A second glass-making company in Portland has voluntarily suspended its use of cadmium in response to tests showing elevated levels of the metal in nearby moss.
Uroboros Glass in North Portland announced Thursday it would stop making red, yellow and orange glass colors because they rely on the use of cadmium, a heavy metal that can raise the risk of lung cancer at elevated levels of exposure.
The announcement followed the release of a new map of elevated levels of cadmium in Portland. The map showed one hot spot around Southeast 22nd and Powell, near the Bullseye Glass facility, and a second hot spot near the Fremont Bridge in North Portland, not far from Uroboros Glass on North Kerby.
Bullseye Glass suspended its use of cadmium and arsenic last week after health and environmental officials announced test results showing elevated levels of both pollutants in the area. The areas were identified through a study that tested metals in moss around the city in an effort to correlate air pollution levels with the levels detected in moss.
"These moss tests are news to us and certainly troubling given how close this hot spot is to Uroboros, and our history of using Cadmium for red, orange and yellow glass colors," Uroboros President Eric Lovell said in a letter released Monday. "Therefore, we have decided to suspend production of these colors until there is time to learn more about whether or not we have any hazardous emissions from our process."
Air quality manager David Monro said the Department of Environmental Quality is planning to deploy additional air testing devices to help the Oregon Health Authority determine the health risks associated with elevated metals in the air. The agency is also looking at sampling soil around the areas where the moss tests detected elevated metals.
One air monitor is going to go near the CCLC at Fred Meyer daycare facility in Southeast Portland. Other air monitor locations are yet to be determined.
The DEQ map of areas with cadmium levels above the health benchmark covers a large swath of Portland. Monro said that's because there are other sources of cadmium around the city, including diesel emissions from trains.
Based on the results of the moss tests, DEQ placed an air testing device near the hot spot in Southeast Portland. The results showed a 30-day average level of arsenic at around 150 times healthy levels and cadmium levels at about 50 times the state's health benchmark for ambient air.
"When we've monitored in the past, we'd refer to high levels of cadmium at about 6, maybe 10 times our ambient benchmark concentrations," Monro said. "So now we get levels and we say 'high levels,' but it's really an order of magnitude or two higher. This is kind of a scale change."
Monro said he investigated the pollution controls at Bullseye Glass and found the company to be in full compliance with its permit. He affirmed that means current regulations for small glass-making facilities are allowing these companies to release unhealthy levels of metals.
According to David Farrer, toxicologist with Oregon Health Authority, exposure to elevated levels of arsenic raises the health risks of bladder, skin and lung cancers, and can also impair brain development over time. Increased exposure to cadmium can raise the risk of lung cancer and can damage the kidneys.
Farrer said the levels detected in Southeast Portland raise the cancer risk from one cancer case in a million people to one in 10,000 people.
"Which is still low," he said. "But definitely higher than we think is acceptable."
Multnomah County Health Department is hosting a community open house to address the issue from 5 pm to 9 pm Tuesday at the Cleveland High School cafeteria, 3400 SE 26th Ave., in Portland.