Our senses, such as sight and smell, can often help detect poor air quality, especially when it comes to smoke. “With wildfires, the signs of poor air quality are fortunately very visible in the form of smoke and/or fog,” agrees Masri. “This also applies to cities with particularly polluted air.”

Masri explains that pollutants, including PM2.5, may not be visible to the naked eye, but they scatter light. “When [pollutants] accumulate in the atmosphere, we see reduced visibility at long distances and brown or yellow tints in the air,” he explains, reiterating that your nose can be a good detector of air pollution from wildfire smoke. “For example, smoke from a forest fire also has a smell,” he says. “Here in southern California, I can often smell a wildfire nearby before I see smoke or haze.”

In terms of physical symptoms, sore throats, headaches, dizziness, fatigue, and trouble breathing can all indicate that the air quality in your home is poor.