The hardrock minerals industry and the landscape architect

The landscape architecture profession is a source of creative thinking and planning which is relatively untapped within the mining industry in the United States of America. The landscape architect has been active in European operations for years as indicated by the four examples presented. The landscape architect can provide an important interface with mine design and engineering and environmental affairs. To initiate this interface within the United States, and increase its effectiveness, six objectives are presented and discussed.     

Testing of a sampling system and analytical method for determination of semivolatile organic compounds in ambient air

A sampling system and analytical procedure for determining PCDD/Fs, PCBs, HCB, and PAHs in ambient air was tested. The reproducibility of the concentrations and the gas/particle partitioning was ± 10% for most compounds. The removal of gaseous compounds on the XAD resin trap was greater than 99%. The adsorption of gaseous substances on the glass fiber filter was negligible for compounds primarily found in the gas phase, but could not be ruled out for compounds found mainly on particles.     

Application of a novel modeling tool with multistressor functionality to support management of organic contaminants in the Baltic Sea

Organic contaminants constitute one of many stressors that deteriorate the ecological status of the Baltic Sea. When managing environmental problems in this marine environment, it may be necessary to consider the interactions between various stressors to ensure that averting one problem does not exacerbate another. A novel modeling tool, BALTSEM-POP, is presented here that simulates interactions between climate forcing, hydrodynamic conditions, and water exchange, biogeochemical cycling, and organic contaminant transport and fate in the Baltic Sea. We discuss opportunities to use the model to support different aspects of chemicals management. We exemplify these opportunities with a case study where two emission-reduction strategies for a chemical used in personal care products (decamethylcyclopentasiloxane) are evaluated, and where the confounding influence of future climate change and eutrophication on the impact of the emission-reduction strategies are assessed.     

Identifying source regions for the atmospheric input of PCDD/Fs to the Baltic Sea

PCDD/F contamination of the Baltic Sea has resulted in the European Union imposing restrictions on the marketing of several fish species. Atmospheric deposition is the major source of PCDD/Fs to the Baltic Sea, and hence there is a need to identify the source regions of the PCDD/Fs in ambient air over the Baltic Sea. A novel monitoring strategy was employed to address this question. During the winter of 2006–2007 air samples were collected in Aspvreten (southern Sweden) and Pallas (northern Finland). Short sampling times (24 h) were employed and only samples with stable air mass back trajectories were selected for analysis of the 2,3,7,8-substituted PCDD/F congeners. The range in the PCDD/F concentrations from 40 samples collected at Aspvreten was a factor of almost 50 (range 0.6–29 fg TEQ/m³). When the samples were grouped according to air mass origin into seven compass sectors, the variability was much lower (typically less than a factor of 3). This indicates that air mass origin was the primary source of the variability. The contribution of each sector to the PCDD/F contamination over the Baltic Sea during the winter half year of 2006/2007 was calculated from the average PCDD/F concentration for each sector and the frequency with which the air over the Baltic Sea came from that sector. Air masses originating from the south–southwest, south–southeast and east segments contributed 65% of the PCDDs and 75% of the PCDFs. Strong correlations were obtained between the concentrations of most of the PCDD/F congeners and the concentration of soot. These correlations can be used to predict the PCDD/F concentrations during the winter half year from inexpensive soot measurements.     

Ecology of sandy beaches in Oman

The benthic macrofauna and physical features of 10 sandy beaches along the coast of Oman were surveyed quantitatively. This is a mesotidal regime mostly subject to low to moderate wave energy but more exposed in the south. Five northern beaches are tide-dominated, with low wave energy, and their profiles consist of a berm, a steep, swash-dominated upper shore and a broad tide-dominated terrace from mid-shore downwards. They are composed of moderately sorted fine to medium sands. Southern beaches experience greater wave energy, particularly during the summer southwest monsoon, and exhibit smoother, concave profiles with fine, fairly well sorted carbonate sand. 58 species and species groups were recorded, with crustanceans, polychaetes and molluscs dominant. In general species richness was high, at least 19–25 species per beach, but dry biomass moderate to low at 26–90g/m shoreline, with one high value of 450g/m. Total abundance was moderate at 3–73×10³ organisms/m of beach. Some zonation was evident with ocypodid crabs andTylos in the supralittoral, cirolanid isopods on the upper shore and a variety of species on the lower shore. The coast of Oman appears to constitute a single zoogeographic region, but with some regional differentiation between north and south due to varying physical conditions. Thus, OmanÕs beaches are characterized by tide-dominated morphodynamics and exceptionally high species richness.     

The importance of seed dispersal in the Alexandria Coastal Dunefield, South Africa

The endozoochorous dispersal of seeds by mammals and birds between distinct vegetation communities was assessed to determine the importance of these processes in coastal dune field management. Isolated pockets of thicket vegetation (bush-pockets) within a large coastal dune field provided the opportunity to study vertebrate seed dispersal and its contribution to their origin and maintenance. Mammalian and avian faeces were collected for the quantification of seeds dispersed via endozoochory. Birds and mammals showed considerable overlap, dispersing intact seeds of 17 and 29 plant species, respectively, but mammals dispersed a greater diversity and size range than birds. Extrapolation of mammalian faecal data indicates an annual input of 23 million intact seeds to the dune field. Significantly more seeds are deposited by mammals and birds in the bush-pockets than on open sand, and birds deposited greater numbers of seeds nearer the seed source. Zoochory appears to be critical for the maintenance of the bush-pocket habitats through the dispersal of climax woody plant species into the dune field. Directional dispersal by birds and mammals to the bush-pockets is considered to be responsible for the maintenance and possible origin of these bush-pockets. The high number of exotic plant propagules dispersed by both avian and mammalian zoochory highlights the importance of management of the Alexandria Coastal Dunefield (ACD) beyond the reserve boundaries. In a dynamic system such as the ACD which is within a declared nature reserve, the continued existence of the bush-pockets may depend on the maintenance, beyond the reserve boundaries, of a reservoir of not only plant material but vertebrate dispersers as well.     

In-vivo passive sampling to measure elimination kinetics in bioaccumulation tests

The application of in-tissue passive sampling to quantify chemical kinetics in fish bioconcentration experiments was investigated. A passive sampler consisting of an acupuncture needle covered with a PDMS tube was developed together with a method for its deployment in rainbow trout. The time to steady state for chemical uptake into the passive sampler was >1 d, so it was employed as a kinetically limited sampler with a deployment time of 2 h. The passive sampler was employed in parallel with the established whole tissue extraction method to study the elimination kinetics of 10 diverse chemicals in rainbow trout. 4-n-nonylphenol and 2,4,6-tri-tert-butylphenol were close to or below the limit of quantification in the sampler. For chlorpyrifos, musk xylene, hexachlorobenzene, 2,5-dichlorobiphenyl and p,p′-DDT, the elimination rate constants determined with the passive sampler method and the established method agreed within 18%. Poorer agreement (35%) was observed for 2,3,4-trichloroanisole and p-diisopropylbenzene because fewer data were obtained with the passive sampling method due to its lower sensitivity. The work shows that in-tissue passive sampling can be employed to measure contaminant elimination kinetics in fish. This opens up the possibility of studying contaminant kinetics in individual fish, thereby reducing the fish requirements and analytical costs for the determination of bioconcentration factors.     

Landscape-scale distribution and persistence of genetically modified oilseed rape (<Emphasis Type="Italic">Brassica napus</Emphasis>) in Manitoba,Canada

Background, aim and scope  

Genetically modified herbicide-tolerant (GMHT) oilseed rape (OSR; Brassica napus L.) was approved for commercial cultivation in Canada in 1995 and currently represents over 95% of the OSR grown in western Canada. After a decade of widespread cultivation, GMHT volunteers represent an increasing management problem in cultivated fields and are ubiquitous in adjacent ruderal habitats, where they contribute to the spread of transgenes. However, few studies have considered escaped GMHT OSR populations in North America, and even fewer have been conducted at large spatial scales (i.e. landscape scales). In particular, the contribution of landscape structure and large-scale anthropogenic dispersal processes to the persistence and spread of escaped GMHT OSR remains poorly understood. We conducted a multi-year survey of the landscape-scale distribution of escaped OSR plants adjacent to roads and cultivated fields. Our objective was to examine the long-term dynamics of escaped OSR at large spatial scales and to assess the relative importance of landscape and localised factors to the persistence and spread of these plants outside of cultivation.     

Immersed solid phase microextraction to measure chemical activity of lipophilic organic contaminants in fatty tissue samples

It is known that solid phase microextraction (SPME) fibers can be equilibrated directly within environmental matrices such as water, sediment and soil slurries. Here it is shown that this method can also be applied to biological tissue. SPME extraction of biological matrices reportedly causes lipophilic fouling of the fiber. However, we found no significant measurement bias when combining equilibrium sampling with fiber surface cleaning. The uptake of lipophilic organic pollutants from the tissue and into the SPME fiber coating was characterized by fast equilibrium partitioning without sample depletion and without impacting the sorptive properties of the fiber. The precision of the method when applied to hexachlorobenzene and several PCB congeners in harbor porpoise blubber was 15%, which includes the variation between SPME samplings, manual injections and the instrumental analysis. A good correlation (r(2)=0.95) was obtained between SPME measurements of PCB 153 in blubber and concentrations obtained via a traditional analytical approach. These results indicate that SPME is a promising technique for measuring chemical activity in biological tissue, which would make it a useful tool for studying chemical distribution in organisms as well as biodilution and biomagnification phenomena.     

Aluminium and calcium in soil and food from Guam,Palau and Jamaica: Implications for amyotrophic lateral sclerosis and parkinsonism-dementia syndromes of Guam

Low calcium and high aluminium concentrations in the soils, waters and native foods have been hypothesised as environmental factors contributing to the unusually high incidence of amyotrophic lateral sclerosis and parkinsonism with dementia (ALS-PD) found on the island of Guam. The amounts of elemental aluminium and calcium were measured in foods of the native diet of the Chamorro people of Guam. The amount of aluminium eluted from topsoil by water at pH 7 at 22 °C was also measured. For comparison, food, water and soil samples were collected from two islands which have not reported a high incidence of ALS-PD syndromes: Palau and Jamaica.Compared with agricultural soils of Jamaica or Palau, the agricultural soils of Guam averaged 42-fold higher yield of elutable aluminium. The food data, however, do not indicate a differentially high exposure to elemental aluminium or low calcium intake in the diet of any one population. While this study did not detect an unusually high dietary aluminium or low dietary calcium content, the soils and possibly the dusts of Guam may be a major source of aluminium entering the body of the native people, particularly through the respiratory epithelium. Since iipid soluble organic ligands of aluminium more readily penetrate epithelial membranes, further study of soil aluminium ligands is required.