A curved tube protruding from the ground near the Rogue Valley Mall sign at the corner of Riverside Avenue and McAndrews Road isn't some marketing ploy to hook shoppers. It's part of a Department of Environmental Quality air quality monitoring system — a carbon monoxide monitor, to be exact.
In the 1970s and '80s, the Rogue Valley was plagued by pollution, regularly violating federal standards for the amounts of carbon monoxide, particulates and ozone in the air, said John Becker, air quality manager at the Oregon Department of Environmental Quality office in Medford. The region now meets standards for all those pollutants, but must continue to monitor to make sure it remains in compliance.
The Environmental Protection Agency requires monitors to be placed where the pollution they test for is most likely to occur, Becker explained. Most carbon monoxide comes from tailpipe emissions, so the busy intersection of Riverside Avenue and McAndrews Road is a prime place to check it. Monitoring is done during the winter.
The air samples must be collected from a set point 10 feet off the ground and a certain distance from the roadway, said Jeff Smith, air quality monitoring manager at DEQ's Portland office, where Medford's data is compiled and analyzed. That's why the sampling tube sticks out in its peculiar shape.
A small pump continuously sucks air in through the tube to the monitoring equipment housed in a small climate-controlled chamber inside the mall's sign, Smith explained. The monitoring instrument shines infrared light through the air sample and, based on how the light disperses, it can measure how much carbon monoxide is in the sample.
The instrument sends hourly reports to Portland via the Internet. Its data is available to the public at www.deq.state.or.us; just look for the quick link to the Air Quality Index.
The state previously operated another carbon monoxide monitor on the Brophy Building near the intersection of West Main Street and Central Avenue, but budget constraints and improved air quality put an end to it. It had a similar hooked air-sampling tube that dangled down off the building and out over the sidewalk, Becker said.
Monitors for other pollutants continue to work around the valley.
Particulate matter, which is mostly tiny smoke and soot particles from wood burning, is heaviest in residential neighborhoods, Becker said. The DEQ has a particulate monitor in a backyard of a home near the intersection of Belmont Street and Grant Avenue in Medford that tests samples every third day and one on Dodge Road that tests every sixth day. Both operate year round.
An ozone monitor functions during the summer months on a private, rural property outside Talent. Becker said ozone, the principle component of smog, can travel great distances and takes time to form in a reaction that is prompted by sunlight. The valley's winds predominately blow from west to east, so smog drifting along at upper levels tends to pile up along the eastern foothills around Talent and Ashland.
Reach reporter Anita Burke at 776-4485, or e-mail firstname.lastname@example.org.