Research has shown that, in addition to massive destruction and direct loss of life, wildfire smoke poses a health risk to populations far beyond the immediate fire zone. As many as 1.6 million deaths per year worldwide are attributed to wildfire smoke and its effects on respiratory diseases, heart attacks and strokes, worsening of type 2 diabetes, and dementia.
As large structural fires become more frequent, new hazards have emerged, including deposits of persistent pollutants such as heavy metals in soil and groundwater; inhalation of asbestos and other contaminants during cleanup, demolition, and re-entry into buildings; and the presence of hydrocarbons and metals in drinking water.
A study in Canada measured an increased risk of lung and brain cancer among people living near forest fires. Another study of residents whose homes were not destroyed but were located near the Marshall Fire in Colorado in 2022 reported increases in eye irritation or tearing, headaches, coughing, sneezing, and sore throat — even one year after the fire. These symptoms were more common among those whose homes were damaged by smoke or ash.
