WHITEHALL, Wis. — A western Wisconsin county that has issued more frack sand mining permits than any other county in the state and in neighboring Minnesota has decided to take a hiatus on new projects while it addresses health and environmental concerns.

The Trempealeau County Board’s decision to impose a moratorium of up to a year was met with applause from an overflow crowd at Monday night’s meeting.

“I’m very pleased,” said Sally Miller, the board member who authored the resolution. “This is going to slow things down and give us a chance to catch our breath.”

Questions about the effects of sand mining on human health and the environment have largely gone unanswered as the county has approved permits for 26 companies that are mining and processing silica sand on 4,733 acres in the scenic county across the Mississippi River from Winona. The sand is used in hydraulic fracturing, or fracking, in which oil and gas are extracted from rock by injecting high-pressure mixtures of water, sand or gravel and chemicals.