Toxic Tuesdays

CHEJ highlights several toxic chemicals and the communities fighting to keep their citizens safe from harm.


With news of the massive wildfire outside California’s Yosemite Park covering over 18,000 acres of land in June 2022, we wanted to talk about the problems associated with forest fires and pollution. Wildfires are destructive in their own right but are not what one would typically consider a source of pollution. Fires serve many natural purposes – they clear dead organic materials from forests and return valuable nutrients to the soil for instance. But when they reach large proportions and burn uncontrollably, they can release a number of air pollutants that decrease air quality and can cause significant health problems in nearby communities.

A number of air pollutants can be released from wildfires. Heavy metals like lead, zinc, and manganese have been found in elevated levels in the air and in the soil after wildfires, especially in areas that contained man-made buildings and other structures. Nitrogen oxides, a widespread air pollutant that has national air quality standards for indoor air, can be released in significant quantities during a forest fire. These chemicals can cause several respiratory problems such as increased inflammation of the airways, cough and wheezing, and reduced lung function.

Perhaps the most serious health threats from forest fire pollution comes in the form of particulate matter pollution. Particulate matter is a mix of very tiny solid and liquid particles suspended in air. These particles range in size but can be so small that they can enter a person’s lungs and remain lodged deep inside them. The health effects associated with this form of pollution are similar to those of nitrogen oxides. Short term effects such as eye, nose, throat, and lung irritation; coughing; sneezing; runny nose; and shortness of breath are common. In the long-term, severe effects like chronic bronchitis, reduced lung function and increased mortality from lung cancer and heart disease have been observed.

The drought currently being experienced by California and much of the continental US is fueling fires like the one outside Yosemite, and we can only expect more in the future. Climate change driven by human activity is creating these drought conditions and in turn making wildfires like this one much more common occurrences. The pollution created by these fires in turn will affect those that cannot afford to move to avoid it, who more often than not are low-income and minority communities. We need to be conscious that the emission of greenhouse gasses by industry is not just a problem that will affect us and our children in the future, but is something that is killing people now.

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