Scientists from the Barcelona Institute for Global Health released a study on September 9 that confirms something that probably surprises no one—microorganisms capable of spreading disease float in the air, even really high up in the air.
The team, led by Xavier Rodo, a computational ecologist, flew a Cessna small plane over the Sea of Japan and into winds that originated from China. The plane got high enough to overcome the turbulence in the lower atmosphere, familiar to any jet plane traveler, and reached as high as 10,000 feet to sample the air outside. The plane was equipped with an inlet to admit air that flowed through a tube with a filter to catch the particles at the back end.
After 10 flights, the teams took the air filters to the lab to see that they picked up. All of this was done in biohazard gear with respirators. What they found were spores from fungus, bacteria lodged in grains of dust, and a rare mineral called hafnium believed to have originated in Chinese mines. The scientists cultured some of the microorganisms in petri dishes.
Lead scientist Rodo said that a third of the bacteria, and a bit more of the fungi, “can be considered potential human pathogens.” He was careful to say, though, that the work by the team didn’t give any hard evidence that pathogens settling down to earth from the upper atmosphere are necessarily responsible for any disease outbreaks. But Rodo did say the question of whether wind can spread disease “deserves attention.”
From a ground-level perspective, if winds can spread disease-causing pathogens, then this has been going on forever and is simply part of the background of daily life.
Rodo got the idea for the study while he was examining a condition called Kawasaki disease. The ailment causes rash, fever, and in some cases, fatal heart attacks. The question outstanding for scientists: is Kawasaki an autoimmune problem or is it caused by a pathogen, or both?
The disease seems to come in waves. Rodo and his team have correlated surges in Kawasaki in Japan with times when winds from northeast China were blowing into Japan. They also say the same wind patterns cause surges in cases in California.
Rodo said the team did not actually expect wind patterns to affect outbreaks, and they were surprised to see that they appear to do just that.
One hypothesis is that the places in China from which the winds originate have huge livestock farms and open mines. Could microorganisms—and the mineral hafnium—in the wind be lofted from China?
All told, DNA analysis found that the team had collected 266 different types of fungi and 305 varieties of bacteria. Some of these grow well in even polluted solid, some are part of the human microbiome found in all of us, and still others could trigger severe infections or disease.
