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Nitrogen Oxides - Emissions and Pollution 1995

Map Description

Emissions and Calculated Pollution

In the three Maps 03.03.1, 03.03.2 and 03.03.3, the emissions for the primary polluter groups industry, domestic heating and traffic are presented for the year 1994 resp. 1993, each in 1 × 1 km – Grid. The Maps 03.03.4, 03.03.5 and 03.03.6 give respectively the calculated yearly average for pollution concentrations in 1994 resp. 1993 from those main polluter groups.

Industry 1994

The Map 03.03.1 of the industry emissions 1994 shows a very irregular picture. It influenced above all through the twelve power-, heating power- and heating plants, which are distributed throughout the whole city and display relative high emissions. The highest grid value, with more than 2,000 t/km2 and year, can be found at the heating power plant Reuter. It still lies at only a third of the 1989 maximum value (c.f. Map 03.03 SenStadtUm 1994b). This change, which is recognizable at the majority of major polluter sites demonstrates significantly the effect of the emission reduction measures shown in Table 2.

Since according to TA-Luft the height of industry smokestack is dependent on how heavy their pollution emission is; the heavier the pollution, the higher the smokestack. Thereby, the pollutants of these plants are discharged at higher elevations and distributed evenly in and over the entire urban area and the surrounding countryside. Therefore increased concentrations in the vicinity of the plants are as a rule neither calculated near, as Map 03.03.4 shows, nor measured, as Map 03.03.8 documents.

However, Map 03.03.4 shows only minimal influence of industrial plants on nitrogen oxide pollution. It shows two flat maximum values between 5 and 6 µg/m3 in the western city center and with respect to the main leeward wind direction at the eastern city perimeter. A value of between 1 and 3 µg/m3 has been calculated for the other areas at the city’s edge.

Domestic Heating 1994

The Map 03.03.2 of domestic heating emissions 1994 shows in the inner city area a ring of higher nitrogen oxide values, which lies at a relative minimum in the center of town. The low values in the center are due to the influence of the Grosse Tiergarten and a high share of long-distance heat. The ring of higher values, with maximums of 20 to 30 t/km2 and year in Prenzlauer Berg and in the parts of Wilmersdorf resp. in Kreuzberg and Neukölln, is caused through a high share of oil and coal-fueled single- and central heat at very high residential density. With the decrease in residential density, the emissions also decline in the direction of the city edges. The more densely-settled outskirts of the city in direction West (Spandau), North (Tegel), Southeast (Treptow) and Southwest (Zehlendorf) can be recognized by their slightly higher values. The large settlements Märkisches Viertel, Hellersdorf and Marzahn as well as Gropiusstadt do not show up as emission maximums because they are provided with long distance energy (c.f. Maps 08.01 and 08.02 SenStadtUmTech 1996b resp. 1996c). The same distribution, limited to West Berlin, already appeared in the Environmental Atlas of 1985, whereby the single values in the highly polluted areas lay up to 10 t/km2 and year higher (c.f. Maps 03.03.2 and 03.03.5 SenStadtUm 1985).

The results of the dispersion calculation in the area of domestic heating (Map 03.03.5) show essentially the same structure as the emission field. The maximum value of 6 µg/m3 is the same as that for the industrial plants and forms a ring around the city center.

Traffic 1993

In the Map 03.03.3 of traffic emissions 1993 the half open city expressway ring and the west-east axis along the Bismarck Strasse – Kaiserdamm in the western part of the city appears most prominently. South of the intersection of the city expressway and the boulevard Bismarck Strasse – Kaiserdamm, in the vicinity of the fairgrounds maximum nitrogen oxide emission levels are up to 150 t/km2/a. Emission levels of more than 100 t/km2/a have also been recorded for the borough Mitte, in the former eastern part of the city. The maximum emission level of 150 t/km2/a is even less than half as high as in 1989 (c.f. Map 03.03.3 SenStadtUm 1994b) in part because of emission reductions resulting from the increased percentage of automobiles with catalytic converters. It is also due to the new grading of car and truck emissions performed for the Federal Environmental Agency on 27 makes of cars and trucks (Umweltbundesamt 1996b). In the case of traffic emission, it is easier to recognize a star-shaped distribution of increased nitrogen oxide levels with the Berlin urban area than with domestic heating emissions. They extend from the city center in every direction following the main traffic arteries. At the northerneast outskirts, the course of the highway Berlin Ring with its access roads and branch to Prenzlau and Stettin can be clearly recognized.

The calculated pollution for traffic (Map 03.03.6) displays emissions in greatly leveled-out form as with domestic heating. A definite maximum of 50 µg/m3 has been calculated for the area east of the western city ring up to Ernst-Reuter-Platz which already lies beyond the maximum emission level.

The pollutant load of the city air is caused not only through emissions in the urban area and in the direct surrounding countryside, but also by a national pollution level, which is caused by a multitude of pollutant sources in Germany and Europe. After the German union the Federal Environmental Agency spread its monitoring network, with whose help these background levels are determined, to the new federal states. In the Berlin region are the stations Kyritz, Neuglobsow and Angermünde northwest an northeast of the city as well as Wiesenburg and Lindenberg southwest and southeast of the city. The yearly averages for 1994 are available as background value for Berlin (c.f. Umweltbundesamt 1996a). These lie between 8 and 14 µg/m3. They correspond to the 10 µg/m3, the measured at 300 m from the Frohnau broadcasting tower. On the basis of these measurements, a national near-ground pollution level for nitrogen oxide of approximately 12 µg/m3 has been calculated for Berlin.

Total Calculated Pollution 1993/94

Map 03.03.7 shows the totals for calculated nitrogen oxide pollution from the three primary polluter groups industry, domestic heating and traffic. These appear in the form of yearly averages for 1994 for places which are not directly influenced by motor vehicle traffic. The maximum pollution load from urban pollutant sources amounts to just about 60 µg/m3 and can be found just a bit southwest of the city center. Due to the emission distribution and the dispersion of the pollutants by the wind, the concentration decreases from the maximum in the main wind direction to the city’s edge faster toward the West than toward the East. At the city’s edge, a significantly lower pollution load of between 10 and 20 µg/m3 can be found than in the city center.

The causes for the nitrogen oxide pollution can be calculated with sufficient accuracy, if the sum calculated for the polluter groups’ concentrations and the national background load conforms to the measuring results.

Given the national background levels, the map of total calculated pollution (c.f. Map 03.03. SenStadtUm 1994b) shows, in contrast to previous years, a close correspondence with the measurements at comparable grid measuring points in the Air Quality Monitoring Network (c.f. Map 03.03.8), if one takes into account that these contain in part local effects of nearby main traffic arteries.

With the help of a dispersion calculation, it is possible to estimate the relative shares from each polluter group toward the pollutant concentration of inner-city residential areas. Table 3 shows as an example the area of the maximum in Charlottenburg.

With this calculation, a high portion of the road traffic-induced nitrogen oxide concentration can even be determined for other areas of the city.

Tab. 3: Calculation of the Road Traffic-induced Share of the Nitrogen Oxide Concentration at the Maximum in Charlottenburg
Tab. 3: Calculation of the Road Traffic-induced Share of the Nitrogen Oxide Concentration at the Maximum in Charlottenburg
Image: Umweltatlas Berlin

Measured Pollution

Sum of Nitrogen Oxide – Yearly Average 1995

For comparison, the yearly average sum of nitrogen oxide is also depicted with the dispersion calculation of the nitrogen dioxide concentration in Map 03.03.8. This is because of the problem presented by the transformation of nitrogen oxide to nitrogen dioxide in the atmosphere. In this map, the concentration differences for near street and off-street are more noticeable than for nitrogen dioxide (c.f. Map 03.03.9), because nitrogen monoxide, primarily from motor vehicle exhaust, is also taken into account. Its concentration declines very quickly with the distance from the streets through the double effect of dispersion and transformation.

The highest levels were all measured at street monitoring stations. That means the city expressway near the interchange Spandauer Damm in Charlottenburg, the Schildhorn Strasse in Steglitz, the Karl-Marx-Strasse in Neukölln recorded more than 200 µg/m3. 166 µg/m3 has been recorded in the Frankfurter Allee.

Nitrogen Dioxide – Yearly Average 1995

Generally it can be said that the level of measured pollution depends on the distance of the measurement stations from the main traffic arteries. The Map 03.03.9 shows values of 28 to 34 µg/m3. at the inner-city measuring points positioned at more than 20 m distance from streets. That is 35 to 45 % of the pollution IW1 specified in TA-Luft. In comparison to 1991 (c.f. SenStadtUm 1994b) this means a load reduction of about 15 %. The minimum level of 28 µg/m3 in Wedding was measured at a distance of more than 200 m from the main traffic arteries. The highest level of 34 µg/m3 were recorded near the Red City Hall (Rote Rathaus) at the monitoring station Mitte. This monitoring station is located 25 m from the heavily traveled Gruner Strasse and thereby in the wider impact area of the main traffic arteries.

A yearly average of 32 µg/m3 can be assigned to the area center. At the city’s edge, levels between 15 and 18 µg/m3 have been measured, only about half that found in the city center. The forest station Grunewald, with 19 µg/m3, shows only minimal impact from the AVUS which is located 700 m away.

The street measuring stations in Charlottenburg, Steglitz, Neukölln and Charlottenburg exhibit considerably higher values than the grid stations, each with an yearly average of 53 to 56 µg/m3. Only the station at the intersection of Frankfurter Allee and Warschauer Strasse, with 46 µg/m3 exhibits a somewhat lower level. The Charlottenburg station lies directly on the city expressway, exit ramp Spandauer Damm, in open terrain. The air samples are drawn about 5 m above the level of the southbound lane at the height of the nearest sidewalk. The city expressway has a traffic volume of approx. 150,000 motor vehicles per day in the vicinity of the measuring point. The other stations lie in traffic corridors with traffic volume between 35,000 and 60,000 vehicles per day. The air samples were taken at 3.5 m between the roadway and the sidewalk.

As a yearly average, all stations reach practically the same yearly average level for nitrogen dioxide despite large differences in the volume of traffic and nitrogen oxide emissions. In the case of total nitrogen oxide (Map 03.03.8), the differences are greater yet do not correspond to variances in traffic volume. This can be explained by the fact that the stations on the city expressway are subject to free air flows while the other stations lie in traffic corridors of varying breadth. The wind speed is thereby lower and therefore the pollutant dilution is considerably reduced. Since nitrogen dioxide is formed primarily in the atmosphere, the nearness to the polluter is a fairly insignificant emission factor.

This also explains the relatively slight nitrogen dioxide concentration at the street measuring station intersection Frankfurter Allee / Warschauer Strasse. Of course, these streets have a traffic volume of 70,000 respectively 22,000 motor vehicles per day. The samples were drawn from a height of 4 m above a green strip in 25 resp. 15 m distance from the streets. In addition, the adjacent house facades are far removed from the traffic lanes, so that the intersection is always well ventilated. Analogous to the Environmental Atlas 1994, no excesses of IW1 for TA-Luft were ascertained at the street monitoring points in 1995.

The EC Guideline limit of 50 µg/m3 for the 50 % nitrogen dioxide concentration is observed only at points in Berlin not directly affected by motor vehicle traffic. At the street monitoring points, it is exceeded. It can therefore be concluded that the limits are exceeded in many of the city’s main traffic arteries- particularly in traffic corridors.

Measured Nitrogen Dioxide Pollution – 98 % Value 1995

The Map (03.03.10) of measured pollution I2 shows a similar picture to that of the map of I1-levels of nitrogen dioxide (Map 03.03.9). With a maximum of 124 µg/m3, no pollution values in excess of the IW2 of the TA-Luft at 200 µg/m3 and the same upper EC nitrogen dioxide limit were ascertained. Also the EC Guideline limit of 135 µg/m3 is complied with. Since this 98 % value is heavily influenced by weather, the compliance for 1995 cannot be assumed as based upon a general tendency toward values below the compliance norm.

The nitrogen dioxide concentration in the outskirts lies at about 60 % of the inner city values or somewhat higher than the yearly average. This is due to the fact that the high concentrations which determine the I2-value occur predominantly under weather conditions in which low-lying inversions occur. Here the pollutants cannot expand vertically and therefore are carried in relatively high concentration to the outskirts.