Clean air is of great importance for people's health. The level of air pollution is largely controlled by technical possibilities to reduce pollutant emissions and by improving the efficiency of combustion processes. Besides policies and measures to reduce emissions, such as better filters for exhaust gases, and the use of different materials for tyres or asphalt, among others, better measurement methods also need to be developed. But most gains can be made by increasing the efficiency of combustion processes. Combustion methods have improved very much over the last 15 years. Further optimisations are likely to further improve emissions. The question is therefore how long it will take before there are fewer particles in flue gases than in the ambient air we live in. If that becomes true, from then on our engines will no longer pollute the air, but rather purify it.
Connecting character
This question is on the one hand about developing efficient combustion processes and efficient techniques to reduce emissions of particulates and other pollutants and pathogens, and on the other hand about developing cheap and sensitive measurement methods to detect harmful particles, gases and pathogens. Eighty to ninety per cent of our current energy is produced by combustion. With the sharply rising demand for energy, this percentage will remain high in the coming decades, even as we increasingly use renewable sources such as solar energy. Particulate matter produced by those combustion processes causes significant deterioration of air quality, especially in densely populated areas. Despite prospects of emissions-free combustion, it is still important to measure where and to what extent pollution occurs. Air pollution is now calculated with a model and partly measured. More real-time information is therefore needed to give asthma patients, for instance, insight into the air quality of their immediate environment every hour. There are opportunities here for forms of citizen science: citizens measuring the air quality in their immediate environment themselves using relatively simple techniques.
