List three types of toxic substances found in cigarette smoke. why are these substances harmful?

Tar, carbon monoxide, nitrogen oxides, theyre harmful because they cling to the red cells in the blood and up to 15% of a smoker's blood may be carrying carbon monoxide round the body rather than oxygen.Smoking 'lower tar' cigarettes can increase the carbon monoxide levels as smokers inhale more deeply.Cigarette smoke has high levels of nitrogen oxide.
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