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.

The Role of Urban Environment, Social and Health Determinants in the Tracking of Leisure-Time Physical Activity Throughout Adolescence.

PURPOSE: Adolescence may be a period particularly relevant for acquisition of lifelong habits of physical activity (PA). We investigated the tracking of leisure-time PA from 13 to 17 years old and the influence of urban environment and other determinants. METHODS: As part of the EPITeen cohort (Portugal), we evaluated 969 adolescents living in the city of Porto. Participants were assembled in public and private schools at 13 years and reevaluated at 17 years. Leisure-time PA was evaluated by self-reported questionnaires. The shortest routes from residence to urban green spaces and open sports spaces were calculated using the street network within a Geographical Information System. Odds ratio (OR) and 95% confidence intervals were calculated by multinomial logistic regression. RESULTS: Among sedentary girls at 13 years, 33.1% were still sedentary at 17 years, 39.8% changed to low, 22.3% to moderate, and only 4.6% changed to vigorous PA. In boys, the respective values were 32.3%, 17.3%, 36.2%, and 14.2%. High PA levels were maintained by 19.5% of the girls and by 41.1% of the boys. After adjustment for parental education and body image at 13 years, practice of sports at 13 years was strongly associated with stable high PA at 17 years: in girls OR = 3.96 (2.21, 7.12); in boys OR = 6.81 (3.30, 14.07). Distance to urban green spaces or to open sports spaces was not associated to changes in leisure-time PA. CONCLUSION: Practice of sports in early adolescence may be important to promote maintenance of high PA. Urban environment in the vicinity of residence did not affect changes in the practice of leisure-time PA.