Lead,cadmium, arsenic and zinc in the ecosystem surrounding a lead smelter

A lead smelter has been operating at Belledune in the province of New Brunswick, in eastern Canada, since 1966. This paper presents data on the concentrations of the four primary metals emitted from the smelter — lead, cadmium, arsenic and zinc — which were measured in the terrestrial environment near the smelter and the concentrate transport route. Deposition of these metals to the snowpack and the uptake by grass forage are discussed in relation to non-regulatory guidelines, toxicity and atmospheric emissions. A 1992 snowpack transect survey extending 0.5–40 km northwest, southeast and south of the smelter revealed lead concentrations of 2–3193 ppb, cadmium <0.10–49.7 ppb, arsenic <3.0–72.0 ppb, and zinc 3–401 ppb. Deposition estimates within this zone for lead were between 0.046 and 20.1 kg/ha/yr, cadmium <0.007 and 313 g/ha/yr, arsenic <0.016 and 453 g/ha/yr and zinc 0.020 and 2.52 kg/ha/yr. Concentrations of these metals in the snowpack were highest within 3 km of the smelter and were detectable at greater distances SE of the smelter. Lead was dispersed greater distances from the smelter than cadmium or arsenic. Snowpack samples collected within 5–20 m of the railway contained 140–7270 ppb of lead, 0.4–36.9 ppb of cadmium, <3.0–72.0 ppb of arsenic and 41–13100 ppb of zinc. Grass forage sampled within 0.6–16 km of the smelter contained lead 5–152 ppm, cadmium 0.10–4.1 ppm, and zinc 22–154 ppm. Highest concentrations of lead, cadmium and zinc in grass forage were found were found within 2.2 km of the smelter. Grass forage collected within 10–70 m of the railway contained lead 13–288 ppm, cadmium 0.4–1.3 ppm and zinc 98–831 ppm.     

Elevated concentrations of primordial radionuclides in sediments from the Reedy River and surrounding creeks in Simpsonville, South Carolina

A gamma-ray survey and analysis of 16 riverbed samples from the Reedy River watershed near Simpsonville, SC were conducted and compared with national and international studies of primordial radionuclides. The study reported here follows on a recent discovery of anomalously high uranium concentrations in several private well waters in the area. An HPGe spectrometer was used for quantification of gamma emitting radionuclides in the sediments. All sediments contained radionuclides from the uranium and thorium series as well as (40)K. Uranium-238 concentrations in sediment samples ranged from 11.1 to 74.2Bqkg(-1). The measured radionuclide concentrations were compared with data from UNSCEAR and NURE reports. The river and stream sediment data were augmented by in situ NaI(Tl) gamma-ray spectrometer measurements. Comparisons between the ex situ and in situ measurements indicate equivalently distributed uranium in the surface soils and stream sediments, the source of which is likely attributed to the monazite belts that are known to exist in the area.     

Rail ruminations for process safety improvement

Process safety practices have undergone multiple refinements over the past few decades, but major accidents continue to occur. Most organizations strive to improve performance by strengthening existing methods or by adopting new and/or different approaches. Central to these continual improvement efforts is the practice of applying lessons learned as a means to drive out potential risk exposures. Often, lessons learned may be transferred from other industries; indeed, high-performing organizations regularly benchmark practices outside of their immediate industry.In pursuit of continual process safety improvement, this paper examines risk management practices in the Rail Industry, and explores how methods intended for managing passenger and public rail safety may be transferred to drive continual improvement of process safety. Rail safety has its roots in engineered safety solutions; modern practices have additionally embraced the human aspects of safety performance. A selection of approaches for rail safety assessment and risk management are described in three areas considered fundamental to safety management: management of systems, management of technology, and management of human elements. In light of these examples, the authors provide views regarding how the field of process safety management may leverage the rail experience.     

Determining the native/non-native status of newly discovered terrestrial and freshwater species in Antarctica - current knowledge, methodology and management action

Continental Antarctic terrestrial and freshwater environments currently have few established non-native species compared to the sub-Antarctic islands and other terrestrial ecosystems on Earth. This is due to a unique combination of factors including Antarctica's remoteness, harsh climate, physical geography and brief history of human activity. However, recent increases in national operator and tourism activities increase the risk of non-native propagules reaching Antarctica, while climate change may make successful establishment more likely. The frequency and probability of human-assisted transfer mechanisms appear to far outweigh those of natural propagule introductions by wind, water, birds and marine mammals. A dilemma for scientists and environmental managers, which is exacerbated by a poor baseline knowledge of Antarctic biodiversity, is how to determine the native/non-native status of a newly discovered species which could be (a) a previously undiscovered long-term native species, (b) a recent natural colonist or (c) a human-mediated introduction. A correct diagnosis is crucial as the Protocol on Environmental Protection to the Antarctic Treaty dictates dramatically different management responses depending on native/non-native status: native species and recent natural colonists should be protected and conserved, while non-native introductions should be eradicated or controlled. We review current knowledge on how available evidence should be used to differentiate between native and non-native species, and discuss and recommend issues that should be considered by scientists and managers upon discovery of a species apparently new to the Antarctic region.     

Dose assessment for marine biota and humans from discharge of (131)I to the marine environment and uptake by algae in Sydney, Australia

Iodine-131 reaches the marine environment through its excretion to the sewer by nuclear medicine patients followed by discharge through coastal and deepwater outfalls. ¹³¹I has been detected in macroalgae, which bio-accumulate iodine, growing near the coastal outfall of Cronulla sewage treatment plant (STP) since 1995. During this study, ¹³¹I levels in liquid effluent and sludge from three Sydney STPs as well as in macroalgae (Ulva sp. and Ecklonia radiata) growing near their shoreline outfalls were measured. Concentration factors of 176 for Ulva sp. and 526 for E. radiata were derived. Radiation dose rates to marine biota from ¹³¹I discharged to coastal waters calculated using the ERICA dose assessment tool were below the ERICA screening level of 10 μGy/hr. Radiation dose rates to humans from immersion in seawater or consumption of Ulva sp. containing ¹³¹I were three and two orders of magnitude below the IAEA screening level of 10 μSv/year, respectively.     

Movement of a tritium plume in shallow groundwater at a legacy low-level radioactive waste disposal site in eastern Australia

Between 1960 and 1968 low-level radioactive waste was buried in a series of shallow trenches near the Lucas Heights facility, south of Sydney, Australia. Groundwater monitoring carried out since the mid 1970s indicates that with the exception of tritium, no radioactivity above typical background levels has been detected outside the immediate vicinity of the trenches. The maximum tritium level detected in groundwater was 390 kBq/L and the median value was 5400 Bq/L, decay corrected to the time of disposal. Since 1968, a plume of tritiated water has migrated from the disposal trenches and extends at least 100 m from the source area. Tritium in rainfall is negligible, however leachate from an adjacent landfill represents a significant additional tritium source. Study data indicate variation in concentration levels and plume distribution in response to wet and dry climatic periods and have been used to determine pathways for tritium migration through the subsurface.