A rule approved last year by the US Mine Safety and Health Administration would cut the federal limit for allowable respirable crystalline silica dust exposure by half to help protect miners of all types nationwide from the current driving force of black lung and other illnesses.

But, now, it's in jeopardy amid other US administration cutbacks and proposals targeting workers' health and safety guardrails: stuck in a politically charged environment that promotes industry, with lawmakers arguing to change it and the federal agency that wrote the rule not pushing to enforce it.