The state Department of Environmental Quality has closed its downtown Helena office after initial tests found up to 40 times the acceptable level of lead.
DEQ Director Tracy Stone-Manning said Monday the results from tests above the building's ceiling tiles have triggered additional lead testing of the air and surfaces in the office space.
The building houses the DEQ's remediation division. The 98 employees who work there have been put on leave until Wednesday while state officials search for temporary office space.
Department of Administration Director Sheila Hogan says blood testing will be available for free for those workers and for former employees who used to be located in the building.
Hogan says the building was constructed in 1942 and housed a firing range for the Montana National Guard.