The work of LAEQ is part of the current research trend on environmental justice. It is interested in the overexposure to pollutants and the low accessibility to a positive urban environment experienced by specific groups of the population (defined by income, age, ethnicity). More generally, the LAEQ research program contributes to broader debates about socio-spatial justice in geography and urban studies. It aims to enrich discussions on the definition of the equitable city across the notions of distributional justice, recognitional justice and procedural justice
The main types of positive and negative aspects of the urban environment
Atmospheric pollution. The health impacts of exposure to air pollutants generated mainly by road transport (nitrogen dioxide, fine particles, carbon monoxide, etc.) are now well known: respiratory problems, heart problems and even the increase certain types of cancer.
Traffic noise. Prolonged exposure to high noise levels can cause health problems and have adverse effects on the well-being of individuals: risk of hypertension and cardiovascular disease, psychological stress, concentration difficulties and loss of sleep, together reducing the quality of life of the subjects.
Vegetation. By contrast, vegetation has been shown to have multiple benefits for cities, spanning from ecological and health to social and economic benefits. Vegetation improves the quality of the urban environment by reducing air and noise pollution as well as surface runoff, by contributing to saving energy and by minimizing the negative impacts of urban heat islands on human health. In terms of well-being and social benefits, the presence of vegetation helps reduce stress levels as well as various forms of crimes and contributes to the walkability of neighbourhoods and the social integration of seniors, children and adolescents.
Urban parks. The benefits of the proximity and use of a park have been widely documented in the literature. Within the city, parks are ideal places for meeting, socializing and doing physical, recreational and cultural activities. They also contribute to the physical health and psychological well-being of individuals. Regarding physical activity, some authors have demonstrated that park users have higher levels of physical activity than non-users; while other authors showed that a greater proximity to a park is positively associated with physical activity. Relative to well-being, according to several studies, in particular psychological studies, the use of urban parks helps to reduce stress and anxiety.
Urban resources. The issue of accessibility to urban resources (shops, health services, etc.) was also analyzed in terms of environmental equity to see whether the access to resources of residents from poor areas was comparable to that of residents from other parts of the city. Indeed, the absence or presence of easily accessible services was shown to make a difference. Absence exacerbates poverty, while a generous offer of services, including public services, can compensate, at least partially, the low income of people.
Targeted segments of the population
LAEQ’s work focuses on four population groups: disadvantaged households, racial and ethnocultural minorities, recent immigrants, and children and the elderly.
When researching environmental inequities in urban settings, we examine in particular the first two groups— disadvantaged households and racial and ethnocultural minorities. This is because these two groups have more limited economic resources and are subject to residential segregation, meaning that they often find themselves in less favourable living environments as a result of their more limited choice of where to live. These two groups are also more confined to their residential environments as they tend to be less motorized.
The issue of environmental inequities is less explored for children and the elderly, which may seem surprising because of the greater physiological vulnerability of these segments of the population to the negative aspects of their environment. Note also that these two groups also tend to be more bound to their residential environment due to their more limited mobility. Children, for example, are more vulnerable to the effects of high concentrations of various air pollutants since their bodies and nervous systems are not fully developed and since they require more oxygen per unit of body mass. It was also shown that traffic noise negatively affects their cognitive development, which may result in delays in their psychomotor development, speech, coordination and motor skills. Finally, a high level of traffic noise affects children’s’ memory and reading skills. As for the elderly, due to their greater vulnerability to disease compared to younger adults, they are more likely to develop health problems related to the exposure to high concentrations of air pollutants and noise. The lack of vegetation that contributes to heat islands can have negative consequences for the elderly during heat waves. Compounded by the fact that the elderly are a marginalized segment of the population as it is, and that the aging of the population, as a phenomenon, is a major challenge in urban planning and development, the authors consider that the elderly merit greater attention in research conducted on environmental justice.
Notions of concentration and exposure
Spatial concentration. Overall, the aim is to identify the urban areas with the highest levels of pollution and to determine whether, among the resident population, vulnerable groups such as low-income households, ethnic minorities, children and the elderly are overrepresented. The approach is very similar with regard to the beneficial elements. The aim here is to identify the urban areas with the least or the most vegetation, services or infrastructure and to verify whether vulnerable groups there are overrepresented. This approach is more relevant in terms of development and urban planning because it allows to identify the areas affected by pollutants and environmental nuisances that are amenable to the implementation of corrective actions, mitigation or even compensatory measures for the resident populations.
Exposure. Approaches based on measurements of spatial concentrations do not allow assessing the real exposure, defined as an individual’s actual contact with a pollutant (air or noise) over a certain period of time. By contrast, exposure measurements allow estimating the impacts of urban environmental pollution on the health and well-being of a city’s residents. In addition, the methods for calculating concentrations are rarely intricate enough to be able to refer to a specific time or day, although it is known that pollutant levels vary based on these parameters. Yet, at the methodological level, measuring exposure can also be complex and requires means that few research teams have. On the one hand, it requires building a targeted sampling of one or more population groups. And on the other hand, it requires equipping each selected individual with portable devices measuring exposure to air or noise pollution in real time, and this over a given period of time (e.g., one week).
Focus area 1. Concentration and distribution of harmful and beneficial elements
For this first focus area, LAEQ research activities aim to explore and analyze the following topics at the intra-urban level:
- the spatial distribution of nuisances, namely air pollution and traffic noise, and beneficial elements, being vegetation and accessibility to urban resources;
- the complex interrelationships between the distributions of nuisances and beneficial elements;
- types of spaces based on combinations of nuisances and positive elements;
- the development of multidimensional environmental equity diagnostics for different population groups (young children, elderly, disadvantaged households, visible minorities, etc.).
This will involve building specific indicators on the spatial concentration and distribution of harmful and beneficial elements. In turn, this will allow to inform public decision-making with regard to urban development and planning in order to reconcile sustainable development, health and the fight against exclusion.
Focus area 2. Human exposure to harmful and beneficial elements
The second focus area is about measuring human exposure to pollution and beneficial elements taking account of their mobility practices. The objectives of this area revolve around:
- analyzing the variation of the actual exposure of individuals to pollution and noise simultaneously based on their habits, schedules, and modes and routes for commuting;
- linking exposure to pollution with landscapes in terms of their vegetation, service offer, and type of land use;
- ascertaining, based on qualitative methods, whether individuals are aware of the levels of pollution they are exposed to; whether they are developing mitigation strategies by adapting their mobility practices; and whether they are making compromises between pollution exposure and accessibility to urban resources.