PORTLAND, Ore. – Portland Public Schools announced late Wednesday night that tests showed elevated levels of radon in multiple schools in the district. The revelation comes as PPS faces criticism for its response to tests that showed high levels of lead.

"We’ve heard our community, they want to know right away. So as soon as we got the information our staff stayed late we put out the information; we want to keep them informed as best as possible," said PPS spokesperson Christine Miles.

Nine rooms in six schools, Meek, Beaumont, Whitman, Roseway Heights, Lents and Marysville, exceeded a standard that requires immediate follow up testing, according to a memo sent to the school board and Superintendent Carole Smith.

The tests, done in March, focused on 26 PPS buildings that had higher radon levels in 2001, the last time radon levels were tested, according to PPS. The district was required to do testing again before January 2021.

Tests showed nine rooms exceeded the measurement of 10 picocuries per liter (pCi/L), the Environmental Protection Agency’s standard for “higher action level,” the memo says. Follow up tests will begin Monday, June 6, and last for 48 to 72 hours.

Portland Association of Teachers president said she appreciated the information being delivered in a more timely manner than information on lead contamination was. But she said there is huge concern over another dangerous substance in schools like Whitman Elementary.

"I’m also a parent in the district and a teacher and I can’t help think if it were my kids going here or I was teaching here how would I feel about this.. and I wouldn’t be comfortable being here, without knowing more information," said Gwen Sullivan.

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Of more than 800 rooms tested at the 26 buildings, 121 rooms exceeded EPA standards of 4 pCi/L, which requires further long-term testing. According to the memo, EPA guidelines say a test must be done for nine months during the school year. These tests will begin in the fall of the 2016-17 school year.

The EPA says radon is a radioactive gas that is the second leading cause of lung cancer after smoking, accounting for about 20 percent of lung cancer deaths.

Radon gas enters from the soil beneath the school through cracks and openings in the foundation, according to the EPA.

File: Radon hot spots popping up in Oregon

PPS says it will share the results of further tests with all families and staff. The district is working to increase ventilation in the affected schools to mitigate the problem.

The Oregon legislature passed a law in 2015 that requires all school districts in Oregon to create radon testing plans by this September. The tests must be completed by December 2020. A PPS spokesperson told KGW Thursday that testing was started early to be proactive.

Portland State University Geology professor and radon expert Scott Burns helped advise legislators on the law. Burns applauded PPS for getting started on testing earlier than the law requires.

"They’re proactive they were mandated to do it and they’re doing it way ahead of time, they’re doing a great job," said Burns.

The Oregon Health Authority has a comprehensive guide to radon risks statewide.

Read the school district memo: