Soil and plant characteristics as determining factors in site selection for surface coal mine reclamation

Four vegetative associations occur on surface mines located in Mercer County, Pennsylvania. Seventeen different species of grasses and legumes and 30 different species of trees and shrubs were evaluated for their ability to become established and control erosion on surface mines. The amount of organic matter and soil moisture are the principle factors regulating the establishment of vegetative cover on surface mines. Those species possessing a fibrous root system are better able to adapt for erosion control than tap rooted species. Likewise, shrubs such as bristley locust (Robina hispida) and Silver Bush or Autumn Olive (Elaeagnus umbellata) that will produce shoots when a root becomes exposed due to erosion are better adapted for erosion control than other species. The methods and species utilized during reclamation will determine, at least in part, the future use of the land and should establish conditions for natural succession to occur.This study was supported by funds from the National Geographical Society and the Office of Water Resources, U.S. Department of Interior.     

Challenges in biodegradation of trace organic contaminants--gasoline oxygenates and sex hormones.

Advances in analytical methods have led to the identification of several classes of organic chemicals that are associated with adverse environmental effects. Two such classes of organic chemicals, gasoline oxygenates and sex hormones, are used to illustrate challenges associated with the biodegradation of trace organic contaminants. Gasoline oxygenates can be present in groundwater, alone, or commingled with xylene, at appreciable concentrations. However, target-treated water standards dictate that gasoline oxygenates be reduced to the microgram-per-liter concentration range before consumption. Sex hormones, on the other hand, are present in wastewater matrixes in the part-per-trillion concentration range, and the biggest challenge that must be met, before optimizing their removal, is facilitating their detection.     

The teacher stress process: A cross-cultural analysis

A cross-cultural systems analysis was performed on teacher stress data from Canada and Sweden. The LISREL structural analysis was based on a conceptual model adapted from Kyriacou and Sutcliffe. Although the LISREL solution did not reach statistical significance it was concluded that the conceptual model in the essential features was corroborated by the LISREL analyses. Measurement errors, as well as the sensitivity of the used goodness of fit test (chi square) to the size of the samples was put forward as explanations of the failure to reach statistical significance for the LISREL structural solutions. Furthermore, it was argued that the heterogeneity of the teachers with respect to the stages of their professional careers should be considered in further research on teacher stress, to be able to capture the process aspects more adequately.     

Seasonal and spatial trends in the sources of fine particle organic carbon in Israel,Jordan, and Palestine

A study of carbonaceous particulate matter (PM) was conducted in the Middle East at sites in Israel, Jordan, and Palestine. The sources and seasonal variation of organic carbon, as well as the contribution to fine aerosol (PM_2.5) mass, were determined. Of the 11 sites studied, Nablus had the highest contribution of organic carbon (OC), 29%, and elemental carbon (EC), 19%, to total PM_2.5 mass. The lowest concentrations of PM_2.5 mass, OC, and EC were measured at southern desert sites, located in Aqaba, Eilat, and Rachma. The OC contribution to PM_2.5 mass at these sites ranged between 9.4% and 16%, with mean annual PM_2.5 mass concentrations ranging from 21 to 25 ug m^?3. These sites were also observed to have the highest OC to EC ratios (4.1–5.0), indicative of smaller contributions from primary combustion sources and/or a higher contribution of secondary organic aerosol. Biomass burning and vehicular emissions were found to be important sources of carbonaceous PM in this region at the non-southern desert sites, which together accounted for 30%–55% of the fine particle organic carbon at these sites. The fraction of measured OC unapportioned to primary sources (1.4 μgC m^?3 to 4.9 μgC m^?3; 30%–74%), which has been shown to be largely from secondary organic aerosol, is relatively constant at the sites examined in this study. This suggests that secondary organic aerosol is important in the Middle East during all seasons of the year.     

Fate of sex hormones in two pilot-scale municipal wastewater treatment plants: conventional treatment

The fate of seven sex hormones (estrone (E1), estradiol (E2), estriol (E3), ethinylestradiol (EE2), testosterone, androstenedione, and progesterone) was determined in two pilot-scale wastewater treatment plants operated under conventional loading conditions. The levels of hormones in both the liquid and the solid matrixes of the plants were determined. Each of the two 20-l/h pilot-scale plants consisted of a primary clarifier followed by a three-stage aeration tank and a final clarifier. The primary sludge and the waste activated sludge (WAS) were digested anaerobically in one pilot plant and aerobically in the other. The pilot plants were fed a complex synthetic wastewater spiked with the hormones. Levels of testosterone, androstenedione and progesterone were close to method detection limit (MDL) concentrations in the final and digester effluents (both liquid and solid phases) and were considered as completely removed. Average mass flux removals from the liquid streams (plant influent minus secondary clarifier effluent) for the natural estrogens were 82% for E1, 99% for E2, and 89% for (E1+E2). An average overall removal of only 42% was achieved for EE2. These values reflect removals averaged for the two pilot plants.     

Polybrominated diphenyl ethers (PBDEs) in farmed and wild salmon marketed in the Northeastern United States

Recently, we reported on the analysis of polychlorinated biphenyls (PCBs) and chlorinated pesticides in farmed Atlantic salmon (Salmo salar) from Maine, eastern Canada, and Norway, and wild Alaskan Chinook salmon (Oncorhynchus tshawytscha). In this paper, we extend the analysis to polybrominated diphenyl ethers (PBDEs) in these samples. Total PBDE concentrations in the farmed salmon (0.4-1.4ng/g, wet weight, ww) were not significantly different from those in the wild Alaskan Chinook samples (0.4-1.2ng/g, ww), nor were significant differences found among regions. However, significant intra-regional variations in concentrations of total PBDEs and tetra-BDE 47 were observed in the salmon from the Canadian farms (p<0.01). Congener profiles were dominated by BDE-47, followed by the penta-BDEs 99 and 100. PBDE concentrations in the Canadian samples were lower than those reported two years earlier. Removal of skin resulted in no overall reduction in PBDE concentrations in our farmed salmon, and in some cases, PBDE concentrations were higher in skin-off samples. PBDEs were correlated with lipids only in the skinned samples, suggesting that there is greater accumulation and retention of PBDEs in muscle lipids than in skin-associated fat. In skin-on samples, modest correlations were observed between concentrations of PBDEs and PCBs (R(2)=0.47) and mono-ortho PCBs (R(2)=0.50), whereas PBDEs were not correlated with non-ortho PCBs.     

Bioaccumulation of polybrominated diphenyl ethers in harbor seals from the northwest Atlantic

Polybrominated diphenyl ethers (PBDEs) were analyzed in blubber of harbor seals (Phoca vitulina concolor) collected between 1991 and 2005 along the northwest Atlantic. ∑PBDE concentrations (mono- to hexa-BDEs) detected in blubber samples (n = 42) ranged from 80 to 25 720 ng g⁻¹ lw, (overall mean 2403 ± 5406 ng g⁻¹ lw). By age, mean ∑PBDE concentrations were: 3645 ± 7388, 2945 ± 5995, 1385 ± 1265, and 326 ± 193 ng g⁻¹ lw in pups, yearlings, adult males, and adult females, respectively. Unlike the trend for PCBs, no decreasing gradient from urban to rural/remote areas was observed for PBDEs in these samples, likely reflecting inputs from local sources. No significant temporal trend was observed for PBDEs in harbor seals between 1991 and 2005, although congener profiles shifted over time. Tetra-BDE-47 was the dominant congener, followed by BDEs-99, -100, -153, -154, and -155 in varying order, suggesting exposure to the penta-BDE product. In adult males, the hexa-BDEs contributed more to the total (22%) than BDEs-99 and -100 (14%), and concentrations of BDE-155 were elevated compared with -154. Higher BDEs were detected in a subset of seals (n = 12) including hepta-BDE-183, the marker for the octa-BDE mixture, and octa-BDE-197, along with several unidentified hepta- and octa- congeners. BDE-209 was detected in seal blubber at concentrations ranging from 1.1 to 8 ng g⁻¹ lw, indicating that deca-BDE is bioavailable in this marine food web. This is the first study to document the accumulation of BDE-209 at measurable levels in wild harbor seals. While the PBDE patterns in blubber indicate exposure to all three BDE commercial mixtures, the data also suggest that BDE-209 debromination by seal prey fish may contribute to the loading of lower brominated congeners (hexa- to octa-BDEs) in these seals.     

Using ecosystem services valuation to measure the economic impacts of land-use changes on the Spanish Mediterranean coast (El Maresme, 1850–2010)

Over the last few decades, Mediterranean coastal areas have experienced profound land-use changes due mainly to urban sprawl and reforestation at the expense of former traditional agrarian mosaics and natural resources, such as beach areas or freshwaters streams. These changes have had severe negative consequences on the biodiversity and ecological state (i.e. function) of the territory. The overall objective of this study was to evaluate the economic impacts of these consequences on ecosystem services (ES). By reconstructing the landscape of El Maresme County (Barcelona Province, Spain) for three historical points in time (1850, 1954 and 2010), we were able to assess how these land-use changes have affected the total ecosystem value (TEV) by estimating the ES non-market and market values provided by each land-use through market prices and benefit transfer methods. Results show an important decrease in the value of TEV since the 1950s (23.6 million Euros per year) due to urban sprawl. Despite the major changes occurring between the 1850s and 1950s, non-market values did not alter very much due to the type of agricultural practices. Our results show the necessity to take into account the value of non-market ES when designing land planning policies, and especially those concerning beaches and coastal systems to fully integrate the contribution on natural systems into decision-making processes.