Studies on the acute toxicity of fluoride ion to stickleback,fathead minnow,and rainbow trout

We have studied the acute toxicity of fluoride ion to $\text{Gasterosteus aculeatus}$, $\text{Pimephales promelas}$, and juvenile $\text{Salmo gairdneri}$. LC50 values varied with species and (due to precipitation) initial water hardness. Exposure to elevated fluoride levels in water resulted in increased blood fluoride levels in $\text{Salmo gairdneri}$.     

a study of the temporal variability of atrazine in private well water. part i: study design, implementation, and database development

In 1988, the Iowa Department of Natural Resources, along withthe University of Iowa conducted the Statewide Rural WellWater Survey, commonly known as SWRL. A total of 686private rural drinking water wells was selected by use of aprobability sample and tested for pesticides and nitrates. Sixty-eight of these wells, the 10% repeat wells, were additionallysampled in October, 1990 and June, 1991. Starting inNovember, 1991, the University of Iowa, with sponsorshipfrom the United States Environmental Protection Agency,revisited these wells to begin a study of the temporalvariability of atrazine and nitrates in wells. Other wells, whichhad originally tested positive for atrazine in SWRL but werenot in the 10% repeat population, were added to the studypopulation. Temporal sampling for a year-long period beganin February of 1992 and concluded in January of 1993. Allwells were sampled monthly, one subset was sampled weekly,and a second subset was sampled for 14-day consecutiveperiods. Two unique aspects of this study were the use of animmunoassay technique to screen for triazines before gaschromatography/mass spectrometry (GC/MS) analysis andquantification of atrazine, and the use of well owners to samplethe wells. A total of 1771 samples from 83 wells are in thefinal data base for this study. This paper reviews the studydesign, the analytical methodologies, and development of thedata base. A companion paper (Pinsky et al., 1997) discussesthe analysis of the data from this survey.     

The Development of Biological Objectives for Streams in a Single Catchment: A Case Study on the Catchment of Western Port Bay, Victoria, Australia

Government environment protection policies for waterways have traditionally relied on water quality indicators and their objectives. In this paper we describe the development of biological objectives based on invertebrate indicators for inclusion in a government policy for the catchment of Western Port Bay, Victoria. The first step of defining segments (areas with streams in which the same objectives are applied) was problematic, requiring two different approaches, as follows. Site groups initially based on invertebrate community composition derived using multivariate techniques (ordination and classification) proved to be unsuitable for policy segments. Segment boundaries were subsequently defined using topographical (e.g. boundary of foothills and lowland plains), climate (e.g. rainfall) and land-use (e.g. urban) features. We used information and data from reference sites inside as well outside the catchment to derive specific biological objectives based on aquatic invertebrates for these segments. Objectives were specified for the following four indicators--number of invertebrate families, the SIGNAL index, the AUSRIVAS predictive model and the number of key families.     

Work stress and problem alcohol behavior: a test of the spillover model

Although previous research has found weak support for the model of stressful work ‘spilling over’ to negative coping responses during nonwork hours, we argue that a variety of conceptual and methodological problems may partially explain the weak and inconsistent findings. Two important shortcomings are inadequately specified models and a failure to consider nonescapist responses to job-related stress. We therefore propose that there may be escapist (i.e. increased drinking, working through job dissatisfaction for those who believe that alcohol consumption is an effective means to reduce stress) and nonescapist (i.e. decreased drinking for those who are dissatisfied with their jobs but do not believe alcohol is an effective coping strategy) responses to work stress. These hypotheses were tested on a sample of 972 production workers in the Pacific northwest. Results show moderate support for the existence of both escapist and nonescapist responses to job-related stresses. © 1998 John Wiley & Sons, Ltd.     

Seafloor ecosystem functioning: the importance of organic matter priming

Organic matter (OM) remineralization may be considered a key function of the benthic compartment of marine ecosystems and in this study we investigated if the input of labile organic carbon alters mineralization of indigenous sediment OM (OM priming). Using ¹³C-enriched diatoms as labile tracer carbon, we examined shallow-water sediments (surface and subsurface layers) containing organic carbon of different reactivity under oxic versus anoxic conditions. The background OM decomposition rates of the sediment used ranged from 0.08 to 0.44 μmol C ml_ws⁻¹ day⁻¹. Algal OM additions induced enhanced levels of background remineralization (priming) up to 31% and these measured excess fluxes were similar to mineralization of the added highly degradable tracer algal carbon. This suggests that OM priming may be important in marine sediments.     

Heading for the hills: climate-driven community relocations in the Solomon Islands and Alaska provide insight for a 1.5 °C future

Whilst future air temperature thresholds have become the centrepiece of international climate negotiations, even the most ambitious target of 1.5 °C will result in significant sea-level rise and associated impacts on human populations globally. Of additional concern in Arctic regions is declining sea ice and warming permafrost which can increasingly expose coastal areas to erosion particularly through exposure to wave action due to storm activity. Regional variability over the past two decades provides insight into the coastal and human responses to anticipated future rates of sea-level rise under 1.5 °C scenarios. Exceeding 1.5 °C will generate sea-level rise scenarios beyond that currently experienced and substantially increase the proportion of the global population impacted. Despite these dire challenges, there has been limited analysis of how, where and why communities will relocate inland in response. Here, we present case studies of local responses to coastal erosion driven by sea-level rise and warming in remote indigenous communities of the Solomon Islands and Alaska, USA, respectively. In both the Solomon Islands and the USA, there is no national government agency that has the organisational and technical capacity and resources to facilitate a community-wide relocation. In the Solomon Islands, communities have been able to draw on flexible land tenure regimes to rapidly adapt to coastal erosion through relocations. These relocations have led to ad hoc fragmentation of communities into smaller hamlets. Government-supported relocation initiatives in both countries have been less successful in the short term due to limitations of land tenure, lacking relocation governance framework, financial support and complex planning processes. These experiences from the Solomon Islands and USA demonstrate the urgent need to create a relocation governance framework that protects people’s human rights.     

A new technique for reducing extremely low frequency magnetic field emissions affecting large building structures

When large structures such as residential compounds or public buildings are under the influence of extremely low frequency (ELF) magnetic fields, such as the one generated by a system of railways fed by 16.67 Hz, standard methods of designing shielding structures by numerical methods usually fail. The latter can be explained by the difficulty posed in the computing process by the large aspect ratios involved due to thin layers of metal (a few millimetres or centimetres) in contrast to the large dimensions of the affected structure (several tens of meters). In some cases one has to utilize special approximations such as surface conductivity, which are not easy to handle when the designed shielding structure is clearly three -dimensional. Other alternatives such as experimentation in situ are very costly. Here, a new technique is presented of mitigating the field by using three-dimensional propagation of induced currents optimizing the field reduction factors and minimizing the cost of shielding material. The particular designing method is a hybrid of numerical simulations combined with lab experimentation using scaled models of the large structure. The method is rather cost-effective and flexible as various designs can be easily tested. Results are presented in the form of magnetic field values, at various locations in the buildings, before and after this mitigation technique is applied.     

Survey of Columnar Cacti and Carrying Capacity for Nectar-Feeding Bats on Curaçao

We estimated the population sizes of the three species of columnar cacti that grow on the island of Curaçao using ground and aerial transects, and we examined the island's carrying capacity for two species of nectar-feeding bats that depend on nectar from the flowers of these cacti. We calculated carrying capacity based on the daily availability of mature flowers between January and December 1993 and the field energy requirements of bats as estimated from an equation for eutherian mammals (low estimate) and one for passerine birds (high estimate) based on body mass. Additional energy requirements of pregnancy and lactation were taken into account. We estimated that 461,172 columnar cacti were present on Curaçao (38% Subpilocereus repandus , 51% Stenocereus griseus , and 11% Pilosocereus lanuginosus ). May through September are the critical months when bats rely most heavily on cactus for food. July 1993 was a bottleneck with the smallest number of mature flowers per day. July and August were months of greatest energy demand because females were lactating. We estimate that the carrying capacity for Glossophaga longirostris in July, when the bat ( Leptonycteris curasoae ) population was 900, was near 1200, an estimate that fits the observed population size of nectar-feeding bats on the island. We suggest that the extensive removal of native vegetation occurring on Curaçao be strictly regulated because further destruction of the cacti will result in a decrease and potential loss of the already low populations of nectar-feeding bats.     

Multi-residue determination of pharmaceuticals in sludge and sludge enriched soils using pressurized liquid extraction, solid phase extraction and liquid chromatography with tandem mass spectrometry

An analytical method to determine a selection of 27 frequently prescribed and consumed pharmaceuticals in biosolid enriched soils and digested sludges is presented. Using a combination of pressurized liquid extraction, solid phase extraction and liquid chromatography with tandem mass spectrometry, it was possible to detect all analytes in each sample type at the low-sub ng g(-1) level. Solid phase extraction efficiencies were compared for 6 different sorbent types and it was found that Waters Oasis HLB cartridges offered enhanced selectivities with 20 analytes showing final method recoveries > or =60% in both soils and digested sludges. The method was validated for linearity, range, precision and limits of detection in both sample matrices. All analytes were then determined in sludge enriched soils as well as the precursor thermally dried sludge fertilizer produced from a primary wastewater treatment plant. Levels of the antibacterial agent triclosan were found to exceed 20 microg g(-1) in digested sludge and 5 microg g(-1) in thermally dried sludge cake. Significant traces of carbamazepine and warfarin were also detected in the above samples.