ANSTO :: Browsing by Author "Corry, M"

Browsing by Author "Corry, M"

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Functional role of the soft coral Dendronephthya australis in the benthic food web of temperate estuaries
(Inter-Research, 2018-04-12) Corry, M; Haristi, D; Gaston, T; Mazumder, D; Cresswell, T; Moltschaniwskyj, N
The soft coral Dendronephthya australis, with its limited distribution along the central New South Wales (NSW) coastline, forms a habitat within the benthic estuarine environment that supports commercially significant and protected marine species. However, the functional role of the soft coral within this system is unknown. Organisms from primary producers through to secondary consumers were sampled from soft coral and sponge habitats inside the Port Stephens estuary, NSW, Australia in 2014. A food web model of the benthic habitat, created using stable isotopes of carbon and nitrogen, was used to describe the functional role of the soft coral in comparison to sponges, another important habitat for commercially significant and protected marine species. Primary consumers accessed a range of benthic and pelagic energy sources; however, secondary consumers were almost entirely dependent on pelagic energy sources. Soft coral and sponges accessed different primary sources for their energy requirements. There was no evidence that D. australis was used as a direct food source by consumers other than nudibranchs. In contrast, sponges were trophically linked with secondary consumers and are likely to play a direct role in pelagic energy transfer. Amphipods collected from the branches of D. australis were identified as major prey components in the diet of protected syngnathids, suggesting that while the soft coral functions as critical habitat, it is indirectly linked to higher trophic levels. © 2018 Inter-Research
Investigating the kinetics of Cd transport between internal organs of the freshwater decapod Macrobrachium australiense
(SETAC, 2014-09-14) Cresswell, T; Simpson, SL; Mazumder, D; Callaghan, PD; Nguyen, AP; Corry, M
The bioaccumulation of metals by aquatic organisms can be studied in great detail using radiotracers, allowing insights into rates of uptake and fate of the metals accumulated in tissues. While there have been numerous studies on the whole-body bioaccumulation of metals by organisms, little is known about the kinetics of organ-specific bioaccumulation. This study used the radioisotope 109Cd to explore the internal uptake kinetics of this non-essential metal following accumulation from solution by the freshwater decapod crustacean Macrobrachium australiense. The first stage of the study involved exposing 24 organisms for up to 2 weeks to 0.55 µg Cd/L in synthetic river water with three individuals being removed at pre-defined time points. Following exposure, animals were rinsed in a 0.1 mM EDTA solution to remove any loosely-bound metal, rapidly frozen and the anatomical distribution of the radionuclide visualised from fresh frozen sections (20 um) using autoradiography. The second phase of the study consisted of exposing organisms to the same radiotracer solution for a short period (6 h) and long period (7 d), followed by depuration in metal- and isotope-free water for up to 3 weeks. Organisms were removed from depuration at pre-defined time points, rapidly frozen, the anatomical distribution of the radionuclide determined as above. Preliminary results suggest that the gills appeared to saturate after 7 d exposure, with negligible increase over another 7 d of exposure. However, the ratio of Cd between the hepatopancreas and gills increased over time, suggesting the organism was actively processing accumulated metal. Rates of accumulation into different internal compartments in response to changes in uptake and depuration durations will be discussed. The findings of the study provide new information on the processing of a non-essential metal by M. australiense and could potentially be used to estimate the exposure history of field-caught organisms.
Metal transfer among organs following short- and long-term exposures using autoradiography: cadmium bioaccumulation by the freshwater prawn macrobrachium australiense
(American Chemical Society, 2017-03-16) Cresswell, T; Mazumder, D; Callaghan, PD; Nguyen, AP; Corry, M; Simpson, SL
The uptake, depuration, and organ distribution of the radioisotope 109Cd were used to explore the internal kinetics of this nonessential metal following accumulation from waterborne cadmium by the freshwater decapod crustacean Macrobrachium australiense. Short- (6 h) and long-term (7 to 14 days) exposures to the radioisotope in solutions of 0.56 μg Cd/L were followed by depuration in metal- and isotope-free water for up to 21 days. The anatomical distribution of the radionuclide was visualized using autoradiography at predefined time points. The gills did not become saturated with cadmium after 14 days of exposure and demonstrated a greater rate of cadmium uptake relative to the hepatopancreas. Cadmium concentrations decreased rapidly during depuration from both gills and hepatopancreas after short exposures but slowly following long-term exposures. This suggests that the duration of cadmium exposure influences the depuration rate for this organism. The study demonstrates the complex behavior of cadmium accumulated by M. australiense and improves our understanding of how exposure duration will influence the internal location and potential toxicity of metals. © 2017 American Chemical Society
Radioisotope techniques and aquatic ecotoxicology: importance of understanding kinetics and internal location of metals
(University of New South Wales and Australian Nuclear Science and Technology Organisation, 2015-07-08) Cresswell, T; Mazumder, D; Callaghan, PD; Nguyen, AP; Corry, M; Simpson, SL
Aquatic ecotoxicology is primarily concerned with the bioaccumulation and effects of anthropogenic contaminants to a range of biota. Traditional methods of assessing the bioaccumulation of contaminants by an organism have typically relied on destructive techniques, generally involving the dissection of internal organs, followed by acid digestion and analysis. To understand how organisms accumulate contaminants over time using these traditional methods, a large number of organisms was required to be sacrificed. Gamma-emitting metal radioisotopes are valuable tools for studying metal bioaccumulation in aquatic invertebrates, allowing the influx and efflux of multiple metals to be analysed rapidly, at multiple intervals in live organisms during an exposure period (Hervé-Fernández et al., 2010, Cresswell et al., 2015). Furthermore, autoradiography of sacrificed and cryosectioned organisms enables the organ distribution of accumulated metals to be visualised and quantified. To cryosection, organisms are snap-frozen to limit the mobilisation of chemical species, preserve the integrity of the organs and allow much higher resolution of organ-specific metal analysis compared to tradition dissection-digestion techniques. This paper describes two studies on a freshwater decapod crustacean that examined the kinetics of non-essential (cadmium) and essential (zinc) metal accumulation in a mixture, and the kinetics of internal partitioning of cadmium among major organs using radioisotope techniques to model environmental conditions.
Radionuclide uptake in vegetables & herbs cultivated within the ANSTO Buffer Zone
(South Pacific Environmental Radioactivity Association, 2018-11-06) Gedz, A; Loosz, T; Corry, M; Hoffmann, EL
The Australian Nuclear Science and Technology Organisation (ANSTO) operates the production OPAL research reactor for the production of medical radioisotopes, scientific research, and the irradiation of silicon for use in microelectronics and other specialised irradiations for research and industry. During routine operations, small amounts of radionuclides are released through filtered emissions to air and treated liquid effluent discharged to the Sydney Water sewer. Airborne emissions from licenced facilities are bound by regulatory limits for radioactivity set by ARPANSA and are continuously monitored. Analysis of local environmental media provides confirmation as to the radionuclides released. including radioiodines from medical isotope production and low levels of tritium from the OPAL reactor. The effective dose to the local population from ANSTO’s authorised airborne releases is modelled quarterly as meteorology and stack emission data. At less than 5 uSv/year. the maximum potential airborne dose to the pus : residing at the 1.6 km Buffer Zone boundary remains well below the 1 mSv/year dose limit recommended by ARPANSA, As there is no longer any commercial food production within the Buffer Zone, sampling of foodstuffs has not been part of the ANSTO Environmental Monitoring program since the last dairy was closed in the 1980's. However, the construction of a new nuclear medicine facility and a childcare centre at ANSTO, in addition to proposed housing developments in the local community, has highlighted the need for renewed testing of locally-grown foodstuffs. In November 2017 and January 2018, two separate sampling campaigns were conducted at ANSTO as part of a scoping study to investigate potential radionuclide uptake in vegetation cultivated on-site, in particular radioiodine. Following these investigations, a working garden was established to determine seasonal radionuclide uptake in common vegetable and herb varieties, and to assess the potential dose from consumption of this produce. Results will be presented from gamma spectrometry analysis conducted to date, as well as a short discussion on the methodology and challenges associated with quantifying the radionuclides of interest and determining detection limits. The World Health Organisation General Standard for Contaminants and Toxins in Food and Feed (CODEX STAN 193-1995) will be applied for the calculation of potential dose associated with the ingestion of vegetables and herbs containing radioactivity.
Screening assessment of dose rates to local wildlife from ANSTO's radiological effluent releases
(South Pacific Environmental Radioactivity Association, 2018-11-06) Corry, M; Johansen, MP; Loosz, T
A screening assessment was undertaken to investigate the potential dose rates received by local wildlife from radiological effluent releases associated with operations at the Australian Nuclear Science and Technology Organisation (ANSTO) Lucas Heights site in Sydney, NSW. The expected releases from the planned ANSTO Nuclear Medicine Mo-99 production facility were also considered. The assessment applied the methodology laid out in ARPANSA Guide: Radiation Protection of the Environment, which is consistent with current best practice approaches set forth by the international Commission on Radiological Protection and the International Atomic Energy Agency. A range of terrestrial organisms that occur in the bushland perimeter surrounding the Lucas Heights site were selected for assessment because of their potential exposure to ANSTO’s stack emissions - considered the air pathway. A range of marine organisms known to reside close to the outlet (where tertiary-treated sewage from the Sutherland Shire, including ANSTO, is discharged to the ocean) were assessed because of their potential exposure to liquid effluent discharges - considered the water pathway. Dose assessments were performed using the ERlCA tool using radioactivity concentrations for air and water determined from data collected during routine monitoring of ANSTO stack emissions and liquid effluent releases to sewer. Concentration values along the air and water pathways were overestimated, consistent with the decision to use conservative assumptions for this screening assessment. The analysis was unusual in that it considered dose from noble gas isotopes. For the air pathway, the largest predicted dose contribution was from xenon isotopes, followed by tritium. For the water pathway, it was found that the proportion of potential dose from ANSTO discharges was very small compared with those from local medical facilities. Even using a very conservative approach, the potential risk quotients for all organisms were below standard benchmark levels (Garnier-Laplace, J. et al., issues and practices in the use of effects data from FREDERICA in the ERICA integrated Approach; J. Environ. Radioact. 2008, 99 (9), 1474-1483). Dose rates to all organisms were below the lowest benchmark for potential harmful effects (10 uGy hr1). These results were consistent with previous studies that concluded no significant impacts to wildlife from ANSTO’s operations. Therefore, potential radioactivity releases from the planned ANM facility are unlikely to impact local wildlife.
Screening assessment of dose rates to wildlife related to the nuclear medicine Mo99 facility
(Australian Nuclear Science and Technology Organisation, 2017-04-27) Johansen, MP; Corry, M
ANSTO has performed a screening assessment on potential dose rates to environmental receptors (wildlife) associated with the planned ANSTO Nuclear Medicine (ANM) Mo99 Facility. The ANM facility will be located on the 50 hectare ANSTO Lucas Heights site, which is surrounded by a 1.6 km radius buffer zone owned by the Commonwealth or its Agencies. The buffer zone is used by humans for recreational purposes and is home to a range of plant and animal wildlife. During its routine operations in producing medical isotopes and performing research, ANSTO releases small amounts of radionuclides through stack emissions and, after testing, through liquid discharges to the public sewer system. The purpose of this assessment is to use a standard screening approach to determine if potential dose rates to local wildlife from future releases, including the ANM Mo99 Facility, are below international benchmarks. The assessment used methods from international best practice as laid out by the ARPANSA Guide: Radiation Protection of the Environment, which is consistent with current approaches set forth by the International Commission on Radiological Protection (ICRP) and the International Atomic Energy Agency (IAEA). The screening evaluations considered exposure to a range of terrestrial organisms in the buffer zone from stack emissions via the air pathway, and, to a range of marine organisms near the ocean outlet at Potter Point, New South Wales via the liquid effluent pathway. Dose assessments were performed using the ERICA tool with radioactivity concentrations for air and water determined from data collected during routine monitoring of stack emissions and effluent releases at ANSTO. Concentration values along air and water pathways were overestimated, consistent with an approach of using conservative assumptions in this screening assessment. In summary, despite using overestimates for radioactivity concentrations associated with ANSTO’s emissions, results indicate potential risk quotients that are below standard benchmarks for all organisms and all pathways considered. Dose rates to organisms were determined to be below the lowest benchmark for potential harmful effects (10 μGy hr-1). These results are consistent with previous studies in determining no significant impacts from ANSTO effluents. Therefore, potential radioactivity releases from the ANM Facility are unlikely to impact local wildlife. Although projected dose rates are low, the release of low levels of radionuclides in air and water discharges indicates the need for ongoing monitoring and periodic re-evaluation.
To fish or not to fish: stable isotopes uncover the functional role of soft coral in temperate estuaries
(University of New South Wales and Australian Nuclear Science and Technology Organisation, 2015-07-09) Corry, M; Moltschaniwskyj, N; Mazumder, D; Gaston, T; Cresswell, T; Harsati, D
Not supplied to ANSTO Library.
Wildlife dose assessment to determine the impact of radiological releases on local flora and fauna at a nuclear facility in Australia.
(Norwegian Radiation and Nuclear Safety Authority (DSA), 2022-09-09) Corry, M
Not available

Browsing by Author "Corry, M"

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