Social indicators are predictors of airborne outdoor exposures in Berlin

• Berlin planning areas offer the opportunity to investigate environmental injustice.
• Social indicators were tested as predictors of outdoor airborne human exposures.
• Lower values of social indicators are associated with higher airborne exposures.
• Maps show the double discrimination by airborne exposures and social status.
• The increased exposures result in increasing health risks.

Exposure by airborne pollutants adversely affects human health and well-being. Particulate matter (PM10, PM2.5) and nitrogen oxides (NOX, NO2) are two of the most important airborne pollutants in Germany. Epidemiological studies found that these pollutants significantly increase morbidity and mortality by cardiovascular, respiratory and other diseases. Inner-urban differences of human exposure are often higher than mean differences between cities. Therefore it is necessary to investigate the inner-urban spatial distributions of human exposures. Additionally the question arises if the social situation of population is also related to airborne outdoor exposures.On the example of Berlin the spatial distribution of airborne exposures of PM2.5 and NO2 was determined for the 447 Berlin planning areas (PLAs), each characterized by about 7500 inhabitants, rather unique structure of buildings, big roads, and certain social structure. In this study we also investigated the combined exposure by PM2.5 and NO2. Because both types of air pollutants are traffic related, traffic parameters were included into the assessment.In order to investigate the socio-spatial distribution of PM2.5 and NO2 at the planning area level the air pollution was statistically and spatially correlated with the development index of the Berlin Social Urban Development Monitoring and other social indices. Generally, but also in Berlin, there exists a strong tendency that decreasing social indicators are related to increasing human exposures. About 10% of Berlin's population live in PLAs with a very low or low development index and with very high or high air pollution levels and thus are discriminated twice. The lower the development index in a PLA, the higher is the share of population exposed to high air pollution and vice versa.