Wildfire smoke and air quality: Protecting Outdoor Workers
Smoke from wildfires burning in northern Ontario and Quebec is causing air quality concerns across many parts of Ontario. This has some workplaces wondering if anything can, or should be done, to keep workers safe from exposure.
How does wildfire smoke affect air quality?
Wildfire smoke is a complex combination of fine particulate matter (PM2.5) and chemical gases. Fine particulate matter (PM2.5) is a concern due to its ability to penetrate deeper into the respiratory tract and bloodstream and cause health effects, especially among “at risk” individuals.
Potential health effects and symptoms for outdoor workers
The likelihood and severity of health effects depend on smoke concentration, duration of exposure, physical exertion and individual susceptibility. Although the long-term health risk associated with an isolated, short-term exposure to low or moderate smoke levels is generally considered low, short-term exposure can still cause symptoms, aggravate existing conditions and affect a worker’s ability to perform work safely.
Mild symptoms can include:
- Headache,
- Mild cough,
- Production of phlegm,
- Watery eyes, and
- Nose and throat irritation.
Severe, but uncommon symptoms can include:
- Shortness of breath,
- Wheezing,
- Severe cough,
- Dizziness,
- Chest pains and irregular heartbeat.
Factors that increase health and safety risks for outdoor workers
Pre-existing Health Conditions: Individuals with heart or lung conditions such as asthma, chronic bronchitis, emphysema, and congestive heart failure, or diabetes, and cancer face a higher risk of experiencing health effects from wildfire smoke exposure.
Pregnancy: Pregnant individuals may be more susceptible to the adverse health impacts of wildfire smoke.
Advanced Age: Older individuals may be more vulnerable to the health effects of wildfire smoke compared to younger individuals.
Prolonged Exposure and Strenuous Work: Long work schedules and physically demanding outdoor tasks can lead to higher exposure. For instance, heavy exertion can result in a 10 to 20 times increase in air intake, intensifying potential health risks.
Ontario does not have a workplace occupational exposure limit (OEL) specifically for wildfire smoke. However, employers remain responsible under the Occupational Health and Safety Act for taking every precaution reasonable in the circumstances to protect workers.
Concerned about wildfire smoke entering your building? WorkBright can conduct a targeted indoor air quality assessment to help you evaluate conditions and put occupants’ minds at ease.
What can workplaces do to protect the health and safety of workers?
Monitor the Air Quality Health Index (AQHI) and follow Health Messages from the Ministry of Environment, Conservation and Parks: Check the current Air Quality Health Index (AQHI) forecast and applicable air-quality alerts before outdoor work begins and continue monitoring conditions throughout the shift. During wildfire-smoke events, PM2.5 concentrations and AQHI readings can change quickly. The chart below illustrates how hourly AQHI readings varied in Mississauga from June 5 to 7, 2023. It is a historical example of how substantially air quality can change over the course of a day.
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- 1 to 3 = ‘low’ health risk
- 4 to 6 = ‘moderate’ health risk
- 7 to 10 = ‘high’ health risk
- Above 10 = ‘very high’ health risk.
Reschedule strenuous outdoor work to periods in the day where the AQHI is not as high: For example, on June 5, 6 and 7, 2023 the AQHI in Mississauga began to spike at about 1pm, 11am, and 9am, respectively. Strenuous outdoor work could be scheduled before the spike occurs.
Move outdoor work indoors if possible: Relocate work to an enclosed, air-conditioned area with effective filtration. Simply moving indoors may not be sufficient because wildfire smoke can enter through doors, windows and ventilation systems. Confirm that the indoor location provides meaningfully cleaner and thermally safe conditions.
Discuss health risks with employees: Inform workers about the health risks, symptoms and measures and procedures. Encourage workers to promptly report symptoms to their supervisor.
Reduce physical exertion: Provide extra work breaks, use mechanical aids such as carts or dollies, and lift/carry heavy objects in teams.
Keep equipment and vehicle windows and doors closed: For those that drive or operate heavy equipment, keep windows closed and turn on the air conditioner set to recirculate.
Consider respiratory protection where exposure cannot be adequately reduced: A properly selected N95 filtering facepiece respirator can reduce exposure to fine particles when it is worn correctly. Where respirators are required for work, the employer must have an appropriate respiratory protection program that addresses selection, fit testing, training, inspection, maintenance and the worker’s ability to use the respirator safely.
Example of hourly AQHI readings in Mississauga
during a wildfire-smoke event, June 5 to 7, 2023.
Respond Promptly to Symptoms
Workers experiencing smoke-related symptoms should stop or reduce strenuous work, move to cleaner air and notify their supervisor. Workers experiencing chest pain, severe breathing difficulty, an asthma attack, severe coughing, dizziness or heart palpitations should obtain urgent medical attention. Call 911 where a medical emergency is suspected.
By implementing these measures, workplaces can effectively address the concerns of outdoor workers regarding wildfire smoke exposure, and can ensure that individuals who are at risk are protected.
WorkBright™ provides expert health and safety consulting and training solutions tailored to help your workplace comply with the law, avoid costly compensation claims, and keep employees healthy, safe and productive. Contact us today to learn more.