(1) Aldehydes, nitrides and alkenes can stimulate respiratory tract.
(2) Nicotine can stimulate sympathetic nerve and cause intimal injury.
(3) Amines, cyanide and heavy metals are all toxic substances.
(4) Radioactive substances such as phenylpropyl pyrene, arsenic, cadmium, methylhydrazine and aminophenol. These substances are carcinogenic.
⑤ Phenolic compounds and formaldehyde, etc. It has the effect of accelerating cancer.
(6) Carbon monoxide will reduce the ability of red blood cells to transport oxygen to the whole body.