Trees and Life, Heat and Death: Integrating Temperature and Green Spaces with Social Determinants of Health in Hamilton, Ontario, Canada.

Objectives Climate change has wide-reaching implications for planetary and human health; one of its rising impacts is deaths related to extreme heat. This study attempts to integrate remotely sensed measures of temperature and greenness into the methodology of Code Red, a study examining the relationship between health and a variety of social determinants in Hamilton, Ontario, Canada, initially using data from 2006-2008, with the aim of examining whether heat and temperature could explain differences in the average age of death across different neighbourhoods alongside socioeconomic variables. Methods Land surface temperature (LST) and normalized difference vegetation index (NDVI) were calculated for each census tract of Hamilton using Landsat satellite data for Jun-Aug of 2006-2008. They were then entered into a factor analysis along with 14 other variables utilized in the initial Code Red study. A multiple least-square regression was then run between the resulting factors and average age of death. Results Temperature and greenness loaded significantly along with income and education related variables onto a factor referred to as the “working class” factor. This factor had a highly significant (p<0.001) correlation with average age of death in multiple regression. Conclusion Temperature and greenness have a significant correlation with socioeconomic deprivation and age of death, and may have value both as a predictor variable for death and a potential cause of increased deaths. Further studies may make use of detailed cause of death data or change-over-time analysis.