Two million incidents of illness are caused by second-hand smoke each year in the UK alone.
Second-hand smoke contains 4,000 toxic chemicals and it is estimated that it causes thousands of deaths each year.
You may think just opening a window is good enough to get rid of smoke, but it can take over 2 hours for the unseen chemicals to leave a room.
Bad news for women
Smoking can cause premature births and even miscarriages...and that's if you're lucky enough to get pregnant in the first place, as smoking also reduce your chances of conceiving.
Bad news for men
Men should also know that smoking increases the risk of erectile dysfunction and infertility. In particular, the risk of erectile dysfunction rises by around 50% for men in their 30s and 40s. Smoking significantly impairs the blood flow to the penis resulting in a 'floppy'. Not good news and certainly not sexy.