Re: bbc news shisha
I could definitely see how tests they do get bad results. They probably use poor tobacco that is not properly packed with enough quick lights to burn a house down. Then typically use a vacuum to pull smoke through at a constant rate (which is not how you smoke hookah) and don't adjust the coals/purge harsh smoke. This study does test the amount that the smokers exhale though which is a better method then most the studies you read about.