AB079. Modifying effect of particulate matter (PM10) on the association between ambient temperature and cause-specific mortality in Klang Valley
Abstract

AB079. Modifying effect of particulate matter (PM10) on the association between ambient temperature and cause-specific mortality in Klang Valley

Muhammad Alfatih Pahrol1, Bala Murali Sundram1, Muhamad Fadhil Mohd Pua’at Zuzaki1, Mohd Faiz Ibrahim2, Rohaida Ismail2

1Department of Social and Preventive Medicine, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia; 2Environmental Health Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Selangor, Malaysia

Background: Extreme temperatures and air pollution are well-established environmental risk factors for mortality. While the independent effects of temperature have been extensively studied, less is known about how air pollution, particularly particulate matter less than 10 µm (PM10), may modify temperature-related mortality in tropical urban settings. This study aims to assess the short-term effects of ambient temperature on non-accidental, cardiovascular, and respiratory mortality in Klang Valley, Malaysia, and to examine the modifying role of PM10.

Methods: A time-series analysis was conducted using daily mortality, temperature, and air pollution data from 2008 to 2023. Distributed lag non-linear models (DLNMs) with quasi-Poisson regression were used to estimate cumulative temperature-mortality associations across a 21-day lag period. Analyses were stratified by PM10 category using a cut-off based on the World Health Organization 24-hour Air Quality Guideline (WHOAQG) 2021 (45 µg/m3). Heat and cold effects were evaluated by comparing the 99thvs. 90th percentile and 1stvs. 10th percentile temperatures, respectively.

Results: Approximately 33% of days exceeded the WHOAQG level. Non-accidental mortality increased at both heat [relative risk (RR): 1.07; 95% confidence interval (CI): 1.04–1.11] and cold extremes (RR: 1.11; 95% CI: 1.06–1.17) without clear modification by PM10. Cardiovascular mortality was more strongly associated with cold, rising by 17% (RR: 1.17; 95% CI: 1.07–1.27); however, this association diminished under both PM10 levels. In contrast, respiratory mortality increased at high temperatures (RR: 1.35; 95% CI: 1.22–1.50), with risks significantly elevated across PM10 categories.

Conclusions: Temperature extremes significantly impact mortality in Klang Valley, with varying effects by cause of death. PM10 modifies these associations, particularly enhancing heat-related respiratory mortality. These findings highlight the need for integrated public health strategies that address both temperature and air pollution to protect vulnerable populations in tropical urban environments.

Keywords: Air pollution; ambient temperature; cardiovascular; mortality; respiratory

Footnote

Conflicts of Interest: The authors have no conflicts of interest to declare.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the noncommercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

doi: 10.21037/jphe-26-ab079
Cite this abstract as: Pahrol MA, Sundram BM, Mohd Pua’at Zuzaki MF, Ibrahim MF, Ismail R. AB079. Modifying effect of particulate matter (PM10) on the association between ambient temperature and cause-specific mortality in Klang Valley. J Public Health Emerg 2026;10:AB079.

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