CALLS are being made for "clean air zones" in cities across the UK, after a study of one of Britain's largest cities found air pollution could shorten a child's life by up to seven months.

An eight-year-old child born in 2011 may die two to seven months earlier if given a lifetime of exposure to projected future pollution concentrations, Kings College London researchers found in Birmingham.

It is the first time new Government guidance on the "mortality burden" of air pollution has been applied to a large city area.

The study looked at the combined impact of two pollutants - particulate matter and nitrogen dioxide - on deaths and lower life-expectancy, but did not include non-fatal health conditions like asthma.

A network of local leaders is now calling for clean air zones to be established in major cities across the country.

Polly Billington, director of the UK100 network, which commissioned the research, said: "This report should be a wake-up call to policymakers not just in Birmingham but across the country.

"We need to tackle this invisible killer, which is cutting the lives of children and causing health misery for thousands of adults.

"By working together, local councils and central government can put in place ambitious and inclusive clean air zones to tackle the most polluting sources of dirty air and let us breathe freely."

The mortality cost to the UK of air pollution has been estimated at £8.5 billion to £20.2 billion a year.

Authors of the Birmingham study said £190 million to £470 million per year should be considered to spend on policies to reduce air pollution.

A spokeswoman for the Department for Environment, Food and Rural Affairs said: "Air quality has improved significantly in recent years, but air pollution continues to shorten lives which is why we are taking concerted action to tackle it.

"We are working hard to reduce transport emissions and are already investing £3.5 billion to clean up our air, while our clean air strategy has been commended by the World Health Organisation as an 'example for the rest of the world to follow'.

"In the strategy we committed to setting an ambitious long-term air quality target and we are examining action needed to meet the WHO annual guidelines to significantly reduce PM2.5 levels.

"Our environment bill will give legal force to that strategy and put environmental accountability at the heart of government."