How polluted is the air you breathe?

Where is the ambient air polluted by diesel exhaust gases?


High concentration of nitrogen dioxide (NO2) in the ambient air is a concrete threat to human health. A major source is road traffic – diesel engines and namely diesel passenger cars. With the support of many citizens, we were able to determine the NO2 concentration of the ambient air at 1,400 locations throughout Germany. The results demonstrate that even beyond the official measuring stations the air is often strongly polluted.

Our experience shows that it is useful to supplement official data with your own measurements and to promote more action with authorities and decision-makers using this information. For that reason, we are now working together with NGOs across Europe. Together we are generating more information about air quality in the respective environment and, therefore, work to achieve better air quality throughout Europe.

Further Information


Copyright: © Christian Gerhardt

Hanna Rhein
Project Assistant Transport and Air Quality
E-Mail: Mail schreiben

Deutsche Infoseite

© picoStudio / Fotolia

The map below displays the NO2 Hot Spots that we found

GreenCity e.V. ¹
Land Berlin
rbb / TU Berlin
VCD e.V.
Nitrogen dioxide exposure in µg/m3
30 - <40
* The number in the coloured circles represents the amount of measurements

Ensuring better air quality is of high relevance not only when it comes to complying with binding air quality standards but also in order to ensure healthy air for everybody. The EU-wide binding nitrogen dioxid limit value of 40 µg /m³ is exceeded in many places. According to the European Environment Agency (EEA Air Quality Report 2018), in Germany 13,100 people died prematurely due to air pollution with NO2 in 2015. In the opinion of many medical experts, the limit values for nitrogen dioxide are too low. A study published by the Federal Environment Agency (UBA) in March 2018, pointed out that in 2014, at concentrations well below the limit value, around 6,000 premature deaths, 437,000 diabetes cases and 439,000 asthma cases can be attributed to NO2 exposure in the air we breathe.

Many hundreds of thousands of people who live or work on busy roads, go to kindergartens or schools suffer from the diesel exhaust poison. Especially for older people, pregnant women and particularly for children, this pollution is a health hazard. Alarmingly high values were measured in Germany in front of health facilities, schools and kindergartens. The air at children's height (1 metre) is often even more polluted with harmful diesel exhaust gases.

With 247 traffic-related measuring stations in 147 German cities, the official measuring network covers only a fraction of potentially polluted areas. The vast majority of the cities and municipalities dispose of no data on air quality. This lack of information is considered a Europe-wide problem.

With the support of citizens and cooperating NGOs we want to close these gaps. DUH already gathered experience in initiating NO2 Citizen Science measurements at more than 1,400 sites in Germany. We are using diffusion tubes to measure NO2 pollution – a method that is also used by public authorities. The measurement accuracy is proven and fulfills international standards. The results that give evidence of the high degree of NO2 pollution are published in our map.

The diesel exhaust gases, which are particularly toxic for small children, are often concentrated near the ground. Since children are breathing closer to the exhaust pipes of diesel cars, they are exposed to a particularly high level of toxic nitrogen dioxide. In addition, children have a much higher breathing rate than adults. Air pollutants have a more intensive effect on children. So far, official measurements have taken too little account of this: The official measuring stations measure at a height of 1.5 to 4 metres. Therefore, the DUH measures NO2 concentrations additionally at selected locations at a height of 1 meter.

In Germany, the DUH has called on citizens to report road sections with particularly high air pollution in three Citizen Science Campaigns. In a first step, the DUH selected between 400 and 500 locations from the proposals received. Citizens measured the air quality at selected locations. The Citizen Science NO2 measurement campaigns in February and July 2018 focused on smaller cities and municipalities without official measurement stations. In many places, the measurements also indicated that the annual average value for diesel exhaust gas NO2 could be considerably exceeded in smaller communities or peripheral zones of large cities.

In February 2018, for example, a small town called Alsfeld fought with an NO2 load of 53.5 micrograms NO2 per m3, with similar values in Starnberg at 54.6 micrograms NO2 per m3 in June 2018 and Fürth with 50.7 micrograms NO2 per m3 also in June 2018. In our third measurement series in March 2019, we focused on kindergartens, schools, hospitals, and old people homes. At each measuring point, we installed tubes at a height of 2 meters as well as at a height of 1 meter in order to examine the air quality at children's height. In addition to numerous limit values being exceeded in places where children, the elderly, and people with health problems are present, it was also found that the breathing air at children's height (1 metre) is often even more contaminated with NO2 than at 2 metres.

Outside Germany, we so far have initiated NO2 measurements together with our partners in Czech Republic, Slovenia, Serbia, Poland, Romania and Bulgaria. More countries will follow. The measurements are at different stages. First results were received from Ljubljana, Slovenia with alarmingly high NO2 concentrations of up to 70 micrograms NO2 per m3. If your NGO is interested in joining this combined European effort, you can get in touch with us here.

  • Measurement device: Diffusion tubes.
  • Mode of action: The diffusion tubes contain a chemical substance (triethanolamine), which is absorbing the measuring component (in our case nitrogen dioxide - NO2).
  • Placement: Sites where the pollution supposedly is reaching harmful levels due to high levels of traffic. The load of NO2 is often particularly high in busy canyons with little air exchange.
  • Measurement duration: Four weeks.
  • Starting measurements: A red closing cap has to be removed from the tube and replaced by a green weather-protection lid. Now the tube starts to “collect” NO2. The tubes can be fixed with cable ties to traffic poles, street lamps or else. Our main measurement height is 2 meters.
  • Ending measurements: The tube has to be closed again with the red closing cap. Subsequently, we are sending them to the accredited analytical laboratory Passam AG in Switzerland.
  • Advantage: Engaged laymen can carry out this proven and straightforward method. 

The measured values determined by Labor Passam AG on behalf of Deutsche Umwelthilfe do not represent the annual mean value, but the average value for the period of the measurement campaign. The values determined provide information on which measuring locations are contaminated with NO2 and whether an official long-term measurement of air quality should be implemented.

  • Covering short distances by bicycle or on foot

  • Using public transport, avoiding travel by car
  • Car sharing
  • Reducing driving speed when using a car
  • Participating in the preparation of local action plans
  • Demanding effective air pollution control measures from government (e.g. environmental zone)
  • Asserting your right to clean air legally
  • Using low-emission and efficient vehicles
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