Levels and trends of brominated flame retardants in the European environment

In this paper, we review those data which have recently become available for brominated flame retardants (particularly the brominated diphenyl ethers (BDEs) and hexabromocyclododecane (HBCD)) in samples from the European environment. Environmental compartments studied comprise the atmosphere, sediments and soils, sewage sludges, and a variety of biological samples and food chains. This is currently a very active research area, and we cite over 70 studies reported in the literature during 2003-04. Findings include that the input of BDEs (especially BDE209) to the Baltic Sea by atmospheric deposition now exceeds that of PCBs by a factor of almost 40 times. Sewage sludge samples from both industrial and background locations show concentrations of BDEs, HBCD and tetrabromobisphenol-A (TBBP-A) that are of a similar order, indicating that the major source is from diffuse leaching from products into wastewater streams from users, households and industries generally. Point-sources from industries using BFRs (e.g. the textile industry) also generate local hot-spots. Sediment core studies identified the presence of two of the three PBDE formulations. The penta-mix formulation was clearly present from the beginning of the 1970s, but the deca-mix only appeared in the late 1970s. BDE183, BDE209 and HBCD were detected in peregrine falcons from Sweden and other birds feeding on terrestrial food chains. BDEs are found widely distributed in fish, including those from high mountain lakes in Europe, as a consequence of long-range atmospheric transport and deposition. A temporal trend study in archived freeze-dried mussels from the Seine estuary, France, indicated an exponential increase in BDE concentrations during the period 1982-1993, which levelled off in 1999 and 2001 and then began to decline after 2002. HBCD was detected in liver and blubber samples from harbour seals and harbour porpoises from the Wadden and North Seas, though very few animals yielded positive values for TBBP-A. There are difficulties in comparing data on summation operatorBDE from studies in which different suites of BDE congeners have been determined, and we suggest a common suite which will allow the study of all three commercial PBDE formulations.     

Mate sampling behaviour of black grouse females (Tetrao tetrix)

We studied female mate sampling behaviour in lekking black grouse (Tetrao tetrix). Females mainly visited males occupying territories in the centre of the lek with relatively large territories. They were also more likely to visit males that had high attendance. The same factors were also correlated with male mating success. A multiple regression model including these factors explained more of the variance in female visits per male (53%) than in mating success (33%). The pattern of female sampling conformed with a pool comparison (best-of-n) tactic. Such a tactic is expected if the costs of sampling are low. Females of high body mass visited more males than lighter females, however, which indicates that females may vary in their search tactics and suggests that there may be search costs. The existence of costs is further suggested by the fact that if the mate from a previous year was still present, females always mated with the same male in the following year. Though search costs were not measured directly, our findings suggest that some costs are negligible (e.g. energetic exhaustion or predation) whereas others (timing of mating) may be more important.     

Spacing of leks in relation to female home ranges,habitat requirements and male attractiveness in the great snipe (Gallinago media)

Summary In an attempt to examine three main hypotheses on the evolution of leks, data on female home ranges, distance between leks and male site fidelity in the great snipe (Gallinago media) were obtained. In a 30 × 40 km area in central Sweden, the locations of 12 leks were identified. Six were within the study area (7 × 11 km) in which probably all leks were known. In the study area, nearest neighbor distances between leks were longer than the predicted drawing area (diameter of female home ranges plus the detection range of leks). Furthermore, in only 1 of 13 radio-tracked females did the estimated home range enclose many leks. These data do not fit the prediction from the hotspot hypothesis on the dispersion of leks, namely, that the distance between leks should be less than the drawing area and hence an average female home range should enclose more than one lek. The observed distance between leks was about the same as predicted by the female preference hypothesis. This hypothesis also predicts females visit mainly one lek; however, we found they sometimes visit two and nest close to a third. We propose that males may first settle according to hotspot rules, but females will resettle according to preferences for certain males and/or larger leks. In this way some hotspot leks are abandoned, and the distance between leks is increased as males become more tightly clumped. However, when all males and females have settled, the leks still existing would be on hotspots. In the female preference hypothesis, males are assumed to aggregate on leks because females prefer clustered males as they can be more easily compared than if they are dispersed. Alternatively, in the attractiveness hypothesis, it is suggested that females prefer certain males, and hence unattractive males surround the attractive are forced to join leks in order to come close to females. Our data on male site fidelity support the attractiveness hypothesis because successful and dominant males return to the same lek and territory, both within and between years, whereas unsuccessful males move to other leks. Attractiveness of certain males may explain why according to hotspot rules in this species males are more clumped than expected. Offprint requests to: J. Höglund     

Emissions from charbroiling and grilling of chicken and beef

Emission rates for fine particle (<2.5 microm) mass (PM2.5), carbon (organic/elemental), inorganic ions (SO4(2-), NO3-, NH4+), elements (primarily metals), and speciated organic compounds are reported for charbroiling hamburger, steak, and chicken. The PM2.5 rates for charbroiling meats ranged from 4.4 to 11.6 g/kg of uncooked meat in this study. No mass-emission rates are available from grilling, but the speciated organic data are available for these samples. Emission rates varied by type of appliance, meat, meat-fat content, and cooking conditions. High-fat hamburger cooked on an underfired charbroiler emitted the highest amount of PM2.5. The emissions were almost exclusively composed of organic carbon, with small amounts of elements and inorganic ions. Water-soluble K+ and Cl-, which are used as indicators of wood smoke in source apportionment studies, were also present in meat-cooking emissions. The speciated organic compounds that were measured include polycyclic aromatic hydrocarbons (PAHs), cholesterol, and the long-chain gamma-lactones. Charbroiling emissions yielded an average of approximately 3-5 times more PAHs, approximately 20 times more cholesterol, and approximately 10 times more lactones than grilling. These data were utilized in the ambient source apportionment analysis for the 1997 Northern Front Range Air Quality Study source apportionment.     

Emission rates and comparative chemical composition from selected in-use diesel and gasoline-fueled vehicles

Emission samples for toxicity testing and detailed chemical characterization were collected from a variety of gasoline- and diesel-fueled in-use vehicles operated on the Unified Driving Cycle on a chassis dynamometer. Gasoline vehicles included normal particle mass (particulate matter [PM]) emitters (tested at 72 and 30 degrees F), "black" and "white" smokers, and a new-technology vehicle (tested at 72 degrees F). Diesel vehicles included current-technology vehicles (tested at 72 and 30 degrees F) and a high PM emitter. Total PM emission rates ranged from below 3 mg/mi up to more than 700 mg/mi for the white smoker gasoline vehicle. Emission rates of organic and elemental carbon (OC/EC), elements (metals and associated analytes), ions, and a variety of particulate and semi-volatile organic compounds (polycyclic aromatic hydrocarbons [PAH], nitro-PAH, oxy-PAH, hopanes, and steranes) are reported for these vehicles. Speciated organic analysis also was conducted on the fuels and lube oils obtained from these vehicles after the emissions testing. The compositions of emissions were highly dependent on the fuel type (gasoline vs. diesel), the state of vehicle maintenance (low, average, or high emitters; white or black smokers), and ambient conditions (i.e., temperature) of the vehicles. Fuel and oil analyses from these vehicles showed that oil served as a repository for combustion byproducts (e.g., PAH), and oil-burning gasoline vehicles emitted PAH in higher concentrations than did other vehicles. These PAH emissions matched the PAH compositions observed in oil.     

An integrated assessment of estrogenic contamination and biological effects in the aquatic environment of The Netherlands

An extensive study was carried out in the Netherlands on the occurrence of a number of estrogenic compounds in surface water, sediment, biota, wastewater, rainwater and on the associated effects in fish. Compounds investigated included natural and synthetic hormones, phthalates, alkylphenol(ethoxylate)s and bisphenol-A. The results showed that almost all selected (xeno-)estrogens were present at low concentrations in the aquatic environment. Locally, they were found at higher levels. Hormones and nonylphenol(ethoxylate)s were present in concentrations that are reportedly high enough to cause estrogenic effects in fish. Field surveys did not disclose significant estrogenic effects in male flounder (Platichthys flesus) in the open sea and in Dutch estuaries. Minor to moderate estrogenic effects were observed in bream (Abramis brama) in major inland surface waters such as lowland rivers and a harbor area. The prevalence of feminizing effects in male fish is largest in small regional surface waters that are strongly influenced by sources of potential hormone-disrupting compounds. High concentrations of plasma vitellogenin and an increased prevalence of ovotestes occurred in wild male bream in a small river receiving a considerable load of effluent from a large sewage treatment plant. After employing in vitro and in vivo bioassays, both in situ and in the laboratory, we conclude that in this case hormones (especially 17 alpha-ethynylestradiol) and possibly also nonylphenol(ethoxylate)s are primarily responsible for these effects.     

Characterizing In Situ Methane‐Enhanced Biostimulation Potential for 1,4‐Dioxane Biodegradation in Groundwater

This study characterizes the 1,4‐dioxane biodegradation potential for an in situ methane‐enhanced biostimulation field pilot study conducted at Air Force Plant 44, located south of the Tucson International Airport in Arizona. In this study, the use of methane as the primary substrate in aerobic cometabolic biodegradation of 1,4‐dioxane is evaluated using environmental molecular diagnostic tools. The findings are compared to an adjacent pilot study, wherein methane was generated via enhanced reductive dechlorination and where methane monooxygenase and methane‐oxidizing bacteria were also found to be abundant. This article also presents the use of ¹³C and ²H isotopic ratio enrichment, a more recent tool, to support the understanding of 1,4‐dioxane biodegradation in situ. This study is the first of its kind, although alkane gas‐enhanced biodegradation of 1,4‐dioxane has been evaluated extensively in microcosm studies and propane‐enhanced biodegradation of 1,4‐dioxane has been previously studied in the field. ©2016 Wiley Periodicals, Inc.     

Groundwater management and socio-economic responses

The socio-economic aspects of groundwater development and management are briefly examined and set against a background of highly technical management. The variability of socio-economic responses to groundwater and the problems of engaging large numbers of individual users are highlighted. The paper argues that social, institutional and political factors are the primary obstacles to sustainable management of the world's groundwater resources.     

Near-term forecasts of stream temperature using deep learning and data assimilation in support of management decisions

Deep learning (DL) models are increasingly used to make accurate hindcasts of management-relevant variables, but they are less commonly used in forecasting applications. Data assimilation (DA) can be used for forecasts to leverage real-time observations, where the difference between model predictions and observations today is used to adjust the model to make better predictions tomorrow. In this use case, we developed a process-guided DL and DA approach to make 7-day probabilistic forecasts of daily maximum water temperature in the Delaware River Basin in support of water management decisions. Our modeling system produced forecasts of daily maximum water temperature with an average root mean squared error (RMSE) from 1.1 to 1.4°C for 1-day-ahead and 1.4 to 1.9°C for 7-day-ahead forecasts across all sites. The DA algorithm marginally improved forecast performance when compared with forecasts produced using the process-guided DL model alone (0%–14% lower RMSE with the DA algorithm). Across all sites and lead times, 65%–82% of observations were within 90% forecast confidence intervals, which allowed managers to anticipate probability of exceedances of ecologically relevant thresholds and aid in decisions about releasing reservoir water downstream. The flexibility of DL models shows promise for forecasting other important environmental variables and aid in decision-making.