As many as 300 million children around the world - about one in seven - are living in areas where the outdoor air pollution is so toxic it can cause serious health damage, according to a new report from UNICEF.

The UN Children's Fund report, Clear the Air for Children, drew on satellite imagery to show where the affected children live in conditions where air pollution is six or more times higher than international guidelines.

As well as showing 300 million children live in areas with "extremely toxic" levels of air pollution, it confirms that about two billiion children live in areas where outdoor pollution, caused by factors including vehicle missions, heavy use of fossil fuels, dust and the burning of waste, exceeds minimum air quality guidelines set by the World Health Organization. 

Anthony Lake, UNICEF executive director, said air pollution is a major contributing factor in the deaths of some 600,000 children aged under five every year and threatens the lives of millions more.

“Pollutants don’t only harm children’s developing lungs - they can actually cross the blood-brain barrier and permanently damage their developing brains - and, thus, their futures. No society can afford to ignore air pollution.”

UNICEF is calling on world leaders attyending COP 22 in Marrakesh, Morocco, next week to take urgent action to cut air pollution, to increase children's access to healthcare, to ensure sources of pollution are not located within the vicinity of schools and playgrounds, and to better monitor air quality.