A phytoremediation study: Selection of tropical and other vascular plants for decolorization of Poly R‐478 dye

Peroxidases and other lignin‐degrading enzymes and chemicals can potentially degrade persistent pollutants. Fifty vascular plant species were hydroponically tested for the capability of decolorization of Poly R‐478, a lignolytic indicator dye. The top six species that had less than 50 percent of control color at the end of the experiments were Pennisetum purpureum, Rumex crispus, Fimbristylis cymosa, Eleocharis calva, Hibiscus furcellatus, and Cyperus javanicus, in an order from high to low decolorization activity. F. cymosa, E. calva, and C. javanicus are in the Cyperaceae family. Extracellular peroxidase activity was found in vascular plants and correlated to decolorization of polymeric dyes. The plant R. crispus provided the highest guaiacol peroxidase enzyme activity among four of the top six plant species. The Poly R‐478 decolorization could be used as a fast screening technique for vascular plants that may have phytoremediation capability. © 2006 Wiley Periodicals, Inc.     

Organophosphate flame retardants and plasticizers in indoor air

Analytical methods were developed for a broad range of organophosphate flame retardants and plasticizers in indoor air. Screening was performed of various indoor environments at 12 locations in and around Zurich, Switzerland. Method recoveries ranged from 62% for triphenyl phosphate to 100% for tris(2-ethylhexyl) phosphate. Tris(2-chloro-isopropyl) phosphate was found in the highest concentration (260 ng/m(3)) mainly in cars and furniture stores. Tris(2-ethylhexyl) phosphate and triphenyl phosphate, both up to 3.4 ng/m(3), were also detected in quantifiable concentrations at several sites. Tris(1,3-dichloroisopropyl) phosphate, tricresyl phosphate and tri(2-butoxyethyl) phosphate were below the limit of quantification in all samples. The results of the risk assessment indicate that the observed concentrations are below the predicted threshold for human health effects.     

Measuring visual opacity using digital imaging technology

The U.S. Environmental Protection Agency (EPA) Reference Method 9 (Method 9) is the preferred enforcement approach for verifying facility compliance with federal visible opacity standards. Supporters of Method 9 have cited its flexibility and low cost as important technological and economic advantages of the methodology. The Digital Opacity Compliance System (DOCS), an innovative technology that employs digital imaging technology for quantifying visible opacity, has been proposed as a technically defensible and economically competitive alternative to Method 9. Results from the field application of the DOCS at EPA-approved Method 9 smoke schools located in Ogden, UT, Augusta, GA, and Columbus, OH, demonstrated that, under clear sky conditions, the DOCS consistently met the opacity error rate established under Method 9. Application of hypothesis testing on the smoke school data set confirmed that the DOCS was equivalent to Method 9 under clear sky conditions. Under overcast sky conditions, human observers seemed to be more accurate than the DOCS in measuring opacity. However, within the smoke school environment, human observers routinely employ backgrounds other than sky (e.g., trees, telephone poles, billboards) to quantify opacity on overcast days. Under conditions that compel the use of sky as plume background (e.g., emission stacks having heights above the tree line), the DOCS appears to be a more accurate methodology for quantifying opacity than are human observers.     

Benefit–Cost Analysis of StormwaterQuality Improvements

The major purpose of this paper is to explore the potential value of benefit–cost evaluation for stormwater quality management decisions at a local level. A preliminary benefit–cost analysis (BCA) screening method is used for maximum extent practicable (MEP) analysis, identifying promising management practices, and identifying societal and economic tradeoffs for local stormwater problems. Ballona Creek, a major urban storm drain in Los Angeles, California, USA, is used to illustrate the practicality of the benefit–cost evaluation. The Ballona Creek example demonstrates the economic limits of stormwater management in an urban region and attests to the value of coordinated basinwide management compared to uncoordinated management by individual landowners. Evaluation results suggest that in urban areas, the benefit of stormwater quality improvements might be far greater if accompanied by comprehensive redesign of drainage networks and neighboring land uses. In this case, benefit–cost analysis is found to be useful for evaluating and understanding stormwater management alternatives despite the uncertainties in characterizing stormwater quality and the effects of stormwater management on improving receiving water quality.     

Dive Operator Use Patterns in the Designated No-Take Zones of the Florida Keys National Marine Sanctuary (FKNMS)

/ The Florida Keys National Marine Sanctuary (FKNMS), created by Congress in 1990, addressed the issue of resource protection partly by proposing 26 "no-take" zones. These areas, discussed in the 1995 Draft Management Plan, disallowed all extractive activities, and four of the zones also prohibited diving and snorkeling. Furthermore, the Draft Management Plan considered recreational carrying capacity, proposing that use densities be studied and eventually limited in high-use and sensitive areas. Conducted with 62 commercial dive operators from the Florida Keys in 1995-96, this study uses geographic information systems (GIS) to determine the extent of FKNMS zone use by dive operators, assess the regional importance of FKNMS zones to operators, and compare management strategies by which to allow use while minimizing impacts to the coral reef resource. Dive operators took almost 70% of their total trips and 77% of their total divers to FKNMS zones in 1995. Although zone use is generally related to the proximity of dive locations, dive operators do rely disproportionately on single sites in certain regions. The resulting profiles demonstrate that management strategies need to consider disproportionate use, as well as the average number of users per trip, to effectively protect the region's environmental resources. In addition to implementing a carrying capacity plan, the FKNMS should consider a limited-entry system for dive operators.     

The Use of Cluster Analysis in Distinguishing Farmland Prone to Residential Development: A Case Study of Sterling, Massachusetts

k -means nonhierarchical cluster analysis using farm size, slope, and distance to the nearest city center and highway as surrogates of farmland conversion. Discriminant analysis showed that the two groups derived from the cluster analysis were 98.8% accurate (P < 0.0000). Results from the statistical analysis may serve as a starting point for the identification of individual farms prone to residential development. To explain the driving forces of farmland conversion to residential uses, interviews should be conducted with farmers, landowners, and land buyers. The use of multivariate statistical techniques to identify farms in jeopardy of residential development, in conjunction with qualitative assessments that explain the probability of development of individual farms, may prove a useful strategy to understand and predict farmland conversion.     

Import demand for Brazilian ethanol: a cross-country analysis

This study presents an empirical analysis of the import demand for Brazilian ethanol by its six major foreign buyers. The primary objectives of this study were to identify the economic factors affecting the demand for ethanol imports and to derive long-run price and income elasticities of import demand. These elasticities could be used to analyze the impact of government policies such as mandatory gasoline/ethanol blends and import tariffs. Import demand models were estimated with ordinary least squares (OLS), using quarterly time series data for the 1997–2007 time period. The results suggest that the factors influencing the import demand for ethanol vary across countries. Markets adopting mandatory blends of renewable fuels tend to have less price elastic import demand schedules. Ethanol imports were found to be price elastic and statistically significant in the Caribbean region (?1.66), Mexico (?2.08), Japan (?1.44) and Nigeria (?1.38), while import demand was price inelastic and not statistically different from zero in the US (?0.76) and Europe (?0.21). The regression results could not determine the impacts of import tariffs for the United States, Mexico and Nigeria on the quantity of imports because tariffs did not vary during the time period studied. Results show that mandatory gasoline/ethanol blends have been an important determinant of ethanol imports.