Passive smoking, where non-smokers breathe in the second-hand smoke of others, took a little longer to be recognised. After the popular British entertainer Roy Castle died in 1994 from lung cancer caused by passive smoking, people generally began to take notice. Although he had never smoked, Roy Castle had spent much of his life working in smoky clubs.
There was a time not so many years ago when smoking was regarded as a perfectly acceptable and respectable pastime. People smoked in pubs, restaurants, in meetings, in the cinema, on public transport, in fact everywhere. It was only when research proved conclusively that smoking was a major cause of cancer and a whole raft of other life-threatening conditions that this universal practice began to be questioned.
Questions began to be asked. If a husband was a heavy smoker, but his wife was not, would she be at risk from passive smoking, and what about their children? Also, would non-smokers be more at risk from passive smoking in the more confined space of a car?
In 2003 it was estimated that 11,000 deaths were due to passive smoking and by 2007 smoke-free legislation was in place throughout the UK. This covered all enclosed workplaces and places where the public had access, including public transport and work vehicles.
Private homes remained exempt, unless used for childminding, but the anti-smoking lobby would like to see a universal ban on smoking in the home and in cars simply to protect children.
In fact, the overall level of passive smoke exposure in children has substantially fallen in recent years, due, it is thought, partly to the fact that people in general are smoking less and partly because people are more careful about smoking in front of their children.
However, figures suggest that children who live in homes with regular smokers are exposed to about seven times more smoke than children who live in smoke-free homes.
The anti-smoking lobby point out that passive smoking is estimated to cost the National Health Service £9.7 million a year on GP visits and asthma treatments alone, plus a further £13.6 million in hospital admissions. Passive smoking is said to increase the risk of asthma in children by more than 50%, with risks being significantly greater if their mother smokes.
The problem with statistics is that they are often very hard to prove. It has been claimed that tobacco smoke in cars is 23 times more toxic than tobacco smoke in the home, but this figure is disputed in a new study headed by Dr Ray Pawson of the School of Sociology and Social Policy at the University of Leeds.
The study sets out to look at the evidence of risks associated with smoking in cars carrying children, with particular reference to "myths, facts and conditional truths".
The authors say that although evidence is incomplete, it is an incontrovertible fact that exposure in cars is still commonplace and children are particularly vulnerable. This leads to the inevitable conclusion that steps should be taken to ban smoking in all cars carrying children.