Heatwave events are associated with increased hospital admissions and mortality rates worldwide. Heat exposure is often exacerbated by the Urban Heat Island (UHI) effect, especially in large cities. However, an accurate quantification of the additional burden related to heat from urbanisation is understudied in Latin American cities. Therefore, we used advanced meteorological modelling to simulate 2 m air temperature at 1 km spatial resolution across São Paulo, estimating UHI intensity attributing of all-cause mortality to heat and UHI during the 2014 heatwave. The Local Climate Zone classification system provided input land use parameters. Our model was validated against 31 weather stations and bias-corrected using linear regression. We calculated heat-related all-cause mortality, stratified by age, using the modelled temperature data, estimating 394 heat-related deaths. A counterfactual experiment, replacing urban areas with natural land, quantified the additional UHI burden. We found that the UHI may contribute to 69–70% of heat-related mortality (modelled temperature scenario). This work motivates the use of appropriate urban climate data, including careful model validation and bias correction, when assessing heat exposure and health risk assessment. It also highlights the health impacts from heatwaves in cities such as São Paulo, which are likely to increase due to climate change.

中文翻译：

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城市化对巴西圣保罗炎热相关死亡率的潜在负担


热浪事件与全球住院人数和死亡率增加有关。城市热岛效应 (UHI) 往往会加剧热暴露，尤其是在大城市。然而，拉丁美洲城市尚未对与城市化产生的热量相关的额外负担进行准确量化。因此，我们使用先进的气象模型以 1 km 空间分辨率模拟圣保罗各地 2 m 气温，估计 2014 年热浪期间全因死亡率归因于高温和 UHI 的 UHI 强度。当地气候区分类系统提供了输入的土地利用参数。我们的模型针对 31 个气象站进行了验证，并使用线性回归进行了偏差校正。我们使用建模的温度数据计算了与高温相关的全因死亡率（按年龄分层），估计有 394 例与高温相关的死亡。一项反事实实验，用自然土地取代城市地区，量化了额外的城市热岛负担。我们发现 UHI 可能导致 69-70% 的热相关死亡率（模拟温度情景）。这项工作鼓励在评估热暴露和健康风险评估时使用适当的城市气候数据，包括仔细的模型验证和偏差校正。它还强调了圣保罗等城市热浪对健康的影响，由于气候变化，热浪可能会加剧。