If poly bags are recycled correctly they are 100% recyclable. If they are not disposed of properly animals can eat the plastic or become entangled in the plastic.
A material that can be harmful if not properly disposed of is hazardous.
I would say both, but mostly a boon because although it can be damaging to the environment if it is not disposed of properly, it is also a very useful material and can mostly be recycled.
Trash can save your future only if it is disposed of properly or recycled to make new things. If trash is disposed of properly, then landfills won't fill up.
Insulation that contains asbestos should be disposed of by a trained hazard waste crew. Insulation from wiring should be treated as a plastic and disposed of in plastic receptacles for recycling.
Plastic bags can be used to carry groceries and other items, store food in the refrigerator or freezer, or line small trash cans. They are lightweight and convenient for transporting goods. However, they can be harmful to the environment if not disposed of properly.
This is true.
by composting
Used coolant should be properly recycled.
This is true.
there will be more and more polloution
Plastic is dangerous because the paint on it has somewhat of a kind of chemical which makes people, animals, plants die.