The skies over Windsor-Essex may look clear, but health experts say appearances can be deceiving. An orange air quality warning is in effect for the region as wildfire smoke from northwestern Ontario moves in, bringing fine particles that can affect people’s health — even when the smoke isn’t visible. Environment Canada says air quality is expected to deteriorate through Wednesday and could remain poor into Friday. “This is an invisible threat to the eyes right now,” said Jane McArthur, toxics program director with the Canadian Association of Physicians for the Environment (CAPE). “It doesn’t mean that it isn’t harmful. It is indeed harmful.” McArthur said Windsor-Essex already faces air quality challenges because of pollution from local industry and emissions that drift across the border from southeast Michigan. Wildfire smoke only adds to that burden. “Unfortunately for the Windsor-Essex region, it’s not novel that we are concerned about air pollution,” she said. “Then, you add on top these additional pollutants that are coming in with wildfires... really putting our health at risk.” She said children, older adults, people with heart or lung conditions, people with disabilities and those who work outdoors are among those most vulnerable to the effects of wildfire smoke. McArthur added that as wildfire smoke events become more frequent, communities need to move beyond simply reacting to them. “We can’t just respond to these things in an emergency acute way,” she said. “We have to be prepared in advance.” Dr. Mehdi Aloosh, medical officer of health for the Windsor-Essex County Health Unit, said the smoke associated with wildfires poses a greater health hazard than the pollution people typically experience in cities. He said residents should treat the warning seriously, particularly if they have asthma, chronic obstructive pulmonary disease (COPD), heart disease, or other underlying health conditions. “The combination of heat plus wildfire smoke is dangerous,” Aloosh said. He recommends limiting time outdoors, keeping windows and doors closed as much as possible, using a portable air purifier with a HEPA filter indoors, and, for those at higher risk who must spend extended periods outside, wearing a properly fitted N95 respirator. Aloosh said the most common symptoms of wildfire smoke exposure include irritated eyes, nose, and throat, coughing, and headaches. More serious symptoms, such as shortness of breath or chest pain, require immediate medical attention. He also noted Windsor-Essex saw a spike in asthma-related visits during the 2023 wildfire smoke event, highlighting the health impacts poor air quality can have on the community. Environment Canada says residents should continue monitoring air quality forecasts, as conditions can change quickly depending on wind direction and the movement of wildfire smoke.