西班牙巴塞罗那全球健康研究所Mark Nieuwenhuijsen团队研究了通过城市绿色基础设施为城市降温的健康益处。该研究于2023年1月31日发表在《柳叶刀》杂志上。

环境高温与许多健康影响有关，包括过早死亡。气候变化导致的全球变暖和全球建筑环境的扩张，意味着城市热岛（UHIs）效应将加剧，并对人口健康产生不利影响。城市绿色基础设施可以降低当地气温。该研究旨在估计可归因于UHIs的死亡负担，以及通过增加欧洲93个城市的城市树木覆盖率可防止的死亡负担。

2015年夏季（6月1日至8月31日），研究组对93个欧洲城市的UHIs对20岁及以上成年人全因死亡率的影响进行了定量健康影响评估。该研究团队还估计了将每个城市的树木覆盖率提高到30%将导致的气温下降，并估计了可能因此而避免的死亡人数。研究组在高分辨率网格单元水平（250×250米）上进行所有分析，通过使用蒙特卡罗模拟来传播输入分析中的不确定性，以获得点估计和95%置信区间。还进行了敏感性分析，以测试研究组估计的稳健性。

UHI效应引起的人口加权平均气温升高为1.5°C 。总体而言，6700例过早死亡可归因于UHIs的影响（相当于夏季所有死亡人数的约4.33%）。研究组估计，将树木覆盖率提高到30%将使城市平均降温0.4°C，可以避免2644例过早死亡，相当于所有夏季死亡人数的1.84%。

研究结果表明了UHIs对死亡率的有害影响，并强调了增加树木覆盖率以冷却城市环境的健康益处，这也将导致更可持续和气候适应能力更强的城市。

附：英文原文

Title: Cooling cities through urban green infrastructure: a health impact assessment of European cities

Author: Tamara Iungman, Marta Cirach, Federica Marando, Evelise Pereira Barboza, Sasha Khomenko, Pierre Masselot, Marcos Quijal-Zamorano, Natalie Mueller, Antonio Gasparrini, José Urquiza, Mehdi Heris, Meelan Thondoo, Mark Nieuwenhuijsen

Issue&Volume: 2023-01-31

Abstract:

Background

High ambient temperatures are associated with many health effects, including premature mortality. The combination of global warming due to climate change and the expansion of the global built environment mean that the intensification of urban heat islands (UHIs) is expected, accompanied by adverse effects on population health. Urban green infrastructure can reduce local temperatures. We aimed to estimate the mortality burden that could be attributed to UHIs and the mortality burden that would be prevented by increasing urban tree coverage in 93 European cities.

Methods

We did a quantitative health impact assessment for summer (June 1–Aug 31), 2015, of the effect of UHIs on all-cause mortality for adults aged 20 years or older in 93 European cities. We also estimated the temperature reductions that would result from increasing tree coverage to 30% for each city and estimated the number of deaths that could be potentially prevented as a result. We did all analyses at a high-resolution grid-cell level (250×250 m). We propagated uncertainties in input analyses by using Monte Carlo simulations to obtain point estimates and 95% CIs. We also did sensitivity analyses to test the robustness of our estimates.

Findings

The population-weighted mean city temperature increase due to UHI effects was 1·5°C (SD 0·5; range 0·5–3·0). Overall, 6700 (95% CI 5254–8162) premature deaths could be attributable to the effects of UHIs (corresponding to around 4·33% [95% CI 3·37–5·28] of all summer deaths). We estimated that increasing tree coverage to 30% would cool cities by a mean of 0·4°C (SD 0·2; range 0·0–1·3). We also estimated that 2644 (95% CI 2444–2824) premature deaths could be prevented by increasing city tree coverage to 30%, corresponding to 1·84% (1·69–1·97) of all summer deaths.

Interpretation

Our results showed the deleterious effects of UHIs on mortality and highlighted the health benefits of increasing tree coverage to cool urban environments, which would also result in more sustainable and climate-resilient cities.

DOI: 10.1016/S0140-6736(22)02585-5

Source: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(22)02585-5/fulltext