Residents of large German cities have it above all in their own hands how high the concentrations of ultrafine dust are in their homes. The level of pollution in the home depends only partially on the air quality outside. However, it also depends very much on activities inside the home, such as cooking activities or heating of solid fuel. This study was led by the Leibniz Institute for Tropospheric Research (TROPOS) commissioned by the Federal Environment Agency (UBA). To this end, fine and ultrafine aerosol particles were measured inside and outside for about two weeks in each of 40 apartments in Leipzig and Berlin during different seasons of the year. The study was published in English in the journal Aerosol and Air Quality Research. It is the first long-term study on aerosol particles in the size range from10 Nano- to 10 Micrometer to be conducted in such detail in many apartments in Germany over such a long period of time.
Fine and ultrafine aerosol particles are important for public health, because of the links with respiratory and cardiovascular diseases. How many particles remain in the body depends, among other things, on the size of the particles. Among the most important sources of ultrafine particles, which are smaller than 100 Nanometer and can therefore penetrate deep into the body, are combustion engines in road and air traffic, small combustion plants, power stations or even forest fires. For this reason, many industrialized countries now have extensive measures in place to reduce particulate matter in the outside air. According to estimates, however, people in the so-called developed countries spend more than two thirds of their lives inside buildings and most of that time in their own homes. At home, they are exposed to a mixture of pollutants that come from indoor sources such as cooking activities or heating, but also from the outside air.
In order to find out to which kind of fine and ultrafine particle the people are exposed in their own homes, TROPOS has been commissioned by the Federal Environment Agency to investigate the indoor pollution in 40 non-smoking houses or apartments in Leipzig and Berlin between 2016 and 2019. Parallel to the indoor measurements, identical measurements were taken either on the balcony, on the terrace or in the garden. To be able to assess the effects of road traffic, about half of the apartments were located within 150 meters of busy roads. Further apartments were selected in the urban background and in outlying districts to map different quality levels of outdoor air. For the research project, the TROPOS team developed special measuring instruments to determine high-resolution particle number size distributions inside and outside the buildings. Over the course of two years, each of the 40 apartments was visited twice with a measuring period of one week in different seasons.
Read more at Leibniz Institute for Tropospheric Research (TROPOS)
Image: The measurements clearly showed that significant amounts of ultra-fine particles are also released during cooking, baking and toasting. (Credit: Tilo Arnhold, TROPOS)