Why is weed so bad? is it because of the smoke, and chemical toxins in smoke?

Too good: Recreational drugs are bad mainly because they make you feel too good. Bypassing the brain's pleasure, reward, stimulation, and relaxation systems in such a way leads to people no longer interested in productive, pro-social activities. Attention and effort become focused on getting high and staying high. There are other health consequences but they are minor compared to the brain effects.

Weed: I have seen numerous clients over the years who swear the benefits of marijuana and how safe it is to use. Conversly, I have seen more clients that swear they are physically and psychologically addicted to it. Some have had severe reactions to thc resulting in extreme paranoia and hallucinations. The chemicals found in marijuana bought off the street, which vary, are not healthy for you physically.

Lowers IQ: A long term study (32 years) in new zealand found that using any amount of weed before adulthood lowers a person's iq by 8 points. Many studies in many countries have shown a threefold increase in schizophrenia in weed users. Women using weed during pregnancy increase their risk for prematurity & having babies who get learning problems or chromosomal breaks. Weed's bad.