The best pollution masks for cyclists block half of bad particles

Cyclists with pollution masks

Some face masks can reduce exposure to air pollution

Beawiharta Beawiharta/Reuters

City air is a killer. Governments are trying to cut urban pollution by encouraging the use of bikes, but this exposes people who cycle to emissions from the cars of those who don’t. Are anti-pollution face masks the answer?

Fulvio Amato at the Institute of Environmental Research and Water Assessment in Barcelona and his colleagues have tested nine commercially available masks aimed at cyclists for filtering out air pollution. The best screened out nearly half of the most harmful tiny particles that cyclists breathe …