Organotins in marine mammals and seabirds from Norwegian territory

An increasing number of studies indicate that marine mammals and some seabirds are exposed to organotins. However, results from northern and Arctic areas are few. Here results from analysis of tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT) in harbour porpoise (Phocoena phocoena), common seal (Phoca vitulina), ringed seal (Phoca hispida) and glaucous gull (Larus hyperboreus) from Norwegian territory are presented. Relatively high concentrations of DBT, TBT and MBT were observed in muscle, kidney and liver from harbour porpoises caught in northern Norway in 1988, just before restrictions on the use of tributyltin (TBT)(mainly on small boats) were introduced in several European countries. The concentrations in harbour porpoise muscle tissue were reduced significantly 11 years later, possibly as a result of the introduced restrictions. Considerably lower concentrations of butyltins were observed in the seals compared to porpoises. The lowest levels of organotins were found in ringed seals from Spitsbergen, where only traces of dibutyltin (DBT) and monobutyltin (MBT) were observed. Traces of DBT and MBT were also found in some individual glaucous gulls from Bear Island. The sum of the degradation products MBT and DBT in liver samples from all analysed species were generally higher than TBT itself. Triphenyltin (TPhT) was observed in all porpoise samples and in livers of common seals. Also the sum of the degradation products MPhT and DPhT in liver samples from porpoise and common seals were higher than TPhT. No traces of phenyltins were found in ringed seals from Spitsbergen or in glaucous gulls from Bear Island. The limited data available indicate low to moderate exposure to organotins in northern areas (Spitsbergen and Bear Island). Marine mammals are however more exposed further south along the Norwegian Coast.     

On polyphagism

This paper presents a mathematical formulation of the principle of polyphagism. The effect of the principle is illustrated on the polyphagic model worked out after analysis of Ivlev's (1955) experimental data.     

Thermal behaviour of chromium electroplating sludge

Galvanic sludge is classified as a hazardous waste and incineration is one of the techniques used for its treatment. The aim of this work is to study the thermal behavior of a galvanic sludge which contains only chromium as a restriction metal. Simultaneous DTA/TG coupled with mass spectrometer tests were performed to characterize the thermal behavior of the sludge. Besides thermal analysis, sludge samples were heated in a specially designed furnace and these samples were submitted to X-ray diffraction. Vapor from the heated sludge was condensed and the particles were analyzed by EDS microprobe coupled in a scanning electron microscope. The slag formed after the calcination of the galvanic sludge was mainly composed of a mixture of calcium phosphate and fluoride. and minor concentrations of metals. A total weight loss of 34% was observed. The greatest part of this weight loss corresponds to CO2, H2O and SO2. H2O is liberated in the temperature range of 500-1,250 degrees C. CO2 in the range of 500-750 degrees C and SO2 near 1,000 degrees C. Chromium evaporation was not observed in relevant quantities, about 99.6% of the Cr remained incorporated in the slag.     

Ciliated epibionts on the Arctic sympagic amphipod<Emphasis Type="Italic"> Gammarus wilkitzkii</Emphasis> as indicators for sympago–benthic coupling

In September 2003 specimens of the sympagic amphipod Gammarus wilkitzkii were sampled in drifting pack ice above 50 m water depth and in the pelagic/benthic environment beneath in the coastal waters off Svalbard (Norway). Abundance values ranged between 1.5 and 8 individuals m^–2 for the pelagic/benthic and the sympagic environments, respectively, and showed corresponding sex ratios of 1:1.4, favoring males. In the ice a significantly higher number of juveniles prevailed. In contrast, ovigerous females were more abundant among pelagic/benthic living specimens. Approximately 25% of the individuals hosted ciliated epibionts of the genera Ephelota, Cryptacineta, Acineta, Podophrya (all suctoria), and Epistylis (peritrichia). Cryptacineta and Ephelota were the most abundant epibionts on this amphipod species. Female specimens of G. wilkitzkii showed the highest degree of infestation (>2,100 individual epibionts per amphipod specimen: indE/A) followed by juveniles (>1,200 indE/A) and males (>220 indE/A). Highest densities of epibionts were found on anterior body parts with the antennae bearing up to 130 individuals. This is the first sighting of epibionts on crustacea from the sympagic environment. We interpret them as biomarkers that indicate the existence of sympago–benthic coupling processes between the ice and the underlying waters and the seafloor. The population structure and the proportion of infested specimens are equal for the amphipods sampled from both the sympagic and the pelagic/benthic environment, indicating the existence of exchange (coupling) processes between the two habitats. Considering the annual ice cycle, local ice drift patterns, and the shallow water depth in the sampling area, we hypothesize that ice amphipods spend ice-free periods near the seafloor where they may serve as basibionts for protozoans and eventually re-colonize the ice with the onset of ice formation. Our observations strongly emphasize that shallow coastal areas serve as both retention (rather than sink) areas for ice fauna during ice-free periods, and as stepping-stones for re-colonizing the ice when the ice is formed in winter.Communicated by M. Kühl, Helsingor     

Aqueous, solid and gaseous partitioning of selenium in an oxic sandy soil under different microbiological states

The aim of this study was to investigate the role of microorganisms on the behaviour of selenium in natural soil maintained under strictly aerobic conditions. Six-day batch experiments were performed with soils constrained to different microbiological states, either by sterilisation or by adding organic substrates. Selenium was added to the soil as selenite. The distribution of selenium in the gaseous, liquid and solid phases of the batch was measured. Selenium partitioning between the various solid phases was investigated by chemical sequential extractions. Active microorganisms played major effects on the distribution of selenium within the soil. On the one hand, microorganisms could promote selenium volatilisation (in relatively small amounts), leading to the spreading of selenium compounds outside the soil. On the other hand, microbial activities increased both amount of selenium retained by the soil and the strength of its retention (less exchangeable selenium), making selenium less susceptible to remobilisation.     

A simple dermal absorption model: Derivation and application

This paper deals with the derivation of a QSAR for the estimation of:

• the skin permeation coefficient from aqueous solutions in cm h⁻¹,

• the stratum corneum/water partition coefficient.

These QSARs enable the estimation of:

• the aqueous permeation coefficient in cm h⁻¹,

• the maximum dermal absorption in mg cm⁻² h⁻¹ from a saturated aqueous solution at steady state,

• the lag time in hours (h),

• the diffusivity of a substance in the stratum corneum in cm² h⁻¹

By using the independent variables:

• the log(octanol/water partition coefficient),

• the molecular weight,

• the water solubility.

The estimated maximum dermal absorption and the lag time were compared with some recent measured data of substances, which were not used for developing the QSARs. The estimates were generally in the same order of magnitude as the measured absorption and lag time. These QSARs are recommended for risk assessment of chemicals in the scope of the European REACH legislation.     

Recycling of WEEE: characterization of spent printed circuit boards from mobile phones and computers

This paper presents a comparison between printed circuit boards from computers and mobile phones. Since printed circuits boards are becoming more complex and smaller, the amount of materials is constantly changing. The main objective of this work was to characterize spent printed circuit boards from computers and mobile phones applying mineral processing technique to separate the metal, ceramic, and polymer fractions. The processing was performed by comminution in a hammer mill, followed by particle size analysis, and by magnetic and electrostatic separation. Aqua regia leaching, loss-on-ignition and chemical analysis (inductively coupled plasma atomic emission spectroscopy - ICP-OES) were carried out to determine the composition of printed circuit boards and the metal rich fraction. The composition of the studied mobile phones printed circuit boards (PCB-MP) was 63 wt.% metals; 24 wt.% ceramics and 13 wt.% polymers; and of the printed circuit boards from studied personal computers (PCB-PC) was 45 wt.% metals; 27 wt.% polymers and ceramics 28 wt.% ceramics. The chemical analysis showed that copper concentration in printed circuit boards from personal computers was 20 wt.% and in printed circuit boards from mobile phones was 34.5 wt.%. According to the characteristics of each type of printed circuit board, the recovery of precious metals may be the main goal of the recycling process of printed circuit boards from personal computers and the recovery of copper should be the main goal of the recycling process of printed circuit boards from mobile phones. Hence, these printed circuit boards would not be mixed prior treatment. The results of this paper show that copper concentration is increasing in mobile phones and remaining constant in personal computers.     

Multiscale effects of management, environmental conditions, and land use on nitrate leaching in dairy farms

Nitrate leaching in intensive grassland- and silage maize-based dairy farming systems on sandy soil is a main environmental concern. Here, statistical relationships are presented between management practices and environmental conditions and nitrate concentration in shallow groundwater (0.8 m depth) at farm, field, and point scales in The Netherlands, based on data collected in a participatory approach over a 7-yr period at one experimental and eight pilot commercial dairy farms on sandy soil. Farm milk production ranged from 10 to 24 Mg ha(-1). Soil and hydrological characteristics were derived from surveys and weather conditions from meteorological stations. Statistical analyses were performed with multiple regression models. Mean nitrate concentration at farm scale decreased from 79 mg L(-1) in 1999 to 63 in 2006, with average nitrate concentration in groundwater decreasing under grassland but increasing under maize land over the monitoring period. The effects of management practices on nitrate concentration varied with spatial scale. At farm scale, nitrogen surplus, grazing intensity, and the relative areas of grassland and maize land significantly contributed to explaining the variance in nitrate concentration in groundwater. Mean nitrate concentration was negatively correlated to the concentration of dissolved organic carbon in the shallow groundwater. At field scale, management practices and soil, hydrological, and climatic conditions significantly contributed to explaining the variance in nitrate concentration in groundwater under grassland and maize land. We conclude that, on these intensive dairy farms, additional measures are needed to comply with the European Union water quality standard in groundwater of 50 mg nitrate L(-1). The most promising measures are omitting fertilization of catch crops and reducing fertilization levels of first-year maize in the rotation.