University of Sourthern California


Raging Wildfires: Public Health Implications

Firefighter In the midst of a wildfireWhy Wildfire Smoke Is a Threat to Health

While the immediate threat of wildfires is obvious, the smoke generated from these fires is also a serious problem. Direct exposure to wildfire smoke can immediately cause health problems in vulnerable populations, and these problems often last long after exposure.

According to the U.S. Climate and Health Alliance, smoke from wildfire comprises a wide variety of chemicals, many of which can result in negative impacts on a person’s health:

  • Carbon dioxide
  • Carbon monoxide
  • Nitrogen oxide
  • Organic chemicals
  • Water vapor

Wildfire smoke also generally contains particulate matter (PM), which poses the biggest threat to human health. PM is essentially a mixture of liquid and solid particles, some of which are visible to the naked eye while others can only be seen with a microscope.

The reason that PM is so harmful to human health is that the smallest particles are easily inhaled, making their way deep into a person’s lungs, and in some cases, their bloodstream. Prolonged exposure to particulate matter can result in a variety of negative health consequences, including:

  1. Cardiac events such as irregular heartbeat and heart attacks.
  2. Reduced lung function.
  3. Worsening asthma symptoms.
  4. Early death in those with underlying lung or heart disease.

General Health Symptoms

Certain populations face a much greater health risk from wildfires than others. That being said, everyone exposed to the smoke created by wildfires can experience negative health consequences. Those who live in an area where wildfires are a possibility should be aware of the potential health effects so that they can take action before serious harm occurs.

In a report by PBS News Hour discussing the increase in wildfires, several health impacts were listed, many of which are related to the respiratory system. People exposed to wildfire smoke may experience symptoms such as difficulty breathing and shortness of breath, sinus and throat irritation, as well as coughing. Asthma attacks can also be triggered by wildfire smoke exposure. Other symptoms that a person may experience from wildfire smoke include:

  • Rapid heartbeat
  • Chest pains
  • Fatigue
  • Headache

Smoke Exposure and Heart or Lung Disease

Those who suffer from a chronic disease should be the most concerned with the public health implications of wildfires. As mentioned, wildfire smoke is dangerous for everyone, but it is especially dangerous for those who live with chronic lung or heart disease. Prolonged exposure to wildfire smoke can exacerbate these underlying conditions, which is why anyone dealing with those diseases should be aware of how at risk they are from exposure to wildfires.

The American Lung Association recommends that anyone living with a chronic condition that is exposed to wildfire smoke should keep in touch with their physician. If one is unable to leave the area impacted by the wildfire, a doctor can recommend ways to deal with the smoke.

For those diagnosed with lung or heart disease, monitoring symptoms is crucial after exposure to smoke. Wildfire exposure can put a great deal of stress on both the respiratory and cardiovascular systems. For chronic-disease patients, this increased stress can lead to respiratory arrest and possible heart attacks. A person who has trouble breathing or experiences chest pain after wildfire smoke exposure should seek medical treatment as soon as possible.

As stated by the American Lung Association, symptoms of smoke exposure can persist after the smoke has cleared and can be very dangerous if ignored. Because smoke can linger after a fire has ended, some people can experience symptoms as long as two days after a wildfire has been extinguished. Therefore, those with a chronic disease should continue monitoring their health well after a wildfire has been extinguished. Those who have pain or difficulty breathing after a wildfire or who have a persistent cough need to seek immediate medical assistance.

Children and Wildfires

Although children with ongoing respiratory problems are most at risk from wildfire exposure, the smoke from these fires can be a threat to all children because their lungs are not fully developed.

The Children’s Hospital Colorado offers several recommendations for parents who want to protect their children from the risks of exposure to wildfire smoke. Those in the public health field should also keep these recommendations in mind when developing initiatives related to children and wildfire smoke.

Limiting a child’s time outdoors is the most effective way to protect them from exposure to wildfire smoke. In particular, children with respiratory conditions such as asthma should be kept inside until the smoke has cleared, as exposure can aggravate their condition.

Parents can also protect their children by making sure they have an adequate supply of any necessary medications for the duration of the wildfire. For example, a child with asthma may need to use a rescue inhaler more frequently during a wildfire event.

When a wildfire occurs, parents should look for a variety of symptoms indicating that smoke has affected their child:

  • Noises while breathing, such as wheezing
  • Changes in the color or the pallor of the child’s skin
  • Increased fatigue and decreased activity
  • Difficulty breathing and frequent coughing

Children impacted by smoke exposure may also experience something known as retraction, which is when it appears as if their ribs are retracting into their body. Typically, only babies and toddlers will exhibit this symptom.

After noticing one or more of these symptoms, there are several courses of action that a parent can take. First, the child should be brought inside to limit smoke exposure. If the symptoms don’t clear on their own, medical attention is recommended. A doctor may prescribe a rescue inhaler to help the child until the wildfire has ended.

How Firefighters Are Affected by Wildfires

In addition to the dangers posed to civilians, firefighters are susceptible to additional negative implications from wildfires.

The National Institute for Occupational Safety and Health (NIOSH) indicates that there are countless health risks that firefighters face when combating wildfires. Most of  which firefighters contend are related to the fire itself, such as entrapments and burnovers, however firefighters are susceptible to long-term effects such as illnesses resulting from prolonged exposure to intense heat or injuries due to slips and falls.

Smoke inhalation is also a serious concern for firefighters working to extinguish wildfires. Because they are closer to the direct source of the smoke, firefighters can experience much greater negative consequences from smoke inhalation, even when using the proper safety equipment.

Finally, the intense labor in which firefighters must engage can result in severe medical complications, including cardiac arrest which can result in death. Another condition that firefighters are susceptible to is when muscle breakdowns flood the kidneys with proteins and cause lasting damage, known as rhabdomyolysis.

The Long-Term Consequences of Wildfire Exposure

When a wildfire occurs, the main focus of public health officials should be containing and mitigating the health consequences of the fire. Once the fire has ended, public health initiatives may still be needed, as we pointed out earlier, wildfires can have lasting consequences for both people and the environment.

Pacific Standard magazine states that most healthy adults do recover from the effects of inhaling wildfire smoke. For these people, healing from smoke inhalation is similar to getting over a case of pneumonia. Vulnerable populations, unfortunately, will have a much more difficult time recovering.

Limiting further exposure to smoke is the most important step of recovery. Further exposure will make it increasingly more difficult for a person’s lungs to heal. After wildfire smoke inhalation, doctors may prescribe antibiotics to help with recovery and may also provide medicines such as a corticosteroid that can ease breathing.

For instance, those who suffer from chronic obstructive pulmonary disease (COPD) or asthma may find that their condition is exacerbated for an extended period of time after a wildfire. While they may eventually recover from the exposure, there is no guarantee. Prolonged exposure to smoke can also cause a person to develop smoke-triggered asthma, a condition that may not disappear after the wildfire is over.

Medical intervention will likely be needed for people in these situations. To limit the impact of wildfire smoke, public health officials typically recommend that those already dealing with breathing issues should use an N95 respirator while outdoors to filter out particulate matter. People with existing breathing conditions should also be sure to consult with their physician for advice on how to protect themselves from wildfire smoke.

The cardiovascular system may also experience severe impacts during and after smoke inhalation. Inhaling wildfire smoke can cause the lungs to become inflamed. This inflammation then puts strain on the entire cardiovascular system, causing a heightened risk for stroke or heart attack, due to an increase in blood clotting. For some people, these effects will dissipate once the smoke has cleared. Others may not be as fortunate.

Reporting the findings of the American Heart Association, Health Affairs states that people over the age of 65 are 40 percent more likely to experience a cardiovascular event when exposed to large amounts of smoke. If the person is already dealing with a heart condition, this risk may persist for a period of time after the smoke has dissipated. Since the health effects of wildfires can last long after the fire has been extinguished, public health officials should continue monitoring vulnerable populations after a fire to determine if and when medical intervention is necessary.

How Public Health Officials Can Help with Wildfires

Because wildfires pose such a big risk to public health, the EPA offers public officials several recommendations for handling these events. The first, and most important, recommendation is to alert the public to the presence of a wildfire and the likely drop in air quality. Officials can monitor air quality using a variety of online resources and can alert the public using the existing infrastructure.

The EPA also provides guidelines that public officials can use to protect vulnerable populations during a wildfire. For instance, depending on the quality of the air, public health officials can close schools or allow children with respiratory conditions to leave school early to limit their smoke exposure. Clean air shelters can also be established for vulnerable populations who are not able to protect themselves from wildfire smoke inhalation.

Wildfires are just one type of natural disaster that can negatively impact the public’s health and involve public health officials. To learn more about the public health implications of wildfires and other natural disasters, visit the Master of Public Health Program at the Keck School of Medicine of USC.


S. Climate and Health Alliance

PBS News Hour

American Lung Association

Children' Hospital Colorado

Center for Disease Control and Prevention

Pacific Standard

Health Affairs

Environmental Protection Agency