Smoke hazards
New acid discovered in biomass burning
Photo courtesy Joost de Gouw
CIRES Fellow Joost de Gouw and colleagues discovered the presence of isocyanic acid in smoke during controlled burns at the U.S. Forest Service Fire Sciences Laboratory in Missoula, Mont.
Missoula, Mont., that all biofuel types produced the gas. But does a real fire, not a laboratory one, give off the acid?
The team didn’t have to wait long to find out. Starting on Labor Day 2010, the Fourmile Canyon wildfire raged in the foothills above Boulder, Colo., burning more than 6,000 acres and destroying 169 homes. Scientists at the Boulder NOAA research facility wasted no time in learning what they could about the tragedy.
“Boulder has a world-class atmospheric chemistry building, but rarely does it have a full-on hit from a wildfire,” de Gouw said. “So just about everyone in that building turned on their instruments.”
The team’s mass spectrometer detected levels of the acid up to 200ppbv in the air at the site, which was downwind from the fire. “So in Boulder we found that not only is it formed in a laboratory burn, but it also comes out of a real wildfire,” de Gouw said.
The team continues to use their spectrometer to discover other origins of the chemical. “We know so little about isocyanic acid’s behavior in the atmosphere that we want to do a number of follow-up studies,” de Gouw said. “This is just the beginning—we need to do a lot more work.”
CIRES Fellow Joost de Gouw discusses the discovery, significance and potential health impacts of isocyanic acid. Watch the video.
the air. In the laboratory, they found biomass burning produced levels of this molecule approaching 600 parts per billion by volume (ppbv).
In the human body, isocyanic acid dissolves to form cyanate ions, and the researchers found that the acid was very soluble at the pH level of human blood. This means it could potentially enter the bloodstream, de Gouw said. At exposure levels of isocyanic acid greater than 1ppbv, the cyanate ion is expected to be present in blood at levels that can contribute to a variety of health problems, such as cardiovascular disease, cataracts and rheumatoid arthritis.
The researchers discovered in controlled burns at the U.S. Forest Service Fire Sciences Laboratory in
By Jane Palmer
Burning cigarettes, blazing forests and cooking fires can fill the air with smoke, but with acid? CIRES scientists have found when biomass—trees or other plants—burns, it releases an acidic chemical, isocyanic acid (HNCO), not previously known to exist in smoke.
“There is this molecule in smoke that we can now measure, and it is there in very significant quantities,” CIRES Fellow and research scientist Joost de Gouw said. “There are also good reasons to believe that it can have serious health impacts.”
De Gouw and his colleagues were first able to detect isocyanic acid when they developed a new instrument, a mass spectrometer designed to measure gaseous acids in
