Urban areas are growing fast worldwide and there is an increasing concern about the relations between urbanization, environmental threats, the quality of living spaces and human health. A healthy living environment is a prerequisite for good health. Research in environmental epidemiology clearly illustrates a direct health impact of indoor (1–4)and outdoor pollution (5,6). Living in healthy and green areas is associated with better self-assessed health (7,8), better mental health (9), lower risks of cardiovascular and respiratory diseases and lower mortality from related causes(10). This may be due to their lower air pollution and lower noise levels, higher opportunities for physical activity, facilitation of social contacts, and/or promotion of recovery from fatigue and stress.

The GREEN & QUIET project aims to investigate the social inequalities in the health-related outcomes of environmental characteristics in the Brussels Capital Region. The research is commissioned and funded by Innoviris(the Brussels Institute for Research and Innovation) and will be conducted over a four-year period, from 2018 to 2021.

More about the Green & Quiet Brussels-project

To date, there are few studies dealing with the association between the in- and outdoor living environment and health in Belgium, let alone in the Brussels Capital Region. In the GREEN & QUIET project, we will disentangle the interrelations between (indoor and outdoor) environmental factors, social background factors and health in the Brussels Capital Region. The project will investigate the impact of social stratifiers – socioeconomic position, migrant background, age and gender – on the association between environmental quality and health and mortality.

Environmental quality refers to the characteristics of the in- and outdoor living environment and will be measured in this project through characteristics of the dwelling (indoor environment), and characteristics of green spaces, outdoor air and noise pollution (outdoor environment).


GREEN & QUIET will use a mixed method and intersectionality approach, which both are rarely implemented in the field of environmental epidemiology. Intersectionality theory seeks to enhance understandings of social stratifiers by arguing that multiple marginalizations, such as those experienced by migrant women in lower social classes for instance, are mutually constituted and cannot be understood by approaches that treat social class, migrant and sex/gender distinctively. According to Bauer GR(11): “Intersectionality will enrich population health research through improved validity and greater attention to both heterogeneity of effects and causal processes producing health inequalities”.

GREEN & QUIET will thus assume that what it means to live in a polluted environment and what the health implications are, may be different for men versus women, for lower versus higher educated, for young versus old people, for Moroccans and Turkish versus native-born communities. This makes sense in that living environment can be constituted through cultural meanings and processes (11).


The general aim of GREEN & QUIET crystallises into three specific research objectives:

1. to inquire the health impact of the in-and outdoor living environment and the effect that crucial dimensions of social stratification – socioeconomic position, migration background, age and gender – exert on this impact (RQ1)

2. to inquire the relationship between objective and subjective (perceptive) indicators of the living environment taking into account the same dimensions of social stratification – socioeconomic position, migration background, age and gender (RQ2)

3. to inquire the pathways and mechanisms behind the association between living environment and health through a qualitative study including once more the crucial dimensions of social stratification – socioeconomic position, migration background, age and gender (RQ3)

The GREEN & QUIET project intends to move from “description” to “explanation” by digging deeper into pathways and mechanisms behind the threefold association between environmental factors, social stratifiers and health/mortality. The main research question crystalizes into three sub-questions. The first research question probes into the relation between indicators of the in- and outdoor living environment and health in the Brussels Capital Region stratifying the population according to socioeconomic position, migrant background, gender and age. These social stratifiers may determine variation in the experience with, the exposure to and the impact of the living environment on health/mortality and may thus mediate and modify the impact of the living environment on health and mortality, certainly when less-advantageous social positions are coinciding in individuals, as we know from intersectionality theory (12). In order to identify the underlying mechanisms behind the observed patterns, GREEN & QUIET will perform a qualitative analysis. An important pathway to understand the interrelations between social factors, living environment and health undoubtedly relates to the differential way in which in- and outdoor environment is used, experienced and perceived by social groups.


As an intermediate step towards the qualitative analysis, the second research question will probe into the association between objective indicators of the in- and outdoor living environment and subjective (perception) indicators of the environment (perception of green in the neighbourhood, air quality, noisiness, etc.) in an intersectionality approach. This quantitative analysis will show how perceptions differ from ‘objective reality’ (measured through objective indicators) in the distinctive social groups. This research question will thus compare the discrepancy between the objective reality and the perceptions of this reality across men and women, different age groups, socioeconomic groups and migrant communities. This analysis should be considered as an intermediate step towards the qualitative analysis.


The third research question will investigate whether different social groups have different usage, perceptions and convictions about their living environment and health. This part of the project will use a qualitative research strategy, which is very innovative in the field of environmental epidemiology. Quantitative analyses are often not very suitable to shed a clear light on the specific mechanisms making a certain environment more beneficial to health then another. Qualitative research into people’s appreciation of public green spaces and/or their own living environment are better suited to reveal more precise mechanisms and factors (13). Certainly, from an intersectionality perspective differences in perception and use of green spaces and the living environment can reveal crucial insights. For example: do people from all social backgrounds use the same definitions of “accessibility”, “equipment”, “usability” of green places – or do such quality-definitions depend upon social background characteristics? The few existing studies suggest that at least gender and migrant background seem to influence expressions of usability and aesthetics (13).


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