Should we crack down on bangladesh's pollution?

I can't verify each of your statements about their pollution and don't really care to see verification, but as a matter of principle, since Bangladesh is a sovereign state, we should not try to directly intervene as we would in a "crack down" at all. If the problem is as bad as you say, then we could work with them diplomatically to help them recognize the issues that their country faces, though a good deal of that progress will also have to be internal (to their country's political process).