translate English to French: Particulate Matter Standards and Implementation To provide additional protection from the adverse health effects of particles, in 1997, EPA issued NAAQS for PM2.5. The annual standard was set at 15 micrograms per cubic meter (µg/m3) and is met when the three-year average of the annual arithmetic mean PM2.5 concentrations does not exceed 15 µg/m3.
La norme journalière, établie à 65 µg/m3, est respectée lorsque la moyenne triennale du 98e percentile des concentrations de 24 heures ne dépasse pas 65 µg/m3.