Reproduction and distribution of the invasive European fanworm Sabella spallanzanii (Polychaeta: Sabellidae) in Port Phillip Bay, Victoria, Australia

 The European fanworm Sabella spallanzanii (Gmelin, 1791) was recently introduced to Port Phillip Bay and is now a conspicuous component of most benthic communities. Reproduction of the worm was investigated in a population at Queenscliff over a 2 yr period (October 1995 to October 1997) using gonadal histology. The worms are dioecious (sex ratio 1:1, n=250), and attained sexual maturity at ∼50 mm body length. Reproductive periodicity followed a distinct annual cycle, and spawning proceeded through an extended autumn/winter period. Spawning was broadly synchronous between sexes, and coincided with falling seawater temperatures and shorter day-lengths. The females were highly fecund, and >50 000 eggs were probably shed from large females (>300 mm body length) during the annual spawning period. Breeding cycles of S. spallanzanii in Port Phillip Bay are ∼6 mo out of phase with endemic populations located at similar latitudes in the northern hemisphere. The spread of S. spallanzanii within Port Phillip Bay has been monitored by divers on an annual basis since 1994. The most recent dive survey (1998) indicates that S. spallanzanii has extended its range through out the entire 2000 km² embayment, and has invaded most subtidal habitats. Quantitative estimates of S. spallanzanii abundances were highest on pier pylons (12.5 individuals m⁻², 0.5 to 7 m depths). On sediments, estimates were highest at shallow sites (0.3 m⁻², 7 m depth), but numbers declined significantly with depth (0.1 m⁻², 17 to 22 m depth). Mean worm lengths and biomass were, by contrast, significantly higher at intermediate depths (12 to 17 m) than in shallower (7 m) or deeper (22 m) locations. S. spallanzanii demonstrates a clear preference for growth in sheltered, nutrient-enriched waters, so it may not spread from Port Phillip Bay into the adjacent oceanic waters of Bass Strait; however, in view of S. spallanzanii's current high abundance, fecundity and extended spawning periodicity, there is a high risk of future range expansions, mediated by shipping, into other temperate-water ports. Received: 17 November 1998 / Accepted: 6 January 2000     

Characterisation and source apportionment of fine particulate sources at Hanoi from 2001 to 2008

PM_2.5 particulate matter has been collected on Teflon filters every Sunday and Wednesday at Hanoi, Vietnam for nearly eight years from April 2001 to December 2008. These filters have been analysed for over 21 different chemical species from hydrogen to lead by ion beam analysis techniques. This is the first long term PM_2.5 dataset for this region. The average PM_2.5 mass for the study period was (54 ± 33) μg m^?3, well above the current US EPA health goal of 15 μg m^?3. The average PM_2.5 composition was found to be (29 ± 8)% ammonium sulfate, (8.9 ± 3.3)% soil, (28 ± 11)% organic matter, (0.6 ± 1.4)% salt and (9.2 ± 2.8)% black carbon. The remaining missing mass (25%) was mainly nitrates and absorbed water. Positive matrix factorisation techniques identified the major source contributions to the fine mass as automobiles and transport (40 ± 10)%, windblown soil (3.4 ± 2)%, secondary sulfates (7.8 ± 10)%, smoke from biomass burning (13 ± 6)%, ferrous and cement industries (19 ± 8)%, and coal combustion (17 ± 7)% during the 8 year study period.     

Trace metal content in inhalable particulate matter (PM<Subscript>2.5–10</Subscript> and PM<Subscript>2.5</Subscript>) collected from historical mine waste deposits using a laboratory-based approach

Mine wastes and tailings are considered hazardous to human health because of their potential to generate large quantities of highly toxic emissions of particulate matter (PM). Human exposure to As and other trace metals in PM may occur via inhalation of airborne particulates or through ingestion of contaminated dust. This study describes a laboratory-based method for extracting PM_2.5–10 (coarse) and PM_2.5 (fine) particles from As-rich mine waste samples collected from an historical gold mining region in regional, Victoria, Australia. We also report on the trace metal and metalloid content of the coarse and fine fraction, with an emphasis on As as an element of potential concern. Laser diffraction analysis showed that the proportions of coarse and fine particles in the bulk samples ranged between 3.4–26.6 and 0.6–7.6 %, respectively. Arsenic concentrations were greater in the fine fraction (1680–26,100 mg kg^?1) compared with the coarse fraction (1210–22,000 mg kg^?1), and Co, Fe, Mn, Ni, Sb and Zn were found to be present in the fine fraction at levels around twice those occurring in the coarse. These results are of particular concern given that fine particles can accumulate in the human respiratory system. Our study demonstrates that mine wastes may be an important source of metal-enriched PM for mining communities.     

The Selenga River delta: a geochemical barrier protecting Lake Baikal waters

Regional Environmental Change - The protection of Lake Baikal and the planning of water management measures in the Selenga River Basin require a comprehensive understanding of the current state and...     

The Validation of a Passive Sampler for Indoor and Outdoor Concentrations of Volatile Organic Compounds

Abstract

Volatile organlcs compounds (VOCs) are ubiquitous in the air we breathe. The use of passive samplers to measure these concentrations can be an effective technique. When exposed for long durations, a passive sampler may be a good tool for investigating chronic exposures to chemicals in the environment. A passive sampler that was designed for occupational exposures can be used as such a tool. Laboratory validation under as many conditions as possible needs to be accomplished so as to characterize the sampler with known parameters. This paper describes the methods and results of an investigation into the validity of using a passive monitor to sample VOCs for a three-week period. Two concentration levels, two relative humidities, and five VOCs were studied. Results indicate that the samplers work best under conditions of high concentration with low relative humidity and low concentration with high relative humidity. For the passive sampler, excluding chloroform, percent deviations from the predicted values varied between ?41 and +22 percent; while the values between the passive and the active samplers varied between ?27 and +24 percent. Benzene, heptane, and perchloroethylene were sampled with equal precision and accuracy.     

Net Waste Reduction Analysis Applied to Air Pollution Control Technologies

Post-combustion air pollution control technologies were evaluated to determine total waste produced by the operation of these systems. A continuum of air pollution control technology choices providing increasing levels of control is presented and the quantity of waste produced by each air pollution control option has been calculated. In addition, this analysis accounts for waste produced indirectly by the generation of energy required for operation of the control technologies. This type of analysis can be used to select optimal control levels and to demonstrate why a goal of zero air emissions may not be environmentally desirable.     

Neutralization of an extremely acidic sludge and stabilization of heavy metals in flyash aggregates

An extremely acidic, heavy metal-rich sludge (pH=-1.2) was scrubbed with a Class-F fly ash in order to simultaneously neutralize the acidity and stabilize the heavy metals contained in both wastes. This paper outlines the leaching behavior of the aggregate material generated by scrubbing. For proper fly ash/sludge ratios, the fly ash acted as an outstanding neutralizer for the acidic waste. Leaching of heavy metals from the aggregate samples was below the environmental limits within a pH range between 3 and 9. Subsequent washing of the leached aggregate with acidic CALWET solutions did not result in an additional release of heavy metals. It is proposed that coordinative bonding of the metal cations onto neutral surface sites and electrostatic adsorption led to stabilization of the heavy metals within the aggregate structure below hydrolysis pHs.