National Proposed silica dust rules for coal mines may extend to sand, gravel quarries 5:04am August 21, 2023 Share URL copied to clipboard! Copyright 2023 NPR. To see more, visit https://www.npr.org. 300x250 Ad More Morning Edition British twins went on vacation in Mexico and faced a life-or-death battle Economy Morning news brief 300x250 Ad Support quality journalism, like the story above, with your gift right now. Donate