ICUH 2021: 17th International Conference on Urban Health

The ICUH is an annual conference organized for 17 years by the ISUH (International Society for Urban Health). This 17th edition, which was hosted online by SALURBAL and its project partners across Latin America, has as its theme: "Transforming our collective urban future: Lessons from COVID-19". Akuto Akpedze Konou, Vitor Pessoa Columbo, and Andrea Salmi presented respectively a poster and slides, denoting the importance that the subject of health should have in the theoretical and practical studies of architecture, urban planning, urban management, and land use planning.

1. Vernacular architecture and spatial typology: their part in urban health | Akuto Akpedze Konou, Vitor Pessoa Colombo, Jérôme Chenal

Keywords: architecture; building materials; modern; spatial typology; urban health; vernacular.

Globalization and technological progress have facilitated the gradual implementation of "modern" architecture and urban planning in the countries of the South. These countries aim to reproduce Western planning models in African cities. Both at the public and private level, the trends are adopted and promoted, without precise adaptation to socio-cultural and economic realities. We believe that the "modern" typology in architectural and spatial projects in Africa, in terms of choice of materials and spatiality, does not always correspond to the climatic and social realities and can also, in the long term, pose health problems.

Earth, straw, wood, and the communal spatial organization of buildings are being replaced by concrete, glass, and contiguous spaces, resulting in unbearable thermal conditions and increasing health risks. Agriculture, as a traditional activity, is also fought by "modern" urbanism, limiting access to healthy and more available crops and food. On this basis, we will see how the coherence of the choice of materials and spatial typologies is important for the health of urban residents.

However, as much as the capacity of Western technology allows Southern countries to improve their real needs for transactions and data collection, vernacular techniques must be revisited and improved in order to take into account the economic and socio-cultural circumstances of these Southern cities. Furthermore, taking into account the incremental logic, in materiality and spatial typology, or more broadly, in strategies for transforming built environments, could contribute to improving urban health.

2. The issue of housing at the center of health inequalities in urban areas | Vitor Pessoa Colombo, Akuto Akpedze Konou, Jérôme Chenal

Keywords: public housing; informal settlements; inequality; urban health.

While environmental factors are important determinants of health, universal access to adequate housing is critical to addressing urban health inequities. Yet, with more than one-billion urban dwellers having no choice but to live in so-called slums, providing sufficient numbers of housing units that are both adequate and affordable remains a global challenge. In fact, we argue that the lack of access to adequate housing is at the root of inequitable urbanization processes and is a global health challenge because it is structurally linked to urban health inequalities.

Despite the significant public investment, many housing programs in the South have failed to take into account local socio-spatial dynamics, often ignoring the flexible and progressive nature of the building typologies that house the majority of urban dwellers in these regions. Despite several radical housing experiments since the 1950s that explored incremental housing typologies, public housing programs have primarily opted for schemes that rely on subsidized credit to access housing as a finished product. These programs require steady incomes and the ability to save to meet mortgage payments - both of which exclude the urban poor from the outset.

In order to address urban health inequalities, housing and land-use policies must be socially inclusive. Based on recent experiences in different countries in the South, we argue that public housing programs should offer more diverse building typologies and tenure conditions. In addition, pro-poor spatial planning policies are essential to guarantee universal rights to the city and to health, ensuring adequate locations for affordable housing, and equalizing spatial development.

3. Spatial analysis of the built environment and estimation of spatial health data using DNN: the case study of cardiovascular risk factors in Geneva, Switzerland | Andrea Salmi, Jérôme Chenal

The cantonal health report (2017) revealed that life expectancy at birth is 83.6 years (2019), CVD mortality is 162.6 per 100,000 population (2019), and is the 2nd cause after cancer. In addition, there has been an increase in the overweight population from 26% to 42% between 1992 and 2017, and in physical activity, but also an increase in unhealthy eating. Although health has improved overall in the canton of Geneva, inequalities are increasing slightly.

The data sets that were used:

- Health Bus; cross-sectional study on cardiovascular risk factors: extraction of (N= 6500) participants who had a medical visit (1.3% of the resident population), georeferenced by postal address.

- Built Environment (BE) metrics, (SITG3, OSM4 sources) that are 30 variables.

The goal is to understand the spatial variation in health-related characteristics of the built environment (BE): does it provide a good estimate of geospatial health data?

- Cardiovascular risk factors: BMI, MAP, Ldl, Sugar Blood, Heart rate, WHR;

- Spatial sampling lag [m]: 0, 200, 400, 600, 800;

- Built Environment input variables: BE measures (60), Indicators (7).

Deep Neural Networks was adopted for the regression task of estimating geospatial health data directly by BE features (metrics) or by PCA-generated indicators. Remarkable results were found.

First, the spatial aggregation of health data can provide insight into the portion of the population that may have environment-related health problems. Second, it is noted that the phenomena we observe can occur at different geographic scales. Furthermore, the indicators are more efficient in the case of larger geographical scales and for a global spatial analysis. Finally, the active mobility network, public transport, and green spaces contribute significantly to the CVRF estimation.

One perspective of future research may be to better take into account the geospatial (and temporal) contextualization of individual data (activity space, residential history...) to solve the problem of uncertain geographic context. Another will be the use of Bayesian NNs, or convolutional NNs, to adopt respectively a stochastic and a local (weighted geographic) approach. Finally, fine geospatial scales are needed to identify inequalities and consequently adapt the intervention.

In fact, in light of the growing interest in the issue of exponential urbanization, it is clear from these studies that urban health must increasingly receive the attention of experts in the field.