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Characterizing the effects of extreme heat events on all-cause mortality : a case study in Ahmedabad city of India, 2002–2018

Sharma, Ayushi ; Dutta, Priya ; Shah, Priyanka ; Iyer, Veena ; He, Hao ; Sapkota, Amir ; Gao, Chuansi LU and Wang, Yu Chun (2024) In Urban Climate 54.
Abstract

Recent years have seen a rise in extreme heat event (EHE)-related deaths in India. However, the impact of specific temperature thresholds on health risks remains understudied. Using Distributed Lag Non-Linear Models (DLNM), we explored the link between EHEs, defined by various temperature thresholds, and mortality risk in Ahmedabad, India, from 2002 to 2018, considering a 21-day lag. We observed a ‘J'-shaped exposure-response curve, identifying a Minimum Mortality Temperature (MMT) of 26 °C for Ahmedabad. Notably, a higher and sustained risk of all-cause mortality was associated with Tmax > 35 °C. EHEs definition of Tmax ∼ 40 °C (95th percentile) increased all-cause mortality risk by 30% (Relative Risk (RR):... (More)

Recent years have seen a rise in extreme heat event (EHE)-related deaths in India. However, the impact of specific temperature thresholds on health risks remains understudied. Using Distributed Lag Non-Linear Models (DLNM), we explored the link between EHEs, defined by various temperature thresholds, and mortality risk in Ahmedabad, India, from 2002 to 2018, considering a 21-day lag. We observed a ‘J'-shaped exposure-response curve, identifying a Minimum Mortality Temperature (MMT) of 26 °C for Ahmedabad. Notably, a higher and sustained risk of all-cause mortality was associated with Tmax > 35 °C. EHEs definition of Tmax ∼ 40 °C (95th percentile) increased all-cause mortality risk by 30% (Relative Risk (RR): 1.30, 95% Confidence Interval (95% CI): 1.26–1.35), with substantially higher risk at Tmax of 45 °C (RR: 3.08, 95% CI: 2.47–3.83). Analysis of attributable fractions (AF) indicated Tmax ≥ 85th percentile contributed most to total mortalities, with an AF of 3.58% (95% CI: 3.20–3.96). Gender-stratified analysis revealed higher risk of EHE-related deaths for females. The highest mortality risk was identified on the same day of exposure and persisted longer during more intense EHEs. The activation of city's heat action plans should consider the significantly elevated mortality risk below the current threshold (∼40 °C) and the persistent risk during high-intensity EHEs.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Ahmedabad, DLNM, Exposure-response, Extreme heat events (EHEs), Minimum Mortality Temperature (MMT), Mortality
in
Urban Climate
volume
54
article number
101832
publisher
Elsevier
external identifiers
  • scopus:85186467636
ISSN
2212-0955
DOI
10.1016/j.uclim.2024.101832
language
English
LU publication?
yes
id
d07f8ca8-cb9a-49e2-8324-ed22062ba04c
date added to LUP
2024-03-19 17:45:39
date last changed
2024-03-27 15:24:56
@article{d07f8ca8-cb9a-49e2-8324-ed22062ba04c,
  abstract     = {{<p>Recent years have seen a rise in extreme heat event (EHE)-related deaths in India. However, the impact of specific temperature thresholds on health risks remains understudied. Using Distributed Lag Non-Linear Models (DLNM), we explored the link between EHEs, defined by various temperature thresholds, and mortality risk in Ahmedabad, India, from 2002 to 2018, considering a 21-day lag. We observed a ‘J'-shaped exposure-response curve, identifying a Minimum Mortality Temperature (MMT) of 26 °C for Ahmedabad. Notably, a higher and sustained risk of all-cause mortality was associated with T<sub>max</sub> &gt; 35 °C. EHEs definition of T<sub>max</sub> ∼ 40 °C (95th percentile) increased all-cause mortality risk by 30% (Relative Risk (RR): 1.30, 95% Confidence Interval (95% CI): 1.26–1.35), with substantially higher risk at T<sub>max</sub> of 45 °C (RR: 3.08, 95% CI: 2.47–3.83). Analysis of attributable fractions (AF) indicated T<sub>max</sub> ≥ 85th percentile contributed most to total mortalities, with an AF of 3.58% (95% CI: 3.20–3.96). Gender-stratified analysis revealed higher risk of EHE-related deaths for females. The highest mortality risk was identified on the same day of exposure and persisted longer during more intense EHEs. The activation of city's heat action plans should consider the significantly elevated mortality risk below the current threshold (∼40 °C) and the persistent risk during high-intensity EHEs.</p>}},
  author       = {{Sharma, Ayushi and Dutta, Priya and Shah, Priyanka and Iyer, Veena and He, Hao and Sapkota, Amir and Gao, Chuansi and Wang, Yu Chun}},
  issn         = {{2212-0955}},
  keywords     = {{Ahmedabad; DLNM; Exposure-response; Extreme heat events (EHEs); Minimum Mortality Temperature (MMT); Mortality}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Urban Climate}},
  title        = {{Characterizing the effects of extreme heat events on all-cause mortality : a case study in Ahmedabad city of India, 2002–2018}},
  url          = {{http://dx.doi.org/10.1016/j.uclim.2024.101832}},
  doi          = {{10.1016/j.uclim.2024.101832}},
  volume       = {{54}},
  year         = {{2024}},
}