Safer is a broad term. In terms of lethal dose they would be safer. By the author's scale they are safer. Premature death would be a difficult one to study -

Safer is a broad term. In terms of lethal dose they would be safer. By the author's scale they are safer. Premature death would be a difficult one to study - as I don't know if there are as many regular users of shrooms/lsd as there are with steroids/tobacco.