Breathing in other people's smoke, also called second-hand smoke, can cause cancer. Passive smoking can increase a non-smoker's risk of getting lung cancer by a quarter, and may also increase the risk of cancers of the larynx (voice box) and pharynx (upper throat).
Second-hand smoke can cause other health problems too, including heart disease, stroke and breathing problems. It’s estimated that, every year, second-hand smoke kills over 12,000 people in the UK from lung cancer, heart disease, stroke and the lung disease Chronic Obstructive Pulmonary Disease (COPD).