Nine out of 10 people globally are breathing poor quality air, the World Health Organisation said on Tuesday, calling for dramatic action against pollution that is blamed for more than six million deaths a year.

New data in a report from the UN’s global health body “is enough to make all of us extremely concerned,” Maria Neira, the head of the WHO‘s department of public health and environment, told reporters.The problem is most acute in cities, but air in rural areas is worse than many think, WHO experts said.