The first results of a survey investigating the cardiovascular, respiratory and psychological effects of the 2014 Hazelwood mine fire have been released today.
Morwell participants in the Hazelwood Health Study's adult survey were more likely to report doctor-diagnosed asthma since the mine fire, as compared with a control group of participants in Sale, researchers have revealed.
"After the fire, people in Morwell were more likely to report asthma attacks and more severe symptoms," the study's principal investigator Michael Abramson said.
The findings are the first to be released from the study's major research component, the adult survey, which was conducted between May 2016 and February this year with 3096 participants from Morwell and 960 from Sale as a comparison community.
"Adults in Morwell were much more likely to report symptoms than those in Sale, particularly respiratory symptoms such as wheeze, cough, shortness of breath," Professor Abramson said.
According to the results, Morwell participants were one and-a-half times more likely than Sale participants to report that a doctor had diagnosed them with high blood pressure since the mine fire and seven times more likely to report a doctor-diagnosed heart attack since the blaze.
However, researchers said this result should be interpreted with caution as heart attack was reported by a small number of participants.
Psychological impacts of the fire are also being examined through the survey results, which found Morwell participants were more likely to report symptoms of distress following the event.
"Whereas before the fire, there were no real differences between the Morwell participants and the Sale participants," investigator Matthew Carroll said.
"They also didn't have any differences in terms of previous exposure to traumatic life events."
Morwell participants were four times more likely to report that a doctor had diagnosed them with Post Traumatic Stress Disorder, however this result was also based on small numbers.
Dr Carroll said investigators would now "dig into the data" and look at the relationship between what people reported and their level of exposure to the smoke.
A relatively large proportion of eligible adults from both towns did not participate in the voluntary survey, the research noting it was possible the findings did not truly reflect the two communities.
However, Professor Abramson said he had confidence in the results.
"I don't think they're entirely explained by response bias," he said.
In another area of research, the study has found most fire-impacted areas had higher rates of emergency presentations and hospital admissions during the mine fire period.
It found rates of emergency presentation and hospital admissions for asthma and chronic obstructive pulmonary disease and all respiratory diseases were higher during the fire period.
But there was no increase in cardiovascular disease.
The data was not sufficient to link any individual case to the mine fire, the report found.
The analysis only investigated the impact of fine particles known as PM2.5 and didn't include other pollutants like carbon monoxide.
The study will now look at ambulance call-outs, medical services and the dispensing of medications.
The health study is led by Monash University and funded by the Department of Health and Human Services.