The following upper and lower assessment thresholds will apply:
(a)SULPHUR DIOXIDE
| Health protection | Ecosystem 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 limit value (12 μg/m3 ) |
| Lower assessment threshold | 40 % of 24-hour limit value (50 μg/m3 , not to be exceeded more than 3 times in any calendar year) | 40 % of winter limit value (8 μg/m3) |
(b)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 limit value for the protection of vegetation(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 limit value (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 limit value (19.5 μg/m3 ) |
(c)PARTICULATE MATTER(1)
| 24-hour average | Annual average | |
|---|---|---|
| Upper assessment threshold | 60 % of limit (30 μg/m3 , not to be exceeded more than seven times in any calendar year) | 70 % of limit value (14 μg/m3 ) |
| Lower assessment threshold | 40 % of 2 limit value (20 μg/m3 , not to be exceeded more than seven times in any calendar year) | 50 % of limit value (10 μg/m3) |
(d)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 ) |
The upper and lower assessment thresholds for PM10 are based on the following indicative limit values for 1 January 2010, which will be reviewed in the light of further information on health and environmental effects, technical feasibility and experience in the application of the existing “Stage 1” limit values:
| Averaging Period | Limit value | Margin of tolerance | Date by which limit value is to be met | |
|---|---|---|---|---|
1. 24-hour limit value for the protection of human health | 24 hours | 50μg/m3 PM10 not to be exceeded more than 7 times a calendar year | To be derived from date and to be equivalent to Stage 1 limit value | 1 January 2010 |
2. Annual limit value for the protection of human health | Calendar year | 20μg/m3 PM10 | 50% on 1 January 2005 reducing every 12 months thereafter by equal percentages to reach 0% by 1 January 2010 | 1 January 2010 |