London smog
A cyclist on London's the Mall wears a pollution maskReuters

Toxins from air pollution are contributing to the deaths of around 40,000 people a year in the UK, a landmark study has found.

The report by the Royal College of Physicians and the Royal College of Paediatrics and Child Health warns that the health impact of Britain's air pollution is greater than previously thought, with the 40,000 figure a significant increase on the previous estimate of 29,000.

The authors of the new report – led by experts at the University of Southampton and Queen Mary University of London – said the push for diesel, which had been considered a greener fuel had increased pollution.

Diesel vehicles emit much more nitrogen dioxide that petrol cars and ownership of diesel cars in the UK has more than trebled in the past 15 years.

"In 2000, just 14% of new cars were diesel powered, but today this figure has risen to 50 %, and almost all light goods vehicles and vans are now powered by diesel," they wrote.

"The increasing popularity of diesel vehicles can undo the positive benefits from other policies to decrease air pollution."

Co-author Professor Jonathan Grigg said there was now clear evidence air pollution - largely from factories and traffic - was linked to heart disease and lung problems, including asthma.

The study also found that other pollutants that posed a threat included tobacco, wood-burning stoves, spray deodorants, cleaning products, air fresheners and fly spray while mould and mildew in poorly ventilated rooms can also cause illness.

Grigg also said that with escalating NHS costs, it was "essential that policy makers consider the effects of long-term exposure on our children and the public purse".

He called on the Government to monitor exposure to air pollution more effectively and urged the public to use public transport and avoid driving high-polluting vehicles.

A Department for Transport spokesman said: "There have been major improvements in air quality over the past two decades and more than £2bn has been invested in greener transport and other clean air measures since 2011 to improve it further," the Daily Mail reported.