Using PET to Discover Disparities in Children's Heat Exposure

Urban heat islands are not distributed uniformly within cities and previous studies have shown a correlation between sociodemographic characteristics of communities and their urban heat island intensity, partly due to disparities in green infrastructure that exist between low-income and more affluent areas. Furthermore, certain factors may render individuals or groups more sensitive to heat exposure, with children, in particular, as one of the most vulnerable populations. This study determines children’s exposure to heat while walking or cycling to and from school and the correlation with the racial, ethnic, and class makeup of their communities. We hypothesize that students attending schools in low-income communities and communities of color would experience higher levels of heat exposure during their daily commutes compared to communities with larger proportions of white and affluent populations.

This study focused on public elementary schools (n = 86) in Travis County, Texas. We generated Physiologically Equivalent Temperature (PET) maps to reveal the spatial distribution of urban heat island intensity within a two-mile Euclidean buffer around each school to capture multiple commuting routes. We first created rasters of vegetation and buildings from LiDAR point clouds, then inputted these rasters to Solar and LongWave Environmental Irradiance Geometry model (SOLWEIG) model within the Urban Multi-scale Environmental Predictor (UMEP) plug-in in QGIS.

This study represents a first step in a multi-tiered project. Next stages will involve utilizing the PET maps along with data on sociodemographic characteristics and commuting behavior from students at these schools who wore accelerometers and GPS devices during their school commutes as part of the ongoing STREETS Study. This analysis will elucidate heat exposure and stress experienced by children on a microclimate level during their commutes to and from school. The implications of this research extend to quantifying the real-world experience of children exposed to varying degrees of heat. By determining the levels of heat exposure felt by children, this study can inform evidence-based policymaking by identifying areas for urban heat management, which can ultimately result in a more equitable urban environment.