有关吸烟有害健康的英文短文

Smoking is hazardous to health is well known fact..Different cigarette ignited by the release of chemical substances are different,but the main number of tar and carbon monoxide,and other chemicals.Lit cigarette after the release of poisonous substances broadly divided into six major categories:
(1) aldehydes,nitride,olefins category,these substances are stimulating effect on lower respiratory tract.
(2) Class of nicotine may stimulate the sympathetic nervous,caused endometrial vascular damage.
(3) Amine,cyanide and heavy metals,which are toxic substances.
(4) phenylpropanoid pyrene,arsenic,cadmium,dimethyl hydrazine,p-and other radioactive substances.These substances are carcinogenic effect.
(5) and phenolic compounds such as formaldehyde,these substances have accelerated the role of cancer.
(6) carbon monoxide can reduce red blood cells to transport oxygen to the body to capacity.