Choke point

An exclusive Guardian investigation has found that Europe is facing a serious public health crisis, with 98% of people living in areas with toxic air linked to 400,000 deaths a year. What can be done to address the problem?

- Matthew Taylor and Pamela Duncan

• 1 million The number of stillbirths each year that are caused by air pollution, according to a recent study

EUROPE IS FACING A "SEVERE PUBLIC HEALTH CRISIS", with almost everyone across the continent living in areas with dangerous levels of air pollution, a Guardian investigation has found.

Analysis of data gathered using cutting-edge methodology - including detailed satellite images and measurements from more than 1,400 ground monitoring stations - reveals a dire picture of dirty air, with 98% of people living in areas with highly damaging fine particulate pollution that exceeds World Health Organization (WHO) guidelines. Almost two-thirds live in areas where air quality is more than double the limit.

The worst-hit country in Europe is North Macedonia. Almost two-thirds of people there live in areas with more than four times the WHO guidelines for PM2.5, while four areas were found to have air pollution almost six times the figure, including in its capital, Skopje.

Eastern Europe is significantly worse than western Europe, apart from Italy, where more than a third of those living in the Po valley and surrounding areas in the north of the country breathe air that is four times the WHO figure for the most dangerous airborne particulates.

The Guardian worked with pollution experts to produce an interactive map revealing the worst-hit areas. The measurements refer to PM2.5 - tiny airborne particles mostly produced by burning fossil fuels and some of which can pass through the lungs and into the bloodstream and affect almost every organ.