Aspen’s pollution levels on the rise |

Aspen’s pollution levels on the rise

John Colson

Aspen’s recent air pollution problems have basically dropped to levels not considered harmful, but there are indications that the numbers overall are starting to rise.

Lee Cassin, Aspen-Pitkin County environmental health official, delivered that message to the City Council Monday during an informal lunch meeting.

With a series of charts and diagrams, Cassin explained that the city’s levels of “PM-10” (extremely small dust particles) have dropped dramatically since 1991.

That year, local PM-10 levels reached a high of 236 millionths of a gram of PM-10 per cubic meter of air (micrograms per cubic meter). The federal government has concluded that PM-10 is hazardous to human health, and established a permissible level at 150 micrograms per cubic meter.

Every year since 1992, the levels in Aspen have hovered around 80 or 90 micrograms on average, Cassin said. And the number of “moderately-high PM-10 days,” she said, has dropped from 40 days in 1992 to fewer than five in 1998. A “moderately high” day is one when the PM-10 level is more than 50 micrograms.

Cassin said the only “bad news” to come out of a recently received report on Aspen’s air quality is that the average PM-10 level has begun to climb in the last two years. The average dropped from a high of 32 or 33 micrograms in 1992, to roughly 19 or 20 in 1996. But in the following two years, Cassin’s records indicate, the average levels during the winter months have climbed slightly.

“It looks like it’s starting to go up,” Cassin said of the pollution levels. “I’d say, if anything, 1999 will probably be higher.”

She does not consider the elevated levels to be a problem, since they are well below the “moderately-high” level that the federal government views as safe.

Although she could not say exactly why the PM-10 levels seem to be rising, she said it is likely due to either dry winter weather or increases in the traffic volumes coming into town.

“My suspicion is it’s probably because traffic is going up,” she said.

Support Local Journalism

Support Local Journalism

Readers around Aspen and Snowmass Village make the Aspen Times’ work possible. Your financial contribution supports our efforts to deliver quality, locally relevant journalism.

Now more than ever, your support is critical to help us keep our community informed about the evolving coronavirus pandemic and the impact it is having locally. Every contribution, however large or small, will make a difference.

Each donation will be used exclusively for the development and creation of increased news coverage.

For tax deductible donations, click here.

Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.

User Legend: iconModerator iconTrusted User


See more