JUNEAU - The Environmental Protection Agency reported that Alaska led the nation in 2018 toxic chemical releases. But a state commissioner contends a large portion should not be categorized as toxic.

Alaska Department of Environmental Conservation Commissioner Jason Brune argued that releases caused by unearthed rocks moved at mining sites do not have a significant effect on public health, The Juneau Empire reported Friday.

More than 99% of Alaska’s releases, 970.6 million pounds, were land releases connected to metal mining, Brune said.

"Big mines like Red Dog (near Kotzebue) move a significant amount of material as part of their daily operations, but such actions do not adversely impact human health and the environment," Brune said in a statement. "Characterizing such releases as toxic is disingenuous at best."

The EPA reported that 30 Alaska facilities released about 972 million pounds of Toxic Release Inventory (TRI) chemicals in 2018, which is the most in the U.S. by volume and the 11th most per square mile.

The release of any of the 755 listed TRI chemicals must be reported to the EPA. The agency's annual analysis tracks the management of toxic substances at the state and national levels.

David Chambers, president of the Montana-based Center for Science in Public Participation, found TRI analysis to be fair and useful.

“I think EPA’s critique of releasing all these metals is legitimate,” said Chambers, whose organization provides mining and water quality assistance to public interest groups and tribal governments.

Unearthing and moving rocks containing toxic chemicals should be characterized as a release creating potential for harmful materials to enter the environment, Chambers said.

"If you let them loose they can be a real problem," Chambers said. "That's basically what mining does to these metallic elements."

In Alaska, Red Dog Operations accounted for more than 90% of the state’s releases in 2018, or about 885.7 million pounds, according to the EPA analysis.