THE FIRST public report that the Tasmanian Government was intending to test for toxins, synthetic chemicals & pollutants in Tasmanian devils was reported three years ago in January 2005 [The Mercury newspaper 24 Jan; Pilot trial to test for toxins - Devil in danger]. It was noted that a pilot survey to test the range of potentially damaging chemicals to which wild devils might be environmentally exposed was being drawn up and reviewed. Up to 20 specific poisons, persistent organic pollutants, environmental contaminants and heavy metals were under consideration.
Without any publicity in July 2005 a Commonwealth Government toxicological study reported that 8 randomly sampled wild Tasmanian devils had to detectable levels of a new group of persistent organic pollutants, the polybrominated biphenyl ethers (PBDEs). At the time the toxicologist in charge of the Commonwealth Government’s organic pollutants analysis unit, Dr Bob Symons said they hadn’t expected the findings in the devils to be so high. “It was a complete surprise to us. We always thought Tasmania was a pretty pristine place, but a result like this shows how far these chemicals can reach and how quickly they can build up in the environment.” Of somewhat more interest perhaps was the high levels found in a small sampling of Tasmanian farmed salmonids. Three fillet samples of sea-cage Tasmanian Atlantic salmon (11-34 ppb) and in one fillet from a farmed Rainbow Trout (8 ppb) (Organohalogen Compounds 2004). The levels reported to be double the highest PBDEs residue levels detected in a recent study of Great Lakes salmon in North America.
The Tasmanian Government engaged with the preliminary review of the scope & budget of this toxicological review in late 2005. According to the FOI document’s the first tender-costing was provided by National Measurements Institute in December 2005. In October 2005 an important feature article on the Devil Facial Tumour Disease appeared in The Australian Magazine. The journalist, Matthew Denholm quoted senior DPIW veterinary pathologist, Dr Stephen Pyecroft again stating that this pilot toxicological study was to take place.
Despite calls from the Tasmanian Greens parliamentarians to this study to proceed there was no progression in the toxicological study throughout 2006; this was despite the storage hundreds of wild devil samples specifically collected over the previous 3 years for just such an investigation. The priority of the particular field of investigation was identified in numerous public documents and newsletters prepared the Tasmanian government-managed DFTD program.
In November 2007, Matthew Denholm of The Australian newspaper submitted a formal FOI request for the documents relating to the Tasmanian devil toxicology studies; the study first proposed by Dr Stephen Pyecroft in January 2005.
The large dossier of some 160 pages was released under FOI was provided. On 21 January 2008 Dr Steven Smith, the Project Leader of the Save the Tasmanian Devil Project provided at media release on the topic to Matthew Denholm.
At Mr Denholm’s request I reviewed the documents consisting of emails and correspondence preliminary to the chemical selection and sample submission to the selected toxicological laboratories, as well as the raw chemical residue data from the National Measurement Institute (Australian Government Analytical Labs, Pymble, NSW) who analysed residues of Dioxins, PCB congeners, Furans and PBDE congeners in tissue fat samples. The Analytical Services Tasmania (a joint funded UTAS/DPIW analytical facility) was contracted to perform inorganic metal analysis (arsenic, lead, mercury) and the organo-chlorines & metabolites, the organo-phosphates and the triazine herbicides on liver samples. The Queensland Department of Natural Resources Chemistry Laboratory - Alan Fletcher Research Station - undertook the detection of residues of sodium monofluoroacetate [the vertebrate poison -1080] on devil tissue samples.
No toxicological samples appear to have been sent to the above mentioned toxicological labs until May 2007. All raw data results had been received back by September 2007, although no qualitative or comparative assessment of those results appears to have been provided. According the Senior Scientist co-opted to the DFTD Program, a panel of environmental toxicology experts is to be set up to analyse and comment on these results.
Firstly the sample size is small; 16 devils 8 DFTD-affected and 8 non-DFTD affected. Five were selected from locations in central Northern Tasmania (none from the presumed DFDT site of origin in the North-east); 3 from the Central Highlands; 7 from the South-east and only 1 from the far North-West.
The tissue levels of inorganic elements are less than 1ppm. No 1080 residues were detected in any samples. Only one devil showed residues above the analytical detection range for the Organo-chlorine metabolites (Limit of Detection
<0.20 ppb). No triazines (atrazine/simazine) were detected. The absence of detectable residues of triazines, organophosphates & 1080 is not unexpected, given the tendency of these chemical not to accumulate in tissues post exposure. The low concentrations of inorganic heavy metals: arsenic, lead and mercury is encouraging, as is the below detection concentrations or organo-chlorine residues in all but one devil. [Repeat tests at another NATA-accredited toxicology laboratory would of course provide greater confidence in these low residue detections.]
The most significant chemical residue detected were of the synthetic persistent organic pollutants (POPs), namely the poly-chlorinated biphenyls (PCBs), the dioxins, the poly-chlorinated dibenzofurans and polybrominated diphenyl ethers (PBDEs). For the purposes of a quick analysis, I have graphed the detectible POPs for each devil (male and female) aggregated according to geographic region and expressed as the World Health Organisation - Toxic Equivalence for all measured dioxins, furans & PCBs [WHO-TEQDFP] and the sum of all PBDE congeners (ΣPBDEs).
Despite the very sample sampling, it is noteworthy that two devils from the Northern region (Beaconsfield & Deloraine) had the highest recorded ΣPBDE levels - i.e. 55 and 28 ppb in their body fat respectively; another devil from Richmond had 13 ppb of ΣPBDEs. The highest residues for the PCBs, Furans and Dioxins - expressed as WHO-TEQDFP - were found in a devil from Dunalley (15 ppb) whilst two male devils from Marrawah and Dilston each had 8 ppb of these POPs.
Like many top-order predators, Tasmanian Devils have the potential to bioaccumulate over their lifetime certain POPs through carrion feeding. Devils are opportunistic scavengers of any animal carcase; they also would actively predate slow, sick or weakened wildlife, feral animals or domestic animals.
Analysis of the compositional ratios of PBDE & PCB congener profiles from devils may help to identify specific commercially available products that may have been responsible for certain high residue levels in some devils. In addition to the global distribution of these POPs through atmospheric spread and localised precipitation/deposition in cooler middle and higher latitudes, the proportions of the PCB and PBDE congeners may be diagnostically useful in determining whether any specific candidate products from Tasmanian households, land management practices (refuse management; horticulture or forestry activities) or industrial processes can be incriminated in these bioaccumulations.
The presence of these persistent organic pollutants in devil fat tissues in not entirely unexpected. It does highlight the scarcity of wildlife, food and environmental toxicological sampling that has been allowed to take place in Tasmania.[For example in 2003 a global assessment of POPs in farmed salmon was undertaken with samplings from aquaculture industries in North America, South America, Scandinavia and Scotland; no samples were made available from Tasmania.]
A range of POPs including organo-chlorines, PCBs, furans and dioxins have already been detected in fat samples from Tasmanian platypus, another Tasmanian native mammal that is experiencing to unusual disease pathobiology (Platypus Ulcer Disease/Mycomycosis) and from only one sample from a Tasmania Echidna (Reference National Dioxins Program Technical Report No. 7, May 2004). The only other Tasmanian wildlife tested were from stranded whales; no ducks, no trout and no wallabies or possums.
Some PCBs congeners and the dioxins are among the most potent chemical carcinogens known whilst PBDEs are recognised as immunotoxic, affecting nervous system development and potential endocrine disruptors, particularly to the thyroid and reproductive tissues.
The residue concentration of PBDEs in human breast milk (Swedish study) has increased 50-fold over the period 1972 to 1997, with dramatic increases from 1990 onwards (Meironyté et al, 1998). The presence of these POPs in devils, of themselves, is not confirmatory of a causal association with the first spontaneous cases(s) of the spontaneous facial cancer that is now called devil facial tumour disease; however, they represent a disturbing detection none the less. It is noteworthy that the devils in the region where the facial cancer was thought to have begun were not sampled (i.e. far NE Tasmania).
David Obendorf’s analyses for Tasmanian Times: Here
Earlier, The Advocate:
Devil poison fears
By AMBER WILSON
THE State Government has defended its decision to sit on information that could have dire implications not just for Tasmania’s vulnerable devil populations, but for Tasmanians themselves. The State Government released laboratory results on Monday showing no difference in chemical levels between Tasmanian devils with the facial tumour disease, and those that didn’t.
Yet The Australian newspaper yesterday revealed, through data obtained under Freedom of Information, that 16 sampled devils showed very high levels of potentially carcinogenic flame retardants, which could compromise animal immune systems.
Polybrominated Diphenyl Ethers, which could be far more insidious than first thought, are commonly found in carpets and furniture among other household items.
Dr David Obendorf, wildlife veterinarian pathologist, said PBDEs accumulated in the food chain, starting at a micro-organism level - particularly in cooler climates like Tasmania.
He said that meant it might not only compromise the health of devils, but other mammals like humans.
“It’s going to get bigger than just the devil now,” he said.
“People are going to question food quality, food safety.
“It will be put on the national agenda.”
Hamish McCallum, head of the Governments Devil Facial Tumour Disease Program, yesterday admitted it was “conceivable” the chemicals could potentially compromise the devils’ immune system, making transmission of DFTD easier.
Greens Deputy Leader Nick McKim criticised the Government for failing to openly release the “alarming” results.
Primary Industries and Water Minister David Llewellyn was yesterday unavailable for comment, but department spokesperson Warwick Brennan said the Government was unwilling to speculate until expert toxicologists had seen the data.
He denied the Government had acted secretly.
Meanwhile, Mole Creek wildlife park operator Androo Kelly said animal experts had been campaigning on the issue of PBDEs for years.
“For a long time we’ve known about these PBDEs and PBCs and how insidious all these toxins are in the global environment,” he said.
Mr Kelly said the disease seemed to be decreasing, given it was first spotted in 1996, some six devil generations ago.
“I’m optimistic that we’ve seen the worst of the disease in the eastern side of the State.” He said the way research was being done at a government level was often “dubious” and showed an “underlying insidiousness” geared at obtaining funding dollars and “kudos” for career scientists.
David Obendorf Timeline of the toxicology study in Tasmanian devils
A range of POPs including organo-chlorines, PCBs, furans and dioxins have already been detected in fat samples from Tasmanian platypus, another Tasmanian native mammal that is experiencing to unusual disease pathobiology (Platypus Ulcer Disease/Mycomycosis) and from only one sample from a Tasmania Echidna (Reference National Dioxins Program Technical Report No. 7, May 2004).The only other Tasmanian wildlife tested were from stranded whales; no ducks, no trout and no wallabies or possums.