Wildfires release three times the particulate pollution than traditionally believed – and serve as a major source of pollution during intense seasons, according to a new study.

The new findings, which were made from a series of risky flights into the plumes emitted by the uncontrolled blazes, buck the previous data that had been collected from flights over milder controlled burns.

The wildfires burn much more – and release much more into the air, according to the study in the Journal of Geophysical Research: Atmospheres.

“We actually went to measure, right above the fire, what was coming out,” said Greg Huey, from the Georgia Institute of Technology, the leader of the multi-institution team.

“A prescribed fire might burn five tons of biomass fuel per acre, whereas a wildfire might burn 30,” added Bob Yokelson, an expert on atmospheric chemistry at the University of Montana, and another of the authors. “This study shows that wildfires also emit three times more aerosol per tons of fuel burned than prescribed fires.”

The three wildfires all broke out on the West Coast in the summer of 2013: the Colockum Tarps fire in Washington, the Big Windy Complex blaze in Oregon, and the biggest of all, the Rim Fire in California.

The team flew through the plumes over these fires in a NASA DC-8 research plane, which was loaded with instruments to analyze a wide variety of chemical compounds and minute particles that were being thrown into the air by the massive fires.

The materials included methanol, benzene, ozone precursors, carbon monoxide, nitrogen oxides, volatile organic compounds, and a wide array of nitrates not known to be products of wildfires.

The team was given virtually all the tools that they requested of NASA and the U.S. Department of Energy. They used cavity ring down spectroscopy to detect the carbon dioxide and methane. Cavity enhanced absorption was used to detect carbon monoxide. Chemiluminescence was used for most of the nitrogen compounds. The volatile organic compounds and their oxygenated counterparts were detected by proton transfer reaction mass spectrometry.

The major finding was the particulate matter – which was a whopping three times the level of the controlled burns, as measured by specialized mass spectrometry for soot.

The plane got as low as 1.2 kilometers of altitude (for the Colockum Tarps fire), although it had to fly more than twice that height for the massive Rim Fire incident.

Even with such distance, the researchers were still subject to the pollutants, said Yokelson.

“The smoke leaks into the cabin and makes you nauseous,” he said. “You’re trying to take notes, run your instrument, look at the fire, talk on the headset, and get pictures. And at the same time, it’s crazy bumpy.

“Normally, if you’re in a smaller plane, your stomach is not too happy,” Yokelson added.

The scientists aren’t the only ones who may be feeling the effects of massive wildfires. Even residents back on the ground who are miles away from the blazes may be affected, when the particulates are carried by winds to populated areas, said Huey.

“Cars and power plants with pollution controls burn things much more cleanly (than wildfires),” he explained.