USU scientist studies chemicals in Cache Valley air

Published: Friday, September 19, 2008

USU scientist Phil Silva has spent the last four years studying what conditions and chemicals in Utah’s atmosphere cause air pollution and inversions, in particular, the chemistry behind the pollution, and what sources cause particular chemical emissions.

“We live in this small little bowl,” Silva said regarding Cache Valley’s geographical structure. “It’s the combination of having the agricultural emissions with the urban emissions, and then in winter when we get cold temperatures, the inversion has no place to go. It’s like putting a lid on a pot.”

Silva said he started doing sampling in Cache Valley two years ago to figure out what types of particles made up the bad air.

“We did a couple air samplings during the years when we had really bad inversions, 2004 and 2005,” he said. “The major component is a mixture of ammonium nitrate, which comes from the combination of the ammonia in agriculture and nox from vehicles.”

The state government has drawn from Silva’s earlier work in analyzing the air, and have been using it as a baseline for how to address air pollution, Silva said.

“The state of Utah is now been declared a non-attained and over the next couple years the state and the local body here, the Board of Health, have to come up with plans on how to meet the standards in the future,” he said.

The Board of Health regulates air pollution because there are links between poor air quality and poor health affects, Silva said.

“There has been a lot of work done to try to figure out what the health agent, but there is still a lot of debate as to which compound is the culprit. All we know is that there is a statistical correlation between levels of particular matter and observed affects, not just short-term affects, but things like asthma,” he said.

The first step towards better air is to look at the emmissions from vehicles and try to find ways to reduce harmful emissions from them, Silva said. The agricultural side is harder to figure out how to reduce, he said, because it is more difficult to address.

Silva said he is working with a team of graduate and undergraduate students, who take regular air pollution samplings, as well as samplings at USU’s agricultural facilities, “so that we can study the chemistry of the chemicals out there and try to understand them better.”

Silva said he is has been collaborating with the University of California the last two years to observe this particular research regarding “some other constituents that are not the main pollutants, but from the standpoint of a chemist, are interesting because the chemistry had not been studied very much.”

“Basically we have been trying to understand the chemistry in Cache Valley, we have a pretty good idea of what the important chemical compounds are, and so that gives us an idea of what issues need to be addressed in order to address pollution levels,” he said. “However, we have gone off in this different direction because the question of some of these agricultural emissions have a broader impact, that these might be important compounds to look at.”

Silva, who has now been researching Cache Valley air quality for four years, said he will be continuing his research because, “as is the case with science, as you try to answer questions, you typically come up with more questions.”