Extreme Heat Stress and Cardiovascular Diseases in the Tropical Megacity of Jakarta (Indonesia)

The Jakarta Metropolitan Area (JMA) of Indonesia officially becomes the most populated urban area with 40M inhabitants. Despite its limited diurnal temperature variability, JMA is currently confronted with an exacerbation of climate change and the urban heat island (UHI) that affects health of the urban communities. Nonetheless, the number of studies on the health implications of heat exposure within this tropical environment remain limited. Prior significant research has successfully incorporated both Indonesian National Health Insurance (BPJS) and meteorological observation datasets. However, these studies have exclusively relied upon observed daily mean air temperature as the thermal proxy. Consequently, the cumulative exposure arising from the diurnal variation associated with UHI effects is potentially underestimated.

This study aims to analyze and quantify the influence of heat-stress on CVD morbidity across the thirteen districts within JMA. Consequently, this study utilizes a five-year dataset (2020-2024) incorporating hourly meteorological parameters sourced from nine stations, thereby reflecting the diurnal variation of atmospheric dynamics in the analysis. Furthermore, rather than employing the 2-m air temperature, Physiological Equivalent Temperature (PET) is examined as offering a reliable indicator for human thermoregulation. The analysis concentrates on the correlation between heat stress and the morbidity of cardiovascular disease (CVD) within primary healthcare facilities.

Preliminary findings indicate that the UHI effect influences healthcare visits for CVD in urban areas. Cumulative exposure to extreme daytime heat stress environments, as quantified by PET values in urban areas, substantially increases the incidence of CVD admissions. Conversely, the daily maximum air temperature proves to be a more suitable indicator for rural areas. These results emphasize the necessity of integrating appropriate meteorological indicators to effectively address and mitigate heat-related health risks for urban populations.