gram to gram, i hear yes, but i'm not really sure because cannabis doesn't have mad chemicals in it like cigs do.
It's all been covered..... Smoking anything is bad for you, but I would definetly say that tobacco is worse. Nicotine for a start is toxic. Then you have the radioactive chemicals they use to fertilise it by law. It's also addictive, meaning that even if it was less harmful, you're smoking 10 to 20 a day, and not 3 or 4 joints.