Fuzzy decision analysis for integrated environmental vulnerability assessment of the mid-Atlantic Region

A fuzzy decision analysis method for integrating ecological indicators was developed. This was a combination of a fuzzy ranking method and the analytic hierarchy process (AHP). The method was capable of ranking ecosystems in terms of environmental conditions and suggesting cumulative impacts across a large region. Using data on land cover, population, roads, streams, air pollution, and topography of the Mid-Atlantic region, we were able to point out areas that were in relatively poor condition and/or vulnerable to future deterioration. The method offered an easy and comprehensive way to combine the strengths of fuzzy set theory and the AHP for ecological assessment. Furthermore, the suggested method can serve as a building block for the evaluation of environmental policies.     

Combined use of rapid bioassessment protocols and sediment quality triad to assess stream quality

Physical, chemical and biological conditions at five stations on a small southeastern stream were evaluated using the Rapid Bioassessment Protocols (RBP) and the Sediment Quality Triad (SQT) to assess potential biological impacts of a municipal wastewater treatment facility (WWTF) on downstream resources. Physical habitat, benthic macroinvertebrates and fish assemblages were impaired at Stations 1 and 2 (upstream of the WWTF), suggesting that the degraded physical habitat was adversely impacting the fish and benthic populations. The SQT also demonstrated that Stations 1 and 2 were degraded, but the factors responsible for the impaired conditions were attributed to the elevated concentrations of polycylclic aromatic hydrocarbons (PAHs) and metals (Mn, Pb) in the sediments. The source of contaminants to the upper reaches of the stream appears to be storm-water runoff from the city center. Increased discharge and stabilized base flow contributed by the WWTF appeared to benefit the physically-altered stream system. Although the two assessment procedures demonstrated biological impairment at the upstream stations, the environmental factors identified as being responsible for the impairment were different: the RBP provided insight into contributions associated with the physical habitat and the SQT contributed information on contaminants and sediment quality. Both procedures are important in the identification of physical and chemical factors responsible for environmental impairment and together they provide information critical to the development of appropriate management options for mitigation.     

Correction to: Status and trends of circumpolar peregrine falcon and gyrfalcon populations

While collating contributions and comments from 36 researchers, the coordinating authors accidentally omitted Dr. Suzanne Carrière from the list of contributing co-authors. Dr. Carrière’s data are described in Tables 1 and 3, Figure 2 and several places in the narrative. The new author list is thus updated in this article.     

Laboratory testing of a continuous emissions monitor for hydrochloric acid

Continuous monitoring of exhaust flue gas has become a common practice in power plants in response to Federal Mercury and Air Toxics Standards (MATS) standards. Under the current rules, hydrochloric acid (HCl) is not continuously measured at most plants; however, MATS standards have been proposed for HCl, and tunable diode laser (TDL) absorption spectroscopy is one method that can be used to measure HCl continuously. The focus of this work is on the evaluation and verification of the operation performance of an HCL TDL over a range of real-world operating environments. The testing was conducted at the University of California at Riverside (UCR) spectroscopy evaluation laboratory. Laboratory tests were conducted at three separate temperatures, 25ºC, 100ºC, and 200ºC, and two distinct moisture levels for the enhanced temperatures, 0%, (2 tests) and 4%, over a concentration range from 0 ppmv to 25 ppmv-m at each of the elevated temperatures. The results showed good instrument accuracy as a function of changing temperature and moisture. Data analysis showed that the average percentage difference between the ammonia concentration and the calibration source was 3.33% for varying moisture from 0% to 4% and 2.69% for varying temperature from 25 to 100/200ºC. An HCl absorption line of 1.742 μm was selected for by the manufacturer for this instrument. The Hi Tran database indicated that CO₂ is probably the only major interferent, although the CO₂ absorption is very weak at that wavelength. Interference tests for NO, CO, SO₂, NH₃, and CO₂ for a range of concentrations typical of flue gasses in coal-fired power plants did not show any interference with TDL HCl measurements at 1.742 μm. For these interference tests, CO₂ was tested at a concentration of 11.9% concentration in N₂ for these tests. Average precision over the entire range for all 10 tests is 3.12%.

Implications: The focus of this study was an evaluation of the operation performance of a tunable diode laser (TDL) for the measurement of hydrochloric acid (HCl) over a range of real-world operating environments. The results showed good instrument accuracy as a function of changing temperature from 25ºC to 200ºC and moisture from 0% to 4%. Such as an instrument could be used for continuous monitoring of exhaust flue gas in power plants once the Federal Mercury and Air Toxics Standards (MATS) standards have been fully implemented.     

Sorption and predicted mobility of herbicides in Baltic soils

This study was undertaken to determine sorption coefficients of eight herbicides (alachlor, amitrole, atrazine, simazine, dicamba, imazamox, imazethapyr, and pendimethalin) to seven agricultural soils from sites throughout Lithuania. The measured sorption coefficients were used to predict the susceptibility of these herbicides to leach to groundwater. Soil-water partitioning coefficients were measured in batch equilibrium studies using radiolabeled herbicides. In most soils, sorption followed the general trend pendimethalin > alachlor > atrazine approximately amitrole approximately simazine > imazethapyr > imazamox > dicamba, consistent with the trends in hydrophobicity (log K(ow)) except in the case of amitrole. For several herbicides, sorption coefficients and calculated retardation factors were lowest (predicted to be most susceptible to leaching) in a soil of intermediate organic carbon content and sand content. Calculated herbicide retardation factors were high for soils with high organic carbon contents. Estimated leaching times under saturated conditions, assuming no herbicide degradation and no preferential water flow, were more strongly affected by soil textural effects on predicted water flow than by herbicide sorption effects. All herbicides were predicted to be slowest to leach in soils with high clay and low sand contents, and fastest to leach in soils with high sand content and low organic matter content. Herbicide management is important to the continued increase in agricultural production and profitability in the Baltic region, and these results will be useful in identifying critical areas requiring improved management practices to reduce water contamination by pesticides.     

Relations of Habitat-Specific Algal Assemblages to Land Use and Water Chemistry in the Willamette Basin, Oregon

Benthic algal assemblages, water chemistry, and habitat were characterized at 25 stream sites in the Willamette Basin, Oregon, during low flow in 1994. Seventy-three algal samples yielded 420 taxa — mostly diatoms, blue-green algae, and green algae. Algal assemblages from depositional samples were strongly dominated by diatoms (76% mean relative abundance), whereas erosional samples were dominated by blue-green algae (68% mean relative abundance).Canonical correspondence analysis (CCA) of semiquantitative and qualitative (presence/absence) data sets identified four environmental variables (maximum specific conductance, % open canopy, pH, and drainage area) that were significant in describing patterns of algal taxa among sites. Based on CCA, four groups of sites were identified: streams in forested basins that supported oligotrophic taxa, such as Diatoma mesodon;small streams in agricultural and urban basins that contained a variety of eutrophic and nitrogen-heterotrophic algal taxa; larger rivers draining areas of mixed land use that supported planktonic, eutrophic, and nitrogen-heterotrophic algal taxa; and streams with severely degraded or absent riparian vegetation (> 75% open canopy) that were dominated by other planktonic, eutrophic, and nitrogen-heterotrophic algal taxa. Patterns in water chemistry were consistent with the algal autecological interpretations and clearly demonstrated relationships between land use, water quality, and algal distribution patterns.     

Determining the size of a complete disturbance landscape: multi-scale,continental analysis of forest change

The scale of investigation for disturbance-influenced processes plays a critical role in theoretical assumptions about stability, variance, and equilibrium, as well as conservation reserve and long-term monitoring program design. Critical consideration of scale is required for robust planning designs, especially when anticipating future disturbances whose exact locations are unknown. This research quantified disturbance proportion and pattern (as contagion) at multiple scales across North America. This pattern of scale-associated variability can guide selection of study and management extents, for example, to minimize variance (measured as standard deviation) between any landscapes within an ecoregion. We identified the proportion and pattern of forest disturbance (30 m grain size) across multiple landscape extents up to 180 km². We explored the variance in proportion of disturbed area and the pattern of that disturbance between landscapes (within an ecoregion) as a function of the landscape extent. In many ecoregions, variance between landscapes within an ecoregion was minimal at broad landscape extents (low standard deviation). Gap-dominated regions showed the least variance, while fire-dominated showed the largest. Intensively managed ecoregions displayed unique patterns. A majority of the ecoregions showed low variance between landscapes at some scale, indicating an appropriate extent for incorporating natural regimes and unknown future disturbances was identified. The quantification of the scales of disturbance at the ecoregion level provides guidance for individuals interested in anticipating future disturbances which will occur in unknown spatial locations. Information on the extents required to incorporate disturbance patterns into planning is crucial for that process.     

Evaluation of Watering to Control Dust in High Winds

ABSTRACT

A field study was conducted to determine the effectiveness of watering in controlling PM₁₀ emissions under high wind conditions. The focus of the study was the pickup of soil by a belly scraper at a landfill. Four low-volume PM₁₀ samplers were positioned downwind of the storage pile (at two distances, 80 and 110 m, and two elevations, 1 and 3 m) and one was located upwind at 3 m elevation. Integrating nephelometers, which measure the particu-late light scattering coefficient, b_sp, were also set up at locations 80 and 110 m downwind of the storage pile. Wind speed and direction were measured on-site. Samples were collected for two periods, one with and one without water being applied. Watering was effective at reducing PM₁₀ emissions at wind speeds up to the maximum 18 m sec^-1 observed at the landfill soil pickup operation. Measurement of b_sp provided an indication of PM₁₀ concentrations with better time resolution than samplers, but not with sufficient resolution, under the instrumental conditions used, to correlate with wind gusts.     

Ambient measurements of 2,2,4-trimethyl, 1,3-pentanediol monoisobutyrate in Southern California

2,2,4-trimethyl, 1,3-pentanediol monoisobutyrate (TPM) is a widely used solvent found in water-based coatings. Ambient measurements of TPM are reported here for the first time. Although this compound has been previously measured in indoor air, this study illustrates successful detection and quantification of TPM in ambient air at three locations in Southern California: Pico Rivera, Azusa, and Riverside. TPM was detected in every sample collected, with concentrations ranging from 0.7 to 49.5 parts per trillion (ppt). Collections took place during summer 2009, fall 2009, winter 2009/2010, and spring 2010, for 5–7 days during each season. The highest mean concentrations were observed during the summer months for each city, when coating activities are typically at their highest.

Implications 2,2,4-Trimethyl, 1,3-pentanediol monoisobutyrate (TPM) is a widely used solvent found in water-based coatings. Ambient measurements of TPM are reported here for the first time. The highest mean concentrations were observed during the summer months for each city, when coating activities are typically at their highest. Unreacted TPM constitutes approximately 0.01% of the total nonmethane hydrocarbon (NMHC) concentrations in the Los Angeles air basin and given its slow reactivity rate in forming ozone, this would be an approximate upper limit for the fraction of ozone that it is responsible for forming.     

Development of a new aerosol monitoring system and its application in Fukushima nuclear accident related aerosol radioactivity measurement at the CTBT radionuclide station in Sidney of Canada

A high volume aerosol sampler ("Grey Owl") has been designed and developed at the Radiation Protection Bureau, Health Canada. Its design guidance is based on the need for a low operational cost and reliable sampler to provide daily aerosol monitoring samples that can be used as reference samples for radiological studies. It has been developed to provide a constant air flow rate at low pressure drops (∼3 kPa for a day sampling) with variations of less than ±1% of the full scale flow rate. Its energy consumption is only about 1.5 kW for a filter sampling over 22,000 standard cubic meter of air. It has been demonstrated in this Fukushima nuclear accident related aerosol radioactivity monitoring study at Sidney station, B.C. that the sampler is robust and reliable. The results provided by the new monitoring system have been used to support decision-making in Canada during an emergency response.