Pollutant

Permissible value or limit

Mexican official norm

Acute exposure

Chronic exposure

Concentration (µg/m³) 24-hour average

Maximum allowed frequency

Concentration (µg/m³) annual arithmetic mean

TSP

210

2% per year measurements

-

NOM-025-SSA1-1993 [3]

PM10

120

2% per year measurements

50

PM2.5

65

2% per year measurements

15