Wildfires can be bad. Now they can be worse.

 

New research indicates that wildfires release more air pollution, in the form of smoke and the accompanying toxic gases, than previously thought. 

The updated estimate is an increase of 20% or so, and it is primarily in the form of un-estimated volatile organic compounds. But for a big wildfire, that can be a lot more smoke and associated stuff nobody wants to breathe.

Wildfires Could Emit More Air Pollution Than Previously Estimated

"Each year, large swaths of forests, grass and peat burn in wildfires, releasing a complex mix of water vapor, ash and carbon-based compounds into the air. Some of these carbon-based compounds are gases called volatile organic compounds (VOCs). Others that evaporate and turn into gases at warmer temperatures are known as intermediate- and semi-volatile organic compounds (IVOCs and SVOCs, respectively). And in the air, these partially-volatile compounds form fine particles — pollutants that can be harmful if breathed in — more easily than VOCs."

"However, most studies assessing wildland fire emissions overlook IVOCs and SVOCs because of their large number, which makes it hard to measure these compounds. Researchers led by Shuxiao Wang wanted to take IVOCs and SVOCs emissions along with VOCs into consideration to offer better insight into wildland fires’ impact on air quality, health and climate."

That's a direct quote.  First question, what does "large number" mean?  I have my suspicions, but I have to look in the actual article. So I did. And I think my suspicion was wrong. I thought the large number might be molecular weight, but I think it's saturation vapor concentration.  I.e., the VOCs fully volatilize, reaching their maximum saturation vapor concentration, but the IVOCs and SVOCs don't, so it's harder to estimate or measure how much of them is in the smoke.

I'm not sure of that. But the bottom line is that more organic compounds are released by wildfires, so that the total amount, the sum of VOCs, IVOCs, and SVOCs, is more than the previous estimates, which was just based on VOCs.

If you want to know more, the reference is below, and you can try to contact the researchers.

REFERENCE: Huang L, Zhao B, He Y, et al. Global wildland fire emissions of full-volatility organic compounds from 1997 to 2023. Environmental Science and Technology 2025:acs.est.5c10217. doi: 10.1021/acs.est.5c10217

Psst:  You can actually read the full paper here, if you are so inclinated.

And remember, where there's fire, there's usually smoke.