English - Alps Know-How - Cipra

Chapter C – Effects of Transport and Mobility in the Alps
son for this may be the continuously increasing traffic loads
(see chap. A2 and A3) which compensate for the NOx reduction
effects caused by technical improvements. Furthermore
there are likely to be increasing emissions of NO 2
due to the
use of diesel particulate matter filters (UBA 2006b).
Number of stations
Stations where limits were not exceeded
Stations where limits were exceeded
(>50-60 µg/m 3 )
Stations where limits were exceeded (>40/50 µg/m 3 )
Stations where limits were exceeded
(>60 µg/m 3 )
Fig. C3‐2: Annual means of NO 2
on traffic stations in the Alps (data from
AT, CH, DE, FR, no longtime data series available for the other countries).
Instances when the annual limit value for NO 2
was
exceeded
By 2010 the limit value of 40 µg/m³ of NO 2
(annual mean)
has to be attained Europe-wide (Directive 1999/30/EC).
Until this date a decreasing margin of tolerance (MoT) was
defined, triggering the development of air quality management
plans if the limit is exceeded.
Since the EU-Directive (1999) came into effect, the number
and percentage of stations exceeding the limit value
plus the MoT have been increasing (as the MoT limit value
decreased). In 2005 the sum of limit values and MoT was
exceeded at 32% of all traffic stations in the Alps (see Tab.
C3‐2), both in urban and rural areas. In contrast, these values
were not exceeded at urban and rural background stations.
Year
Limit value plus
margin of
tolerance
Number
of traffic
stations
Number
(percentages)
of stations where
limit was exceeded
2000 60 µg/m³ 22 1 (5%)
2001 58 µg/m³ 24 1 (4%)
2002 56 µg/m³ 33 4 (12%)
2003 54 µg/m³ 57 11 (19%)
2004 52 µg/m³ 60 16 (27%)
2005 50 µg/m³ 31 10 (32%)
Tab. C3‐2: Stations which exceeded the limit values plus margin of
tolerance between 2000 and 2005 (data from AT, CH, DE, FR, IT, LI).
Fig. C3‐3: Percentage of traffic-related stations showing where the future
European long-term limit value for NO 2
(40 µg/m³) was exceeded at all
stations (data from AT, CH, DE, FR, IT, LI).
Instances when the short-term limit value for NO 2
was
exceeded
The EU short-time limit value of less than 19 days (per calendar
year) of the one hour average of 200 µg/m³ will have
to be met from 2010 on. For the period until 2010, however,
higher limit values are effective (200 µg/m³ plus margin of
tolerance). For this report only data from Austria have been
delivered. Though for Austria it is known that – taking advantage
of the margin of tolerance – the value has not been
exceeded in the last years except at one traffic station in
2005.
Considering only the limit value of 200 µg/m³ without tolerance,
the limits were exceeded on more than 18 occasions
(the future EU short-time limit value) at some traffic stations,
especially in the last two years. In 2005, one hour mean values
above 200 µg/m³ were measured at almost 20% of all
traffic-related monitoring sites (see Fig. C3‐4). Thus the new
general tendency of increasing annual means of NO 2
in areas
strongly influenced by traffic is also reflected by a higher
frequency of short-time peak values.
Several traffic stations record increasing annual means
above the future limit value of 40 µg/m³ so that it is likely that
the limit value will not be met by the attainment date. Nine
out of a total of 15 stations which exceeded the limits in 2005
are situated in an urban environment, three in the rural area
near the motorways A10, 12 and 13 in Austria.
In the last three years, about 50% of all traffic stations recorded
values in excess of the future limit value of 40 µg/m³
(see Fig. C3‐3).
Fig. C3‐4: Percentage of traffic stations in the Alps exceeding the European
short-term limit value for NO 2
(data from AT, CH, DE, FR, LI).
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