He says "how we use water" is one of the issues needing to be addressed if the environment and in turn all species including humans are to be healthier.

"I think in a prolonged dry period it is an important time to be reflecting on that and thinking are we using the water that we have in the most sensible way," he said.

"For example, is it wise for us to be using a large amount for cotton in Australia or would it be preferable to use that water for growing food where there is potential for greater share value for Australian people?"

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Professor Capon, from the School of Public Health at the University of Sydney, says action is also required on carbon emissions.

"There's no doubt Australia has had cycles of prolonged dry weather, historically," he said.

"But together as a global community we urgently need to be reducing our carbon emissions and I think the science is very clear about that and Australia needs to do more."

The professor, who was born and raised in rural communities in Australia and New Zealand, argues that if the environment is in good shape then people have a better chance of staying well.

"We need to keep our eye on the bigger picture because unhealthy, degraded natural systems ultimately have flow-on impacts for the health of all species," he said.

Professor Capon said the impacts of the current "very long and deep drought" ranged from a rise in the price of fresh food and fish kills in the Murray-Darling Basin to a decline in farmers' incomes and mental health.

"When we think about health on a day-to-day basis we often think about doctors and nurses, healthcare services, hospitals and community healthcentres, and they are really important things," he said.

"We've had remarkable biomedical advances in recent decades and new treatments in areas such as heart disease and cancers."

But the professor said "we wouldn't be alive without natural systems".

"We entirely depend on nature for the food we eat, the water we drink, the air we breath and all the other resources we derive from natural systems."

Professor Capon is coming to Dubbo to speak at the sixth Western NSW Health Research Network conference with the theme of Growing Health Research from the Ground Up.