Coal industry groups are concerned that the conviction of former coal executive Don Blankenship could expose other industry leaders to criminal conspiracy charges.

Coal Associations from Illinois, Ohio and West Virginia shared concerns in a brief Tuesday with the 4th U.S. Circuit Court of Appeals, which is considering Blankenship's appeal.

Blankenship is serving a one-year sentence for conspiring to willfully violate mine safety standards at West Virginia's Upper Big Branch coal mine, which exploded in 2010, killing 29 men.

The coal groups expressed worry that mine safety citations could be used to hold anyone at a coal company liable for criminal conspiracy in the event of future violations.

They wrote that their brief isn't intended to support either side, or say whether Blankenship's conviction should be overturned.