To reduce stress among urban residents, the consortium members of the European Council Horizon 2020 research program DivAirCity install different stress reducing, noise reducing and air quality improving means in the five cities of the consortium. This study measures physiological and psychological stress and health factors before and after the implementation of the project (at intervention sites) and compares the change (improvement) to the change in comparable places where no means were installed (control site).

Scientific studies show that increased stress can favor the development of e.g. high blood pressure, heart disease, mental illness, infectious diseases, headaches and sleep disorders. This means that stress causes considerable costs for western healthcare systems, including in our city and this neighbourhood. In large cities, where there are often hardly any natural green and forest areas left, depression and anxiety syndromes, for example, are more common than among the rural population.

For example, in Germany, more than three quarters of the population live in densely or moderately populated areas, while the global average is more than 50 per cent. Due to increasing urbanisation, people living in cities will be heavily dependent on urban nature, which can be a relevant health-promoting factor. Several studies have shown that natural spaces such as city parks, parks and even greenery on streets have a positive impact on the health of residents, both individually and collectively.

The European Council Horizon 2020 project DivAirCity (acronym explanation in the text below) is about making formerly busy public spaces in European cities more attractive again for residents and citizens. The aim is to redesign the spaces in such a way that people of different age groups, social classes and identities ("Div") can (once again) come together and meet in these places on a daily basis. To this end, these places are to be changed through various installations (planting trees, redesigning parks, shading, watering in summer) in such a way that the local air quality ("Air") in the cities ("City") improves significantly. This is realized on the one hand by installing air quality measuring equipment and by recording the number of people and the time they spend in these places (objective measurements).

In addition to these objective measurements, this study records the impact on psychological and physiological health that the installations (intervention) has on the residents. To this end, it will be measured how residents feel in terms of quality of life, current stress, general health, and whether they feel safe and secure in the specific place (comfort, safety and security) and whether they enjoy going there and staying there,. These measurements will take place both before (day -60 to day -30) and after (day +30 and day +60) the installment of the intervention.

Finally, we would like to know your age group, your gender and how close you live to the location of the conversion/installation. We would like to invite you to take part in this survey again after the remodelling project.

Inclusion Criteria:

• Participants must live or work at or near the installation (intervention group) or control site (control group)

Exclusion Criteria:

• none

Residents of the five cities (18+ years of age)