More than 30 of Europe’s air pollution and health experts have teamed up with clean air campaigners to highlight a pollutant that is being overlooked in environmental regulations.
The health impacts of air pollution have been linked to the mass of particles in the air around the world, but by only weighing them we miss the tiny, ultrafine particles, less than 100 nanometres across. They have little mass but are very numerous.
The cloud scientist and meteorologist John Aitken found between 40,000 and 200,000 particles in each cubic centimetre of London’s air in the 1880s. Similar numbers were found when modern measurements began about 15 years ago, suggesting little improvement in more than a century.
Things are better today, at about 10,000 particles per cubic centimetre, following laws to clean sulphur from diesel fuel. Due to their small size, ultrafine particles are thought to pass beyond our lungs to have whole-body health impacts including heart attacks, and recent research has pointed to a link with brain cancer. Some sources of ultrafine particles are already being controlled by actions targeted at other pollutants, such as scrubber systems for vehicle exhausts. But other sources are being overlooked including airports, shipping, wood burning and commercial cooking.
