Comparison of methods for the extraction and determination of polychlorinated biphenyls in shiphull antifoulings

A method is presented for the determination of PCBs in chlorinated rubber antifoulings. In ten different brands, no PCB concentrations above 0.5 mg kg^?1 were found.     

Bioaccumulation of cadmium by the freshwater isopod Asellus aquaticus (L.) from aqueous and dietary sources

Experiments were conducted to determine the kinetics and relative importance of aqueous and dietary uptake of cadmium by the freshwater isopod Asellus aquaticus (L.). Test animals were exposed during 30 days to aqueous Cd in a continuous flow system (exposure levels: 0.2 - 10 microg litre(-1)) and kept on a diet of previously contaminated Elodea sp. (range of Cd concentrations: 2-350 microg g(-1), dry weight). Preceding semi-static experiments on dosage-control of the dietary factor revealed a rapid uptake of Cd by Elodea, with relatively high concentration factors (CF), which ranged from 4.8 to 5.5 (dry weight log (CF) after 16 days). For Asellus uptake from water appeared to be the predominant route. Highly significant bioconcentration of cadmium from water was observed in the animals, even at exposure levels below 1.0 microg litre(-1). In the various treatments, direct uptake from water accounted for 50-98% of the body burdens after 30 days exposure. The experimental results were described with a first order one-compartment bioaccumulation model. Model parameter estimates (mean +/- standard error) were obtained for rate constant of uptake (560 +/- 110 day(-1)), rate constant of elimination (0.032 +/- 0.017 day(-1)) and assimilation efficiency of Cd uptake from food (1.1 +/- 0.7%). The (dry weight) bioconcentration factor (BCF) and bioaccumulation factor (BAF) for extrapolated steady state conditions were estimated at 18 000 (BCF) and 0.08 (BAF). Experiments conducted at two different pH levels (5.9 versus 7.6) revealed no significant effects of pH on the uptake of aqueous Cd by the isopods. The results are discussed in relation to their potential significance to the field situation.     

Kinships in a natural meadow vole population

Summary We have devised a radionuclide technique that allows the assessment of matrilineal kinship by the transfer of unique combinations of gamma-emitting radionuclides from pregnant and lactating female meadow voles (Microtus pennsylvanicus) to their offspring. A pool of prospective fathers can be established from field records of reproductively active males that were alive at the time of conception of the female's litter. Electrophoresis of 6 proteins allowed us to eliminate genetically incompatible males from the prospective pool of fathers. A log-likelihood statistic provided an estimate of the probability of paternity. In the case of numerical ties physical proximity of the males to the mother at the time of conception was used. With these techniques, we established 40 kinships in a field population of meadow voles.     

Persistence of perfluoroalkylated substances in closed bottle tests with municipal sewage sludge

BACKGROUND, AIM, AND SCOPE: Perfluoroalkylated substances (PFAS) are chemicals with completely fluorinated alkyl chains. The specific properties of the F-C bond give PFAS a high stability and make them very useful in a wide range of applications. PFAS also pose a potential risk to the environment and humans because they have been recently characterized as persistent, bioaccumulative, and toxic. The objective of this work is to study the bacterial degradation of PFAS under aerobic and anaerobic conditions in municipal sewage sludge as a contribution toward understanding their environmental fate and behavior. MATERIALS AND METHODS: Bacterial communities from sewage sludge were exposed to a mixture of PFAS under aerobic or anaerobic conditions. Individual PFAS concentrations were determined in the experiment media at different exposure times using liquid chromatography-mass spectrometry analysis after extraction with solid-phase extraction. RESULTS: The PFAS analyses of samples of sludge showed repeatable replicate results, allowing a reliable quantification of the different groups of PFAS analyzed. No conclusive evidence for PFAS degradation was observed under the experimental conditions tested in this work. Reduction in concentrations, however, was observed for some PFAS in sludge under aerobic conditions. DISCUSSION: The largest concentration decrease occurred for the fluorotelomer alcohols (FTOHs), especially for the 8:2 FTOH, which have been described as biodegradable in the literature. However, this concentration decrease could be due to different causes: sorption to glass, septa, or matrix components, as well as bacterial activity. Therefore, it is not certain that biodegradation occurred. CONCLUSIONS: PFAS are very recalcitrant chemicals, especially when fully fluorinated. Although some decreases in concentration have been observed for some PFAS, such as the FTOHs, there is no conclusive evidence for biodegradation. It can be concluded that the PFAS tested in these experiments are non-biodegradable under these experimental conditions. RECOMMENDATIONS AND PERSPECTIVES: Since the presence of PFAS is ubiquitous in the environment and they can be toxic, more research is needed in this field to elucidate which PFAS are susceptible to biodegradation, the conditions required for biodegradation, and the possible routes followed. A possible inhibitory effect of PFAS on bacteria, the threshold concentrations, and conditions of inhibition should also be investigated.     

Characterisation of perfluorooctane sulfonate (PFOS) in a terrestrial ecosystem near a fluorochemical plant in Flanders,Belgium

Bioaccumulation of perfluorooctane sulfonate (PFOS) in a restricted terrestrial food chain was investigated with the omnivorous wood mouse (Apodemus sylvaticus) on top of the studied food chain. The levels detected are very high compared with literature as a result of the presence of fluorochemical plant in the immediate vicinity of the study area. Soil, surface water, fruits of European elder and common blackberry, invertebrates, bank vole and wood mouse were collected at two sites, e.g. Blokkersdijk, adjacent to the fluorochemical plant, and Galgenweel, a reference site 2 km further away. In wood mouse, the highest PFOS concentrations were found in the liver followed by the pancreas, lungs and kidneys, with the spleen having the lowest levels. In the liver, the concentrations ranged from 787 to 22,355 ng/g ww at Blokkersdijk and these were significantly correlated with those detected in the kidneys (13.7–4,226 ng/g ww). If current results are compared to the findings of a previous study conducted in 2002 at the same sites, a significant decrease of PFOS in livers of wood mouse is observed. To the best of our knowledge, so far no studies reported levels of PFOS in terrestrial invertebrates under field conditions. At Blokkersdijk, PFOS was detected in all invertebrate species ranging from 28 to 9,000 ng/g. Soil and water were also contaminated with levels of respectively 68 ng/g and 22 ng/L. Biota-to-soil accumulation factors ranged from 0.11 to 68 for earthworms. Biomagnification factors (BMFs) of liver wood mouse/berries were as high as 302. BMFs for invertebrates were remarkably lower (up to 2).     

Anxiety in women with low maternal serum alpha-fetoprotein screening results

The purpose of this study was to measure anxiety in pregnant women who had low maternal serum alpha-fetoprotein (MSAFP) screening test levels, received genetic counselling and chose to undergo amniocentesis for fetal chromosome analysis. Their anxiety levels were compared with the levels in women undergoing amniocentesis because of advanced maternal age. The results indicate a higher level of anxiety in women with low alpha-fetoprotein (AFP) levels.     

Reduced breeding success of Cormorants (Phalacrocorax carbo sinensis) in relation to persistent organochlorine pollution of aquatic habitats in The Netherlands

Cormorants (Phalacrocorax carbo sinensis) breeding in the heavily contaminated sedimentation area of the rivers Rhine and Meuse have a severely reduced breeding success as compared to several other Dutch colonies. A detailed analysis of reproductive performance in combination with chemical analysis of eggs and food from colonies in differently contaminated aquatic habitats is presented. The differences in breeding success between colonies are caused mainly in the egg-stage of breeding. Eggshell thinning and increased embryonic mortality cause the differences in hatching success. The observed effects seem to be related to chlorinated hydrocarbons. Significant correlations are found for concentrations of DDE with eggshell thinning and for concentrations of PCBs with hatching and breeding success. The correlations between concentrations of chlorinated hydrocarbons in eggs and biological effects measured in the field are established both on colony and individual clutch level.     

Space use,longevity, and reproductive success in meadow voles

Summary We addressed the question of how reproductive success (RS) was limited in the shortlived but highly fecund meadow vole, Microtus pennsylvanicus. In so doing, we asked how differential space use patterns could affect longevity and hence RS in each sex. The sample comprised all voles achieving sexual competency over the course of a 40-week breeding season in a live-trapped population in Manomet, MA USA. Matrilineal families were determined using a radionuclide labelling technique; paternity was estimated using a maximum likelihood model. Individual RS was defined as the number of offspring successfully recruited into the trappable population per adult. We found that the variance in RS among female meadow voles was greater than the variance among males. In an attempt to explain this pattern, reproductively successful individuals were compared to reproductively unsuccessful individuals with regard to survivorship, maximum body weight achieved, and spatial mobility. The only difference between fathers and reproductively unsuccessful males was that fathers were heavier. In contrast, mothers differed from unsuccessful females in every measurement. Females lived longer than males, and mothers lived longer than either fathers or reproductively unsuccessful females. The observed differences in longevity may have been largely the result of differences in levels of mobility, assuming more mobile voles were more susceptible to predation. Mothers were significantly more site tenacious than were either males or unsuccessful females. These patterns explain the distribution of RS in our population if predation differentially affects male and female meadow voles. The meadow vole is the only non-polyandrous vertebrate reported to date in which the variance in RS among females exceeds the variance in RS among males.     

Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of ΣPFAS were estimated to be ∼6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea.     

Comparison of the performances of land use regression modelling and dispersion modelling in estimating small-scale variations in long-term air pollution concentrations in a Dutch urban area

The performance of a Land Use Regression (LUR) model and a dispersion model (URBIS – URBis Information System) was compared in a Dutch urban area. For the Rijnmond area, i.e. Rotterdam and surroundings, nitrogen dioxide (NO₂) concentrations for 2001 were estimated for nearly 70 000 centroids of a regular grid of 100 × 100 m.A LUR model based upon measurements carried out on 44 sites from the Dutch national monitoring network and upon Geographic Information System (GIS) predictor variables including traffic intensity, industry, population and residential land use was developed. Interpolation of regional background concentration measurements was used to obtain the regional background. The URBIS system was used to estimate NO₂ concentrations using dispersion modelling. URBIS includes the CAR model (Calculation of Air pollution from Road traffic) to calculate concentrations of air pollutants near urban roads and Gaussian plume models to calculate air pollution levels near motorways and industrial sources. Background concentrations were accounted for using 1 × 1 km maps derived from monitoring and model calculations.Moderate agreement was found between the URBIS and LUR in calculating NO₂ concentrations (R = 0.55). The predictions agreed well for the central part of the concentration distribution but differed substantially for the highest and lowest concentrations. The URBIS dispersion model performed better than the LUR model (R = 0.77 versus R = 0.47 respectively) in the comparison between measured and calculated concentrations on 18 validation sites. Differences can be understood because of the use of different regional background concentrations, inclusion of rather coarse land use category industry as a predictor variable in the LUR model and different treatment of conversion of NO to NO₂.Moderate agreement was found between a dispersion model and a land use regression model in calculating annual average NO₂ concentrations in an area with multiple sources. The dispersion model explained concentrations at validation sites better.