Parent document       IMECA
IMECA

Good

0 -100

Not satisfactory

100 - 150

Bad

150 - 200

Very bad

200 - 300

 

Favorable for any outdoor activities Minor annoyances in sensitive people Increased annoyance in persons with respiratory problems Manifestation of several symptoms with potential risks to healthy people
UV -INDEX

Low 0 - 4

Medium 4 - 7

High 7 - 9

Extreme 9 -15

Criteria for Air Quality Standards

Mexican Valuesa

versus Int. Values

 

Immediate Exposure

Cronic Exposure

min. threshold values

Pollutant

Concentration and Timeframe

Maximum
Aceptable
Frecuency

EEA
(EU)b

NAAQS
(US)c

NEPM
(AUS)d

Ozone (O3)

0.11 ppm
(1 hour)

Once every 3 years

0.12 ppm

0.12 ppm

0.10 ppm

Sulfur Dioxide(SO2)

0.13 ppm
(24 hours)

Once every year

0.125ppm

0.14 ppm

0.08 ppm

Nitrogen Dioxide (NO2)

0.21 ppm
(1 hour)

Once every year

0.04 ppm

0.053ppm

0.03 ppm

Carbon Monoxide (CO)

11 ppm
(8 hours)

Once every year

10 ppm

9 ppm

9 ppm

Total Suspended Particulates (TSP = PST)

260 g/m3
(24 hours)

Once every year

-

-

-

Particulate Matter less than 10 microns (PM10)

150 g/m3
(24 hours)

Once every year

120 g/m3

150 g/m3

50 g/m3

Lead (Pb)

-

-

0.5 g/m3

1.5 g/m3

0.5 g/m3

IMECA Criteria Levels


IMECA

PST
(24hr) g/m

PM10
(24hr) g/m

SO2
(24hr) ppm

NO2
(1hr) ppm

CO
(8hr) ppm

O3
(1hr) ppm

100

260

150

0.13

0.21

11

0.11

200

546

350

0.35

0.66

22

0.23

300

627

420

0.56

1.1

31

0.35

400

864

510

0.78

1.6

41

0.48

500

1000

600

1

2

50

0.6

Source:
a)Federal Official Daily - Instituto Nacional de Ecologia
  Sistema de Informacin Ambiental - SIMA
b)European Environment Agency - EEA
c)National Ambient Air Quality Standards - NAAQS
d)Ambient Air Quality - NEPM