Fire's Air Pollution: Understanding The Impact And Risks

Fire and air pollution are closely linked. Smoke from fires is made up of a complex mixture of gases and fine particles produced when wood and other organic materials burn. These fine particles are the biggest health threat from smoke, as they can enter the eyes and respiratory system, causing burning eyes, a runny nose, and illnesses such as bronchitis. Particle pollution from wildfires can spread thousands of miles away, causing breathing difficulties even in healthy individuals. In addition to particle pollution, wildfire smoke also contains harmful emissions such as carbon monoxide, nitrogen oxides, and other hazardous air pollutants.

Particle pollution

The health impacts of wildfire-specific PM2.5 are not yet fully understood and may differ from PM2.5 from other sources due to differences in concentrations and chemical composition. Toxicological studies suggest that wildfire particulate matter may be more toxic than equal doses of ambient PM2.5. Exposure to wildfire-specific PM2.5 has been linked to increased respiratory hospitalizations, with a 10 μg m−3 increase leading to up to a 10% increase in hospitalizations.

It is important to note that particle pollution is not limited to outdoor environments. These particles can easily penetrate homes and buildings, increasing indoor particle concentrations. Individuals with cardiovascular or respiratory diseases, older adults, children, pregnant women, outdoor workers, and those of lower socioeconomic status are at greater risk of health effects from wildfire smoke.

Health effects of smoke

Smoke is a complex mixture of gases and fine particles produced when wood and other organic materials burn. The biggest health threat from smoke is from these fine particles. They are so small that they can enter and lodge deep in the lungs, causing a range of respiratory issues. These include persistent coughing, phlegm, wheezing, and difficulty breathing. Even in healthy individuals, exposure to fine particles can lead to transient reductions in lung function and pulmonary inflammation. Particle pollution may also affect the body's ability to remove inhaled foreign materials, such as viruses and bacteria, from the lungs.

Inhaling smoke can cause immediate effects, including eye, nose, and throat irritation, and its odour can be nauseating. Studies have shown that exposure to heavy smoke can lead to temporary changes in lung function, making breathing more difficult. Additionally, smoke can cause changes in heart function, with carbon monoxide reducing the body's oxygen supply and aggravating heart conditions. Those with pre-existing cardiovascular or respiratory conditions, such as asthma, as well as young children and older adults, may be at higher risk of adverse health effects from smoke exposure.

Frequent exposure to smoke, even for brief periods, has been linked to an increased risk of long-term health effects. Studies of firefighters, for example, have shown a higher rate of cancer, lung disease, and cardiovascular disease. Prolonged exposure to smoke can also increase the risk of mortality, particularly for those with chronic heart and lung diseases.

It is important to limit exposure to smoky areas and to reduce physical exertion when high levels of smoke cannot be avoided. Proper respiratory protection can help reduce the inhalation of fine particles and gases in smoke. Staying informed about local air quality and following news coverage or health warnings related to smoke can help individuals take appropriate precautions to protect their health.

Carbon monoxide

To address carbon monoxide pollution, organizations like the Environmental Protection Agency (EPA) in the United States have set standards and guidelines to maintain safe levels of CO in outdoor air. These standards assist state, tribal, and local agencies in monitoring and managing carbon monoxide levels to ensure they remain within acceptable ranges. Additionally, the Clean Air Act, enacted by the EPA, plays a crucial role in controlling and reducing CO pollution.

Climate change and wildfires

Fire is a significant contributor to air pollution. Wildfires, in particular, can spread air pollution not only nearby but also thousands of miles away, causing breathing difficulties even in healthy individuals.

The Earth's warming climate is increasing fire activity, particularly in northern and temperate forests. Warmer temperatures, extended drought, and a thirsty atmosphere have been key drivers of the increase in fire weather in the Western United States. As the planet warms, hotter weather, earlier melting of winter snow, warmer nighttime temperatures, and decreasing summer rainfall are all contributing to increased fire activity.

Research shows that changes in climate create warmer and drier conditions, leading to longer and more active fire seasons. For example, in 2023, Canada experienced its warmest and driest conditions since 1980, which fuelled extreme fires that lasted for five months and released about 640 million metric tons of carbon. Similarly, in the Western United States, drought and persistent heat from 2020 to 2022 resulted in extraordinary wildfire seasons, with each year far surpassing the average of 1.2 million acres burned.

In addition to climatic factors, other factors such as forest health, weather patterns, topography, and forest management practices also influence wildfire behavior. Historical efforts to reduce all wildfires have led to a buildup of fuels in some forests, further exacerbating the problem.

While some sources dispute the extent of the impact, the consensus is that climate change is a significant contributor to the increasing frequency and intensity of wildfires.

Reducing smoke exposure

Smoke is a complex mixture of gases and fine particles produced when wood and other organic materials burn. The biggest health threat from smoke is from these fine particles, which can get into your eyes and respiratory system, causing health problems such as burning eyes, a runny nose, and illnesses such as bronchitis. Fine particles can also aggravate chronic heart and lung diseases and are even linked to premature deaths in people with these conditions.

Avoid Burning

When smoke levels are high, avoid using anything that burns, such as wood fireplaces, gas logs, gas stoves, or candles. It is also important not to vacuum, as this stirs up particles already inside your home.

Avoid Smoking

Refrain from smoking, as this puts even more pollution in your lungs and the lungs of those around you.

Air Conditioning

If you have air conditioning, run it with the fresh air intake closed and the filter clean to prevent bringing additional smoke inside. If you do not have an air conditioner, staying inside with the windows closed may be dangerous in extremely hot weather. In these cases, seek alternative shelter.

Keep Informed

Pay attention to local air quality reports, news coverage, and health warnings. Visit websites such as AirNow to find out the Air Quality Index in your area. As smoke levels increase, the steps you should take to protect yourself may also need to change.

Medical Advice

If you have asthma or other lung diseases, follow your doctor's directions about taking your medicines and have an asthma management plan in place. Call your doctor if your symptoms worsen. If you have heart or lung disease, are an older adult, or have children, talk with your doctor about whether and when you should leave the area.

Frequently asked questions