A new report by the Organisation for Economic Cooperation and Development (OECD) reveals the impact of air pollution on the world's largest economies.

The study shows air pollution causes costs the world's most advanced economies plus China and India $3.5 trillion (£2.1 trillion) a year.

China alone - which is not an OECD member - incurs an additional $1.4 trillion in costs, while India is estimated to incur costs of $0.5 trillion.

The cost to the economies of OECD's 34 member countries - which includes the UK and many other European countries - is estimated to be $1.7 trillion.

More than 3.5 million people are estimated to die each year from outdoor air pollution, with the number rising by four per cent between 2005 and 2010.

Presenting the report at the International Transport Forum's 2014 summit in Germany earlier this month, OECD secretary-general Angel Gurria said: "The price we pay to drive doesn't reflect the impact of driving on the environment and on people’s health. Tackling air pollution requires collective action."