Courthouse News reports that air tests for asbestos-like fibers must continue at a Minnesota mining plant because a 1975 order to do so has been folded into the state's environmental laws, the 8th Circuit ruled.

Northshore Mining Co., a taconite processing facility in Silver Bay, Minn., has tried for several years to get fiber tests removed from state permits.

But the St. Louis-based 8th Circuit agreed with a district court that the 34-year-old law is moot because it "has been effectively incorporated into state administrative law."