The chemists worry that emissions will increase as new uses are found for sulfuryl fluoride especially given the ban of methyl bromide, an ozone-depleting pesticide regulated under the Montreal Protocol. Sulfuryl fluoride emissions are not regulated, though officials do consider it a toxic contaminant.
The insecticide is pumped into a tent that covers a termite-infested structure. When the tent is removed, the compound escapes into the atmosphere. Sulbaek Andersen, Blake and Rowland believe a suitable replacement should be found, one with less global warming potential.
To measure sulfuryl fluoride's atmospheric lifetime, the chemists put it inside a Pyrex chamber with compounds that are well understood in the atmosphere, such as ethane. They shined lamps on the chamber to simulate sunlight, which caused chemical reactions that eliminated the compounds from the air.
By monitoring sulfuryl fluoride changes compared with changes to the well-known compounds, they were able to estimate its atmospheric lifetime.
"This is a cautionary paper," said Rowland, Donald Bren Research Professor of Chemistry and Earth System Science. "It tells us that we need to be thinking globally and acting locally."
|Contact: Jennifer Fitzenberger|
University of California - Irvine