overuse of nitrogen fertilisers
radiation on human cells cause mutation.. if u dont take physics i'll explain a bit more.. though i doubt you'll need the info.. but good to know a lil extra..
here it is.. The rays of radiation. (alpha, beta, n gamma) can ionise and knock the molecules/particles of out body out of place.. this causes their DNA structure and information to get changed and mutated.. thus causing mutation, and often diseases such as cancer..
but it can also be used to cure cancer ironically because it can bump our molecules back into place.. or something like that..
Nicotine.. IT's a stimulant,, IT's the thing that gets u addicted and coming back for more.. It affects the brain if taken in excess amounts..
Tar will line the bronchus/trachea and stick to the alveolus.. it could destroy the bronchus/alveolus causing difficulty in breathing/lung cancer.. also it destroy the ciliated cells in the trachea whicha re important because they filter out bacteria and dust out of the throat.. They also push mucus away from the bronchus
towards the throat..
heroine?hmm lemme try.. heroine is a stimulant.. it causes the body to feel on a high causing euphoria and experiences which are very *interesting*.. the individual will experience halucinations.. if they get hurt they will not feel anything/barely anything.. it could lead to a variety of health problems..