Is city-level travel time by car associated with individual obesity or diabetes in Latin American cities? Evidence from 178 cities in the SALURBAL project.

There is growing evidence that longer travel time by private car poses physical and mental risks. Individual-level obesity and diabetes, two of the main public health challenges in low- and middle-income contexts, could be associated to city-level travel times by car. We used individual obesity and diabetes data from national health surveys from individuals in 178 Latin American cities, compiled and harmonized by the SALURBAL project. We calculated city-level travel times by car using the Google Maps Distance Matrix API. We estimated associations between peak hour city-level travel time by car and obesity and diabetes using multilevel logistic regression models, while adjusting for individual characteristics and other city-level covariates. In our study we did not observe a relationship between city-level peak-hour travel time by car and individual obesity and diabetes, as reported in previous research for individual time spent in vehicles in high-income settings. Our results suggest that this relationship may be more complex in Latin America compared to other settings, especially considering that cities in the region are characterized by high degrees of population density and compactness and by a higher prevalence of walking and public transportation use.

Support for market-based and command-and-control congestion relief policies in Latin American cities: Effects of mobility, environmental health, and city-level factors.

Public support for the implementation of congestion relief policies is critical for the policies' technical and political success. To identify the personal, social, and city-level factors associated with higher acceptance towards such policies, this study uses a 2016 survey of 8178 residents from 11 cities across 10 Latin American countries collected by the Development Bank of Latin America (Corporación Andina de Fomento or CAF). We examined support for two demand-side approaches to managing the traffic congestion externality: congestion pricing - a market-based approach, and driving restrictions or bans - a command-and-control approach. Logit regression models show that personal mobility such as owning or using a private vehicle during a respondent's main commute trip are associated with decreased support, while higher congestion delay in one's commute and having a young child recently diagnosed with respiratory problems increases support for either congestion relief policy. In addition, residents of cities with higher levels of median annual particulate matter and with prior experience with traffic bans expressed higher support for either policy. Residents of cities with higher income inequality supported only driving restrictions; while those of cities with higher GDP per capita had lower support only for congestion pricing. To improve the public acceptance of congestion relief policies in Latin America, policy makers could: (1) explicitly seek to mitigate the costs it brings on individuals by investing in substitutes like public transportation; (2) promote the personal and social environmental and health benefits; (3) consider beginning with temporary, pilot programs; and in the case of driving restrictions, (4) take into account city-specific conditions related to income inequality that may influence public support for the policies.

Impacts of land use transitions on ecosystem services: A research framework coupled with structure, function, and dynamics.

Rapid urbanization in China has resulted in drastic land use transitions (LUT) and has had a severe impact on the supply of regional ecosystem services (ESs). To improve ecosystem security and promote sustainable development regionally, it is essential to clarify spatial correlations between the multi-dimensional characteristics of LUT and ESs. We developed a theoretical framework to examine how LUT influenced regional ESs in three dimensions: land use structure, function, and dynamics. Using the Taihu Lake Rim urban agglomeration (TLRUA) as an example, we explored the process by which LUT affected the change in regional ESs. The results indicated that the TLRUA experienced accelerated urbanization between 2000 and 2018, with LUT and ESs exhibiting distinct characteristics in urban, suburban, and rural areas in different regions. The impact of LUT on ESs, as we analyzed them from different dimensions, embraced interactive effects and significant spatial spillover effects. The land use structural transitions were globally positively correlated with habitat maintenance, carbon sequestration, and recreation potential, whereas land use intensity and dynamics transitions exhibited negative correlations. Given their interactions at the local scale, we propose corresponding land management strategies, which can offer practical guidance for coordinating regional land resource development and ecosystem conservation.

City-Level Travel Time and Individual Dietary Consumption in Latin American Cities: Results from the SALURBAL Study.

There is limited empirical evidence on how travel time affects dietary patterns, and even less in Latin American cities (LACs). Using data from 181 LACs, we investigated whether longer travel times at the city level are associated with lower consumption of vegetables and higher consumption of sugar-sweetened beverages and if this association differs by city size. Travel time was measured as the average city-level travel time during peak hours and city-level travel delay time was measured as the average increase in travel time due to congestion on the street network during peak hours. Vegetables and sugar-sweetened beverages consumption were classified according to the frequency of consumption in days/week (5-7: "frequent", 2-4: "medium", and ≤1: "rare"). We estimate multilevel ordinal logistic regression modeling for pooled samples and stratified by city size. Higher travel time (Odds Ratio (OR) = 0.65; 95% Confidence Interval (CI) 0.49-0.87) and delay time (OR = 0.57; CI 0.34-0.97) were associated with lower odds of frequent vegetable consumption. For a rare SSB consumption, we observed an inverse association with the delay time (OR = 0.65; CI 0.44-0.97). Analysis stratified by city size show that these associations were significant only in larger cities. Our results suggest that travel time and travel delay can be potential urban determinants of food consumption.

Latin American cities with higher socioeconomic status are greening from a lower baseline: evidence from the SALURBAL project.

The characteristics of urban green space have context-dependent associations with socioeconomic status (SES). Latin American cities provide a unique but understudied context to assess the green space-SES associations. We measured the quantity and quality of green space as greenness from satellite-derived Normalized Difference Vegetation Index, and we modeled the relationship between greenness and SES in 371 major Latin American cities between 2000 and 2010. We found that SES was negatively associated with average greenness at city and sub-city scales, which could be explained by urbanization generally improving SES while reducing the provision of green space. About 82% of the cities and 64% of the sub-cities experienced greening or increases in greenness over time. Although with lower average greenness, cities with higher SES had greater greening; however, it was the opposite for sub-cities. We suggest that greening is more likely to take place in peripheral sub-cities where SES tends to be lower. The findings challenge the belief that places with higher SES have better access to environmental resources and amenities; instead, this relationship is context dependent.

Built environment profiles for Latin American urban settings: The SALURBAL study.

The built environment of cities is complex and influences social and environmental determinants of health. In this study we, 1) identified city profiles based on the built landscape and street design characteristics of cities in Latin America and 2) evaluated the associations of city profiles with social determinants of health and air pollution. Landscape and street design profiles of 370 cities were identified using finite mixture modeling. For landscape, we measured fragmentation, isolation, and shape. For street design, we measured street connectivity, street length, and directness. We fitted a two-level linear mixed model to assess the association of social and environmental determinants of health with the profiles. We identified four profiles for landscape and four for the street design domain. The most common landscape profile was the "proximate stones" characterized by moderate fragmentation, isolation and patch size, and irregular shape. The most common street design profile was the "semi-hyperbolic grid" characterized by moderate connectivity, street length, and directness. The "semi-hyperbolic grid", "spiderweb" and "hyperbolic grid" profiles were positively associated with higher access to piped water and less overcrowding. The "semi-hyperbolic grid" and "spiderweb" profiles were associated with higher air pollution. The "proximate stones" and "proximate inkblots" profiles were associated with higher congestion. In conclusion, there is substantial heterogeneity in the urban landscape and street design profiles of Latin American cities. While we did not find a specific built environment profile that was consistently associated with lower air pollution and better social conditions, the different configurations of the built environments of cities should be considered when planning healthy and sustainable cities in Latin America.

Physical Disorders and Poor Self-Rated Health in Adults Living in Four Latin American Cities: A Multilevel Approach.

Considering that urban environments may affect self-rated health through behavioral and psychosocial mechanisms, the aim of this study was to investigate the association between self-rated health and perceived urban environment characteristics among adults living in four Latin American cities. Data is from a population-based survey by Development Bank of Latin America, encompassing adults between 20 and 60 years old in Buenos Aires, Lima, Mexico City, and Panama City. Self-rated health was measured using a single question and the response options were categorized as poor and good. The explanatory variables were empirical Bayes estimates of self-reported area physical disorder, social disorder, access to services, and access to leisure spaces derived from the survey. The covariates were: individual age, sex, education, wealth index, and length of residency in the neighborhood; and an area social environment index. Multilevel logistic regressions with two levels (individual and sub-city areas) were fitted. Poor self-rated health was reported by 34.73% (95% CI: 33.17 to 36.29) of the participants and was associated with physical disorder (OR = 1.16 per SD; 95% CI: 1.02 to 1.32). Our findings suggest that public policies to promote population health should consider area urban environment factors, especially those associated with disorder.

Commute patterns and depression: Evidence from eleven Latin American cities.

INTRODUCTION: Although travel behavior is expected to influence personal health, few studies have examined associations with mental health. This study examines associations between commute patterns and mental health using survey data in 11 Latin American cities. METHODS: Using a survey conducted by the Development Bank of Latin America in 2016, we measured the presence of depressive symptoms using the 10-item Center for Epidemiologic Studies Depression (CESD-10) screening scale. We used multilevel non-linear models to estimate the magnitude of the associations between commute patterns and depression risk, adjusting for socio-demographic and neighborhood characteristics. RESULTS: We found that, on average, every 10 more minutes of commuting time is associated with 0.5% (p = 0.011) higher probability of screening positively for depression. Furthermore, when decomposing commuting time into free-flow time and delay time, we found that delay and not free-flow time, were associated with depression. Specifically, every 10 additional minutes of traffic delay is associated with 0.8% (p = 0.037) higher probability of screening positively for depression. When examining differences by travel mode, we find that users of formal transit (e.g. subway or bus rapid transit) are 4.8% (p = 0.040) less likely to be screened positively for depression than drivers. In addition, not having transit stops within a 10-min walk from home is associated with higher probability of screening positively for depression. CONCLUSIONS: Our findings provide preliminary evidence that better access to mass transit systems and less congestion may be linked to better mental health among urban residents.

Effects of potential calcium sensing receptor inducers on promoting chemosensitivity of human colon carcinoma cells.

We have previously reported that by inducing calcium sensing receptor (CaSR), calcitriol, the active form of vitamin D, promoted the sensitivity of the human colon carcinoma cells to anticancer drugs. In the current study we tested several other potential CaSR modulators, calcipotriol and the effective components of Chinese herbal medicine lentinan, for their functions in inducing CaSR expression in human colon carcinoma cell line CBS, Moser, Fet, and SW480 cells and subsequently promoting sensitivity of the cells to anticancer drugs. Calcipotriol and lentinan suppressed invasion of the colon carcinoma cells and enhanced the cytotoxicity of anticancer regimen FOLFIRI to cells in culture or in anchorage-independent growth. In the mechanism study we found that calcipotriol and lentinan suppressed protein expression and gene transcriptional activities of survivin and thymidylate synthase, increased E-cadherin cell membrane localization and complex formation of E-cadherin and beta-catenin, and repressed TCF4 transcriptional activation. These effects were attenuated, however, in CaSR knocked-down cells, indicating that CaSR was required in the pathway. We concluded that calcipotriol and lentinan are efficient in promoting chemosensitivity in colon carcinoma cells. Since both compounds have much less side effects than calcitriol in clinic, they have greater potential to be applied as supplements of colon cancer therapy.