Saturday, August 18, 2007

Where there's smoke, there's...fungus

We've long known that smoke is hazardous, but perhaps not in how many ways.

Wildfires blaze across the Hawaiian landscape during one of the state's most significant droughts, and research suggests that among the threats to humans are active fungal and bacterial spores.

Fires cause dramatic damage beyond just blackening the plants that burn.

Fires destroy the cover and promote subsequent erosion. They remove habitat for any number of bird, insect, mammal and other forms of life. They can so reduce populations of rare species that extinction looms.

And of course they threaten homes, agriculture, businesses, even lives.

But if you've ever coughed or had an allergic reaction in the presence of smoke, you might have wondered what was in there besides particles of soot.

More than we might have imagined, write researchers Sara and Forrest Mims, Texas researchers who conduct atmospheric studies and have worked at the Big Island's Mauna Loa Observatory. See, for recent photographs, including one taken from Mauna Loa this year that Forrest Mimms says shows Asian dust visible in the atmosphere.

In a paper published in Atmospheric Environment, they review evidence that wildfires virtually always carry spores, and can carry them for thousands of miles. The paper is not new, having been published in 2004, but its message is topical in Hawai'i today.

Perhaps their most amazing finding: They were able to detect at Mauna Loa Observatory spores in smoke that originated from fires in Asia.

And the fires haven't necessarily sterilized the spores.

Mims and Mims found viable spores from both bacteria and fungi from smoke originating in the Yucatan, and they found spores from an Arizona fire.

They tried creating their own fires and testing the smoke. The result: grass, leaves, twigs and debris from a flood, when burned, all produced spores in the smoke.

Among the spores they've identified: Alternaria, which has been associated with hay fever and asthma; Cladosporium, which has been associated with respiratory disease; and Curvularia, which has been associated with infections of the eye.

Another good reason to stay out of the smoke, whether it's from a brush fire in your neighborhood or a campfire at the beach.

As a side note, the research on smoke also suggests that bacteria and fungi driven on the winds from Asia might have been some of the earliest inhabitants of the Hawaiian archipelago.

© 2007 Jan W. TenBruggencate

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