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OHA News Release





Media contact:
Jennifer Flynt
Oregon DEQ 503-229-6585
Technical contact:
Additional contacts:
Jonathan Modie
OHA Public Health 971-246-9139

5/5/2016

Air data: Hexavalent chromium persists, but selenium levels drop

Cement, rail, trucking, chrome-plating sites are potential chromium sources

State agencies continue to investigate the source of hexavalent chromium in the air in southeast Portland that has averaged above health-based targets since 24-hour monitoring began in early March.

Authorities say they’re encouraged by the latest air monitoring data that show levels of the heavy metal selenium have returned to levels expected in urban environments. Selenium levels had jumped after Bullseye Glass Co. in southeast Portland increased use of selenium in its manufacturing process beginning April 6.

Still, the persistence of increased hexavalent chromium readings over time remains a concern to the Oregon Department of Environmental Quality and Oregon Health Authority, even as all metals collected by DEQ air monitors remain below Oregon 24-hour screening levels. Oregon 24-hour screening levels are short-term concentrations below which immediate health effects are not expected to occur.

DEQ investigators continue to seek the source of the heavy metal that has been, on average, elevated in southeast Portland since March 1. The target concentration for hexavalent chromium is 0.08 nanograms per cubic meter of air (ng/m3) when compared to an annual average, but the 57-day average ranged between 0.0827 nanograms and 0.297 nanograms across the four monitoring locations surrounding Bullseye Glass. The company did not use chromium in glass production during this period.

DEQ is looking at several potential sources, including a cement plant, rail yard, trucking facility and two chrome-plating facilities, and have visited, or are planning visits to these sites in the coming days. They also are studying wind data and are planning to move air monitors to these areas in an attempt to “triangulate” the source.

Weekly air monitoring data from southeast and north Portland are reported each week by the interagency group that includes DEQ and OHA, and published at SaferAir.Oregon.gov. For information about the Cleaner Air Oregon initiative to align industrial air toxics regulations with human health, visit CleanerAir.Oregon.gov.

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