Wildfire Smoke
An orange haze currently sweeps the skies of Western Canada, drowning the towns in smoke and prompting a state of emergency in the province of Alberta. More than 500 wildfires raged across the Canadian forests and prairies this year, having already charred two million acres of land.
The smoke now hovers through Saskatchewan and British Columbia, even leaving plumes in parts of the U.S. including Montana, Wisconsin, Minnesota, Ohio, and Michigan. Air quality remains poor, with officials urging Canadians to stay indoors or evacuate, depending on where they live.
However, some individuals have outdoor jobs and cannot stay indoors at all times. Outdoor workers such as firefighters, truck drivers, construction staff, farmers, and clean-up crews can suffer from high exposures to wildfire smoke.
How can employers protect their outdoor workers from wildfire smoke exposure? This post explores the root of wildfires and defines some controls to reduce smoke exposure for employees.
THE PATH OF A WILDFIRE
Wildfires typically start in the spring season, following snowmelt, windy conditions, and dry weather. Western Canada saw unusually high temperatures this May, melting the snow quicker, making the air drier, and potentially sparking the fires.
Fires erupt and spread when heat combines with oxygen and a fuel. A fuel is anything that catches fire, also known as a combustible or flammable substance. In this case, the thick vegetation inside the forests and grasslands acted like the fuel for the wildfires. Some scientists believe that quicker snowmelt makes certain trees such as pine or fir trees excessively dry, leading to quicker and bigger blazes.
Wildfires can also be caused by lightning and human activity. Human activity can include unattended campfires, negligent disposal of cigarette butts, or industrial accidents.
THE HEALTH HAZARDS OF WILDFIRE SMOKE
Wildfire smoke contains complex mixtures of water vapor, carbon dioxide, particulate matter, carbon monoxide, nitrogen oxides, acid gases, polycyclic aromatic hydrocarbons (PAH’s), volatile organic compounds (VOC’s), and many other chemicals.
In 2021, wildfires released nearly 1.76 billion tons of carbon globally. This number exceeds annual emissions by 151% between the years of 2000 and 2020. Companies released 36.3 billion tons globally in that same year.
Particulate matter can be defined as small suspended solids or liquid droplets in the air. Wildfires heat and burn different types of vegetation, building materials, and objects in their path, leading to a slew of smokes, mists, fumes, and dusts.
When inhaled, these particulates can be small enough to enter the lungs and invade the bloodstream. Upon acute exposure, wildfire smoke can immediately lead to coughing, bronchitis, shortness of breath, chest pain, headaches, irritated sinuses, stinging eyes, and a faster heartbeat.
Depending on the wildfire, chemical concentrations can vary and affect individuals differently. Excessive nitrous oxide exposure can lead to dizziness, while long-term effects include infertility. Exposure to polycyclic aromatic hydrocarbons can reduce lung function and increase the rates of cardiovascular disease. VOCs can also lead to nausea and damage the liver, kidneys, or central nervous system.
Smoke containing carbon monoxide can displace oxygen, leading to breathing difficulties and suffocation. Wildfire smoke can also worsen pre-existing cardiac or respiratory conditions such as asthma or heart disease, increasing the risk of heart failure, stroke, asthma attacks, and premature death. An estimated 15,000 people suffer a premature death from wildfire smoke inhalation every year in the United States.
In a 2022 study, scientists at McGill University found a link between wildfire smoke and the increased risk of cancer. The study showed that persons living 50km of wildfire activity over the last 10 years, had a 10% higher incidence of brain tumors and a 4.9% higher chance of developing lung cancer. More research is needed to identify long-term health effects of wildfire smoke.
High-risk groups include older adults, children, expectant mothers, asthmatic patients, and individuals with pre-existing respiratory or heart conditions. However, learning from the studies mentioned above, wildfires can affect anyone, be it immediately, or at a later point in their lives.
CONTROLLING WILDFIRE SMOKE EXPOSURE
In the United States, about 85% of all fires are caused by human activity. In Canada, the number of human-induced wildfires reduces to around 45% with natural occurrences such as lightning and abnormal heat waves taking the lead on sparking wildfires.
Can companies play a role in preventing wildfires?
Yes. Since human activity causes the majority of fires, companies can influence their employees to remain vigilant of fire hazards by implementing clear policies and training standards.
Although companies cannot actively fight natural occurrences, they can control their contribution towards a fiery event. Industrial fires can enhance the chance of a wildfire and need proper protocols for prevention and containment.
To avoid an industrial fire, all companies must follow a set of procedures surrounding suitable storage, usage, housekeeping, and disposal of flammable or combustible material.
Store flammable liquids in approved, UL (Underwriters Laboratory) listed flammable storage cabinets or in a UL listed, ventilated, specially-designed flammable liquid storage room. Seal and dispose of flammable waste through an environmental waste management company.
A company need not store or use flammable liquids to have a fire. Poorly maintained electrical systems, equipment, vehicles, and machines can also lead to excess heat and fire.
Proper access to fire suppression equipment like fire extinguishers, hoses and sprinkler systems help hold down a fire before it spreads. A structured incident reporting policy will also ensure quick containment of a larger fire.
Companies may have little authority over what employees do outside of work. However, they can still raise awareness through newsletters and safety talks to discuss campfires, disposal of cigarette butts, stove or barbecue safety, and maintaining household equipment.
How to protect employees from wildfire smoke
Risk Assessments
Always assess the risk of wildfire smoke before establishing any rules and procedures. Most weather channels or apps will warn the public about air quality during a wildfire event.
In the United States, the Air Quality Index (AQI) includes 6 types of ranges to communicate good, to unhealthy, to hazardous levels of pollution. For example, an AQI value of 100 to 150 indicates unhealthy levels of pollution for sensitive groups. An AQI between 201 and 300 implies health alerts for everyone in the affected areas.
During a wildfire event, check the AQI daily to understand how and if the smoke can affect employees.
Next, determine the length of time and time of day an employee may spend around the smoke. A truck driver may have lesser exposure than a construction worker. Truck drivers normally sit inside an enclosed truck and may only step out during loading and unloading time. A construction worker would have lesser exposure than a firefighter who has to stand closer to the line of fire.
The time of day also matters when it comes to wildfire smoke. Smoke increases during the hotter times of the day, most likely in the afternoons. Smoke settles and hangs low during early mornings and late nights.
After understanding the risk, implement appropriate controls to address the hazard.
Engineering Controls
Employees working in indoor workplaces such as offices, some manufacturing plants, hospitals, and warehouses can get respite from the smoke by closing their doors and using HEPA air purifiers or air conditioners with the highest MERV (minimum efficiency reporting value) possible. The higher MERV, the higher the particle arrestance. Make sure your HVAC system has the capability of handling a higher MERV rating.
Running the air conditioner on “recirculate” mode can help avoid pulling in the smoky outdoor air. Drivers can also make use of this feature in their vehicles and keep their windows closed.
Air purifiers with HEPA filters or electrostatic precipitators can trap harmful particles to allow cleaner air into an indoor space. Maintain the HVAC system and air purifiers on a periodic basis.
Unfortunately, for outdoor workers, these controls provide little relief except for when they work indoors or come inside for breaks. In addition to engineering controls, companies should also implement administrative controls and PPE for outdoor workers.
Administrative Controls
Excess physical activity or strenuous work can increase air intake up to tenfold. When employees inhale more air, they inhale more smoke. Lower physical activity and strenuous work to reduce air intake. Companies should provide machinery or automation to help with heavy work.
Encourage employees to eat healthy, drink enough water, and catch sufficient sleep. A healthy lifestyle can counter or slow down the negative effects of wildfire smoke. Proper nutrients and antioxidants can also help workers maintain their energy when combating low oxygen levels or poor air quality.
Have employees work indoors as much as possible. Reschedule outdoor work tasks to less smoky parts of the day. Construction normally ceases in extreme weather anyway. Do the same for days with excess smoke. Wildfires spread the most in the afternoons. Provide plenty of breaks for employees to decrease their wildfire smoke exposure.
Provide training to raise awareness of air quality conditions, wildfire smoke hazards, and company policies and controls.
Lastly, all companies near wildfire-prone locations must create an emergency evacuation plan. Wildfires can prompt entire cities to evacuate. The plan should cover details about evacuation steps, communication paths, escape routes, first aid kits, respirators, food and water supply, emergency hotlines, and adequate transportation.
Personal Protective Equipment (PPE)
A fitted air-purifying respirator can help protect employees from some wildfire smoke particles. Most respirators do not provide much protection against gases and chemicals. PPE should be used as a last resort, however some professionals such as firefighters should wear a self-contained breathing apparatus (SCBA) if the AQI exceeds 101 or if the particulate matter concentration reaches 35.5 µg/m3 or higher.
Bandanas, scarves and surgical face masks must be avoided during wildfires. These items will not provide any protection and give people a false sense of confidence to go outdoors without any safeguarding.
At-Risk Employees
Since at-risk employees have a higher chance of suffering adverse symptoms or worse, create and promote modified duties for them. Modified duties can include indoor work, lighter work, or work from home.
Some employees may not initially feel comfortable revealing pre-existing conditions such as asthma. To help them overcome this fear, try announcing the possibility of modified duties and assure them of the company’s duty to maintain confidentiality. Encourage them to visit their family physician and follow their advice.
For firefighting or industries that boast regular exposure to smoke, schedule periodic health-screening such as a pulmonary function test to ensure health and safety against a major workplace hazard, in this case, the hazard being smoke.
ONGOING RESEARCH
Wildfires rip through wooded and grassy regions every year. Smoky summers have unfortunately become a norm in many areas, causing people to wheeze, cough, and tear-up.
Scientists continue to research wildfire smoke effects. The United States Environmental Protection Agency (EPA) reports quite a few research highlights focusing on indoor particulate matter reduction, long-term health impacts, societal strain, economic burden, and environmental distress of wildfire smoke.
Some studies are concentrating on reducing wildfires all together and making the forest more resilient. Possible solutions include “prescribed” burning of forests, which can rid the habitat of dead leaves, older or fallen trees, debris, invasive species, and other forms of excess fuel.
Fire-resistant building materials may also prevent fires from spreading or getting bigger.
Hopefully, ongoing research can help curb this fairly common phenomenon and protect the people, property and the environment.
REFERENCES
Exposure to wildfires increases risk of cancer. (n.d.). Newsroom. Retrieved May 19, 2023, from https://www.mcgill.ca/newsroom/channels/news/exposure-wildfires-increases-risk-cancer-339499
Outdoor workers exposed to wildfire smoke. (2022, March 22). Cdc.gov. https://www.cdc.gov/niosh/topics/firefighting/wffsmoke.html
Prescribed fire. (2016, December 6). US Forest Service. https://www.fs.usda.gov/managing-land/prescribed-fire
Us Epa, O. (2019). Why Wildfire Smoke is a Health Concern. https://www.epa.gov/wildfire-smoke-course/why-wildfire-smoke-health-concern
U.S. wildfire smoke deaths could double by 2100. (2018, September 10). AGU Newsroom. https://news.agu.org/press-release/u-s-wildfire-smoke-deaths-could-double-by-2100/
Wildfire smoke. (2019, April 2). Cdc.gov. https://www.cdc.gov/disasters/wildfires/smoke.html
