Oregon Health Sciences University. (Photo credit: Wikipedia)

Oregon public health officials on Wednesday lifted warnings to Portland residents to stop eating vegetables grown in gardens near a glass factory where elevated airborne levels of hazardous metals were detected.

Soil analysis found “low risk” to residents’ health near Bullseye Glass Co. in Southeast Portland, officials said. State health officials said they would release an analysis next week of soil samples collected near a second plant, Uroboros Glass Studio.

Oregon officials also said rates of metals-related cancers were not elevated among residents living near Bullseye and Uroboros. Elevated levels of heavy metals in the air have prompted a class-action lawsuit and a protest march by concerned residents.

Chris Edmonds, a spokesman for Bullseye Glass, said the soil tests affirm that “the company is not a source of harm to the community.” Calls to Uroboros Glass were not immediately returned.

The soil was tested under the supervision of the Oregon Health Authority and the Department of Environmental Quality, after state air monitors showed airborne levels of the metals significantly higher than Oregon safety benchmarks.

The analyses showed samples of soil from around Bullseye were generally below naturally occurring or “background” levels of heavy metals chromium, arsenic, and cadmium, the department told a news conference.

“This is only the first round. We will see more soil and air data in the coming weeks,” said Department of Environmental Quality interim director Joni Hammond.

“Residents are free to get their gardens planted” but should wash their vegetables and dirty hands, Oregon Health Authority toxicologist David Farrer said.

Oregon Health Authority toxicologists found that the levels of metals in the soil were too low to be harmful to people, including children at an area child care facility.

Experimental moss tests conducted by the U.S. Forest Service first detected the toxic heavy metals. Those findings led to a class-action suit and demands for more oversight.

Last week, about 50 residents mounted a protest in downtown Portland, chanting “clean air now” and delivering boxes of rotting produce harvested from their gardens to the state’s environmental quality offices.

Long-term arsenic exposure is linked to skin cancer and cancers of the lung, bladder, and liver as well as skin color changes and nerve damage, health officials said. Long-term cadmium exposure is linked to lung and prostate cancer, as well as kidney disease and fragile bones.

(Reporting by Eric M. Johnson in Seattle; Editing by Sara Catania and David Gregorio)