CHILDREN needing hospital treatment due to chest infections may have dropped by as much as a fifth since anti-smoking laws were introduced, research suggests.

A study led by the University of Edinburgh and the Erasmus University Medical Centre in the Netherlands combined data from 41 papers in countries where tobacco control policies have been introduced.

The figures suggest rates of children requiring hospital care for severe chest infections have dropped by more than 18% since bans were introduced.

Professor Aziz Sheikh, director of the University of Edinburgh's Usher Institute and the Asthma UK Centre for Applied Research, said: "Our evaluation provides compelling evidence of the considerable impact of tobacco control policies on child health.

"This work should spur governments to take action to implement tried and tested policies - strongly advocated by the World Health Organization - to reduce second-hand smoke exposure and improve a range of important health outcomes in infants and children."

Data was taken from more than 57 million births and 2.7 million hospital admissions.

The paper estimates severe asthma attacks have also fallen by almost 10% while the number of babies born prematurely has dropped by around 4% overall.

Dr Jasper Been, of the Erasmus Medical Centre, said: "Our study demonstrates that children's health benefits substantially from smoke-free laws and raising tobacco prices.

"To protect the health of some of the most vulnerable members of society, implementation of such tobacco control policies should be accelerated across the globe. The effectiveness of additional strategies also needs to be evaluated."

About half of all children globally are regularly exposed to tobacco smoke.

Children who breathe second-hand smoke are more prone to serious chest infections such as pneumonia and bronchitis.

They are also more likely to develop asthma and attacks can be more severe, needing hospital care.

Babies of mothers who smoke during pregnancy have a higher chance of being born early, which exposes them to health complications in later life.