There are more than 7,000 harmful chemicals in tobacco smoke, at least 250 are known to be harmful. Some of these chemicals are:
Nicotine
Formaldehyde
Lead
Arsenic
Ammonia
Radioactive elements such as Polonium-210
Benzene
How some of those chemicals affect the body:
Nicotine is highly addictive and can cause an increase in blood pressure, heart rate, flow of blood to the heart and a narrowing of the arteries (vessels that carry blood).
Symptoms for formaldehyde are watery eyes; burning sensations in the eyes, nose, and throat; coughing; wheezing; nausea; and skin irritation
High levels of lead may cause anemia, weakness, and kidney and brain damage. Very high lead exposure can cause death.
Arsenic poisoning occurs over a brief period of time, symptoms may include vomiting, abdominal pain, encephalopathy, and watery diarrhea that contains blood. Long-term exposure can result in thickening of the skin, darker skin, abdominal pain, diarrhea, heart disease, numbness, and cancer.
High concentrations of ammonia in air causes immediate burning of the eyes, nose, throat and respiratory tract and can result in blindness, lung damage or death.