Text Size:   A+ A- A   •   Text Only
Site Image

OHA News Release

Media contact:
Tony Andersen
OHA External Relations 971-239-6483
Technical contact:
Additional contacts:
Jennifer Flynt
DEQ 503-730-5924


State agencies to update short-term risk levels for air toxics

OHA recommends lower short-term levels for chromium in glassmaking

PORTLAND, Ore. — State environmental quality regulators and health experts will review and update established 24-hour screening levels for air toxics as part of the state’s Cleaner Air Oregon program. State agencies use the 24-hour levels to determine whether emissions from nearby sources pose an immediate health risk to people.

In advance of the full review, scientists at the Oregon Health Authority (OHA) have recommended to the Department of Environmental Quality (DEQ) a reduced short-term level for hexavalent chromium as part of rules governing art glass manufacturing, which DEQ will propose to the Environmental Quality Commission for adoption.

Reviewing levels for assessing immediate health risks

The process for re-evaluating the 24-hour screening levels is set to begin this month and is planned to be completed by the end of the year. The purpose of the review is to ensure Oregon has rigorously reviewed 24-hour screening levels as the state expands air monitoring near industrial sources of air toxics. In addition, DEQ and OHA scientists will consider establishing levels for toxics that may not have 24-hour levels in place now. All of the 24-hour screening levels will be rigorously reviewed by third-party, independent toxicologists and subject to public comment.

“Short-term screening levels are an important tool that help regulators and health experts know if air emissions cross a line that could put the public at risk,” said OHA Director Lynne Saxton. “They give us the data we need to take immediate action if neighbors are in jeopardy.”

DEQ and OHA developed current screening levels for certain metals in February to compare data on heavy metal concentrations detected by air monitors in southeast Portland, near Bullseye Glass Co., and in north Portland, near Uroboros Glass. However, these preliminary screening levels were developed rapidly and without external scientific peer review.

After several months of using the standards to assess air quality data, the agencies’ toxicology experts believe some of the current 24-hour screening levels may be too conservative, such as in the case of selenium. Others—such as levels identified for hexavalent chromium—may not be conservative enough. In addition, the existing screening list also doesn’t include other non-metal air toxics produced by industrial emissions around the state.

“The current 24-hour screening levels were developed in just a few days to respond to an immediate need, using the most stringent, health-protective values we could find from our peers in other states in that short time frame, in response to intense community concern about emissions from Bullseye and Uroboros,” said David Farrer, Ph.D., toxicologist with the OHA Public Health Division Environmental Public Health Section. “We now have the opportunity to take the time needed to get appropriate review by external scientists and people in the community.”

The current list of air toxics includes arsenic, beryllium, cadmium, total chromium,  chromium +6—also known as hexavalent chromium—cobalt, lead, manganese, nickel and selenium. The new list will add acetone, hydrogen sulfide, methyl ethyl ketone (MEK), naphthalene, and styrene. The agencies also have proposed a provisional 24-hour screening level for naphthalene, which will be evaluated in the new review.

Farrer said the re-evaluation of the 24-hour screening levels “is necessary to ensure these values are up to date, and reflect what existing data tell us about their effects on human health. An important part of the scientific process is to allow other scientists to check your work. We are glad that we now have the time to allow that to happen.”

OHA recommends revised short-term standard for hexavalent chromium in new glass rules

OHA health experts also are recommending a more health-protective 24-hour provisional screening level for one metal: hexavalent chromium. Since the agency won’t complete the 24-hour screening level review process before DEQ proposes new art glass rules to the Environmental Quality Commission, OHA scientists have submitted public comment to DEQ recommending it modify a section of the rules that revises the daily acceptable source impact level for hexavalent chromium, which was based on OHA’s original 24-hour screening level, from 36 nanograms per cubic meter (ng/m3) of air to 5 ng/m3. The change would “ensure that the daily acceptable source impact level in the permanent rule is protective of health,” according to the comment OHA submitted July 29.

Review process

OHA and DEQ are recommending the following timeline for reviewing the revised list of 24-hour screening levels and gathering public input:
  • Early September 2016—OHA and DEQ toxicologists review list, develop proposed revisions and recruit external scientific peer reviewers.
  • Mid-September 2016—External scientific review by EPA, academic and other toxicology peers.
  • September-October 2016—OHA and DEQ incorporate feedback from external scientific peer reviewers.
  • October-November 2016—Public comment period.
  • November 2016—OHA and DEQ incorporate and prepare responses to public comment.
  • December 2016—Revised 24-hour screening levels are released to the public.

The current comparison values for metals in air can be viewed on the OHA Public Health website. The proposed peer reviewed 24-hour screening levels will be posted, and public comment can be made, starting Oct. 6 at CleanerAir.Oregon.gov.

# # #