Ambient nitrogen dioxide in 47 187 neighbourhoods across 326 cities in eight Latin American countries: population exposures and associations with urban features

Social disparities in neighborhood flood exposure in 44,698 urban neighborhoods in Latin America

Climate change is expected to greatly increase exposure to flooding, particularly among urban populations in low- and middle-income countries. Here we used daily flood data (2000-2018) to describe socioeconomic disparities in flooding on the basis of neighborhood educational attainment, comparing disparities across and within cities. We used multilevel models to examine disparities in area flooding by city- and neighborhood-level factors, including 44,698 neighborhoods in 276 cities from eight countries with a total of 223 million residents and 117 distinct flood events. One in 4 of residents of neighborhoods in the lowest quintile of educational attainment were exposed to flooding, compared with 1 in 20 residents of neighborhoods in the highest quintile of educational attainment. Neighborhoods experiencing more flooding included those with lower educational attainment, that were coastal, less dense, further from the city center and greener, and that had steeper slopes. We show large social disparities in neighborhood flooding within Latin American cities. Policymakers must prioritize flood adaptation and recovery efforts in neighborhoods with lower socioeconomic status.

Urban Environments, Health, and Environmental Sustainability: Findings From the SALURBAL Study

Despite the relevance of cities and city policies for health, there has been limited examination of large numbers of cities aimed at characterizing urban health determinants and identifying effective policies. The relatively few comparative studies that exist include few cities in lower and middle income countries. The Salud Urbana en America Latina study (SALURBAL) was launched in 2017 to address this gap. The study has four aims: (1) to investigate social and physical environment factors associated with health differences across and within cities; (2) to document the health impact of urban policies and interventions; (3) to use systems approaches to better understand dynamics and identify opportunities for intervention and (4) to create a new dialogue about the drivers of health in cities and their policy implications and support action. Beyond these aims SALURBAL, has an overarching goal of supporting collaborative policy relevant research and capacity -building that engages individuals and institutions from across Latin America. In this review we provide an update on the SALURBAL data resource and collaborative approach and summarize key findings from the first aim of the study. We also describe key elements of our approach, challenges we have faced and how we have overcome them, and identify key opportunities to support policy relevant evidence generation in urban health for the future.

Social disparities in flood exposure and associations with the urban environment in 44,698 neighborhoods in 276 cities in eight Latin American countries

Background

Climate change is expected to greatly increase exposure to flooding, particularly in urban populations in low- and middle-income countries. We examined within-city social disparities in exposure to flooding in 276 Latin American cities and associated features of the neighborhood urban environment.

Methods

We used a spatially granular dataset of historical flood events from 2000 to 2018 to describe neighborhood flooding within cities across eight Latin American countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Guatemala, Mexico, and Panama). We estimated the percentage of the population living in flooded neighborhoods, described social disparities in flooding based on neighborhood educational attainment, and compared the magnitude of disparities across and within cities. We used multilevel models to examine how city- and neighborhood-level factors are related to neighborhood flooding.

Results

We examined 44,698 neighborhoods in 276 cities from eight countries with a total of 223 million residents and 117 distinct flood events from 2000-2018. One in four residents in neighborhoods in the lowest education quintile lived in neighborhoods with flooding, compared to one in 20 residents of the highest neighborhood education quintile. Greater neighborhood flooding was associated with lower neighborhood-level educational attainment and with neighborhoods that were coastal, less dense (population or intersection), further from the city center, greener, and had steeper slopes. There was no association between city-level educational attainment and flooding.

Conclusion

There are large social disparities in neighborhood flooding within Latin American cities. Residents of areas with lower education attainment face substantially higher risks of flooding. Policymakers must prioritize flood adaptation and recovery efforts in neighborhoods with lower socioeconomic position.

Short-term associations between fine particulate air pollution and cardiovascular and respiratory mortality in 337 cities in Latin America

Ambient air pollution is a health concern in Latin America given its large urban population exposed to levels above recommended guidelines. Yet no studies have examined the mortality impact of air pollutants in the region across a wide range of cities. We assessed whether short-term levels of fine particulate matter (PM2.5) from modeled estimates, are associated with cardiovascular and respiratory mortality among adults in 337 cities from 9 Latin American countries. We compiled mortality, PM2.5 and temperature data for the period 2009-2015. For each city, we evaluated the association between monthly changes in PM2.5 and cardiovascular and respiratory mortality for sex and age subgroups using Poisson models, adjusted for seasonality, long-term trend, and temperature. To accommodate possibly different associations of mortality with PM2.5 by age, we included interaction terms between changes in PM2.5 and age in the models. We combined the city-specific estimates using a random effects meta-regression to obtain mortality relative risks for each sex and age group. We analyzed 3,026,861 and 1,222,623 cardiovascular and respiratory deaths, respectively, from a study population that represents 41 % of the total population of Latin America. We observed that a 10 μg/m3 increase in monthly PM2.5 is associated with an increase of 1.3 % (95 % confidence interval [CI], 0.4 to 2.2) in cardiovascular mortality and a 0.9 % increase (95 % CI -0.6 to 2.4) in respiratory mortality. Increases in mortality risk ranged between -0.5 % to 3.0 % across 6 sex-age groups, were larger in men, and demonstrated stronger associations with cardiovascular mortality as age increased. Socioeconomic, environmental and health contexts in Latin America are different than those present in higher income cities from which most evidence on air pollution impacts is drawn. Locally generated evidence constitutes a powerful instrument to engage civil society and help drive actions to mitigate and control ambient air pollution.