Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stress
In 2021, the Japanese government changed the exposure indicator of the national heat-health warning system (HHWS) from air temperature ( T _air ) to Wet Bulb Globe Temperature ( T _WBG ), reflecting the growing concerns about the escalating humid heat stress. However, a clear validation of the advan...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ad3a81 |
| _version_ | 1797213123147464704 |
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| author | Qiang Guo Lei Yuan Chris Fook Sheng Ng Masahiro Hashizume |
| author_facet | Qiang Guo Lei Yuan Chris Fook Sheng Ng Masahiro Hashizume |
| author_sort | Qiang Guo |
| collection | DOAJ |
| description | In 2021, the Japanese government changed the exposure indicator of the national heat-health warning system (HHWS) from air temperature ( T _air ) to Wet Bulb Globe Temperature ( T _WBG ), reflecting the growing concerns about the escalating humid heat stress. However, a clear validation of the advantages of using heat stress indicators (HSIs) that combine T _air and humidity in heat alerts and heat-health applications are still being explored. Here, by using the latest epidemiological data (2015–2019) before the COVID-19 pandemic, we examined the rationality of the revised HHWS for 47 prefectures in Japan. Specifically, we investigated the predictive power of different HSIs in modeling mortality and morbidity caused by different diseases (e.g. all causes, circulatory, respiratory, and heatstroke) and age groups. Our findings revealed substantial differences among the HSIs in identifying periods of intense heat stress, potentially leading to differences in the activation dates of the HHWS if various indicators were employed. While HSIs exhibited comparable performances in modeling daily mortality, our analysis demonstrates distinct advantages in using T _WBG for daily morbidity predictions, and the quasi-Akaike Information Criterion of T _WBG is much lower than the previously used T _air . The merits of T _WBG are consistent in modeling all causes, non-external, as well as heatstroke-related morbidity. Overall, this study underscores the practicality of incorporating HSIs in heat stress early warnings and provides critical insights for refining the HHWS to mitigate health impacts from heat stress under future climate change. |
| first_indexed | 2024-04-24T10:53:16Z |
| format | Article |
| id | doaj.art-82fcb434eab44503aa1ec5c47d773b9b |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-04-24T10:53:16Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-82fcb434eab44503aa1ec5c47d773b9b2024-04-12T07:44:13ZengIOP PublishingEnvironmental Research Letters1748-93262024-01-0119505400210.1088/1748-9326/ad3a81Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stressQiang Guo0https://orcid.org/0000-0001-6539-5988Lei Yuan1https://orcid.org/0000-0002-4493-701XChris Fook Sheng Ng2https://orcid.org/0000-0003-1025-0807Masahiro Hashizume3https://orcid.org/0000-0003-4720-1750Department of Global Health Policy, Graduate School of Medicine, The University of Tokyo , Tokyo 113-0033, JapanDepartment of Global Health Policy, Graduate School of Medicine, The University of Tokyo , Tokyo 113-0033, JapanDepartment of Global Health Policy, Graduate School of Medicine, The University of Tokyo , Tokyo 113-0033, JapanDepartment of Global Health Policy, Graduate School of Medicine, The University of Tokyo , Tokyo 113-0033, JapanIn 2021, the Japanese government changed the exposure indicator of the national heat-health warning system (HHWS) from air temperature ( T _air ) to Wet Bulb Globe Temperature ( T _WBG ), reflecting the growing concerns about the escalating humid heat stress. However, a clear validation of the advantages of using heat stress indicators (HSIs) that combine T _air and humidity in heat alerts and heat-health applications are still being explored. Here, by using the latest epidemiological data (2015–2019) before the COVID-19 pandemic, we examined the rationality of the revised HHWS for 47 prefectures in Japan. Specifically, we investigated the predictive power of different HSIs in modeling mortality and morbidity caused by different diseases (e.g. all causes, circulatory, respiratory, and heatstroke) and age groups. Our findings revealed substantial differences among the HSIs in identifying periods of intense heat stress, potentially leading to differences in the activation dates of the HHWS if various indicators were employed. While HSIs exhibited comparable performances in modeling daily mortality, our analysis demonstrates distinct advantages in using T _WBG for daily morbidity predictions, and the quasi-Akaike Information Criterion of T _WBG is much lower than the previously used T _air . The merits of T _WBG are consistent in modeling all causes, non-external, as well as heatstroke-related morbidity. Overall, this study underscores the practicality of incorporating HSIs in heat stress early warnings and provides critical insights for refining the HHWS to mitigate health impacts from heat stress under future climate change.https://doi.org/10.1088/1748-9326/ad3a81humid heatheat alert systempublic healthurban heat islandJapan |
| spellingShingle | Qiang Guo Lei Yuan Chris Fook Sheng Ng Masahiro Hashizume Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stress Environmental Research Letters humid heat heat alert system public health urban heat island Japan |
| title | Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stress |
| title_full | Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stress |
| title_fullStr | Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stress |
| title_full_unstemmed | Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stress |
| title_short | Evaluating Japan’s revised heat-health warning system in the face of recent escalating heat stress |
| title_sort | evaluating japan s revised heat health warning system in the face of recent escalating heat stress |
| topic | humid heat heat alert system public health urban heat island Japan |
| url | https://doi.org/10.1088/1748-9326/ad3a81 |
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