Previous studies have found that cannabis claims 30,000 lives a year by causing cancer, heart disease and bronchitis, and that it can double the risk of mental illnesses such as schizophrenia.

Now, I wonder where that data is from. Oh look, the British Medical Journal:

It may be argued that the extrapolation from small numbers of individual studies to potential large scale effects amounts to scaremongering. For example, one could calculate that if cigarettes cause an annual excess of 120 000 deaths among 13 million smokers, the corresponding figure for deaths among 3.2 million cannabis smokers would be 30 000, assuming equality of effect.

Genius. Thanks to Dr Ben Goldache for spotting this.

NP: The Good, The Bad & The Queen, The Good, The Bad & The Queen