Complex sentence: Burning tires is lower on the hierarchy of reducing waste than recycling, but it is better than placing the tire waste in a landfill or dump, where there is a possibility for uncontrolled tire fires or the harboring of disease vectors such as mosquitoes.
Split into simpler sentences: Burning tires is lower on the hierarchy of reducing waste than recycling, but it is better than placing the tire waste in a landfill or dump. There is a possibility for tire fires or the harboring of disease vectors such as mosquitoes.