A study has revealed a sharp fall in the number of children admitted to hospital with severe asthma after the introduction of smoke-free legislation.
Researchers at Imperial College in London found a 12 in the year before the non-smoking rules were introduced in July 2007.
With that taken into account, they calculated that the fall in admissions in the next 12 months was 12 in each of the following two years. They concluded that the over a three-year period, this was the equivalent of about 6,800 hospital admissions.
The BBC reports that fall was seen among children of both sexes and of of all ages, across wealthy and deprived neighbourhoods, in cities and in rural areas.
Prof Christopher Millet who lead the study, said that the smoke-free legislation has prompted unexpected, but very welcome, changes in people's behaviour.
"We increasingly think it's because people are adopting smoke-free homes when these smoke-free laws are introduced and this is because they see the benefits of smoke-free laws in public places such as restaurants and they increasingly want to adopt them in their home," he said. "This benefits children because they're less likely to be exposed to second hand smoke."
Asthma UK spokeswoman Emily Humphreys said she welcomes the findings, but said more still needed to be done to stop children taking up smoking.
"This is something we campaigned for, so it is particularly encouraging that there has been a fall in children's hospital admissions for asthma since its introduction," she told the BBC.
"We have long known that smoking and second hand smoke are harmful - they not only trigger asthma attacks which put children in hospital but can even cause them to develop the condition."
She repeated Asthma UK's call for tobacco to be sold in plain packaging.