Number Of Sampling Sites Research Articles

First Report of Spot Form of Net Blotch of Barley Caused by Pyrenophora teres f. maculata in Hungary.

A countrywide survey of fungal diseases of barley (Hordeum vulgare L.) was conducted from 2005 to 2009. Unusual leaf necrosis varying in shape from 1 × 2 mm necrotic flecks to 15 × 20 mm ovoid spots was found. Sometimes a chlorotic halo surrounding the dead area was observed. Lesions appeared on various cultivars in many commercial fields and experimental plots at a number of sampling sites. Symptomatic leaves were taken to the laboratory and incubated in a moist chamber at room temperature on the bench to induce sporulation of the pathogen. Conidiophores on the diseased tissues were single or in small groups, dark brown, and bore several hyaline-to-olive brown, almost cylindrical conidia with three to seven pseudosepta. Dimensions of conidia were 75.2 to 100.9 × 16.5 to 18.8 μm. Under a stereo microscope, single conidia were transferred aseptically from the leaves onto potato dextrose agar (PDA) with a sterile needle. Plates were kept in the dark at 20°C for 2 weeks. Cultures were gray to olive green, cottony, and did not form conidia and sexual structures. These characteristics indicated that the pathogens belonged to the genus Pyrenophora. Species identity was confirmed by PCR assays with specific primers developed for the barley pathogenic Pyrenophora spp. (3,4). Of 169 isolates, 41 were identified as P. teres Drechs. f. maculata Smed.-Pet., the spot form of net blotch pathogen (2), and two of them have been deposited at an international culture collection under accession nos. CBS 123929 and CBS 123930. The remaining isolates were either P. graminea or P. teres f. teres, the leaf stripe and net form of net blotch pathogens of barley, respectively. Pathogenicity of four P. teres f. maculata and two P. teres f. teres isolates from different regions was confirmed by Koch's postulates. Each isolate was grown on two 9-cm PDA plates at 22°C in darkness. After 10 days, aerial mycelia were scraped off, blended in 100 ml of sterile distilled water, and filtered through two layers of cheesecloth. Ten seedlings of cv. Botond were sprayed at the two-leaf stage with the mycelium suspension of each isolate and a water control until runoff. Seedlings were kept in a growth chamber at 100% relative humidity and 20°C in the dark for 24 h, then at 70% relative humidity and 24/20°C (day/night) with a 12-h photoperiod. Within 3 weeks, one to four brownish ovoid spots, typical of the spot form of net blotch symptoms, developed on the leaves inoculated with P. teres f. maculata. In contrast, the seedlings inoculated with P. teres f. teres exhibited characteristic net-like lesions, whereas the control plants sprayed with sterile water remained healthy. All strains were reisolated and identified by specific PCRs as described above. To our knowledge, this is the first report of the occurrence of P. teres f. maculata in Hungary. Resistance of barley against P. teres f. maculata and P. teres f. teres is inherited independently (1). Therefore, knowledge regarding the frequency and distribution of these pathogens is important for disease management and resistance breeding.

Pollution by estrogens in river and estuarine waters around Kuala Lumpur, Malaysia, and their effects on the estuarine Java-medaka, Oryzias javanicus

Estrogens (17 B-estradiol and estrone) concentrations in river and estuarine waters around Kuala Lumpur, Malaysia were determined by enzyme-linked immunosorbent assay while estrogenic potential of the waters were ascertained by three in vitro bioassays, namely E-screen, Ishikawa cell-alkaline phosphatase and yeast estrogen screen. Moreover, hepatic vitellogenin, a precursor of yolk protein that is specific to females, were examined in male and female Java-medaka collected in the same area. 17B-estradiol and estrone concentrations were less than 6.1 ng/L and 127 ng/L, respectively. The highest 17B-estradiol equivalent activity, 284 ng/L, was detected by in vitro assay in Sungai Kuyoh, which was adjacent to a sewage plant. 17B-estradiol and estrone concentrations were not equal to their estrogenic potentials determined by in vitro assay implying the presence of other estrogenic chemicals in these waters. Hepatic vitellogenin concentrations of both male and female java-medaka were the same to laboratory-cultured individuals. Although relatively high estrogen concentrations were detected in some waters of Malaysia, these were not high enough to induce hepatic vitellogenin in male fishes. Further research, however, is necessary to cover more number of sampling sites.

Spatial subdivision among assemblages of Spanish mackerel, Scomberomorus commerson (Pisces: Scombridae) across northern Australia: implications for fisheries management

ABSTRACTAim This study investigated the use of stable δ13C and δ18O isotopes in the sagittal otolith carbonate of narrow‐barred Spanish mackerel, Scomberomorus commerson, as indicators of population structure across Australia.Location Samples were collected from 25 locations extending from the lower west coast of Western Australia (30°), across northern Australian waters, and to the east coast of Australia (18°) covering a coastline length of approximately 9500 km, including samples from Indonesia.Methods The stable δ13C and δ18O isotopes in the sagittal otolith carbonate of S. commerson were analysed using standard mass spectrometric techniques. The isotope ratios across northern Australian subregions were subjected to an agglomerative hierarchical cluster analysis to define subregions. Isotope ratios within each of the subregions were compared to assess population structure across Australia.Results Cluster analysis separated samples into four subregions: central Western Australia, north Western Australia, northern Australia and the Gulf of Carpentaria and eastern Australia. Isotope signatures for fish from a number of sampling sites from across Australia and Indonesia were significantly different, indicating population separation. No significant differences were found in otolith isotope ratios between sampling times (no temporal variation).Main conclusions Significant differences in the isotopic signatures of S. commerson demonstrate that there is unlikely to be any substantial movement of fish among these spatially discrete adult assemblages. The lack of temporal variation among otolith isotope ratios indicates that S. commerson populations do not undergo longshore spatial shifts in distribution during their life history. The temporal persistence of spatially explicit stable isotopic signatures indicates that, at these spatial scales, the population units sampled comprise functionally distinct management units or separate ‘stocks’ for many of the purposes of fisheries management. The spatial subdivision evident among populations of S. commerson across northern and western Australia indicates that it may be advantageous to consider S. commerson population dynamics and fisheries management from a metapopulation perspective (at least at the regional level).

The complex responses of social stingless bees (Apidae: Meliponini) to tropical deforestation

Despite concern over a putative “global pollination crisis”, we still have an incomplete understanding of how bee communities respond to land-use change. I studied the responses of social stingless (or “meliponine”) bees (Hymenoptera: Apidae: Meliponini) to surrounding forest cover and floral resources in 35 sites in a largely deforested landscape in Costa Rica over three years, sampling bees with a standardized netting protocol. I recorded a diverse fauna of meliponines, comprised of 20 species and nine genera. I found that meliponine species richness and abundance are strongly related to forest cover, but not floral resource variables (blooming plant species richness and abundance). The effect of forest on meliponine abundance, but not diversity, disappeared when the most common meliponine species, Trigona fulviventris (which comprised ∼45% of sampled individuals), was excluded from analyses. Meliponine community composition, by contrast, was related most strongly to plant species richness, only weakly to forest cover, and not related to blooming plant abundance. This work differs from past work in the same landscape, which did not find evidence of changes in species richness or abundance of meliponines and forest-related variables (distance to forest or forest fragment size), but did find shifts toward meliponine-dominated communities near forests, especially larger ones. The larger true sample size (i.e. number of sample sites) of the present work likely improved the statistical power to detect these relationships. While meliponines are forest dependent, I recorded some species in the smallest forest fragments in the landscape, and as a group they respond strongly to overall forest cover in the landscape (i.e. including both small and large patches of forest). Both of these observations support arguments for preserving even small fragments of forest in agricultural landscapes. Given the ecological and economic importance of meliponine bees, it is imperative that we better understand their long-term conservation needs in the changing tropical landscapes of the world.

Siting analyses for water quality sampling in a catchment

Pollution loads discharged from upstream development or human activities significantly degrade the water quality of a reservoir. The design of an appropriate water quality sampling network is therefore important for detecting potential pollution events and monitoring pollution trends. However, under a limited budgetary constraint, how to site an appropriate number of sampling stations is a challenging task. A previous study proposed a method applying the simulated annealing algorithm to design the sampling network based on three cost factors including the number of reaches, bank length, and subcatchment area. However, these factors are not directly related to the distribution of possible pollution. Thus, this study modified the method by considering three additional factors, i.e. total phosphorus, nitrogen, and sediment loads. The larger the possible load, the higher the probability of a pollution event may occur. The study area was the Derchi reservoir catchment in Taiwan. Pollution loads were derived from the AGNPS model with rainfall intensity estimated using the Thiessen method. Analyses for a network with various numbers of sampling sites were implemented. The results obtained based on varied cost factors were compared and discussed. With the three additional factors, the chosen sampling network is expected to properly detect pollution events and monitor pollution distribution and temporal trends.

Palaeomagnetism of the Older Ontake Volcano, Japan: contributions to the palaeosecular variation for 750-400 Ka, the lower half of the Brunhes Chron

SUMMARY Studies of palaeodirections and palaeointensities were carried out on andesite lavas from the older part of the late Quaternary Ontake Volcano, Japan. Recently published K-Ar ages of the Older Ontake lavas range from 740 to 393 Ka. Palaeomagnetic samples were collected at 24 sites which are either of the same locality or nearby the dating site. Determination of palaeodirections was straightforward at most of the sites. Exceptions are a few sites in which the site mean palaeodirections were obtained only by the great circle method due to large secondary components, possibly lightning strikes in origin. The obtained VGP angular dispersion of 14.3 ◦ (N = 23) around the mean is smaller than the representative value for the site latitude of 36 ◦ N, which could be attributed to an insufficient number of sampling sites. Thellier’s experiments were successful in 25 specimens from three lavas out of 54 specimens from nine lavas, giving a moderate success rate of 46 per cent. The obtained flow mean palaeointensities of 21, 40 and 53 μT conform well with the worldwide trend of the global palaeointensity during the Brunhes Chron, which indicates possible maxima of the global palaeointensity around 0.7 and 0.35 Ma with following gradual decrease.

Integrating vegetation field surveys with remotely sensed data

Summary This paper explores data compatibility issues arising from the assessment of remnant native vegetation condition using satellite remote sensing and field‐based data. Space‐borne passive remote sensing is increasingly used as a way of providing a total sample and synoptic overview of the spectral and spatial characteristics of native vegetation canopies at a regional scale. However, integrating field‐collected data often not designed for integration with remotely sensed data can lead to data compatibility issues. Subsequent problems associated with the integration of unsuited datasets can contribute to data uncertainty and result in inconclusive findings. It is these types of problems (and potential solutions) that form the basis of this paper. In other words, how can field surveys be designed to support and improve compatibility with remotely sensed total surveys? Key criteria were identified for consideration when designing field‐based surveys of native vegetation condition (and other similar applications) with the intent to incorporate remotely sensed data. The criteria include recommendations for the siting of plots, the need for reference location plots, the number of sample sites and plot size and distribution, within a study area. The difficulties associated with successfully integrating these data are illustrated using real examples taken from a study of the vegetation in the Little River Catchment, New South Wales, Australia.

A Simplified Assessment of Factors Controlling Phosphorus Loading from Oxygenated Sediments in a Very Shallow Eutrophic Lake

Factors controlling the release of bioavailable soluble reactive phosphorus (SRP) from sediments in very shallow lakes are not fully understood. Our approach involved relatively simple measurements of four factors affecting the calculation of internal phosphorus load: the number of sampling sites, sediment freezing, incubation temperature and oxic state in Cootes Paradise Marsh, now a very shallow (Z = 70 cm) eutrophic degraded urban lake in Ontario, Canada. Our results indicate that all of these factors need to be considered when attempting to estimate the internal phosphorus load of a shallow system. The total internal load of phosphorus in Cootes Paradise Marsh was 34% of the total loading (both internal and external), with diffusion from the sediment accounting for 23% of all phosphorus inputs. Large carp are now excluded from the lake and were estimated by difference to have contributed 23% to summer internal loading.

Northern Ibero-Atlantic wetland woods: Vegetation types and within-stand structure

This study was carried out in eight stands of wetland woods located in the north-western part of the Iberian Peninsula. The number of sampling sites per stand depended on the physical heterogeneity and area of each stand. Biological data recorded per site included species composition and a list of structural parameters (relative cover in each forest layer, tree height, tree diameter at breast height, number of live and dead trunks and individuals, and morphological adaptations to flooding). Hydro-geomorphologic, geological and climatic variables were also obtained. The floristic data set was subjected to a non-hierarchical cluster analysis and a principal component analysis, which provided an overall image of vegetation grouping based on community composition that only considered perennial species (trees, shrubs, non-annual herbaceous plants and climbers). Three groups of plant communities were distinguished, with an overstorey that was dominated by Betula alba, Salix atrocinerea and Alnus glutinosa, respectively, which presented different environmental drivers. The structural features of each group that was characterised by a different overstorey species were analysed and differences were tested. The number of trunks per individual, number of dead trunks, canopy height and the presence of adaptations to flooding were the structural parameters that best separated the wetland wood groups. Environmental variables were correlated with the ordination axis to analyse community distribution trends and the hydrological regime was found to be the key environmental factor controlling both floristic and structural patterns.

Northern Ibero-Atlantic wetland woodsVegetation types and within-stand structure

This study was carried out in eight stands of wetland woods located in the north-western part of the Iberian Peninsula. The number of sampling sites per stand depended on the physical heterogeneity and area of each stand. Biological data recorded per site included species composition and a list of structural parameters (relative cover in each forest layer, tree height, tree diameter at breast height, number of live and dead trunks and individuals, and morphological adaptations to flooding). Hydro-geomorphologic, geological and climatic variables were also obtained. The floristic data set was subjected to a non-hierarchical cluster analysis and a principal component analysis, which provided an overall image of vegetation grouping based on community composition that only considered perennial species (trees, shrubs, non-annual herbaceous plants and climbers). Three groups of plant communities were distinguished, with an overstorey that was dominated by Betula alba, Salix atrocinerea and Alnus glutinosa, respectively, which presented different environmental drivers. The structural features of each group that was characterised by a different overstorey species were analysed and differences were tested. The number of trunks per individual, number of dead trunks, canopy height and the presence of adaptations to flooding were the structural parameters that best separated the wetland wood groups. Environmental variables were correlated with the ordination axis to analyse community distribution trends and the hydrological regime was found to be the key environmental factor controlling both floristic and structural patterns.

Limnology of four saline lakes in western Victoria, Australia: II. Biological parameters

Major biological parameters of four permanent (Lake Colac, Modewarre, Bolac and Tooliorook), shallow and slightly saline lakes in the volcanic plains of western Victoria, Australia recorded bi-monthly between November 1999–September 2001 are described. Chlorophyll a concentration ranged from 3–29 μg l −1 with peaks in autumn. Phytoplankton taxa recorded were diverse, with Chlorophyta and Bacillariophyta being common. Cyanobacterial blooms were recorded mostly in summer. Zooplankton abundance in the lakes ranged from 12–368 individuals per litre. Rotifera dominated Lake Bolac, Copepoda dominated Lake Modewarre and they co-dominated Lake Colac and Tooliorook. Zooplankton interactions with phytoplankton suggest that simple predator-prey relationships cannot fully explain the trends exhibited and that a more complex model was acting to regulate algal biomass. A decline in the abundance of zooplankton in summer in Lake Modewarre was attributed to predation by high number of exotic larval carp at that time of the year. A total of 25 benthic macroinvertebrate taxa were recorded from Lake Colac, 30 from Modewarre, 22 from Bolac and 35 from Tooliorook. Twenty-one of the 45 taxa identified occurred in at least three lakes. Nine of the 12 taxa that occurred in only one lake were from Lake Tooliorook. Simpson's diversity index was low in Lake Bolac when compared to other three lakes. Lake Modewarre had more benthic individuals (3246 Ind m −2) than other three lakes (range 624–1397 Ind m −2). The combined contribution of Ostracoda, Amphipoda and Gastropoda dominated the benthos in all the lakes throughout the study period. Macroinvertebrate taxa richness was higher in the present study lakes than recorded from the lakes in the region. Frequency of sampling and number of sampling sites seemed more important in determining species richness than the size and shallowness of the lakes.

Optimal adaptive selection of sampling sites

AbstractUnder an assumed population model, the optimal sampling strategy is often an adaptive one. In spatial statistics an important problem is that of optimally locating sample sites for estimation or prediction. In some cases a certain number of sampling sites have already been located and now one would like to optimally choose locations for a set of additional sites. If the optimal strategy is an adaptive one, then the selection of the new sites should take into account not only the locations of the existing sites but also the values of the variable of interest observed at those sites. In this paper, the optimal sampling strategy in two phases is examined and compared with the optimal conventional strategy. While the optimal conventional design is approximately a systematic arrangement of sampling sites, the optimal adaptive selection varies depending on the realized spatial distribution. The relative efficiency of the optimal (adaptive) strategy to the optimal conventional strategy, which is always greater than 1, is seen to be related to the range of influence of the spatial covariance function. Finally, the strategies are compared using data from a study of geothermal with CO2 emissions in Yellowstone National Park. Copyright © 2001 John Wiley & Sons, Ltd.

Screening of potential sites for undeclared nuclear facilities in environmental monitoring for nuclear proliferation

The sensitivity of environmental sampling and analysis for the estimated atmospheric concentrations of radionuclides in effluents from clandestine nuclear facilities may require many sampling sites and exorbitant costs to monitor such large areas. An assessment has been made of the key factors necessary to support the operation of a nuclear facility, e.g., the existence of a nearby transportation network, main electrical power supply, and population centers. Screening, the subject of this paper, evaluates how cartographic data and satellite imagery can be used to identify areas most capable of supporting undeclared nuclear operations. As a result, large geographical areas can be eliminated from environmental monitoring and sampling. This leads to reduced costs, a reduction in the number of sampling sites required, and a reduction in the overall level of effort required to accomplish effective environmental monitoring. The screening methodology and techniques are described and examples given.

Freshwater Critical Loads in Wales

The Steady State Water Chemistry (SSWC) modeland the Diatom model have been used to calculate criticalloads for acidity using annual mean chemistry for 102 acidupland streams in Wales sampled as part of the Welsh AcidWaters Survey (WAWS) in 1995. Diatom critical loads werelower than SSWC values reflecting the higher effective[ANC]limit of the Diatom model compared to the[ANC]limit of zero used in the SSWC model. The WAWSstream sites were all located within 41 10 × 10 km squares andeach square was assigned the lowest critical load value fromamongst the sites located within it. Comparison with valuesassigned under the UK national critical loads mappingprogramme (UKCLMAP) showed that WAWS critical loads were lowerthan UKCLMAP values in approximately 40% of squares.Differences in critical load class were variable, but exceeded2 keq ha-1 yr-1 in up to a maximum of seven squares.It cannot be assumed, therefore, that reducing acid depositionto the currently mapped UKCLMAP critical load will protect allstreams occurring within a given 10 × 10 km grid square inWales. The limited number of sample sites means that even inthose squares where all WAWS sites will be protected, theremay be other, more acid sensitive freshwaters with lowercritical loads. This has important implications for theinterpretation and use of critical loads data for regional andlocal environmental planning.

Developing an optimal sampling design. A case study in a coastal marine ecosystem.

The development of a sampling design for optimising sampling site locations collected from a coastal marine environment has been the purpose of the present work; application of statistical analysis and spatial autocorrelation methods have been carried out. The dataset included data collected from 34 sampling sites spaced out in the Strait of Lesbos, Greece, arranged in a 1 x 1 NM grid. The coastal shallow ecosystem was subdivided into three zones, an inner one (7 stations), a middle one (16 stations) and an offshore zone (11 stations). The standard error of the chlorophyll-a concentrations in each zone has been used as the criterion for the sampling design optimisation, resulting into reallocation of the sampling sites into the three zones. The positions of the reallocated stations have been assessed by estimation of the spatial heterogeneity and anisotropy of chlorophyll-a concentrations using variograms. Study of the variance of the initial dataset of the inner zone taking into account spatial heterogeneity, revealed two different sub-areas and therefore, the number of the inner stations has been reassessed. The proposed methodology eliminates the number of sampling sites and maximises the information of spatial data from marine ecosystems. It is described as a step-by-step procedure and could be widely applied in sampling design concerning coastal pollution problems.

Insecticide‐caused toxicity to Ceriodaphnia dubia (CLADOCERA) in the Sacramento–San Joaquin River delta, California, USA

AbstractIn recent years, populations of resident aquatic species in California's Sacramento–San Joaquin Delta, USA, have declined appreciably in numbers. The cause of these declines is not known, but has been attributed to a number of factors including water diversions, loss of habitat, introduced exotic organisms, and toxic compounds. To detect and characterize the spatial extent, severity, frequency, and causes of potential toxicity caused by anthropogenic pollutants, a monitoring study was conducted over a period of two years (1993–1995). Sites were monitored on a monthly basis using the standardized U.S. Environmental Protection Agency freshwater toxicity test with the zooplankton species Ceriodaphnia dubia. Twenty‐four sites were sampled in 1993 to 1994. During the 1994 to 1995 sampling season, the number of sampling sites was restricted to 20, with special emphasis placed on back sloughs, delta island agricultural drains, and main‐stem river sites. Significant mortality or reproductive toxicity in C. dubia was detected in 9.8% of 400 water samples tested. Ecologically important back sloughs had the largest percentage of toxic samples. Of 71 and 103 samples collected from back sloughs during 1993 to 1994 and 1994 to 1995, respectively, 14.1% and 19.6% were toxic. To determine the causative chemical(s), toxicity identification evaluations (TIEs) were conducted on 23 toxic samples. These included eight follow‐up samples taken to determine whether toxicity at the respective site persisted. Organophosphate (chlorpyrifos, diazinon, malathion) and carbamate (carbofuran, carbaryl) pesticides were identified as primary toxicants. Chlorpyrifos was present at toxic concentrations in 87% of samples tested by TIE. Analysis of data from the follow‐up samples suggested that toxicity may have persisted over periods of several days to weeks.

Practical use of the ISCST3 model to select monitoring site locations for air pollution control

Fil: Mazzeo, Nicolas Antonio. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmosfera y los Oceanos; Argentina

SAMPLING BENTHIC MACROINVERTEBRATES IN A LARGE FLOOD-PLAIN RIVER: CONSIDERATIONS OF STUDY DESIGN, SAMPLE SIZE, AND COST

Estimation of benthic macroinvertebrate populations over large spatial scales is difficult due to the high variability in abundance and the cost of sample processing and taxonomic analysis. To determine a cost-effective, statistically powerful sample design, we conducted an exploratory study of the spatial variation of benthic macroinvertebrates in a 37 km reach of the Upper Mississippi River. We sampled benthos at 36 sites within each of two strata, contiguous backwater and channel border. Three standard ponar (525 cm2) grab samples were obtained at each site ('Original Design'). Analysis of variance and sampling cost of strata-wide estimates for abundance of Oligochaeta, Chironomidae, and total invertebrates showed that only one ponar sample per site ('Reduced Design') yielded essentially the same abundance estimates as the Original Design, while reducing the overall cost by 63%. A posteriori statistical power analysis (α = 0.05, β = 0.20) on the Reduced Design estimated that at least 18 sites per stratum were needed to detect differences in mean abundance between contiguous backwater and channel border areas for Oligochaeta, Chironomidae, and total invertebrates. Statistical power was nearly identical for the three taxonomic groups. The abundances of several taxa of concern (e.g., Hexagenia mayflies and Musculium fingernail clams) were too spatially variable to estimate power with our method. Resampling simulations indicated that to achieve adequate sampling precision for Oligochaeta, at least 36 sample sites per stratum would be required, whereas a sampling precision of 0.2 would not be attained with any sample size for Hexagenia in channel border areas, or Chironomidae and Musculium in both strata given the variance structure of the original samples. Community-wide diversity indices (Brillouin and 1-Simpsons) increased as sample area per site increased. The backwater area had higher diversity than the channel border area. The number of sampling sites required to sample benthic macroinvertebrates during our sampling period depended on the study objective and ranged from 18 to more than 40 sites per stratum. No single sampling regime would efficiently and adequately sample all components of the macroinvertebrate community.

Indoor Nitrous Acid Levels. Production of Nitrous Acid from Open-Flame Sources

Abstract The concentrations of HONO in indoor atmospheres are clearly correlated with open flame sources (e.g., hydrocarbon fuel fired heaters, stoves, etc.). Relatively high levels, 20–90 ppbv, were encountered in a number of sampling sites. The half-life of HONO in a typical indoor environment appears to range from 2 to 8 h.

Atmospheric Polycyclic Aromatic Hydrocarbons at a Point Source of Emissions. Part A: Identification and Determination of Polycyclic Aromatic Compounds in Airborne Particulate Matter Near a Horizontal Stud Soderberg Plant

Abstract This paper summarizes the sampling and analytical methods developed to identify and measure polycyclic aromatic hydrocarbons (PAH) and related aromatic compounds near a Horizontal Stud Soderberg plant at Jonquiere, Quebec, Canada. The primary source of PAH is the coal tar pitch used as a binder in Soderberg anodes. Twice a week at a number of sampling sites, airborne particulate matter was collected on glass-fiber filters using a Hi-Vol sampler for a twenty-four hour period. Organics on the filter were Soxhlet extracted with benzene. Identification was done by gas chromatography-mass spectrometry (GC-MS). The vast majority of compounds present were PAH, but small amounts of alkyl PAH and polycyclic aromatic compounds with heteroatoms such as nitrogen, oxygen and sulfur were also identified. Based on the GC-MS identification, a group of 14 PAH was selected for monitoring. Frequent PAH determinations revealed that the ratio of Benzo(a- )Pyrene to total PAH on the Hi-Vol filters is relatively consta...