
8. If you use an inhaler, make sure you carry it with you and have a prescription refill on hand.
9. Check air quality reports at www.AirNow.gov and avoid smoky areas.
10. Important: If your symptoms persist or get worse, consult a medical professional.

DOWNLOAD