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No. 300: Development in air quality and health effects for 2020 and 2030 in relation to National program for reducing air pollution (NAPCP)

Jensen, S.S., Christensen, J.H., Frohn, L.M., Brandt, J., Ketzel, M., Nielsen, O.-K., Plejdrup, M.S., Winther, M., Hertel, O., Ellermann, T. 2019. Udvikling i luftkvalitet og helbredseffekter for 2020 og 2030 i relation til Nationalt program for reduktion af luftforurening (NAPCP). Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 52 s. - Videnskabelig rapport nr. 300. http://dce2.au.dk/pub/SR300.pdf

Summary 

Aim and background

The aim of the project is to conduct model calculations of scenarios for the development of emissions from 2016 to 2020 and beyond to 2030, and evaluate the impact on air quality, atmospheric nitrogen deposition, and the health effects of air pollution. The model calculations are on a baseline scenario and an alternative scenario with further reduction requirements for the energy sector.

The background for the project is the requirements of an EU directive from 2016 on National Emission Ceilings (NEC directive). The directive requires development of national programmes for the control of air pollution named NAPCP – National Air Pollution Control Programme. Denmark is committed regularly to evaluate the development of the national emissions and their expected future development, and carry out actions to reduce emissions in order to achieve the reduction targets that have been set for Denmark in the NEC directive.

The NEC directive sets out national commitments for reductions in emissions for 2020 and 2030 for the pollutants: sulphur dioxide (SO2), nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOC), ammonia (NH3), and fine particles (PM2.5 - mass of particulate matter less than 2.5 microns). Emissions of these substances are included in the calculations of air quality of NO2 (nitrogen dioxide), PM2.5, PM10 (mass of particulate matter less than 10 microns), and O3 (ozone).

The study

Emissions
The baseline scenario for Denmark originates from the baseline projection of the Danish Energy Agency. This is a forecast based on existing policy actions, also named ‘frozen policy’. That is referred to as: WM – With Measures.

In the alternative scenario with additional measures used for Denmark the emissions are described in details in another DCE report about the projection of emissions (Nielsen et al., 2018a). The alternative scenario only has additional measures within the energy sector and is called WAM – With Additional Measures. The energy sector includes stationary combustion (power plants, heating plants, etc.) and mobile combustion (transport and non-road mobile machinery), as well as fugitive emissions. 

The starting point is 2016, and 2020 and 2030 are scenario years.

Regional background concentrations

The regional background concentrations are calculated with the Danish Eulerian Hemispheric Model (DEHM) with a geographic resolution of 5,6 km x 5,6 km. The regional background represents the average concentration in rural areas over a larger area. The regional air pollution represents the contribution of long-range transported air pollution from emissions from abroad and from Denmark.

Background concentrations with high resolution
The development in background concentrations with high resolution is calculated with the Urban Background Model (UBM). Urban background pollution represents the average background pollution inside and outside cities calculated with a spatial resolution of 1 km x 1 km. Urban background concentrations correspond in a city to the concentration at roof top level or in a back-yard/park. DEHM calculations are input in UBM. For Denmark emissions are available at a spatial resolution of 1 km x 1 km based on the SPREAD model that distributes national emissions based on various geographic variables.

Furthermore, the Average Exposure Indicator is calculated. In principle, the average exposure indicator is determined as an average over three years for PM2.5 measured at urban background locations to reflect population exposure.

In this project the exposure indicator is calculated and only for the scenario years. The Average Exposure Indicator is calculated for Copenhagen, Aarhus, Odense and Aalborg in the same geographic locations as the location of the urban background air quality monitor stations.

Street concentrations
The development in street concentrations is calculated with Operational Street Pollution Model (OSPM) for 98 selected streets in Copenhagen. The selected streets in Copenhagen are the same as those included in the Danish Air Quality Monitoring Program. The development in vehicle emissions is based on the Danish emission model for road traffic and other mobile sources.

Air quality calculations of regional concentrations, urban background concentrations and street concentrations are carried out for NO2, PM2.5 and PM10 for 2016, 2020 and 2030 for the baseline scenario and the alternative scenario.

Health impacts
Health effects of air pollution are calculated with the integrated model system EVA (Economic Valuation of Air pollution). In this project the same version of the EVA system is used as in the Danish Air Quality Monitoring Programme for 2016. The same population is assumed for all years.

Main conclusions

Development in emissions
A reduction in Danish emissions of NOx, NMVOC, NH3 and PM2.5 is seen from 2016 to 2020 and beyond to 2030 in the baseline scenario. SO2 is the only pollutant which is expected to increase in emissions from 2016 to 2020 and beyond to 2030 in the baseline scenario due to increased coal consumption in the baseline scenario. In the alternative scenario for the energy sector, all substances are expected to have slightly lower emissions than the baseline scenario in 2020 and 2030. Foreign emissions are also reduced from 2016 to 2020 and beyond to 2030. The foreign emissions are the same in the Danish baseline scenario (WM) and the alternative scenario (WAM).

Development in deposition of nitrogen
Nitrogen deposition to areas of land calculated with DEHM as average for the entire territory of Denmark is expected to decrease by 7% in 2020 and 15% in 2030 relative to 2016 in the baseline scenario. In the alternative scenario, deposition is reduced by 12% in 2020 and 21% in 2030 in relation to 2016. Reductions in nitrogen deposition is a result of the reductions in national and inter-national NOx emissions but also smaller reductions in NH3 emission.

Nitrogen deposition to Danish maritime areas as an average is predicted to decrease by 8% in 2020 and 18% in 2030 in relation to 2016 in the baseline scenario. The reduction in the alternative scenario is slightly higher, respectively, 12% and 24%, and is a result of the reductions in national and international emissions of NOx and also NH3.

Development in regional background concentrations
The regional concentrations of PM2.5 as an average for the entire territory of Denmark is expected to be reduced by 9% in 2020 and 20% in 2030 in relation to 2016, and for PM10 by respectively 6% and 15%, and for NO2 by respectively 11% and 25% in the baseline scenario. In the alternative scenario (WAM) the percentage reductions in 2020 and 2030 are a little higher as compared to the baseline, reflecting that the emissions are a little lower in the alternative scenario.

Development in background concentrations with high resolution
The average background concentrations for the five regions in Denmark is also calculated with DEHM/UBM for baseline and the alternative scenario. In this case, the calculations are based on a geographical resolution of 1 km x 1 km. A higher resolution than for the DEHM calculations.

As expected higher resolution leads to higher concentrations due to the higher geographic resolution of emissions that result in higher variation in the con-centration surface whereas DEHM calculations result in a more smooth concentration surface.

For the baseline the background concentrations of PM2.5 are reduced by respectively for the five regions 8-11% and 18-20% in 2020 and 2030 in relation to 2016, and for PM10 by respectively 5-8% and 12-16%, and for NO2 by respectively 7-15% and 15-34%. The interval indicates that the percentage re-duction is different from region to region.

In the alternative scenario the percentage reductions in 2020 and 2030 are a little larger as compared to the baseline, reflecting that the emissions are a little lower in the alternative scenario. PM2.5 will be reduced by respectively 10-13% and 23-27% in 2020 and 2030 in relation to 2016, and for PM10 respectively 7-10% and 15-20%, and for NO2 respectively 7-15% and 15-34%.

Development in urban background concentrations in 4 cities
Urban background concentrations of NO2 decrease in the baseline scenario with 13-17% in 2020 and 22-39% in 2030 compared to 2016 for the same locations as the urban background air quality monitoring stations in the four largest cities of Denmark: Copenhagen, Aarhus, Odense and Aalborg. The de-crease for PM10 is 6-7% in 2020 and 11-16% in 2030 compared to 2016. The Average Exposure Indicator for PM2.5 in the base scenario is expected to be reduced by 9-10% in 2020 and 18-22% in 2030 in relation to 2016 for the four cities.

The decrease is a result of reductions in the regional background calculated with DEHM as well as Denmark's contribution calculated with UBM. For all three pollutants there are a few percentage points further reduction in urban background concentrations in the alternative scenario.

Development in street concentrations for 98 streets in Copenhagen
The development in vehicle emissions is based on DCE's national emission model for road traffic (COPERT IV). NOx emissions are expected to decrease by about 26% from 2016 to 2020 and 61% from 2016 to 2030. Particle exhaust emission is estimated to decrease by about 44% from 2016 to 2020 and 81% from 2016 to 2030.

The average NO2 concentration for the 98 streets in Copenhagen is expected to decrease from 29 µg/m3 in 2016 to 24 µg/m3 in 2020 and further to 15 µg/m3 in 2030 in the baseline scenario. There is only a marginal difference between the baseline scenario and the alternative scenario, as background concentrations are only a little lower in the alternative scenario compared to the baseline. Hence, the reduction in street concentrations is driven by the reduction in emissions from traffic in the specific street.

The average PM2.5 street concentration decreases from 13 µg/m3 in 2016 to 11 µg/m3 in 2020 and further to 10 µg/m3 in 2030 in the baseline scenario. 

The decrease for PM10 is from 21 µg/m3 in 2016 to 19 µg/m3 in 2020 and further to 18 µg/m3 in 2030 in the baseline scenario. 

The percentage reduction for PM2.5 and PM10 is not as great as for NO2, since only particle exhaust emissions are reduced, and non-exhaust emissions such as road wear, tire wear and brake wear that makes up a far greater share than the exhaust emission are unchanged.

For PM2.5 and PM10 there is also a marginal difference between the baseline scenario and the alternative scenario. 

Development in health impacts
Development in morbidity and mortality is calculated with the EVA system.

There are about 3,350 premature deaths due to all air pollution from both Danish and foreign emission sources in 2016. In the baseline scenario, the number of premature death decreases to about 3,050 in 2020 and further to about 2,800 in 2030, respectively, a decrease of 9% and 16%. In the alternative scenario, the reduction is greater than in the baseline scenario with about 3,000 premature deaths in 2020 and 2,600 in 2030, respectively, a decrease of 11% and 22%. 

Reductions in the number of premature deaths is primarily due to slightly lower PM2.5 concentrations, but there is also a small contribution from slightly lower ozone concentrations in 2030. The lower concentrations are due to reduction in national and international emissions.