Environmental hazards are present during every step of the open-pit mining process. Hardrock mining exposes rock that has lain unexposed for geological eras. When crushed, these rocks expose radioactive elements, asbestos-like minerals, and metallic dust. During separation, residual rock slurries, which are mixtures of pulverized rock and ... The stop work order was issued to a stone-crushing machine, following complaints of environmental pollution and illegal digging by the private firm which operates the crusher.