Nitrogen Dioxide (NO2) in the Local Atmosphere
in Relation to Road Transport
Rosalie Camilleri
Institute for Sustainable Development, University of Malta, Msida MSD2080, Malta
Contributions to NO2 Emissions in 2008
across the European Union 2
Introduction
Nitrogen dioxide (NO2), is one of the gaseous air pollutants
known to have an adverse effect on human health causing
acute respiratory conditions especially in children and other
sensitive groups1
Agriculture,
2%
Industrial
Processes, 2%
The high temperatures, which characterise the internal
combustion engines of motor vehicles allow the reaction
between Nitrogen and Oxygen present in the air leading to
the formation of nitrogen monoxide. Upon release,
nitrogen monoxide is rapidly oxidised to nitrogen dioxide.
O2 + N2
2NO + O2
Commercial
Institutional
& household,
14%
Energy
exploration
and
production,
20%
Non-Road
Transport, 7%
Energy use in
Industry, 14%
2NO
Road
Transport ,
41%
2NO2
Methods and Analysis
1
Traffic Counts
Daily Number of Vehicles
729 - 10197
10198 - 19665
19666 - 29133
29134 - 38601
38602 - 48070
48071 - 57538
57539 - 67006
67007 - 76474
76475 - 85942
85943 - 95410
Kriged Map - Annual Mean 2010
Nitrogen Dioxide Concentration µg/m3
6.29 - 10.62
10.62 - 12.85
12.85 - 14.92
14.92 - 18.47
18.47 - 21.86
21.86 - 23.3
23.3 - 25.06
25.06 - 27.46
27.46 - 30.23
30.23 - 33.88
33.88 - 37
37 - 89.01
Roads
Vehicles per Day
766 - 10717
10718 - 20668
20669 - 30619
30620 - 40570
2
40571 - 50522
50523 - 60473
60474 - 70424
70425 - 80375
80376 - 90326
90327 - 100277
1
3
1
3
2
2
Data Sources:
Traffic Counts for 2010: Transport Malta
Nitrogen Dioxide Concentration for 2010: Diffusion tube network MEPA
Monitoring and mapping of the Nitrogen dioxide concentrations is an
important means of informing the policy makers and general public on the
risk of elevated pollutant levels.
The surface of Nitrogen dioxide concentration was created from point data
using a Universal Kriging Interpolation, a geostatistical technique which
allows estimation of the observed variable at un-sampled locations.
Conclusions
Road transport is a major contributor to pollution from Nitrogen
dioxide. Therefore, a number of actions should be taken in order to
minimise the effect of road transport on air quality. These include:
1
References
Areas
of
high
Nitrogen
dioxide
concentrations coincide with areas of high
traffic activity, thus highlighting road
transport as an important contributor to
this gaseous pollutant.
Reduction in excessive vehicle use through the
provision of alternative transport.
Replacement of old and outdated technology in
vehicle fleet
Good maintenance of vehicles in use
World Health Organistion (WHO) (2003), Health Aspects of Air Pollution with Particulate Matter, Ozone and Nitrogen Dioxide
2 European Environmental Agency (2010) – European Union emission inventory report 1990- 2008 under the UNECE
Convention on Long-range Transboundary Air Pollution (LRTAP).