Nearly half a million Arizonans work in mining-related jobs, and across the nation, that figure is closer to two million. As a whole, the industry brings in $100 billion annually.

However, despite safeguards and technological improvements put in place over the past century and a half, people still die or are injured every year in mining accidents. In 2013, 42 people died in the United States alone.

Arizona is safer than average, but mining worker still face many risks on the job, according to Mary Poulton, a professor and department head for the UA Department of Mining and Geological Engineering.

"In mining, we are obviously dealing with very large equipment that is moving all of the time," she said. "We're working with shifts around the clock, day and night. We are working in large surface and underground mines."

Eric Lutz, director of the Mining Safety and Health Program for the UA Mel and Enid Zuckerman College of Public Health, people who work in surface mines and those who work below the surface face different dangers.

In underground mines, dangers include, "Roof fall-ins and movement of rock while you are underground, in addition to the complication of moving material and workers around within these tunnels underground," Lutz said.

Above ground, miners, "Don't have the complexity of being underground," he added. However, Lutz said, "these operations are often quite large. The equipment they use within the surface operations are very, very large, and so, with these large pieces of equipment, you have great momentum. They are harder to stop."

The organization, Alpha Foundation for the Improvement of Mine Safety and Health, helps fund projects around the country that are designed to improve the health and safety of miners. Recently, the Alpha Foundation awarded two grants to groups in Pima County, the UA public health college and the UA Lowell Institute for Mineral Resources.

The first grant project will study the best tactics of four participating mines to develop a compendium of practices that can then be distributed to mining operations across the U.S.

The second will study the way miners are trained. Poulton said the federal government largely regulates mining training, which includes requiring 40 hours of "seat-time" before a miner is qualified to work underground. The goal of the grant-funded study is to explore ways of making the training less book and lecture based and more active and applied.

It is part of a move, Poulton said, toward a more competency-based system in which mine workers have to prove by doing.

"That goes from everything from how do you secure yourself on a ladder so you don't fall to how do you operate a heavy crane," she said.