Persistent chemicals in Tasmanian devils

The \u27Save the Tasmanian Devil Program\u27 of the Tasmanian Government commissioned an independent review of a small study of chemical residues in 23 devils affected with Devil Facial Tumour Disease (DFTD) and 22 unaffected devils. Depending on cost and sample size chemicals were measured in either 8 or 16 DFTD +ve and DFTD –ve animals. A range of persistent chemicals were measured. Most animals had detectable residues in their fat or liver of: dioxins, dibenzofurans, PCBs, brominated diphenyl ethers, arsenic, cadmium and lead. No residues were found for 1080 (sodium fluoroacetate). 2 of 32 had DDE. 1 had mercury. No detectable residues were found for a further 27 herbicides and pesticides. Little is known of persistent chemical levels in devils. However residues of these chemicals are expected in most humans, terrestrial animals, birds and fish. Most accumulate in the food chain and are at their highest levels in animals at the top of the food chain such as humans, birds of prey and carnivores such as the Tasmanian devil. The ranges and concentrations of the chemicals in devils are similar to those found in top-of-the-food-chain species. There were no significant differences between chemicals in DFTD +ve and DFTD –ve animals. A small number of chemicals may warrant further investigation including arsenic and some of the brominated diphenyl ethers. The results will be of interest to scientists involved in human health and ecological risk assessments of animals. However they do not show a link between chemicals and DFTD. This report Dr Tony Ross, a specialist veterinary pathologist, was one of two commissioned by Save the Tasmanian Devil. The other is Opinion on a chemical aetiology for facial tumor development in the Tasmanian Devil by Professor Michael Moore, the Director of the National Research Centre for Environmental Toxicolog