Inside Story

Summer’s legacy

As research on the health impact of the fire season continues, the lessons are becoming clearer

Jennifer Doggett 25 June 2020 2845 words

Smoke enveloping the Sydney Opera House and the Harbour Bridge on 6 December last year. Cameron Spencer/Getty Images

Bushfires have long shaped the Australian landscape, but they have generally been relatively isolated events affecting small populations for short periods. All that changed when the Australian summer of 2019–20 brought fires of unprecedented scale, duration and impact.

By the end of the season, according to an ANU survey, the majority of Australians had been directly or indirectly affected by the fires. Around 2.9 million adult Australians had property threatened or damaged, or were evacuated at least once. Around ten million people were affected by smoke, with many experiencing months of prolonged exposure. Another three-quarters of the adult population — around 15.4 million people — had indirect experience of the fires via family and friends.

If there was any good news, it was the fact that deaths and acute injuries were lower than in previous catastrophic fire seasons. Some thirty-four people died during the fires, compared with seventy-five deaths during the Ash Wednesday fires in early 1983 and 173 deaths on Black Saturday in early 2009.

Emergency physician Simon Judkins, immediate past president of the Australasian College of Emergency Medicine, has worked in many disaster settings. He sees the relatively low levels of injuries and deaths in the 2019–20 season as evidence that we have learnt from previous events. “We have got good at evacuating, triaging and getting people out of affected areas when necessary,” he says.

Many of the measures taken during the season were recommended by the Victorian royal commission set up after Black Saturday: clear and consistent public messaging and comprehensive evacuation plans, for example, coordinated emergency services responses and protocols for treating injured people on site or moving them to city hospitals.

Demand on hospitals and local health services was kept manageable by including GPs in field clinics and in the teams sent by the National Critical Care and Trauma Response Centre. Mistakes were made in communications and emergency services responses, of course, but improved evacuation and treatment meant that existing health services were not overwhelmed.

Still, health experts warn against complacency. As Judkins observes, the system functions well because of the dedication of overworked health professionals who do their best in an under-resourced system. He emphasises that an already stretched public hospital system can quickly become overwhelmed.

Iain Walker, director of the ANU Research School of Psychology, agrees. “If we have systems operating at capacity then there is no ability to deal with any additional problems,” he says.“For example, if the Covid-19 pandemic had reached Australia a month earlier when we had mass bushfire-related evacuations we would have had two conflicting events co-occurring and would not have coped.”

With challenges of this kind likely to become more frequent and more intense, Walker adds, “we need to build capacity into our health and social care systems and other essential services to deal with these situations.”

Simon Judkins also stresses the need to do more to support health professionals, first responders and volunteers who worked at the bushfire frontline. “How do we manage not only acute response, such as getting medical and nursing staff to the affected areas, but also ensuring that we support the health professionals on the ground who worked for fourteen-hour days for four or five weeks non-stop?” he asks. “Who looks after GPs working in those areas who absorbed a lot of stress and suffering in their communities? Who relieves solo practice GPs in places like Mallacoota when they need a break?”

The acute effects might be the most obvious legacy of the fires, but by far their greatest health impact came from the smoke they emitted. Because bushfire smoke can travel long distances and linger in the atmosphere, many more people were exposed than experienced the fires’ direct impact — and that makes our limited knowledge of its effects all the more worrying.

Clare Walter, a PhD candidate at the University of Queensland, has analysed the findings of nine Australian studies on the health impacts of air pollution. They show that, in the short-term at least, air pollution causes increased presentations to hospitals for chronic obstructive pulmonary disease, asthma, cardiac arrests and ischaemic heart disease.

These findings are supported by early research into the increased demand for healthcare during the 2019–20 bushfire season. Studies of air quality data for bushfire-affected regions of New South Wales, Queensland, the Australian Capital Territory and Victoria have found that the concentration of small airborne particles exceeded the ninety-fifth percentile of the historical daily mean on 125 of 133 days studied. In other words, concentrations were within the top 5 per cent on most smoke-affected days.

Researchers correlated this data with hospital admissions, emergency department attendances, GP consultations and ambulance call-outs to calculate that smoke was responsible for 417 excess deaths during the 2019–20 bushfire season and around 4500 presentations to hospital for cardiovascular and respiratory problems.

These findings suggest a strong relationship between bushfire smoke and specific health problems. But the exact causal relationship isn’t yet clear.

Almost all research on the health impacts of air pollution is based on measurements of airborne particulate matter, or PM, a mixture of solid particles and liquid droplets. PM is markedly elevated during fires and is widely monitored around Australia; that’s why researchers focus on its link with health problems.

The size and chemical composition of PM differs according to its source (apart from bushfires, the big ones are motor vehicles and coalfired power stations) and also from place to place. Evidence suggests that size matters, with small particles — those measuring less than 2.5 micrometers, or PM2.5 — being particularly damaging because they can penetrate deep into the respiratory system. But we know less about how their chemical composition affects humans.

Walters’s analysis has identified differences between the health effects of bushfire smoke and other forms of air pollution: specifically, respiratory impacts were comparatively stronger for bushfire pollution and cardiovascular impacts were weaker. But she stresses that only further investigation will show whether this is this is a causal relationship.

She has also found that bushfire smoke appears to affect adults more than children — the reverse of traffic pollution — although she can’t yet say whether this reflects biological or behavioural factors.

There’s another big unknown, too: the relative impact of heat and smoke exposure on health. With bushfires tending to occur on days of extreme heat, the two events can have a compound impact on humans. One recent Perth‐based study found a 6.6 per cent joint additive effect of PM2.5 and heat waves on admissions to hospital emergency departments. Again, the interaction is poorly understood.

Respiratory medicine specialist John Wilson, president of the Australasian College of Physicians, suggests that part of the reason that demand for healthcare rises during periods of smoke pollution might be that people with existing conditions are not sticking to their treatment plan. This may be because people delay regular medical appointments in response to public health advice to stay home on days of high pollution or because they are reluctant to seek help early for problems which then escalate into more serious issues.

On the question of the effectiveness of wearing a mask to reduce exposure to airborne particles, he is agnostic. “There is no clear answer from the research,” he tells me. “We have better information about their role in reducing infection due to the Covid-19 pandemic but there have been no clinical trials that definitively establish how effective they are.”

Wilson believes that Australia is the ideal setting for evaluating the effectiveness of masks, and stresses the need for their effectiveness to be confirmed before we face another major bushfire smoke episode. “When it comes to masks we have to either prove it or lose it,” he says.

More challenging from a research perspective is a better undersanding of the longer-term effects of bushfires. Existing Australian research in this area mostly comes from studies of the Ash Wednesday and Black Saturday fires, but the smaller scale of those fires means that it may not accurately predict the impact of the prolonged exposure last summer.

What is clear from the limited research is that the longer-term effects of smoke exposure go beyond the respiratory and cardiovascular systems. Some experts have suggested, for instance, that smoke exposure could increase the risk of Parkinson’s disease, Alzheimer’s disease and other neurological conditions. Some evidence also suggests that babies exposed to prolonged smoke in utero are at higher risk of low birthweight, which brings a heightened lifelong risk of conditions including cerebral palsy and visual or hearing impairment, and an elevated risk of heart disease in later life.

As some of these longer-term effects can be subtle and delayed, large-scale longitudinal studies will be needed to track groups over years and decades. The Menzies Centre for Health Policy’s Lesley Russell, an Inside Story contributor, is among the public health experts who have been arguing that more resources should be put into this kind of research.

She nominates four priority areas: longitudinal studies of all recognised firefighting personnel; longitudinal studies of communities most exposed to bushfires and bushfire smoke; greater awareness among and guidance for clinicians to help them recognise and deal with the health consequences of bushfires; and more focused research projects on high priority issues.

Some of the research gaps are being tackled with funding from the federal government’s Medical Research Future Fund, which has allocated $3 million for research into the physiological impacts of prolonged bushfire smoke exposure and $2 million for research into the mental health impacts of bushfires.

Although Russell welcomes this funding she is concerned by the lack of large-scale longitudinal studies. While she acknowledges this type of research can be very costly, she argues that “there are even greater costs involved in failing to undertake it — along with lost opportunities to improve the ability of the public health and healthcare systems to respond to future crisis situations.” She stresses the need for the findings of studies of the 2019–20 bushfires to be widely distributed and incorporated into the design of government services and programs.

ANU’s Iain Walker nominates social cohesion and resilience as other priorities for future research and action. He describes how the stress of a disaster can expose the “fracture lines” in individuals, families, communities and systems. Although social and community relationships are crucial to resilience, he says, they are often overlooked in research.

Given Australia’s vulnerability to natural disasters, Walker suggests that we should focus more on how to promote resilience to protect us in future disaster situations. He points out that understanding how resilience manifests in individuals, families, communities and systems will help in preparing not only for future bushfires but also for drought, pandemics, economic downturns and other crises.

Although the impact of bushfires on mental health often receives less attention, the evidence suggests that it can be more serious and long lasting. Research on the Black Saturday fires, for instance, found that mental health effects ($1 billion) exceeded the lifetime cost of deaths and injuries ($930 million).

But there are many gaps in our understanding of how natural disasters affect mental health. So far, the attention has been on short-term mental health needs of people directly affected by the fires.

After this summer’s fires, the federal government announced $76 million in funding for counselling and psychological services for people on the fire fronts, for bushfire trauma response coordinators, for emergency services workers and their families, and for youth mental health.

This funding expires in December 2021, though, and ANU’s Iain Walker warns that chronic and delayed mental health effects might not be visible for some time and could persist for years. He has been funded by the Medical Research Future Fund to examine these effects around Canberra and on the southern NSW coast.

“This is a neglected area of research,” he says. “There is some background research on how people respond to disasters more generally but still many gaps in our understanding of the specific impact of bushfires in an Australian context.” His research is looking at the range of psychological responses, including anxiety, depression and post‐traumatic stress disorder, and at the indirect mental health effects of the loss of possessions and property, damage to the environment and the sense of belonging to physical environment and associated changes in jobs.

The Australian Academy of Health and Medical Sciences agrees that mental health effects can emerge at any time and last for years. In its submission to the current royal commission it cites studies of the effects of the Black Saturday fires in 2009, which showed that one in five individuals in affected regions still had some form of psychological disorder five years later. The academy also found an increase in domestic violence in highly bushfire-affected communities. It warns that the twin stresses of Covid‐19 and the bushfires could exacerbate mental health problems.

Iain Walker highlights the vulnerability of healthcare workers, including first responders, who are not only affected by the bushfires themselves but also responsible for caring for others. “If a doctor or mental health worker is unable to work because of the impact of the crisis on themselves and their family then the whole system will fall over,” he says.

Specific population groups and communities were experienced more severe smoke-induced symptoms during last summer’s bushfires. They included people with pre-existing health conditions, elderly people, pregnant women, children, and people preparing to undergo surgery or anaesthesia.

We need to know more about the relative effectiveness of a range of strategies by making sure masks are used if and when appropriate, for example, by reducing the heat load in houses and public spaces, and checking indoor air purifiers and filters more frequently.

Respiratory specialist John Wilson’s message to government and health authorities is to pay more attention to pollution warnings and invest in targeted information campaigns informing people at risk about to reduce exposure and the importance of continuing to take medication, access routine treatment and seek early help.

Wilson also highlights the role that telehealth can play. “We have developed telehealth capacity as a result of Covid-19,” he says, “and we should continue to use this to protect vulnerable patients from infection and air pollution and reduce impact on emergency departments.”

People on low incomes are disproportionately affected by air pollution, says Clare Walter, not least because of their housing. “Australian houses are often not well insulated,” she says, “and even those with air conditioning often pull in air from outside if they don’t have a filter. People living in rented properties often can do little to improve the insulation of their houses and this can compound the existing risks associated with their higher rates of chronic disease.”

Walter recommends creating community-based “clean air shelters” to provide a safe environment for people during periods of high pollution. She also stresses the importance of ensuring clean air in childcare centres, residential aged care and other spaces occupied by vulnerable people.

Aboriginal and Torres Strait Islander people — with their higher rates of chronic disease and, in many cases, closer proximity to bushfire-prone areas — are also disproportionately affected by particulates and the loss of cultural resources during bushfires and other natural disasters.

But Indigenous communities can also be a source of knowledge and strength in combatting the adverse effects of bushfires. Their cultural and historical knowledge of land management and bushfire prevention practices can play a central role in bushfire prevention strategies, and non-Indigenous Australians can learn how cultural knowledge, values and practices assist Aboriginal and Torres Strait Islander peoples in dealing with environmental adversity.

And, of course, people living outside cities are often at the frontline of bushfire-related harms. These communities have received short-term assistance to deal with the immediate impact of the fires, but there are concerns that attention has now moved to Covid-19. “Workforce planning needs to take place to ensure that not only are health professionals brought into affected communities, but that they stay there for enough time to properly respond to the health issues caused by the bushfires,” says the National Rural Health Alliance in its submission to the bushfires royal commission.

Perhaps the group most exposed to risk are prisoners in jails near fire-prone areas. The NSW government was criticised for not moving prisoners in the Lithgow Correctional Centre, 140 kilometres northwest of Sydney, when a nearby bushfire caused surrounding houses and building to be evacuated. Around a quarter of the inmates in the prison identify as Aboriginal and Torres Strait Islanders, many of whom would have been more vulnerable to the effects of smoke because of their poorer health status.

The arrival of Covid-19 at the tail end of the bushfire season is a stark reminder of the many ways in which climate change can threaten health and well-being. It highlights the need for a comprehensive and nationally coordinated approach to dealing with the health impacts of global warming.

As Australia prepares for another bushfire season, which could start as soon as late August, we have a chance to use the lessons of summer 2019–to reduce the risk of harm from bushfires and other extreme weather events. •

The publication of this article was supported by a grant from the Judith Neilson Institute for Journalism and Ideas.