France, PM2.5 and the flight ban
For 25 years now, the air quality index of the “Atmo France” institute has not changed. This index therefore does not take into account certain pollutants or PM2.5, although scientists consider the smaller particles more dangerous than its “big brother” PM10. According to the WHO, pollution due to the particles of PM2.5 should not exceed 10µ/m³ per year on average.