Is external contamination with organic pollutants important for concentrations measured in bird feathers?

Although there is increasing evidence that bird feathers can be used as a non-destructive biomonitoring tool for organic pollutants [such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and p,p'-dichlorodiphenyl-trichloroethane and metabolites (DDTs)], the importance of external contamination of these organic pollutants onto the feathers has not been considered. Here we examine to which extent external contamination of organic pollutants occurs onto the feathers of a predatory bird. We have analysed primary wing feathers of 16 common buzzards (Buteo buteo) collected in Belgium. In order to study differences in external contamination within and among wing feathers, the vane and the shaft of each feather were separated and were analysed in parallel, pooled for the three inner and the three outer primary wing feathers. Most organic pollutants could be measured in these pooled samples of both the vane and the shaft. Concentrations of hexachlorobenzene (HCB), DDTs, PCBs and PBDEs were significantly higher in the vane compared to the shaft. The profiles of PCBs and PBDEs in the shaft closely resembled the profiles in liver and muscle tissue, in contrast with the profile of the vane. The PBDE congeners 47, 99 and 153 had a similar contribution in shafts of primary feathers of common buzzards. Although these results suggest that external contamination could be important on the vane, no differences in the profile of PBDEs or PCBs were found between the inner and outer (more exposed) primary feathers. Furthermore, correlation coefficients with internal tissues were not univocally distinct between the shaft and the vane. Therefore our results indicate that the higher concentrations found in the vane in comparison to the shaft do not originate from external contamination via the air, but that other factors such as structure and chemical properties of the feathers may be of importance. The lack of significant external contamination onto the feather surface is an additional asset for the use of feathers as a non-destructive biomonitor for organic pollutants.     

Comparision of China’s volatile organic compound pollution management: a computable general equilibrium approach

The public health and ecological impacts of volatile organic compound (VOCs) pollution have become a serious problem in China, arousing increasing attention to emissions control. In this context, this paper analyses the effectiveness of VOC reduction policies, namely pollution charges and environmental taxes at the national and industrial sector levels. It uses a computable general equilibrium model, which connects macroeconomic variables with VOC emissions inventory, to simulate the effects of policy scenarios (with 2007 as the reference year). This paper shows that VOC emissions are reduced by 2.2% when a pollution charge equal to the average cost of engineering reduction methods – the traditional approach to regulation in China – is applied. In order to achieve a similar reduction, an 8.9% indirect tax would have to be imposed. It concludes that an environmental tax should be the preferred method of VOC regulation due to its smaller footprint on the macroeconomy. Other policies, such as subsidies, should be used as supplements.     

Endocrine activity of persistent organic pollutants accumulated in human silicone implants — Dosing in vitro assays by partitioning from silicone

Persistent organic pollutants (POPs) accumulated in human tissues may pose a risk for human health by interfering with the endocrine system. This study establishes a new link between actual human internal POP levels and the endocrine active dose in vitro, applying partitioning-controlled dosing from silicone to the H295R steroidogenesis assay: (1) Measured concentrations of POPs in silicone breast implants were taken from a recent study and silicone disks were loaded according to these measurements. (2) Silicone disks were transferred into H295R cell culture plates in order to control exposure of the adrenal cells by equilibrium partitioning. (3) Hormone production of the adrenal cells was measured as toxicity endpoint. 4-Nonylphenol was used for method development, and the new dosing method was compared to conventional solvent-dosing. The two dosing modes yielded similar dose-dependent hormonal responses of H295R cells. However, with the partitioning-controlled freely dissolved concentrations (C_free) as dose metrics, dose–response curves were left-shifted by two orders of magnitude relative to spiked concentrations. Partitioning-controlled dosing of POPs resulted in up to 2-fold increases in progestagen and corticosteroid levels at C_free of individual POPs in or below the femtomolar range. Silicone acted not only as source of the POPs but also as a sorption sink for lipophilic hormones, stimulating the cellular hormone production. Methodologically, the study showed that silicone can be used as reference partitioning phase to transfer in vivo exposure in humans (silicone implants) to in vitro assays (partition-controlled dosing). The main finding was that POPs at the levels at which they are found in humans can interfere with steroidogenesis in a human adrenocortical cell line.     

Consumer willingness to pay for organic and locally grown produce on Dominica: insights into the potential for an “Organic Island”

With the intent of improving agricultural revenues and solidifying her place as an ecotourism destination, it has been proposed that the island nation of The Commonwealth of Dominica convert all agriculture to organic production. This study explores Dominica’s current and potential domestic demand for organic and/or “locally grown” produce. Surveys were conducted with Dominican consumers to assess their opinions and willingness to pay for these products, and evaluated using a maximum likelihood estimation procedure. On average, Dominican consumers are willing to pay 17.5 % more for organic, and 12 % more for locally grown, produce. These results were varied significantly across demographic segments of the sampled population, respondent tastes and preferences, the health status of their family, and the extent to which they were early adopters of new products. Despite several expected challenges of a successful transition to organic, implementation of this policy may offer a net positive welfare increase for Dominica’s permanent residents. Results from this analysis suggest that, from the perspective of domestic consumers, Dominica should continue to pursue the possibility of becoming an “Organic Island.”     

Natural organic matter in drinking water — The “NOM-typing project”, background and basic characteristics of original water samples and NOM isolates

The complex nature of natural organic matter (NOM), and the impact of this matter on drinking water quality, necessitate international co-operative efforts. After several decades of struggle, many experienced NOM scientists world wide recognize the need for international sample references, or better yet, to work together on the same set of samples. The aim of the “NOM-typing project” was a multi-method characterization of a limited number of NOM samples, isolated from different water sources. The background of the project and the nature of the sampling sites are described here, and some data comparing the composition of the samples, before and after the isolation, are presented. The techniques used for isolation were reverse osmosis (RO) and evaporation (EVA). The NOM samples were isolated from eight different locations in the southern part of Norway. The nature of the corresponding catchments differs, however, all samples were from areas with no influence of agriculture or local industry. The key issue of the project was that all samples were isolated with exactly the same methods and by the same team. In spite of the uniformity of the isolation technique used for the nine samples, the recoveries of the material differ from sample to sample. Generally, the loss of NOM is in the range of 10%, however, for one sample, the loss was as high as 35%. These discrepancies are probably partly because of differences in the nature of the NOM and partly due to differences in the general composition of the ambient water. There are a few remarkable differences between the nine samples. There was a high percentage of ash in isolates from acidified areas. These are also the samples where the loss of NOM during the isolation process was highest. The density of the RO-isolates differs 10-fold between the samples. The lipophilisity of the NOM samples, expressed as relative solubility in octanol, differs more than 30-fold.     

Distribution of organic carbon, selected stable elements and artificial radionuclides among dissolved, colloidal and particulate phases in the Rhône River (France): preliminary results

The behaviour of radionuclides discharged from nuclear facilities in the Rh?ne River depends on their distribution among the dissolved, colloidal and particulate phases. A large water sample was fractionated using sequential ultrafiltration. Size distributions of organic carbon, Fe, Al, Si, Ca, Mg, Cu, Zn, 137Cs, 60Co and 106Ru were obtained. Our results show that organic colloids account for 11% of the total organic carbon content. Approximately 20% of the dissolved (< 450 nm) Fe and Al are in colloidal classes. 137Cs is not significantly transferred by the colloidal phase while 25% of 60Co or 106Ru is associated with organic and inorganic colloids.