Traffic-related Emissions and Immissions 2009
In the past, the reduction of emissions from industrial and domestic heating was the main focus of air quality planning. In these segments, sizeable reductions of airborne pollutant emissions could be achieved through extensive rehabilitation programmes and plant closures. Improvements were also achieved in the area of traffic, but nonetheless, traffic is the largest single source of both current and future air pollutants – not only in Berlin – and is the determining factor for the course of future action in air quality planning.
Due to historical development conditions, the spatial residential structure of Berlin and Brandenburg is “traffic-efficient”. No other region in Germany has anywhere near such favourable conditions. Especially characteristic of Berlin are the clearly polycentric structures and the intensive utilization of limited space in the inner city, as well as in the centres on the periphery, with intensive large and small scale multiple uses resulting in a lower degree of suburbanization than in other large cities. Only 20% of the population of the metropolitan area lives in the surrounding suburbs. The share of commuters into Berlin, amounting to only around 10% of employed persons with mandatory social insurance payments, is very low, compared with other metropolitan areas. In must be noted, however, that unusually large sections of the urban peripheral area are within the administrative borders of Berlin, as a result of the establishment of the amalgamated municipality of “Greater Berlin” in 1920.
Since 1990, the city and its immediate suburbs in Brandenburg have experienced considerable changes in their spatial structure, in terms of the distribution of the population, businesses, and jobs. Moreover, significant locations for shopping and leisure activities have been established, especially in the eastern part of the city and in the surrounding areas. The dynamics of change is continuing, but at a reduced rate. To some extent, there has even been a trend toward “rediscovering” the benefits of inner-city living and shopping, a trend which may prove supportive to efforts to achieve a reduced-traffic, compact urban development.
Since reunification, the city of Berlin has been confronted with a considerable increase in traffic. The number of the motor vehicles registered in Berlin increased by 23% between 1989 and 2002, when a high point of 1,440,000 was achieved. This figure dropped continuously over the course of several years, and is now at 1,304,550 motor vehicles (as of Jan. 1, 2011), after a slight recent upturn.
The traffic volume on the Berlin road network has, however, according to the Emissions Register, decreased only slightly, from 12,641,300,000 vehicle-km in 2005 to 12,055,700,000 vehicle-km in 2009 (see Table 3). In future too, moreover, traffic growth is to be expected, especially in road freight transport, which is very impact-intensive.
These far-reaching changes have not ended yet. The increase in non-local traffic is caused, among other things, by the continuing expansion of the combined Berlin-Brandenburg residential and commercial area; the intensification of international economic interdependence; and, especially in Berlin, increasing interdependence with Eastern Europe.
The contribution of motor vehicle traffic to air pollutant concentrations: Origins and trends
Berlin’s motor vehicle traffic has for some years now been the cause not only of considerable noise immissions in significant problem areas (see Maps 07.05.1 and 2, Strategic Noise Maps, Road Traffic; 2008 Edition), but also of air pollution, especially since other categories that originally contributed to air pollution have been substantially reduced. Table 1 shows the combined emissions of all of Berlin’s sources of major pollutants since 1989.
Since the fall of the Berlin Wall in 1989, many industrial enterprises have been rehabilitated or shut down, and the use of coal for fuel for home furnaces in Berlin’s residential areas has been replaced with heating oil, natural gas, or district heating (cf. Map 08.02.1 Predominant Heating Types, Supply Shares of Individual Energy Carriers; 2010 Edition). In 1989, domestic heating and industry were significant sources of sulphur dioxide and particulate pollutants, but these have been reduced substantially. Between 2000 and 2009, total emissions of nitrogen oxides were reduced by almost 30 %, and of particulate matter by over 20 %.
The particulate emissions from motor vehicle exhausts, which are an especially great health threat, also decreased by more than 80% between 1989 and 2002. This finding agrees substantially with the measurements of diesel soot detected in so-called “canyon streets” – the major component of motor vehicle exhaust emissions: the soot concentration measured at Measurement station 174 of the Berlin Air Quality Measurement Network BLUME (on Frankfurter Allee, in the Friedrichshain neighbourhood), dropped by 50% between 2000 and 2008 (see also the evaluations in Map 03.12.1, Station 174). However, since the particulate matter emissions from abrasion and resuspension of road transport decreased by only 43 % during these 20 years, road traffic is the second greatest sources of particulate matter in Berlin, after “other sources”. The calculated decline from 2008 to 2009 was based on the use of new, significantly lower emissions factors; in actual fact, the emissions probably declined only commensurately with the decrease in traffic, or by about 10 %. Road traffic, including abrasion and resuspension, in 2009 accounted for 29 % of the particulate emissions of PM10 in Berlin, while “other sources” a counted for 51 % (for PM2.5 particulate matter, the ratio was 32 % to 44 %).
By the beginning of the 1990s, road traffic had replaced industrial plants as the main source of nitrogen oxides in Berlin. As of 2009, street traffic produced 40 % of the nitrogen oxides in Berlin, whereas industrial plants accounted for 35.2 % of total emissions.
Especially high in relative terms is the pollution from motor vehicle traffic in the inner city, where over one million people live in an area of 100 sq km. If current trends for use of and competition for space continue, motor vehicle traffic will increase especially strongly here. If current conditions continue, freight transport will encounter a particularly major increase in bottlenecks in the streets.
In order to counteract these developments, which are to some extent incompatible with urban living and threatening to public health, two mutually complementary planning strategies have been developed for Berlin:
With the revised Urban Development Plan for Traffic, the Berlin Senate in a resolution of March 29, 2011 presented an updated action plan which combines the possible and necessary steps for the further development of the Berlin traffic system for the coming years with a long term strategic orientation. The core of the action plan is a catalogue of measures that were previously analyzed in detail and coordinated for effectiveness, acceptability and fundability. With regard to the future development of traffic in Berlin and the surrounding area, the investigations for the Berlin Air Quality Plan are based on this long term action concept.
“Health and Safety”, one of the key strategic components of the Urban Development Plan for Traffic, includes a number of important strategies to limit the increase of motor vehicle traffic and its associated effects, with the goal of a reduction of air and noise pollution in the primary road network. The implementation of the measures of the Urban Development Plan for Traffic is expected to be completed by 2015.
The target date for StEP Transport is 2025, which is rather the long term; however, with its “Mobility Programme 2016”, it also takes short and medium term requirements into account.
The standardized Air Quality Plan mandated by the EU was adopted by the Berlin Senate in August 2005; a revision titled “Air Quality Plan, 2009-2020” is in preparation. Under Europe-wide standards, the Air Quality Plan data must include information on:
- pollution measurements
- the causes of high air pollution levels
- the frequency and degree of instances in which the limits are exceeded
- pollution immission and the proportions of the immission for each causative factor (e.g. industry, commercial activity, home heating, traffic)
- planned measures, and a schedule for implementation; and
- a prognosis of the goals to be achieved by such measures.
The present Air Quality Plan provides information about the legal framework and the prevailing situation, and describes the causes of air pollution. The measures take into account the developments to date of the condition of the air (through 2010), and future trends through 2020. The focal point is the presentation of a range of potential measures and their evaluation. Based on the effectiveness of these measures, a strategy will be developed for the Berlin Air Quality Plan. The Air Quality Plan documents that Berlin, like many other large German and European cities, faces a major challenge to meet the new EU limits.
The essential results can be summarized as follows: the locally generated segment of the pollution, the share which can only be reduced by Berlin measures, accounts for about half of the particulate pollution measured at a main traffic street; it is caused by the urban background and by the local sources. The urban background pollution share is caused mostly by road traffic (16 % of total PM10 pollution). The rest (11 %) consists of approximately equal shares of home heating, industry/ power plants, construction, and other emissions.
The results of the measurements of recent year and the model calculations carried out for 2009 lead, among other things, to the following conclusions:
- The multi-year trend of particulate and nitrogen dioxide pollution shows only a very slight decline. Both the high values for PM10 in 2005 and 2006 and the decline in 2007 and 2008, as well as the recovery in 2009 and 2010, show strongly weather-related components. Both the annual mean values, and, even more, the number of cases in which the maximum for the daily average was surpassed, is to a great extent dependent upon the meteorological dispersion conditions and the incidence of low-exchange high-pressure weather conditions with southerly to easterly winds.
For nitrogen dioxide, this strong dependence does not apply. The steady development of emissions values is determined more by factors of the vehicle fleet itself. On the whole, the NO2 levels have in recent years proven to be more resistant to air pollution control measures than has PM10 pollution. Even in the years with the best meteorological dispersion conditions, they still exceeded the limits for the annual average in force since Jan. 1, 2010, at all road sites.
- In 2010, the 24-hour values for particulates and the annual values for nitrogen oxide were exceeded at all measurement stations located close to traffic. The calculations for 2009 and for nitrogen oxide show instances of exceeding the limits in the entire primary road network, especially in the inner city, on a total length of approx. 55 km, while the (calculated) annual mean value for PM10 exceeded the limit value of 40µg/cu.m at only a few sites.
These investigations indicate that the two most problematic pollutants in Berlin are still NO2 and PM10. Because of their physical effect, strict limit values for these substances must be upheld in the European Union and in Germany.
Nitrogen oxides are acidifiers. They are harmful to human health, cause damage to plants, buildings, and monuments, and contribute significantly to the excessive formation of ground level ozone and various noxious oxidants during summer heat waves.
Nitrogen oxides, especially nitrogen dioxide, lead to irritation of the mucus membranes of the respiratory passages in people and animals, and can increase the risk of infection (see Kühling 1986). Cell mutations have also been observed (BMUNR 1987). Various epidemiological studies have shown a correlation between the deterioration of the functions of the lungs, respiratory tract symptoms, and increased nitrogen dioxide levels (see Nowak et al. 1994).
Diesel soot is a major component of particulate matter (PM10) in motor vehicle exhaust. It is a carrier for polycyclic aromatic hydrocarbons (PAH), a carcinogen, but also on its own, it is a possible cause of lung and bladder cancer (see Kalker 1993). Moreover, such ultra-fine particulate as diesel soot, smaller than 0.1 µm, is suspected to increase the risk of cardiovascular disease.
Legal stipulations and limit values
An evaluation of air pollution from motor vehicle traffic has only become concretely possible for immission control authorities since 1985, since the European Community, in the Directive of the Council of 7 March 1985 on Air Quality Standards for Nitrogen Dioxide (Directive 85/203/EEC), specified limits and goals for this pollutant. In addition, it stipulated that measurements be taken of concentrations of nitrogen dioxide on “canyon streets” and major intersections.
In 1996, due to a multiplicity of new findings regarding this and other air pollutants, “Directive 96/62/EC on Ambient Air Quality Assessment and Management (the so-called “Framework Directive “) was drafted and brought into force.
In this Directive, the Commission is called upon to submit, within a specified time period, so-called “subsidiary directives” stipulating limits and details for the measurement and assessment of a specified list of components.
Since then, four subsidiary directives have come into force:
- As of July 19, 1999, Directive 99/30/EV, with limits for sulphur dioxide, particulate matter (PM10), nitrogen dioxide and lead
- As of December 13, 2000, Directive 2000/69/EC, with limits for benzene and carbon monoxide
- As of February 9, 2002, Directive 2002/3/EC, for comparing ozone at ground level to the data and level of excess over the limits; and
- As of December 15, 2004, Directive 2004/107/EC, with limits for arsenic, cadmium, mercury, nickel and PAH.
Germany had two years to enact the first two subsidiary directives into national law, a deadline it missed substantially, as the Seventh Amendment to the Federal Immissions Protection Law (BImSchG), which addressed the first subsidiary directive, was not enacted until September 2002. The new Ozone Directive has now also been enacted into German law with the new 33rd Ordinance of the BImSchG.
The core elements of the Air Quality Directives are the immission limit values, which are “to be attained within a given period and not to be exceeded once attained”. The pollution concentrations, and the time in which the limits must be met, are stipulated in the subsidiary directives, and in the 22nd Ordinance to the BImSchG (22nd BlmSchV).
Table 3 shows the corresponding values for the air pollutants which pose the greatest potential problem for Berlin: PM2.5, PM10 and nitrogen dioxide.
At the European level, EU Directive 2008/50 governs the assessment of air quality based on established limit and target values for all relevant pollutants, including the establishment of common methods and criteria. For the first time, air quality values have been established for the particularly harmful small particulate matter (diam. < 2.5 micrometres; PM2.5).
At the national level, the 39th Federal Immissions Protection Ordinance (BImSchV) on air quality standards and emissions limits governs the implementation of EU Air Quality Directive 2008/50/EC. At the same time, the Ordinance on Immission Values for Atmospheric Pollutants (22 BImSchV) and the Regulation for the Reduction of Summer Smog, Acidification and Nutrient Inputs (33 BImSchV) have been superseded by the 39th BImSchV.
Under §11 of the 39th BlmSchV, Berlin is a metropolitan area in which the air quality must be evaluated annually and, if necessary, measures must be taken to comply with the limits. The entire city was designated as a planning area for the possible establishment of a plan to preserve air quality. Exceeding of the limits occurs throughout the city, especially on primary roads. It therefore makes no sense to limit the planning area to parts of the city, or to divide the city into distinct planning areas.
Problems in applying Directive 99/30/EC and the 39th BImSchV, using the example of PM10 pollution in the city
In the proximity of high pollution immission, such as on canyon streets, high concentrations of immission occur. Unlike in most industrial areas, there are many people on traffic filled streets, be they residents, customers or workers, who face increased exposure to pollution. In order to meet the EU Directives for emissions at the locations of the highest concentrations, quantification of harmful pollutants must be as accurate as possible. For this purpose, such measurements have in Berlin been supplemented by model calculations for all high-traffic streets in which limits could potentially be exceeded.
However, even on a high-traffic canyon street, the proportion of pollution stemming from other sources in the city or transported in from outside , is an important factor. Therefore, for the planning of measures to improve air quality in Berlin, a system of models was used, which can calculate the effect of pollution from the surrounding area as well as the effect of all emitters within the city, even on high-traffic canyon streets. The model uses the levels:
- “canyon streets”
- city wide background pollution, and
- regional background pollution.
The simplified diagram shown in Figure 1, which shows the spatial distribution of PM10 concentrations in Berlin and the surrounding area, was developed from these investigations of the source of particulate matter pollution in Berlin.
There is a broadly distributed background level (green area of chart) which, according to measurements taken at several rural stations in Brandenburg in 2002, amounts to almost 20 µg/cu.m. The component, known as the “regional background pollution”, is distributed relatively evenly outside of the city, as the results of the large-scale model show. Added to that is the proportion of PM10 pollution caused by local Berlin-based sources. It includes:
- that portion obtained by the combination of all of the emissions form all Berlin sources: power plants, industry, residential heating (blue area); together with the regional background, this reflects of the particulate concentrations measured in the residential areas of the city remote from traffic and industry;
- an additional portion caused by local emitters in the immediate area of a source, such as motor vehicle traffic on Frankfurter Allee (red peaks).
In sum for Berlin, barely half the PM10 pollution measured at stations near traffic in the inner city comes from the regional background and the other locally caused particulate pollution. That portion is in turn equally divided between the amounts produced by local traffic, and those produced by the pollution sources in the remainder of the city. Only this last share can be influenced by local measures in Berlin.