Tobacco smoke is a serious environmental hazard and a significant cause of ill health. A review commissioned by the “Europe Against Cancer” Programme of the European Commission in 1997 concluded that:“Tobacco smoke is the most important source of indoor contaminants in environments where smoking occurs.”

Tobacco smoke consists of side-stream smoke emanating from the burning tip of a cigarette or other smoking device (~85%), and main-stream smoke that has been inhaled and exhaled by a smoker (~15%). Other terms to describe tobacco smoke pollution include second-hand smoke, environmental tobacco smoke or air pollution caused by tobacco smoke. The exposure of non-smokers to tobacco smoke is referred to as passive smoking or involuntary smoking.

The composition of tobacco smoke will vary depending on the way the tobacco is smoked, as well as the design and composition of the delivery device. Cigarette smoke has been the most extensively studied. Main-stream and side-stream smoke consist of a gas phase and a particulate phase.As many of the gases are odourless, it is not always easy to sense when the air is not safe. Tobacco smoke contains over 4,000 chemicals, including many regulated hazardous air pollutants and hazardous wastes, more than 50 known carcinogens and more than 100 chemical poisons.

When tobacco is burned to create side-stream smoke, larger amounts of some toxic constituents are generated than when tobacco is burned to generate main-stream smoke, resulting in the tobacco smoke containing substantial amounts of these carcinogens even when extensively diluted. It is generally believed that for many of the carcinogenic constituents that are genotoxic (i.e. cause damage to cellular DNA, resulting in mutations or cancer) there is no safe level of exposure.

Since 1986, there has been a series of authoritative reports analysing the evidence, and concluding, beyond doubt, that there are significant risks to health caused by passive smoking. A range of conditions, including fatal illnesses, are caused by passive smoking and these are shown bellow, which has been adapted from the recent review by the British Medical Association (BMA).

Health effects of second-hand smoke :

Adults

  • Lung cancer
  • Coronary heart disease
  • Onset of symptoms of heart disease
  • Asthma attacks in those already affected
  • Worsening of symptoms of bronchitis
  • Stroke
  • Reduced foetal growth (low-birth-weight baby)
  • Premature birth

Children

  • Cot death (Sudden infant death syndrome)
  • Middle-ear disease (ear infections)
  • Respiratory infections
  • Development of asthma in those previously unaffected
  • Asthma attacks in those already affected

Other proven health effects of second-hand smoke

  • Shortness of breath
  • Nausea
  • Airway irritation
  • Headache
  • Coughing
  • Eye irritation

from: Tobacco or Health in The European Union, 2004