A Durango preschool is considering mitigation work after finding heightened levels of radon in its building.

Recent test results showed radon levels dropped at the Roberta Shirley Center compared to an initial screening, but mitigation is recommended, Tri County Head Start administrators said this week. Tri County oversees the center and other schools in the region.

After a letter about initial testing results was released, the center at 2019 East Third Ave. closed for a week on Jan. 30 because staff members refused to come to work because of safety concerns.

Radon is a naturally occurring gas that after years of exposure increases the risk of lung cancer. High levels of radon are common across La Plata County. The initial screening during winter break showed radon was above 20 picoCuries per liter, TriCounty Head Start Director Lisa Stone Muntz said in an email.

More recent tests found radon levels in the range of 6 to 8 picoCuries per liter, she said.

The state safety standard is 4 picoCuries per liter.

The school expects to get an estimate for mitigation work this week, Muntz said. About 70 students are enrolled in Head Start classes in the building.

The city of Durango owns the building and would likely be responsible for mitigation.

Administrators plan to meet with city and San Juan Basin Public Health staff members to determine a schedule for mitigation, Mandy Clark, the former interim executive director for Head Start, said in an email.

During a meeting in February she said she did not expect the school to close again.

mshinn@durangoherald.com