NASHVILLE, Tenn. (AP) — Assistant Labor Secretary Joseph Main says mine safety and health have improved measurably in the past five years.

Main spoke Tuesday at the National Stone, Sand and Gravel Association's annual convention in Nashville. He said the Mine Safety and Health Administration and the industry have taken action that has improved mine site compliance. The agency said in a news release those actions include reduction of chronic violators, historic low levels of respirable coal dust and silica and record low numbers of mining deaths.

Main says 2015 was the safest year in the history of mining as deaths fell to a record low of 28, down from 46 deaths the year before. In the coal industry, 2015 was also a record year for safety, with 11 deaths reported.

Main says fatality reduction efforts were launched after mining deaths began to increase in late 2013.