A new study on global daily levels of air pollution shows that hardly anywhere on Earth is safe from unhealthy air.

About 99.82% of the global land area is exposed to levels of particulate matter 2.5 (PM2.5) — tiny particles in the air that scientists have linked to lung cancer and heart disease — above the safety limit recommended by the World Health Organization, according to the peer-reviewed study published on Monday in Lancet Planetary Health. And only 0.001% of the world’s population breathes in air that is considered acceptable, the paper says.

Conducted by scientists in Australia and China, the study found that on the global level, more than 70% of days in 2019 had daily PM2.5 concentrations exceeding 15 micrograms of gaseous pollutant per cubic meter — the WHO recommended daily limit. Air quality is particularly worrisome in regions such as southern Asia and eastern Asia, where more than 90% of days had PM2.5 concentrations above the 15 microgram threshold.