A microcosm test of adaptation and species specific responses to polluted sediments applicable to indigenous chironomids (Diptera)

Chironomids may adapt to pollution stress but data are confined to species that can be reared in the laboratory. A microcosm approach was used to test for adaptation and species differences in heavy metal tolerance. In one experiment, microcosms containing different levels of contaminants were placed in polluted and reference locations. The response of Chironomus februarius to metal contaminants suggested local adaptation: relatively more flies emerged from clean sediment at the reference site and the reverse pattern occurred at the polluted site. However, maternal effects were not specifically ruled out. In another species, Kiefferulus intertinctus, there was no evidence for adaptation. In a second experiment, microcosms with different contaminant levels were placed at two polluted and two unpolluted sites. Species responded differently to contaminants, but there was no evidence for adaptation in the species where this could be tested. Adaptation to heavy metals may be uncommon and species specific, but more sensitive species need to be tested across a range of pollution levels. Factors influencing the likelihood of adaptation are briefly discussed.     

Changes in mussel Mytilus galloprovincialis protein profile as a reaction of water pollution

In the present report the changes in mussels Mytilus galloprovincialis protein profile, as a reaction of water pollution, is presented. The antioxidant capacity was determined by the efficacy to scavenge the derived radical in mussel samples using the Trolox Equivalent Antioxidant Capacity (TEAC) assay. The highest percentage of inhibition was estimated in protein mussels from the dirty area (DM) in comparison with the clean samples (CM). The amounts of both zinc and copper determined by atomic spectroscopy were significantly higher in the protein mussels from the dirty than from the clean areas (P<0.05). Fourier Transform Infrared (FT-IR) spectroscopy and fluorescence revealed specific qualitative changes in secondary and tertiary structures of mussel proteins from the dirty area by the shift in the amides I and II positions and fluorescence intensity. Estimated temperature and enthalpy of denaturation in the protein mussels well correlated with fluorescence and spectroscopic measurements and showed the changes influenced by water pollution.     

Risk management for assuring safe drinking water

Millions of people die every year around the world from diarrheal diseases much of which is caused by contaminated drinking water. By contrast, drinking water safety is largely taken for granted by many citizens of affluent nations. The ability to drink water that is delivered into households without fear of becoming ill may be one of the key defining characteristics of developed nations in relation to the majority of the world. Yet there is well-documented evidence that disease outbreaks remain a risk that could be better managed and prevented even in affluent nations. A detailed retrospective analysis of more than 70 case studies of disease outbreaks in 15 affluent nations over the past 30 years provides the basis for much of our discussion [Hrudey, S.E. and Hrudey, E.J. Safe Drinking Water--Lessons from Recent Outbreaks in Affluent Nations. London, UK: IWA Publishing; 2004.]. The insights provided can assist in developing a better understanding within the water industry of the causes of drinking water disease outbreaks, so that more effective preventive measures can be adopted by water systems that are vulnerable. This preventive feature lies at the core of risk management for the provision of safe drinking water.     

Contamination of terrestrial gastropods, Helix aspersa maxima, with 137Cs, 85Sr, 133Ba and 123mTe by direct, trophic and combined pathways

(137)Cs, (85)Sr, (133)Ba and (123m)Te contaminations of terrestrial gastropods, Helix aspersa maxima, by direct deposition, labelled food ingestion or combined (trophic and direct pathways) exposure were carried out under laboratory conditions. The aim of this study was to compare the three contamination pathways: direct, trophic and combined, in terms of individual mortality, radionuclide uptake, depuration and distribution in the tissues. An initial group of 30 snails (2 years old) was exposed to radioactive aerosols during a 20-h period. These aerosols were assumed to be representative of those that would be released during a nuclear accident occurring in a PWR. A second group of 50 snails (same age) was submitted to an ingestion of commercial food contaminated by the same aerosols, twice a week for 21 days (flour at a feeding rate of about 0.2g). A third group of 40 snails was submitted to a combined exposure: exposure to radioactive aerosols (20h), followed by ingestion of flour contaminated by the same aerosols, twice a week for 21 days. No significant difference between the three groups and a reference group of 10 snails was observed, neither in growth nor in mortality. Concerning the direct pathway, at the end of direct deposition (about 1 day after the beginning), cesium was the most bioavailable element, distributed rather homogeneously throughout the whole body (13% of the total Cs in all organs excepting the digestive system and 28% in the muscle). Strontium was measured in the shell (about 70%). Barium was found in the muscle (20%) and in the shell (65%). Tellurium was mainly present in the shell (70%) and in the digestive system (20%). After 21 days of depuration, the faeces eliminated 42% of the Te. As for contamination by ingestion, Te mainly accumulated in the digestive system (72% of Te present in the total body), Ba accumulated in the muscle (75%) and Sr in the shell (70%). Concerning contamination by combined pathways, at the end of the 21-day exposure, the 4 radionuclides had the same tendency as direct deposition. However, the effect of the trophic pathway was significant: it causes an 18% increase of Sr in the shell and an 7% increase of Cs in the digestive system in comparison to direct deposition, resulting in a final 86% in the shell and 27% in the digestive system.     

How environmentally focused is the German sustainability strategy? A critical discussion of the indicators used to measure sustainable development in Germany

There are hardly any critical discussions of sustainable development indicator sets designed for use at the national level. This article aims at rectifying this omission in critical academic research by contributing to the discourse on environmental sustainability with an assessment of the indicator set used for the measurement of sustainable development in Germany. It will evaluate to what extent the sustainable development concept is reflected in the structure of the strategy and analyse in how far fundamental environmental issues are covered by the indicator set. The discussion will show that the environmental dimension of the sustainability concept is not sufficiently integrated in the German National Sustainable Development Strategy. Although the strategy??s indicator set contains a range of environmental indicators, gaps in the German indicator set become apparent when contrasted with important issues of sustainability. It will be concluded that the environmental dimension of the sustainable development concept is not the recurrent theme in either the strategy or the indicator set.     

Dominant features in three-dimensional turbulence structure: comparison of non-uniform accelerating and decelerating flows

The results are presented from an experimental study to investigate three-dimensional turbulence structure profiles, including turbulence intensity and Reynolds stress, of different non-uniform open channel flows over smooth bed in subcritical flow regime. In the analysis, the uniform flow profiles have been used to compare with those of the non-uniform flows to investigate their time-averaged spatial flow turbulence structure characteristics. The measured non-uniform velocity profiles are used to verify the von Karman constant κ and to estimate sets of log-law integration constant B_r and wake parameter П, where their findings are also compared with values from previous studies. From κ, B_r and П findings, it has been found that the log-wake law can sufficiently represent the non-uniform flow in its non-modified form, and all κ, B_r and П follow universal rules for different bed roughness conditions. The non-uniform flow experiments also show that both the turbulence intensity and Reynolds stress are governed well by exponential pressure gradient parameter β equations. Their exponential constants are described by quadratic functions in the investigated β range. Through this experimental study, it has been observed that the decelerating flow shows higher empirical constants, in both the turbulence intensity and Reynolds stress compared to the accelerating flow. The decelerating flow also has stronger dominance to determine the flow non-uniformity, because it presents higher Reynolds stress profile than uniform flow, whereas the accelerating flow does not.     

SETAC GLB and SETAC Europe SAC: a liaison promoting the next generation of ecotoxicologists and environmental chemists

This commentary is an introduction for students to the Society of Environmental Toxicology and Chemistry (SETAC) and its Student Advisory Council (SAC). As young academics face challenges while trying to develop their careers, SETAC and the SAC help facilitate student involvement in the various communities within the society that can help to develop the students’ careers within the environmental sciences [e.g. the German Language Branch (GLB)]. This piece would also like to emphasize and pay homage to the continual cooperation between the SAC and the ESEU, which provides a scientific platform to communicate internationally and beyond the borders of SETAC, as well as offer heartfelt congratulations from the SAC to the GLB for their “20 Years SETAC GLB” and deep gratitude for their strong advocacy and support of the SAC.     

Bridging international relations and disaster studies: the case of disaster–conflict scholarship

International relations and disaster studies have much to gain by thinking critically about their respective theoretical and epistemological assumptions. Yet, few studies to date have sought to assess the potential value of linking these two disciplines. This paper begins to address this shortfall by examining the relationship between disasters and conflict as a research sphere that intersects international relations and disaster studies. Through an analysis of whether or not disasters contribute to intra‐national and international conflict, this paper not only provides a review of the state of the art, but also serves to invite scholars to reflect on related concepts from other fields to strengthen their own approaches to the study of disasters in an international setting. An evaluation of the conceptual and theoretical contributions of each subject area provides useful heuristics for the development of disaster–conflict scholarship and encourages alternative modes of knowledge production through interdisciplinarity.     

The geographic distribution of radionuclide deposition across the continental US from atmospheric nuclear testing

For the first time, calculations for the more than 3000 counties of the US have been completed that estimate the average deposition density (Bq m(-2)) of more than 40 radionuclides in fallout from atmospheric nuclear weapons tests conducted in the US (1951-1962) and 19 radionuclides from tests conducted elsewhere in the world (1952-1963). The geographic pattern of deposition across the US, as well as the amount of fallout deposited, varied significantly depending on whether the tests were conducted within or outside of the US. Fallout deposited from the Nevada Test Site (NTS) varied geographically as a result of dispersion and dilution in the atmosphere, the wind patterns following each test, and the occurrence of localized rainfall events. In general, states immediately east of the NTS received the highest deposition from tests conducted there. In contrast, the variation in deposition across the country from global fallout was less than for NTS fallout primarily reflecting variations in annual precipitation across larger regions. Hence, in the eastern and mid-western US, where rainfall is above the national average, higher levels of global fallout were deposited than in the more arid southwestern states. This paper presents a summary of the methods used and findings of our studies on fallout from NTS and global fallout, with emphasis on two of the most important radionuclides, (131)I and (137)Cs.     

INFLUENCE OF TWO WOODY RIPARIAN SPECIES ON CRITICAL CONDITIONS FOR STREAMBANK STABILITY: UPPER TRUCKEE RIVER,CALIFORNIA1

Over the past 35 years, a trend of decreasing water clarity has been documented in Lake Tahoe, attributable in part to the delivery of fine grained sediment emanating from upland and channel erosion. A recent study showed that the Upper Truckee River is the single largest contributor of sediment to Lake Tahoe, with a large proportion of the sediment load emanating from streambanks. This study combines field data with numerical modeling to identify the critical conditions for bank stability along an unstable reach of the Upper Truckee River, California. Bank failures occur during winter and spring months, brought on by repeated basal melting of snow packs and rain‐on‐snow events. Field studies of young lodgepole pines and Lemmon's willow were used to quantify the mechanical, hydrologic, and net effects of riparian vegetation on streambank stability. Lemmon's willow provided an order of magnitude more root reinforcement (5.5 kPa) than the lodgepole pines (0.5 kPa); the hydrologic effects of the species varied spatially and temporally and generally were of a smaller magnitude than the mechanical effects. Overall, Lemmon's willow provided a significant increase in bank strength, reducing the frequency of bank failures and delivery of fine grained sediment to the study reach of the Upper Truckee River.