The housing environment and ambient temperature (HEAT) study

摘要 如果不干预，到本世纪末，极端高温将导致数万人额外死亡， 尤其是由呼吸系统和心血管疾病引起。除了短期高温事件的影响外， 例如热浪，关键是要了解慢性热暴露的影响，评估最 与高温有关的死亡发生在室内。提高对个人和邻里特征的理解 提高或降低热脆弱性对于指导有效的热适应设计也是至关重要的 战略。然而，目前关于与高温相关的死亡率和脆弱性的知识仍然局限于至少三个 方式。首先，大多数关于与高温相关的死亡的研究都量化了短期温度与 峰值和急性死亡结果，留下了关于慢性高温造成的总死亡负担的不确定性 曝光。其次，大多数研究都计算了与室外温度而不是室内温度的关联， 因此，可能低估了高温对死亡的影响，并在关于 安全最高室内温度阈值。第三，人们几乎不知道住房在多大程度上 提高热舒适性和节约能源的干预措施，如改善隔热或改变 屋面材料，可以防止因长期室内高温暴露而导致的额外死亡。迫切需要填补 这些差距是因为大多数人，特别是包括年龄以上的个人在内的脆弱亚群 65岁，大部分时间都在室内度过。我们提出了有史以来第一个以人口为基础的全国性 慢性室内热暴露对健康影响的代表性、准实验、纵向队列研究 美国的死亡率。我们将使用65岁和老年死亡率参与者的数据 美国社区差异(MDAC)研究与医疗保险和国家死亡指数数据有关。这 非常丰富的数据集，其中包含对个人长达八年的跟踪，将与 使用严格的、经过广泛验证的、基于物理的计算室内温度和湿度变量 模拟模型；个人层面的住房特征；以及高分辨率的土地覆盖数据。为了提高 了解住房环境、长期室内热暴露和死亡率之间的关系， 以及个人和邻居层面的热脆弱性决定因素，我们追求三个目标。在目标1中，我们 量化长期室内高温暴露与全因和特定原因死亡率之间的关系，以及 确定特定气候区域、安全的炎热季节室内温度上限。在目标2中，我们 阐明个人和社区层面的因素，以增强或降低对室内长期高温的易感性 曝光。在目标3中，我们量化了可以通过住房干预措施预防的总超额死亡人数。 在当前和未来的温室气体排放情景下，改善热舒适性。这一影响 该项目将提供迫切需要的信息来指导平衡热适应的干预措施 以减缓气候变化为目标的最弱势群体的健康保护。

Abstract Without intervention, by the end of this century, extreme heat will cause tens of thousands of excess deaths, particularly from respiratory and cardiovascular causes. Beyond the impacts of short-duration heat events, such as heat waves, it is critical to understand the effects of chronic heat exposure, assessed where most heat-related deaths occur: indoors. Improving understanding of individual and neighborhood characteristics that heighten or reduce heat vulnerability is also crucial, for informing the design of effective heat adaptation strategies. Yet, current knowledge of heat-related mortality and vulnerability remains limited in at least three ways. First, most research on heat-related death has quantified associations between short-term temperature spikes and acute mortality outcomes, leaving uncertainty about the total mortality burden of chronic heat exposure. Second, most research has calculated associations with outdoor rather than indoor temperatures, thus potentially under-estimating the mortality impacts of heat and leaving critical gaps in knowledge about safe maximum indoor temperature thresholds. Third, little is known about the extent to which housing interventions that promote thermal comfort and conserve energy, such as improving insulation or altering roofing material, may prevent excess deaths from chronic indoor heat exposure. There is an urgent need to fill these gaps since most people, and especially heat vulnerable subpopulations including individuals over age 65, spend the majority of their time indoors. We propose the first ever population-based, nationally representative, quasi-experimental, longitudinal cohort study of the effects of chronic indoor heat exposure on mortality in the United States. We will use data on age 65 and older adult participants of the Mortality Disparities in America Communities (MDAC) study linked with Medicare and National Death Index data. This remarkably rich data set, which contains follow up on individuals for up to eight years, will be combined with indoor temperature and humidity variables calculated using rigorous, extensively validated, physics-based simulation models; individual-level housing characteristics; and high-resolution land cover data. To improve understanding of associations between the housing environment, chronic indoor heat exposures and mortality, and person- and neighborhood-level determinants of heat vulnerability, we pursue three aims. In Aim 1, we quantify associations between chronic indoor heat exposures and all-cause and cause-specific mortality, and identify climate-zone specific, safe upper thresholds for hot-season indoor temperatures. In Aim 2, we elucidate person- and neighborhood-level factors that enhance or reduce vulnerability to chronic indoor heat exposure. In Aim 3, we quantify the total excess deaths that may be prevented through housing interventions that improve thermal comfort, under current and future greenhouse gas emission scenarios. This impactful project will provide information that is critically needed to guide interventions that balance heat adaptation for health protection in the most vulnerable subgroups with climate change mitigation goals.