Investigation blames regulatory failure for black lung 'epidemic'

An NPR/PBS "Frontline" investigation published on Tuesday found that the government has known for decades about warning signs that preceded a recent black lung "epidemic," which has sickened thousands of coal miners.

The investigation found that federal regulators have been aware of the dangers of silica dust dating back to the Clinton administration but have not introduced measures to control the substance. Silica dust has been linked to black lung disease.