A nine year-old girl's fatal asthma attack is the first death to be linked directly to air pollution.

A government health advisor said there was a “striking association” between the times young Ella Kissi-Debrah was admitted to hospital in an emergency, and spikes of nitrogen dioxide and PM10s, the most noxious pollutants, near her home.

Ella lived just 80ft from London's South Circular Road - a pollution "hotspot" in the city - and in the three years before her death in February 2013 she went to hospital 27 times.

Her inquest found she died from acute respiratory failure, after suffering from years of seizures and hospital stays.

However, her family have launched a legal bid to get the conclusion overturned, citing a report by asthma and air pollution expert Prof Stephen Holgate.