Study shows residents’ lungs aged ‘faster’ after exposure to smoke from Hazelwood coal mine fire
Retired high school teacher Howard Williams remembers “seeing a eucalyptus tree literally explode from the heat.”
It was the start of the Hazelwood Coal Mine Fire, which broke out on February 9, 2014, in the middle of a hot, dry summer.
Williams says he saw the fire spread through the mine and race toward an SEC administration building.
Williams lived at the time in Morwell in the LaTrobe Valley in Victoria, separated from the mine by a fence and a highway.
After helping his wife evacuate, Williams stayed behind, a decision he later questioned. “I was worried the fire would destroy the highway reserve on our side,” he said. “Our property had some large trees and a lot of leaf litter that I was getting wet.”
About six days later, the fire was still raging and firefighters were busy trying to contain the massive blaze, which had a virtually unlimited supply of fuel.
Nearby, Williams had just run some errands and was walking back to his car, “like I always did.” By the time he got there, he was out of breath. An emergency alarm warned of high carbon monoxide levels.
The mine fire ultimately burned for 45 days, blanketing nearby Morwell and the surrounding area in smoke. For 27 of those days, levels of fine particulate pollution – known as PM2.5 – exceeded the national environmental protection measure.
Williams, a community representative on the emergency management team, was concerned that contrary to the standards set for first responders, “the community could be exposed to higher levels of small particles, higher levels of carbon monoxide and other hazardous gases,” he said.
Ten years later, new research has been published in the journal Respiratory Sciences found that Morwell residents showed signs of accelerated lung aging four years after the fire.
Epidemiologist and former pulmonologist and professor emeritus at Monash University Michael Abramson was a co-author of the paper. He was the principal investigator for the Hazelwood Health Study from its inception in 2014 until late last year.
While the analysis did not establish a causal relationship, Abramson says there is a statistically significant association between exposure to the fine particles in the smoke from the fire, which is equivalent to 4.7 years of lung aging. “In other words, these participants’ lungs aged faster than they would have if they had not been exposed to the smoke,” he says.
In late 2017, researchers conducted a clinical trial, called multiple breath nitrogen washout, on 313 residents of Morwell who had been exposed to pollution from the mine fire, and on 166 people from Sale, a town 50km to the east, in early 2018.
During the test, participants breathe in 100% oxygen while special equipment measures the time it takes for nitrogen to clear from the lungs over multiple breaths.
The method was chosen for its ability to identify subtler signs of lung disease, Abramson says. It measures something called “ventilation heterogeneity,” an indication that parts of the lungs aren’t functioning properly by measuring how gases mix.
In young people with healthy lungs, gases mix more evenly and efficiently, he says, compared with older people and those with lung diseases.
According to Abramson, the results show an association between exposure to pollution from the mine fire and increased ventilation heterogeneity – less efficient mixing – about four years after the event, while controlling for other factors such as age, gender, smoking and occupation.
The paper is the result of the Hazelwood Health Study, a series of studies examining the long-term effects of the fire on community health.
Prof Brian Oliver from the University of Technology Sydney researches lung disease and environmental health, including the effects of exposure to air pollution. He says that “any form of air pollution – and that includes both gases and particulate matter – is bad for lung health”.
It’s easy to see the short-term health effects of events like fires, which are episodic and involve higher levels of exposure, Oliver says. “Because generally, when you have massive exposure, there’s a huge influx of people, unfortunately, going to the hospital with things like heart problems or respiratory problems.”
In the longer term, the data are often less clear, although ‘we know for sure it’s bad’.
Williams says that ten years later, many people in the community are still affected by the Hazelwood mine fire, affecting their health, their social lives and their psychology.
“Being exposed to what people went through in those 45 days could not have been helpful,” he said. “The problem is that the people who were most affected died, and many of them died from lung disease.”