Missoula's mountain valley topography and growing population demand that we as citizens and guests, find ways
to limit and reduce air pollution in the valley. We want to continue to maintain and improve on the air quality gains that
have been made in the past.
Missoula is a city located in the Rocky Mountains of western
Montana. The Missoula urban area, located in a mountain valley, contains over 100,000 people and is the largest urban area
in the United States surrounded by the Rocky Mountains. Because of the mountain valley topography, winter temperature inversions
that trap pollution are common. To maintain and improve air quality in Missoula, the growing population of the valley will
have to treat the air shed with extra care and continue to find methods of lowering sources of pollution.
Particulate Matter and carbon monoxide are two issues that local environmental quality specialists
identify as significant pollutants. The 1967 Montana Clean Air Act authorized local air pollution control programs. By 1969,
the Missoula City-County Health Department had developed a local air pollution control program and assumed responsibility
for most sources of air pollution in Missoula County. The first recorded violations were 1969 for particulates and 1977 for
Because the National Ambient Air Quality Standards were exceeded, Missoula had to write State
Implementation Plans detailing how Missoula would attain and then maintain pollution levels below the federal standards. Several
factors were included in that plan that helped to control particulate matter and carbon monoxide levels. They are as follows:
1) The wood stove removal program
2) The use of de-icer in place of street sand on many streets
3) Prompt street sweeping in spring
4) Regulations that require most new vehicle use areas, to be paved inside the Air Stagnation Zone
Additionally cars, such as Missoula's
GREEN TAXI Toyota Prius help reduce carbon monoxide levels with it's practically ZERO emissions.
Reducing idling, reduces
air pollution. Vehicle exhaust contains at least 21 air toxins which, by definition, are hazardous to human health. Major
pollutants from automobiles include hydrocarbons, nitrogen oxides, carbon monoxide, and particulate matter, all of which have
significant health and environmental impacts. Emissions from idling vehicles can be as much as 20 times greater than those
from one traveling at 32 mph. Many communities in the United States and Canada have, or are considering, ordinances that restrict
excessive vehicle idling in order to improve air quality and protect citizen's health.
Most of this information was provided by Missoula County Environmental Health Department.