A leading scientist said today there is no evidence of a link between increased air pollution and a nine-year-old Lewisham girl’s hospital admissions for severe asthma attacks, at an ongoing inquest into her death.

Paul Wilkinson, professor of environmental epidemiology at the London School of Hygiene and Tropical Medicine, said he had analysed levels of nitrogen dioxide and particulate matter on the days Ella Kissi-Debrah was taken to hospital. 

He told Southwark Coroner’s Court he had found no evidence to suggest Ella was hospitalised at times of increased air pollution.

Wilkinson said it was “complicated” to determine, and that while “there is an effect of air pollution… it’s certainly not a prominent effect on Ella’s condition.”

“In Ella’s case, there is no clear evidence that I could determine that symptoms requiring hospital contact were on days when the air pollution was higher than any other days.”

At the time that Ella was severely ill, between 2010 and 2013, it was scientifically accepted that air pollution was a factor in the exacerbation of asthma. Wilkinson said this has been recognised for “probably at least 15 years.”

Air pollution is “a trigger” of asthma, he said, but allergens and respiratory infections have a more significant impact. 

Even though Ella was likely to have been exposed to above average levels of pollution from the South Circular Road, Wilkinson said he could not find a connection between the levels of air pollution and a deterioration in her case.

Ella lived all her life about 25 metres from the South Circular road in Lewisham.

“The South Circular is a busy road and she was within 30 metres of it. And levels from a main road by 30 metres are still above background levels,” Wilkinson said. “So she was likely to be having above average [exposure] even within London.”

Professor Sir Stephen Holgate, professor of Immunopharmacology at the University of Southampton, told the inquest Ella was “living on a knife edge” amid air pollution.

Ella’s inquest was set in motion after a report by Holgate found a ‘striking association’ between Ella’s hospital admissions and spikes of nitrogen dioxide and PM10 levels – the most severe polluters. 

The inquest has heard that Lewisham failed to treat illegal levels of air pollution in the area where Ella lived and died as a public health emergency.

The coroner Philip Barlow must decide whether or not air pollution caused Ella’s death in February 2013 from an acute asthma attack. If he rules air pollution did cause Ella’s death, the finding would make legal history, as it has never been identified as a cause of death before in the UK.

Ella’s mother, Rosamund Adoo Kissi-Debrah, said “moving would have been the first thing” the family would have done if they had known the risks air pollution posed to Ella.

The hearing continues tomorrow.