science

but a wide swathe of studies has failed to ever conclusively establish a connection between cannabis smoke and cancer.

The list of known carcinogens is quite short. That is mostly because it is difficult to conduct studies with a large enough sample to be sure that something is a carcinogen with high statistical reliability.

Given our current knowledge, it may be argued that eating fast food every day is not bad for you, as there are no conclusive studies linking it to increased death rates.

In the laboratory, most mutagenic compounds are labelled as mutagenic despite the fact that they are not known carcinogens.