Northport Washington Blog The Northport Project

Department of Ecology

13 April 2017

TO:  Karen Wood and Chris Hanlon-Meyer

FROM:  Matt Kadlec

SUBJECT:  Regional PM10 Air Monitoring Speciation Network Comparison to
Measured and Predicted Conditions in the Upper Columbia River Valley
near the U.S.-Canadian Border

An analysis was recently completed on observed and estimated recent air quality
conditions for arsenic, cadmium, and lead within the upper Columbia River valley near
the international border.[1]  The report recommended a renewal of monitoring of certain aerosol elements in that area in order to conclusively determine current air quality conditions there.

Those estimates are matched to comparable data from monitors in Washington,
Oregon and Idaho as follows.

In the histograms below, the mean concentrations of US EPA Air Quality System
(AQS)[2] PM10 speciation data are compared to estimates of the mean concentrations
near Northport and the upper Columbia River Valley near the border (UCR). All the
means are of the February 2009 through December 2014 interval.

DISCUSSION

The upper limit of each location’s histogram bar is the ≈ 6-year mean PM10 element
concentration in micrograms per cubic meter (µg/m3). The purple bars are the
estimated concentrations in the upper Columbia River Valley area and near Northport.
The blue bars are the observed mean concentrations at the AQS monitor locations.

CONCLUSIONS

Average airborne PM10 arsenic and lead concentrations in the upper Columbia River
valley near the international border are potentially the highest known levels in
Washington, Oregon and Idaho. Likewise, the average airborne cadmium
concentrations are potentially the highest known anywhere in three states except at the monitor at 2231 N Flint Ave, Portland, OR, which is about 500 feet from an art-glass
foundry known to have emitted high levels of cadmium in particulate matter.[3]

Previously interpreted air monitoring data from 2009 through 2014 suggest that current
emissions from the Trail smelter continue to influence upper Columbia River valley air
quality. PM10 arsenic, cadmium and lead concentrations in the upper Columbia River
valley near the international border exceed expected air quality conditions for a rural
setting. Absent smelter emissions, the particulate metal concentrations in this rural
portion or northeast Washington likely would be about as low as those at the monitors
in rural Oregon and Idaho.

These findings reinforce the need for current PM10 speciation monitoring in the upper
Columbia River Valley near the international border and Northport area.

1 https://fortress.wa.gov/ecy/publications/SummaryPages/1702003.html
2 https://www.epa.gov/aqs accessed by Jill Schulte, 6 April 2017

3 http://www.opb.org/news/article/why-portland-heavy-metals-pollution-went-undetected-for-so-long/ Accessed 11 April 2017