Hope you’ve got a strong stomach because the answer is really gross. Ready for it?

Ok, so imagine breathing in flea powder, nail polish remover and floor cleaner all at the same time. But there’s far more: cigarette smoke contains over 4000 chemicals and 69 of these are known to cause cancer. Even if you don't smoke you can still get sick from these poisonous chemicals just by breathing in other people's smoke.

When you smoke a cigarette, you breathe in some of the following:

• tar, a black, sticky substance that contains many poisonous chemical such as: ammonia (found in floor and window cleaner), toluene (found in industrial solvents) and acetone (found in paint stripper and nail polish remover)
• nicotine, the addictive drug in tobacco
• carbon monoxide, a poisonous gas that reduces the amount of oxygen taken up by a person's red blood cells
• hydrogen cyanide, the poison used in gas chambers during World War ll
• metals, including lead, nickel, arsenic (white ant poison) and cadmium (used in car batteries)
• pesticides such as DDT, methoprene (found in flea powder) are used in growing tobacco. Other chemicals such as benzene (found in petrol) and naphthalene (found in mothballs) are added when cigarettes are being made.

Watch these YouTube clips to see what is really in cigarette smoke.

• The secrets they keep poster (PDF 748kb) 
• What's in a cigarette fact sheet (PDF 618kb)