Cyclic volatile methylsiloxanes in fish from the Baltic Sea

Laboratory studies suggest that the cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) will persist in the aquatic environment and bioaccumulate in fish. Here these cVMS were measured in herring collected in the Swedish waters of the Baltic Sea and the North Sea and in grey seals from the Baltic Proper. D4, D5, and D6 were present in herring muscle at concentrations around 10, 200, and 40 ng g⁻¹ lipid weight, respectively. The ratio of these concentrations was similar to the relative magnitude of estimated emissions to water, suggesting that the efficiency of overall transfer through the environment and food web was similar (within a factor 2–3) for the three chemicals. The concentrations of D5 and D6 were similar in herring caught in the highly populated Baltic Proper and in the less populated Bothnian Sea and Bothnian Bay. The D4 concentrations were lower at the most remote northern station, suggesting that D4 is less persistent than D5 and D6. Herring from the North Sea had lower levels of all three chemicals. The concentrations of D4, D5 and D6 in grey seal blubber were lower than the lipid normalized concentrations in herring, indicating that they do not biomagnify in grey seals.     

Triclosan in individual human milk samples from Australia

Triclosan is a chlorinated phenol ether that has been in widespread use as a broad-spectrum antibacterial agent for four decades. When compared to the limited international data available on human body burden of triclosan, results from a pooled blood study suggested that triclosan concentrations in Australia were a factor two higher than observed in Sweden. This study determined triclosan levels in individual human milk samples (n = 151) collected between 2002 and 2005 from primiparous Australian mothers. It provided the first report of population triclosan levels and individual variation in Australia and gave a measure of infant exposure via breast feeding. The distribution of triclosan concentration was positively skewed, with 7.2% of the samples below the LOQ, 66% with a concentration of less than or equal to 1.0 ng g⁻¹ fresh weight and the remaining samples above 1 ng g⁻¹ reaching a maximum concentration of 19 ng g⁻¹ fresh weight. The mean and median triclosan concentrations were 1.3 ± 2.7 ng g⁻¹ f.w. and 0.26 ng g⁻¹ f.w., respectively. The results of this study showed high variability in triclosan concentrations between individuals and no correlations with maternal age (p = 0.094), maternal weight (p = 0.971) or infant age at the time of sample collection (p = 0.621). A large number of samples contained low or non-quantifiable concentrations of triclosan and so, in Australia, ubiquitous background exposure due to environmental sources is low. This means that body burden can be influenced by an individual’s use of triclosan containing product. Given that triclosan containing product use is continuing, it is important that monitoring in both humans and the environment is continued and that triclosan containing products are adequately labeled so that an individual can choose to avoid exposure.     

Pricing landfill externalities: emissions and disamenity costs in Cape Town, South Africa

The external (environmental and social) costs of landfilling (e.g. emissions to air, soil and water; and 'disamenities' such as odours and pests) are difficult to quantify in monetary terms, and are therefore not generally reflected in waste disposal charges or taken into account in decision making regarding waste management options. This results in a bias against alternatives such as recycling, which may be more expensive than landfilling from a purely financial perspective, but preferable from an environmental and social perspective. There is therefore a need to quantify external costs in monetary terms, so that different disposal options can be compared on the basis of their overall costs to society (financial plus external costs). This study attempts to estimate the external costs of landfilling in the City of Cape Town for different scenarios, using the benefits transfer method (for emissions) and the hedonic pricing method (for disamenities). Both methods (in particular the process of transferring and adjusting estimates from one study site to another) are described in detail, allowing the procedures to be replicated elsewhere. The results show that external costs are currently R111 (in South African Rands, or approximately US$16) per tonne of waste, although these could decline under a scenario in which energy is recovered, or in which the existing urban landfills are replaced with a new regional landfill.     

Placental transfer of polychlorinated biphenyls, their hydroxylated metabolites and pentachlorophenol in pregnant women from eastern Slovakia

The aim of the present study was to understand the placental transfer of polychlorinated biphenyls (PCBs), specific hydroxylated PCB metabolites (OH-PCBs), and pentachlorophenol (PCP) in blood serum, in a birth cohort from eastern Slovakia. During the period 2002-2004, cord blood specimens were collected in parallel with maternal specimens from women delivering in the two eastern Slovak districts of Michalovce and Svidnik/Stropkov. A total of 92 pairs of mother-cord specimens at delivery were selected for this study. 4-OH-CB107, 3-OH-CB153, 4-OH-CB146, 3'-OH-CB138, 4-OH-CB187, and 4'-OH-CB172 were quantified. The median concentrations of Sigma(17)PCBs, Sigma(6)OH-PCBs, and PCP in cord serum were 0.92, 0.33, and 0.69 ng/g wet wt., respectively and highly correlated with the corresponding maternal serum levels (correlations were R(2)=0.61, 0.78, and 0.82, respectively). The median cord to mother ratios of the Sigma(17)PCBs, Sigma(6)OH-PCBs, and PCP were 0.18, 0.75, and 1.10, respectively. The median ratio of the Sigma(6)OH-PCBs to the Sigma(17) PCBs in the cord serum was 0.38 from wet weight based concentrations, which was about four times higher than the ratio of these compounds in maternal serum (0.09). PCP was more abundant than any PCB or OH-PCB congener measured in cord serum. The higher cord to maternal ratios of OH-PCB metabolites as compared with the parent compounds suggests either a higher placental transfer rate or greater metabolism in the fetus as compared with the maternal compartment. These findings are consistent with their preferential binding to TTR that can cross the placenta. The cord to maternal ratio varies by congener (e.g., 4-OH-CB107=0.58, 4-OH-CB146=0.74, 3'-OH-CB138=1.01).     

Equilibrium sampling: partitioning of organochlorine compounds from lipids into polydimethylsiloxane

Polydimethylsiloxane (PDMS) can be used for equilibrium sampling of environmental pollutants in a large variety of matrices including biota. For comparison with lipid-normalized concentrations e.g. from biota monitoring programmes, reliable lipid to PDMS partition ratios (K(Lipid,PDMS)) are required. Additionally, K(Lipid,PDMS) facilitate comparison of equilibrium sampling data obtained in various environmental media and can be helpful to convert equilibrium sampling data into a more informative form. This work investigated the equilibrium partitioning of polychlorinated biphenyls (PCBs) and selected organochlorine pesticides (OCPs) between lipids from biota of different trophic levels and PDMS. One vegetable oil, a fish oil and seal oil were investigated. The lipid to PDMS partition ratios were compound-specific and ranged from 14.5 to 62.9 g/g with correction for lipid uptake into the PDMS and from 13.0 to 54.8 g/g without correction. Additionally, PDMS served as a reference partitioning phase for the accurate determination of lipid to lipid partition ratios, which for all analytes were close to unity. Evaluating the results in a bioaccumulation context, they indicate that the equilibrium partitioning of neutral lipophilic environmental contaminants into the lipids of the three investigated species will be very similar, although they represent three distinct trophic levels.     

Korrosionsschutz und Umwelt

Ohne Zusammenfassung Schlagw?rter: Gesetzgebung: Schweiz; Korrosionsschutz     

The effects of the diarrhetic shellfish poisoning toxins,okadaic acid and dinophysistoxin-1, on the growth of microalgae

The diarrhetic shellfish poisoning toxins okadaic acid (OA) and dinophysistoxin-1 (DTX-1) are potent phosphatase inhibitors produced by certain species of marine dinoflagellates. OA can cause hyperphosphorylation of a broad range of animal and higherpalnt proteins, but little is known regarding the effects of the DSP toxins on marine organisms or their biological function. A variety of microalgae, including a clone ofProrocentrum lima known to produce both OA and DTX-1, were incubated with solutions of OA and in one case DTX-1 or a combination of OA and DTX-1. OA inhibited the growth of all non-DSP-producing test species at micromolar concentrations, butP. lima was not affected even at much higher levels. This differential activity of OA suggests that the DSP toxins may play an allelopathic role and raises questions regarding the strategies adopted by DSP-producing dinoflagellates such asP. lima to avoid autotoxicity. The effects of DTX-1 on microalgal growth were found to be equivalentt to those of OA, and the effects of both toxins in combination were simply additive.     

Perceptions of Species Abundance,Distribution, and Diversity: Lessons from Four Decades of Sampling on a Government-Managed Reserve

/ We examined data relative to species abundance, distribution, anddiversity patterns of reptiles and amphibians to determine how perceptionschange over time and with level of sampling effort. Location data werecompiled on more than one million individual captures or observations of 98species during a 44-year study period on the US Department of Energy's(DOE) Savannah River Site National Environmental Research Park (SRS-NERP) inSouth Carolina. We suggest that perceptions of herpetofaunal speciesdiversity are strongly dependent on level of effort and that land managementdecisions based on short-term data bases for some faunal groups could resultin serious errors in environmental management. We provide evidence thatacquiring information on biodiversity distribution patterns is compatiblewith multiyear spatially extensive research programs and also provide aperspective of what might be achieved if long-term, coordinated researchefforts were instituted nationwide.To conduct biotic surveys on government-managed lands, we recommend revisionsin the methods used by government agencies to acquire and report biodiversitydata. We suggest that government and industry employees engaged inbiodiversity survey efforts develop proficiency in field identification forone or more major taxonomic groups and be encouraged to measure the status ofpopulations quantitatively with consistent and reliable methodologies. Wealso suggest that widespread academic cooperation in the dissemination ofinformation on regional patterns of biodiversity could result byestablishment of a peer-reviewed, scientifically rigorous journal concernedwith status and trends of the biota of the United States. KEY WORDS: Abundance; Amphibian; Biodiversity; Distribution; Landmanagement; Reptile