London - Air pollution "made a material contribution" to the death of nine-year-old London schoolgirl Ella Kissi-Debrah, a U.K. coroner ruled on Wednesday. The landmark ruling is the first time air pollution has been officially listed as a cause of death for anyone in the U.K. Ella Kissi-Debrah died in 2013 after suffering severe asthma attacks for three years, her mother Rosamund Kissi-Debrah told CBS News last year. When she died, the cause of her death was determined to be a severe asthma attack leading to respiratory failure. But a report compiled for Kissi-Debrah by Stephen Holgate, the former chair...