Chemical speciation of inorganic pollutants in river–estuary–sea water systems

Monitoring studies and thermodynamic modeling were used to reveal the changes of inorganic chemical species of some water pollutants (nutrients and trace metals such as Fe, Mn, Zn, Cu, Cd and Pb) inthe river-estuary-sea water system. The case studies were two rivers, Kamchiya and Ropotamo, representing part of the Bulgarian Black Sea water catchment area, and having different flow characteristics. There were no major differences in inorganic chemical species of the two river systems. NO3(-) and NO2(-) chemical species showed no changes along the river-estuary-sea water system. Concerning phosphates six different species were calculated and differences between the three parts of the systems were established. The HPO4(2-) and H2PO4(-) species were found to be dominant in river waters. The H2PO4(-) species quickly decreased at the expense of HPO4(2-) and Ca, Mg and Na phosphate complexes in estuary and seawater. Trace metals showed a great variety of chemical species. Fe(OH)2(+) species prevailed in river waters, and Fe(OH)3(0) species--in sea waters. Me2+ and MeCO3(0) (Me = Cu, Pb) and PbHCO3(+) were dominant in river waters, while Cu(CO3)2(2-) and PbCl(-) species appear also in sea waters. Cd2+ species prevailed in river and estuary waters, and CdCln(2-n) (n = 1-3) species, in seawater. Free Zn2+ species predominated in all systems but downstream their percentage decreased at the expense of Zn phosphates, carbonates,sulfates and chlorides complexes. Only free Mn2+ species were dominant along the systems.     

Regional assessment of marine and estuarine sediment toxicity in Southern California, USA

Sediment toxicity was investigated at 222 stations in the Southern California Bight (SCB) during 2008. This represented the first time that assessment methods established by California's new Sediment Quality Objectives program were employed in a survey of this scale. The goal was to determine the extent and magnitude of sediment toxicity in the SCB, how toxicity compared among specific environments, and whether toxicity has changed over the last decade. Two toxicity tests were used: the 10-day amphipod whole sediment survival test with Eohaustorius estuarius and a 48-h embryo development test with the mussel Mytilus galloprovincialis exposed at the sediment–water interface. Less than 1 % of the area of the SCB was found to be toxic to the amphipod test. No toxicity was found in offshore stations, but 14 % of embayment areas were toxic to the amphipods. The mussel test identified 13 % of the embayment areas to be toxic. Estuary and marina locations had the greatest areal extent of toxicity for both tests. The two toxicity methods agreed that sediments were not toxic at over half of the stations tested. The mussel test showed a greater magnitude of response than the amphipod. Sediment toxicity was shown to have declined in both extent and magnitude from levels measured in 1998 and 2003.     

Correction to: Documenting lemming population change in the Arctic: Can we detect trends?

Ambio - In the original published article, some of the symbols in figure 1A were modified incorrectly during the typesetting and publication process. The correct version of the figure is provided...     

Bioventing of No. 2 Fuel Oil: Effects of Air Flowrate,Temperature, Nutrient Amendment,and Acclimation

A 14‐month pilot‐scale bioventing study, sponsored by the New Hampshire Department of Environmental Services, was conducted by the University of New Hampshire to determine the effects of the time between the contamination event and the onset of bioventing, as well as air flowrate, temperature, and nutrient amendments. Freshly contaminated soil was not readily amenable to bioventing. Bioventing was effective (82–92.5 percent removal) for acclimated soil amended with nutrients at 10 °C and 20 °C for the 275 cm³/min and 140 cm³/min air flowrates, respectively. First order degradation rates after nutrient addition were ?6.11 ± 0.83 (×10^?3)/day and ?6.57 ± 1.71 (×10^?3)/day, respectively. The results indicate that bioventing will be best applied when the contamination has occurred at least two years before the onset of treatment. © 2014 Wiley Periodicals, Inc.     

Inhibition equivalency factors for microcystin variants in recombinant and wild-type protein phosphatase 1 and 2A assays

In this work, protein phosphatase inhibition assays (PPIAs) have been used to evaluate the performance of recombinant PP1 and recombinant and wild-type PP2As. The enzymes have been compared using microcystins-LR (MC-LR) as a model cyanotoxin. Whereas PP2A_Rec provides a limit of detection (LOD) of 3.1 μg/L, PP1_Rec and PP2A_Wild provide LODs of 0.6 and 0.5 μg/L, respectively, lower than the guideline value proposed by the World Health Organization (1 μg/L). The inhibitory potencies of seven MC variants (-LR, -RR, -dmLR, -YR, -LY, -LW and -LF) have been evaluated, resulting on 50 % inhibition coefficient (IC₅₀) values ranging from 1.4 to 359.3 μg/L depending on the MC variant and the PP. The PPIAs have been applied to the determination of MC equivalent contents in a natural cyanobacterial bloom and an artificially contaminated sample, with multi-MC profiles. The inhibition equivalency factors (IEFs) have been applied to the individual MC quantifications determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, and the estimated MC-LR equivalent content has been compared to PPIA results. PPIAs have demonstrated to be applicable as MC screening tools for environmental applications and to protect human and animal health.     

Uptake of microcontaminants by crops irrigated with reclaimed water and groundwater under real field greenhouse conditions

The use of reclaimed water for agricultural irrigation has emerged as a new strategy for coping with water scarcity in semiarid countries. However, the incorporation of the organic microcontaminants in such water into the diet through crop uptake poses a potential risk to human health. This paper aims to assess the presence of organic microcontaminants in different crops irrigated with groundwater and reclaimed water (secondary or tertiary effluents) in a greenhouse experiment. The determination of microcontaminants in water and vegetation samples was performed by solid-phase extraction and matrix solid-phase dispersion procedure with GC–MS/MS, respectively. The presence of nitrates in the groundwater used for irrigation increased biomass production by a higher proportion than the harvest index. The concentration of microcontaminants in lettuce, carrots, and green beans ranged from less than the limit of quantitation to 571 ng?g^?1 (fresh weight). Tributyl phosphate and butylated hydroxyanisole exhibited the highest concentration levels in crops. The concentration and frequency of detection of microcontaminants were lower in green bean pods than in green bean roots and leaves. Although the concentrations were generally low, the simultaneous presence of a variety of microcontaminants should be taken into consideration when assessing the risk to human health.     

Aerial application of copper for dothistroma control in New Zealand’s planted forests—effect on stream environments

Environmental Science and Pollution Research - Limited information is available on the risk to aquatic environments from the aerial application of copper fungicides to treat dothistroma needle...     

The role of respondents’ comfort for variance in stated choice surveys: evidence from a SCUBA diving case

Preference elicitation among outdoor recreational users is subject to measurement errors that depend, in part, on survey planning. This study uses data from a choice experiment survey on recreational SCUBA diving to investigate whether self-reported information on respondents’ comfort when they complete surveys correlates with the error variance in stated choice models of their responses. Comfort-related variables are included in the scale functions of the scaled multinomial logit models. The hypothesis was that higher comfort reduces error variance in answers, as revealed by a higher scale parameter and vice versa. Information on, e.g., sleep and time since eating (higher comfort) correlated with scale heterogeneity, and produced lower error variance when controlled for in the model. That respondents’ comfort may influence choice behavior suggests that knowledge of the respondents’ activity patterns could be used to plan the timing of interviews to decrease error variance in choices and, hence, generate better information.     

Development of an enzyme-linked immunosorbent assay for atrazine monitoring in water samples

The implementation of the Water Framework Directive (2000/60/EC) requires the establishment of monitoring programs. However, conventional procedures for sample preparation prior to chromatographic analysis are rather expensive and time consuming, being the development of cost-effective and easy tool a necessity. The aim of this work was to develop an enzyme-linked immunosorbent assay (ELISA) able to determine atrazine in water samples. Matrix effects evaluation showed that the increase of humic acid (HA) concentration leads to flattened calibration curves and to the loss of the sigmoidal shape. However, such interference was overcome, by the presence of an environmental sample buffer, incubated together with the samples. Recoveries from 88.5 to 119.2 % were obtained in the presence of HA concentrations up to 20 mg?L^?1. An analytical range from 0.003 to 1 μg?L^?1 was obtained, and atrazine was detected in a sewage treatment plant with concentrations ranging from 14 to 52 ng?L^?1.     

A systematic review of biodiversity and demographic change: A misinterpreted relationship?

Demographic change is supposed to be the most important indirect driver for changing biodiversity. In this article, a systematic review of 148 studies was conducted to examine the scientific evidence for this relationship and to identify potential gaps in research. We explored the spatial distribution of studies, the categories addressed with respect to biodiversity and demographic change, and the ways in which their relationships were conceptualised (spatially and temporally) and valued. The majority of studies were carried out in Africa, Europe and North America. Our analysis confirms the trend that demographic phenomena were mostly found to negatively influence biodiversity. However, a considerable number of studies also point towards impacts that were context dependent, either positive or negative under certain circumstances. In addition to that we identified significant gaps in research. In particular, there is a lack of addressing (1) other demographic aspects such as population decline, age structure or gender differences, (2) spatial variability of, e.g. human population growth, (3) long-term effects of demographic processes, and (4) the context dependency (e.g. regulations/law enforcement, type of human activities, and choice of scale or proxy). We conclude there is evidence that the relationship between biodiversity and demographic change is much more complex than expected and so far represented in research. Thus, we call for a social–ecological biodiversity research that particularly focusses on the functional relation between biodiversity and human activities, namely the different types, context, and interdependent dynamics (spatial and temporal) of this complex relation.