Dr Ralph Cobcroft will speak on the use of human excreta as fertiliser, exploring its value, safety and ecological benefits. His main career was as Director of Haematology at the Princess Alexandra Hospital for 25 years. Following retirement, he was actively involved with the conservation movement having been a council member of the Australian Conservation Foundation.

For the past four years he has been a tutor and lecturer with the School of Medicine, University of Queensland. A major interest has been in ecologically sustainable food production and diets that are good for maintaining health as well as being gentle on the environment.

His web site, www.eateco.org contains an extensive review of this subject with analysis from an expert medical point of view. He has investigated many aspects of urban sustainability and has, among other initiatives such as solar power and storm water harvesting, been using human urine to promote production in his garden.