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Report: Levels of metals in air, soil near Uroboros too low to harm health

September 20, 2018

OHA public health assessment applies to adults, children living near glass maker

Levels of metals measured in the air and soil around Uroboros Glass in north Portland are too low to harm the health of people living, working and playing near the facility, according to a new state public health assessment.

The Oregon Health Authority Public Health Division today released the assessment for a 45-day public comment period. Uroboros was an art glass manufacturer that ended operations at its North Kerby Avenue location in September 2017. The Uroboros public health assessment concluded that concentrations of arsenic, cadmium, chromium and other metals detected near the facility between March and July 2016 were below health-based concentration limits, and too low to harm human health. It also found that soil samples collected around Uroboros in February 2016 contained levels of metals that were below health risk values.

"The Uroboros public health assessment was important for determining just what level of health risk people in the area faced related to emissions from the glass factory prior to 2016 and going forward," said Todd Hudson, a toxicologist with the division's Environmental Health Assessment Program (EHAP). "What we found was that risk was, and has been, low."

The 2016 data comes from air samples collected by four Oregon Department of Environmental Quality air monitors deployed around Uroboros. The monitors operated 24 hours a day, with one air sample taken each day, resulting in more than 350 individual samples collected. DEQ also collected a total of 27 soil samples from Albina Park, Albina Community Gardens and a nearby daycare facility.

"It is safe to eat homegrown produce that was grown around the area of Uroboros Glass," Hudson said. "Most garden vegetables do not absorb metals."

The Public Health Division began work on the Uroboros assessment, along with similar assessments for Bullseye Glass Co. and Precision Castparts Corp. in southeast Portland, in spring 2016. The assessments were launched in response to significant community concerns about health risks from past, present and future exposures to heavy metals emitted from the facilities after a research project discovered elevated levels of metals in tree moss around Portland.

In its assessment, EHAP used the federal Agency for Toxic Substance and Disease Registry (ATSDR) standard public health assessment process. The assessments examine health risks based on soil and air data collected near the facilities. Such assessments are not community health studies and do not determine whether existing health issues are caused by environmental exposures.

In addition to 2016 data, the Uroboros assessment looked at past exposures to metals emitted from the facility. Examining air sampling results from U.S. Environmental Protection Agency studies at Harriet Tubman Middle School, located northeast of Uroboros, in 2009 and 2011, OHA toxicologists found that cadmium levels were above "cancer-based" health values in 2009 and chromium levels were above those values in 2011. However, the increased risk of getting cancer after exposure to the measured levels of cadmium, chromium and arsenic in the air—one additional cancer case for every 10,000 people exposed—did not meet the threshold for health risk as defined by ATSDR.

"The 2009 and 2011 data show us that there may have been some risk from past exposure, although that risk was low. Unfortunately, that data is extremely limited," Hudson said. EPA took only 13 air samples over 13 weeks in 2009 and 46 samples over eight weeks in 2011. These small numbers increase uncertainty about health risk in those years. However, the extensive 2016 monitoring allows OHA to state with confidence that risk of harm to health remained extremely low.

Hudson noted that Uroboros had not used arsenic for many years and agreed in early 2016 to stop using trivalent chromium, a less-toxic form of the metal. He also said that proposed new rules made through Cleaner Air Oregon, the state initiative to strengthen Oregon’s regulation of industrial sources of air toxics, would apply emission limits on any new industrial facility that moves into the building where Uroboros once operated.

To read a summary of the report and the full report findings and recommendations, visit the OHA Uroboros webpage. Copies of the report can also be reviewed during regular library hours at the Multnomah County Library, 3605 NE 15th Ave., Portland.

OHA is accepting public comment on the draft Uroboros public health assessment until Nov. 5 at 4 p.m. Comments can be emailed to or sent to: Attn: EHAP, 800 NE Oregon Street Suite 640, Portland, OR 97232.

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 Media contact

Jonathan Modie

OHA External Relations


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