teepee or beehive burners are used to dispose of waste wood in logging yards and sawdust from sawmills by incineration. as a result, they produce a large quantity of smoke and ash, which is vented directly into the atmosphere without any sort of filtering or cleaning, contributing to poor air conditions wherever they are used. the burners are considered to be a major source of air pollution and have been phased out in most areas. there are a few beehive burners still in use in western canada.