Synergistic associations of ambient air pollution and heat on daily mortality in India

IF 10.3 1区环境科学与生态学 Q1 ENVIRONMENTAL SCIENCES

Environment International Pub Date : 2025-03-29 DOI:10.1016/j.envint.2025.109426

Jeroen de Bont , Ajit Rajiva , Siddhartha Mandal , Massimo Stafoggia , Tirthankar Banerjee , Hem Dholakia , Amit Garg , Vijendra Ingole , Suganthi Jaganathan , Itai Kloog , Bhargav Krishna , Kevin Lane , R.K. Mall , Jyothi Menon , Amruta Nori-Sarma , Dorairaj Prabhakaran , Abhiyant Suresh Tiwari , Yaguang Wei , Gregory A. Wellenius , Joel Schwartz , Petter Ljungman

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引用次数: 0

Abstract

Background

Limited studies have evaluated the interaction between ambient air pollution and heat on mortality, especially in regions such as India, where extreme levels of both exposures occur frequently. Accordingly, we aimed to investigate the potential synergistic effects between ambient air pollution and heat on daily mortality in India.

Methods

We applied a time-series analysis for ten cities in India between 2008–2019. We assessed city-wide daily particulate matter ≤ 2.5 μm (PM_2.5) and temperature levels using two nationwide spatiotemporal models. We estimated city-specific exposure-outcome associations through generalised additive Poisson regression models, and meta-analysed the associations. To evaluate the interaction between PM_2.5 and air temperature (modelled at lag 0–1), a product term was incorporated between linear PM_2.5 and non-linear air temperature. From this model, we estimated the effect of air pollution for increasing levels of temperature, and vice versa.

Findings

Among ∼ 3.6 million deaths, we found that the association of PM_2.5 on mortality was particularly stronger beyond the 75th percentile of temperature. When we compared the associations of PM_2.5-mortality at the 75th and 99th temperature percentile, we observed an increase from 0.8 % (95 % CI: −0.3 %, 1.9 %) to 4.6 % (95 % CI: 2.9 %, 6.5 %) increase in mortality per 10 μg/m³ increments, respectively. In addition, we observed a 22.0 % (95 % CI: 13.5 %, 31.2 %) increase in daily mortality risk due to an increase in temperature from the 75th to the 99th city-specific percentiles. Percent change in mortality risk increased linearly from 8.3 % (95 % CI: 2.2 %, 14.9 %) when daily PM_2.5 was 20 μg/m³ to 63.9 % (95 % CI: 38.7.%, 93.7 %) at 100 μg/m³.

Interpretation

Our findings reveal a substantial synergistic interaction between ambient air pollution and temperature in India. This calls for efforts to tangibly reduce common sources of air pollution and climate change to immediately lower their combined effects on daily mortality and mitigate their long-term health consequences.

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对环境空气污染和高温对死亡率的相互作用进行评估的研究很有限，特别是在印度等地区，那里的极端天气对死亡率的影响更大。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Environment International 环境科学-环境科学

CiteScore

21.90

自引率

3.40%

发文量

734

审稿时长

2.8 months

期刊介绍： Environmental Health publishes manuscripts focusing on critical aspects of environmental and occupational medicine, including studies in toxicology and epidemiology, to illuminate the human health implications of exposure to environmental hazards. The journal adopts an open-access model and practices open peer review. It caters to scientists and practitioners across all environmental science domains, directly or indirectly impacting human health and well-being. With a commitment to enhancing the prevention of environmentally-related health risks, Environmental Health serves as a public health journal for the community and scientists engaged in matters of public health significance concerning the environment.