Pollution

European Upper and lower assessment thresholds for pollutants in ambient air

ae-slider-3-blur

Determination of requirements for assessment of concentrations of sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter (PM10 and PM2,5), lead, benzene and carbon monoxide in ambient air within a zone or agglomeration

body effect pollutantsA.   Upper and lower assessment thresholds

The following upper and lower assessment thresholds will apply:

1.   Sulphur dioxide

Health protection

Vegetation protection

Upper assessment threshold

60 % of 24-hour limit value (75 µg/m3, not to be exceeded more than 3 times in any calendar year)

60 % of winter critical level

(12 µg/m3)

Lower assessment threshold

40 % of 24-hour limit value (50 µg/m3, not to be exceeded more than three times in any calendar year)

40 % of winter critical level

(8 µg/m3)

2.   Nitrogen dioxide and oxides of nitrogen

Hourly limit value for the protection of human health (NO2)

Annual limit value for the protection of human health (NO2)

Annual critical level for the protection of vegetation and natural ecosystems (NOx)

Upper assessment threshold

70 % of limit value (140 µg/m3, not to be exceeded more than 18 times in any calendar year)

80 % of limit value (32 µg/m3)

80 % of critical level (24 µg/m3)

Lower assessment threshold

50 % of limit value (100 µg/m3, not to be exceeded more than 18 times in any calendar year)

65 % of limit value (26 µg/m3)

65 % of critical level (19,5 µg/m3)

3.   Particulate matter (PM10/PM2,5)

24-hour average PM10

Annual average PM10

Annual average PM2,5  (1)

Upper assessment threshold

70 % of limit value (35 µg/m3, not to be exceeded more than 35 times in any calendar year)

70 % of limit value (28 µg/m3)

70 % of limit value (17 µg/m3)

Lower assessment threshold

50 % of limit value (25 µg/m3, not to be exceeded more than 35 times in any calendar year)

50 % of limit value (20 µg/m3)

50 % of limit value (12 µg/m3)

4.   Lead

Annual average

Upper assessment threshold

70 % of limit value (0,35 µg/m3)

Lower assessment threshold

50 % of limit value (0,25 µg/m3)

5.   Benzene

Annual average

Upper assessment threshold

70 % of limit value (3,5 µg/m3)

Lower assessment threshold

40 % of limit value (2 µg/m3)

6.   Carbon monoxide

Eight-hour average

Upper assessment threshold

70 % of limit value (7 mg/m3)

Lower assessment threshold

50 % of limit value (5 mg/m3)

B.   Determination of exceedances of upper and lower assessment thresholds

Exceedances of upper and lower assessment thresholds shall be determined on the basis of concentrations during the previous five years where sufficient data are available. An assessment threshold shall be deemed to have been exceeded if it has been exceeded during at least three separate years out of those previous five years.

Where fewer than five years’ data are available, Member States may combine measurement campaigns of short duration during the period of the year and at locations likely to be typical of the highest pollution levels with results obtained from information from emission inventories and modelling to determine exceedances of the upper and lower assessment thresholds.

Back to list