National parks worldwideare worthabout $8.7 trillion($US6 trillion)a yearin the improved mental health of their visitors, according to initial estimates published by a team of Griffith University researchers.

Griffithecologists, psychologists and economistsled the peer-reviewed Perspective ‘Economic value of protected areas via visitor mental health’, which has been published in the prestigious journalNature Communications.

The Perspective study was jointlyfundedby Griffith University, Queensland Parks and Wildlife Service and Parks Victoria.

The team included Professor Ralf Buckley, Professor Paula Brough, Professor Chris Fleming, Associate Professor Neil Harris, Dr Ali Chauvenet, Leah Hague, Elisha Roche and Dr ErnestaSofijafrom across Griffith’s School of Environment and Science, Centre for WorkOrganisationand Wellbeing,Environmental Futures Research Institute,Griffith Business School and School of Medicine.

Using a concept called quality-adjusted life years, which measureda person’s ability to carry out the activities of daily life free from pain and mental disturbance, theresearchers estimated the economic value of national parks using data collected from a representative sample of the Australian population in the states of Queensland and Victoria (19,674).

They used these data to estimate the value for the whole of Australia andglobally andfound a direct link between visits to protected areas and individual mental health.

For Australia, the team estimated theannualhealth services value of Australia’s national parks was around $145 billion($US100 billion)a year.

“The article suggests several ways to calculate health services value, and these numbers are from just one of those methods– now we need to extend that research to other methods and other countries,”Professor Buckley said.

“Protected areas are there for conservation, which gives us aliveableplanet and underpins our entire economy, but conservation is not very powerful politically. People and politicians pay more attention to health, because it affects them personally.”

“This value alreadyexists,it just was notrecognised. People already visit parks to recover from stress. In healthcare terms, it’s patient-funded therapy. Without parks, costs of poor mental health in Australia would rise by$145billion a year.”

Currently, the costs of poor mental health in Australia amount to approximately 10% of GDP, and the researchers’ estimates indicate that these costs could be7.5% higher without protected areas such as national parks.

The economic costs of poor mental health include treatment, care and reduced workplace productivityand affect individuals, families, employers, insurers and taxpayers.

The health-related benefits of spending time in nature are thought to include improved attention, cognition, sleep and stress recovery, but the economic value of national parks is in terms of their impact on the mental health of their visitorshas been previouslyunknown.

“The next step will be to test how mental health benefits depend on individual personalities, and on particular aspects of park visits,” Dr Chauvenet said.

“It’s possible that park visits could then become a routine part of the healthcare system, prescribed by doctors and funded by insurers.

“From a park management perspective, it means that maximum economic return to government treasuriesmay befrom investing in low-key hiking tracks, lookouts, and other visitor facilities, to attract people to visit with their children as often as possible.”

Theteam stated thefindingswerebased on calculations from pilot studies and more detailed analysiswouldberequired to refine the estimates.