Vascular Responses Among Adults Four Years Post Exposure to 6 Weeks of Smoke from the Hazelwood Coal Mine Fire

Juan Mundisugih; Caroline X Gao; Jillian F Ikin; Michael J Abramson; David Brown; Sinjini Biswas; Elizabeth M Dewar; Danny Liew; Dion Stub

doi:10.2147/VHRM.S339439

Vascular Responses Among Adults Four Years Post Exposure to 6 Weeks of Smoke from the Hazelwood Coal Mine Fire

Vasc Health Risk Manag. 2022 Apr 13:18:253-265. doi: 10.2147/VHRM.S339439. eCollection 2022.

Authors

Juan Mundisugih^{1

2}, Caroline X Gao^{1

3}, Jillian F Ikin¹, Michael J Abramson¹, David Brown¹, Sinjini Biswas^{1

2}, Elizabeth M Dewar^{2

4}, Danny Liew¹, Dion Stub^{1

2

4}

Affiliations

¹ School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia.
² Department of Cardiology, Alfred Health, Melbourne, VIC, Australia.
³ Centre for Youth Mental Health (Orygen), University of Melbourne, Melbourne, VIC, Australia.
⁴ Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.

Abstract

Background and aims: Mega-wild fires are exposing large communities to weeks or months of high concentration smoke-related fine particulate air pollution (PM). However, little research has examined the long-term vascular responses from exposure to PM of this concentration and duration. We investigated whether level of exposure to 6 weeks of PM from the 2014 Hazelwood coal mine fire was associated with abnormal vascular responses approximately four years later.

Methods: A cross-sectional analysis was undertaken of 387 participants (225 exposed, 162 unexposed) aged 55-89 years, 3.5-4 years after the mine fire. The primary outcome was flow-mediated dilatation (FMD), with time to reach peak diameter as the secondary outcome. Other secondary markers included high-sensitivity C-reactive protein (hsCRP) and ischaemic Electrocardiogram (ECG) changes.

Results: There was no evidence of a difference in FMD between participants with high, medium, low or no mine-fire related PM_2.5 exposure (4.09% vs 4.06% vs 4.02% vs 3.98%, respectively, p=0.99). Likewise, there was no difference in hsCRP or ischaemic ECG changes. In contrast, there was evidence of a difference in time to peak diameter (p=0.002) with more unexposed participants reaching peak diameter within 30 seconds (36%) compared to those who had high, medium, or low exposure (23%, 22%, 13%, respectively). Multivariate ordinal logistic regression analysis suggested that township, Morwell (exposed) vs Sale (unexposed), but not level of PM_2.5 exposure, was associated with delayed time to peak diameter (OR 2.71; 95% CI 1.56, 4.69). Smokers also had delayed time to peak diameter.

Conclusion: There was no association between level of exposure to PM_2.5 from the 6-week Hazelwood coal mine fire smoke event and reduced FMD, elevated hsCRP or ischaemic ECG four years later. Evidence of delayed time to peak diameter observed in adults from the exposed town, compared to an unexposed town, requires further investigation.

Keywords: air pollution; epidemiology; flow mediated dilatation; particulate matter; time to peak diameter; vascular responses.

MeSH terms

Adult
Air Pollutants* / analysis
C-Reactive Protein / analysis
Coal* / analysis
Cross-Sectional Studies
Environmental Exposure / analysis
Humans
Particulate Matter / analysis

Substances

Air Pollutants
Coal
Particulate Matter
C-Reactive Protein

Grants and funding

This study was funded by the Victorian Department of Health. The paper presents the views of the authors and does not represent the views of the Department.