Why must mine tailings be stored and disposed of carefully

The mining tailings are the leftovers of the porces in which some minerals (the part that they do not want to keep) are separatd from a given ore. This leftovers usually contain some chemical compounds that may be dangerous for the enviroment, and other problem is the fact that some of the separated minerals can be also dangerous, for example things like the arsenic or the mercury.

This is why the mine tailings must be stored and disposed carefully

answer: strength i guess

explanation:

ill do it for 100, also this isnt 80 its 40