Aspen’s September second warmest in 19 years | AspenTimes.com

Aspen’s September second warmest in 19 years

Aaron Hedge
The Aspen Times
Aspen, CO Colorado

ASPEN – The city of Aspen reported Monday that September was the second-warmest month in the last 19 years, resulting in higher-than-normal particulate air pollution, or PM-10 levels.

Highs that averaged about 72 degrees and dry conditions caused a large amount of dry dust to swirl with traffic, said Lee Cassin, the city’s Environmental Health director.

“Whatever dust was on the road gets ground up by traffic and kicked into the air,” Cassin said.

September is normally much wetter than it was this year, which results in a far lower PM-10 level, Cassin said.

She said the high levels of PM-10 correlate with the global warming trend.

The high levels of PM-10 – 18 parts per million, as compared with 15 parts per million in 2008 and 2009 – were caused primarily by vehicles, as evidenced by much lower levels during night hours and weekends when fewer people were driving.

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But it was still lower than busier times of the year for Aspen’s tourism economy, Cassin said.

The hottest September in the last 19 years, which is the period of time the city started collecting PM-10 data, was in 1998, when an average high of 75 degrees was recorded.

Average high September temperatures in Aspen have stuck around 69 degrees for the last 19 years, Cassin said.

PM-10 particles, which are “not as big as the diameter of a human hair,” Cassin said, can be inhaled into the lungs, causing respiratory diseases. A press release issued Monday says high PM-10 levels can cause widespread health issues in a community. Scientists estimate that they are responsible for “tens of thousands” of American deaths each year, according to the statement.

The levels are measured in parts per million by an atmospheric measuring device located on the roof of the Pitkin County Library.

ahedge@aspentimes.com