Unbeknownst to anyone I know, the US Army Corps of Engineers on Wednesday night burned driftwood at Saylorville Lake, just north of Des Moines. The smoke was so thick it infiltrated my dreams. Presumably, it also infiltrated the lungs of Des Moinesians with medical conditions, placing them at risk.

I’ve never seen Des Moines’ AQI hit anywhere near 200, let alone exceed it. Officials categorize 200+ as “very unhealthy” and issue an alert that reads, “The risk of health effects is increased for everyone (emphasis mine).” (Check out the graph.)

For the past week, smoke from fires in western Canada have eroded air quality across the upper Midwest. But it’s likely that something else triggered Wednesday’s alert. While the case isn’t closed, the best conclusion is that the spike was caused by the Corps’ burn piles coupled with an unusual hot-cold air inversion that kept the smoke in the Des Moines River valley. Continue Reading →