BUTTE, Mont. -

Federal officials say work to cleanup up toxic material left over from more than a century of mining operations in the Butte area is working based on the findings of a health study.
    
The Montana Standard reports (http://bit.ly/1lt49IW) that the U.S. Environmental Protection Agency released the 199-page study Friday.
    
One of the findings of the Butte Priority Soils Operable Unit Public Health Study, Phase 1 Report, is that children are being exposed to lower levels of lead.
    
The report is the first of five studies planned over the next 30 years to determine if efforts to remove contamination from the Superfund site are effective.
    
Environmental Protection Agency spokeswoman Nikia Greene says the study shows the Superfund cleanup is working.