The quality of the air around us depends on many factors and can vary widely from one location to another – sometimes even a few meters can make a difference. Emissions from many different sources (emitters) contribute to a deterioration in air quality. In this regard, nitrogen oxides and particulate matter are currently regarded as the most relevant types of air pollution, particularly in terms of air quality in large cities. However, natural factors such as temperature, wind conditions and solar radiation also have a major impact on air quality.
Road traffic is by no means the only source of emissions. Emissions from other sources are also responsible for increasing air pollution. The primary emitters of particulate matter, for example, are agriculture, industry, power stations, fireplaces and heating in homes, and road traffic. Emissions of particulate matter are produced independently of the type of vehicle powertrain, as a high percentage is caused by road and tire wear particles as well as brake dust.
In order to understand air quality, air pollution and their effects on people and the environment, it is important to distinguish between emissions and immissions. Emissions refer to output at its respective source, e.g. the nitrogen oxide output by a car directly at its exhaust pipe. In other words, what comes out at the back. Immissions, however, denote the volume of these emissions at a certain place with their corresponding impacts.
For example, particulate matter emissions do not have the same effect everywhere; a certain percentage sticks to the ground, is blown away by the wind or washed away by rain. Accordingly, only a small percentage is actually inhaled by people. Stations for measuring air quality do not therefore record all emissions in their entirety, but rather only the percentage which actually reaches them in the form of immissions. As they potentially record percentages of emissions from every conceivable source, they cannot be attributed to individual emitters any longer.
In order to better understand the connections between emission sources and the environment, Bosch has developed immission measuring systems which constantly send their local measurement data to the cloud for analysis and further processing. This measurement data can be used to draw up precise immission maps, for example, and to make road traffic forecasts. If, for example, forecasts indicate increased traffic volumes, the infrastructure can be adapted in advance in such a way as to prevent the specified immission limit values from being exceeded – e.g. by changing traffic light settings.
The compact immission measurement boxes from Bosch are currently being trialed internationally, in the greater Stuttgart, Marseille and Nice regions. In such infrastructure, Bosch not only develops the required measurement technology, but also provides cities with traffic planning and management advice based on the respective measurement data.
Carbon dioxide is a greenhouse gas prevailing in nature which also arises when fossil energy sources are burned. An increased concentration of CO2 in the air contributes to global warming. For this reason, reducing CO2 emissions worldwide is a central goal pursued by climate protection.
Nitrogen oxides are oxygen compounds (oxides) of nitrogen and also a naturally occurring gas. However, the largest shares of NOx are produced during combustion processes. That is why NOx pollution is higher in densely-populated urban centers than in the countryside. It was possible to reduce NOx emissions by road traffic in Germany by almost 70%** between 1990 and 2015. And they can be reduced even further using technology which is already available today.
Particulate matter comprises a complex mixture of solid and liquid particles. A distinction is made between various categories depending on the particle diameter: PM₁₀ with maximum 10 micrometers, PM₂.₅, and ultra-fine particles with a diameter of less than 0.1 micrometers.
*Quelle: EEA, Greenhouse gas data viewer (2018)
**Quelle: EEA, Air pollutant emissions data viewer (2018)
Chairman of the Board of Management at Robert Bosch GmbH
The best way to improve air quality is to reduce emissions in all areas as much as possible. For this reason, Bosch pursues a vision of ideally emission-free mobility with minimum impacts on people and the environment. Technology already available and new innovative developments by Bosch are helping to achieve more sustainability and improved quality of life, particularly in densely-populated urban centers subject to extensive pollution.
In the development of new solutions, Bosch goes beyond the actual powertrain and the car by including traffic management and planning as well as climate protection and the company’s own responsibility as a globally-operating corporation and employer. Bosch therefore makes an important and future-oriented contribution toward solving a complex challenge which affects each and every one of us.