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A comparison of submicrometer particle dose between Australian and Italian people Full text
2012
Buonanno, G. | Morawska, L. | Stabile, L. | Wang, L. | Giovinco, G.
Alveolar and tracheobronchial-deposited submicrometer particle number and surface area data received by different age groups in Australia are shown. Activity patterns were combined with microenvironmental data through a Monte Carlo method. Particle number distributions for the most significant microenvironments were obtained from our measurement survey data and people activity pattern data from the Australian Human Activity Pattern Survey were used. Daily alveolar particle number (surface area) dose received by all age groups was equal to 3.0 × 10¹⁰ particles (4.5 × 10² mm²), varying slightly between males and females. In contrast to gender, the lifestyle was found to significantly affect the daily dose, with highest depositions characterizing adults. The main contribution was due to indoor microenvironments. Finally a comparison between Italian and Australian people in terms of received particle dose was reported; it shows that different cooking styles can affect dose levels: higher doses were received by Italians, mainly due to their particular cooking activity.
Show more [+] Less [-]Atmospheric fate of poly- and perfluorinated alkyl substances (PFASs): II. Emission source strength in summer in Zurich, Switzerland Full text
2012
Wang, Zhanyun | Scheringer, Martin | Macleod, Matthew | Bogdal, Christian | Müller, Claudia E. | Gerecke, Andreas C. | Hungerbühler, Konrad
Fluorotelomer alcohols (FTOHs) and perfluorooctane sulfonamides (FOSAs) are present in consumer products and are semi-volatile precursors of persistent perfluoroalkyl acids (PFAAs). The high variability of levels of FTOHs and FOSAs in products makes it difficult to derive FTOH- and FOSA-emissions from urban areas based on emission factors. Here we used a multimedia mass balance model that describes the day–night cycle of semi-volatile organic chemicals in air to interpret measurements of 8:2 FTOH, 10:2 FTOH, MeFOSA and EtFOSA from a sampling campaign in summer 2010 in Zurich, Switzerland. The estimated emission source strength of the four substances follows the sequence: 8:2 FTOH (2.6 g/h) > 10:2 FTOH (0.75 g/h) > MeFOSA (0.08 g/h) > EtFOSA (0.05 g/h). There is no FTOHs- or FOSAs-related industry in Zurich. Accordingly, our estimates are representative of diffusive emissions during use and disposal of consumer products, and describe noticeable sources of these PFASs to the environment.
Show more [+] Less [-]Bioaccumulation of Fe₂O₃(magnetic) nanoparticles in Ceriodaphnia dubia Full text
2012
Hu, Ji | Wang, Demin | Wang, Jiangtao | Wang, Jianmin
While nano-Fe₂O₃(magnetic) is generally considered non-toxic, it could serve as a carrier of other toxic chemicals such as As(V) and enhance their toxicity. The bioaccumulation of nano-Fe₂O₃(m) with different exposure times, NP concentrations, and pH conditions was investigated using Ceriodaphnia dubia (C. dubia) as the model organism. Under natural pH conditions, C. dubia significantly accumulated nano-Fe₂O₃(m) in the gut, with the maximum accumulation being achieved after 6 h of exposure. The concentration of nano-Fe₂O₃ also impacted its accumulation, with the maximum uptake occurring at 20 mg/L or more. In addition, the highest bioaccumulation occurred in a pH range of 7–8 where the highest feeding rate was reported, confirming that the ingestion of NPs is the main route of nano-Fe₂O₃(m) bioaccumulation. In a clean environment without NPs, depuration of nano-Fe₂O₃(m) occurred, and food addition accelerated the depuration process.
Show more [+] Less [-]A contribution towards the risk assessment of soils from the São Domingos Mine (Portugal): Chemical, microbial and ecotoxicological indicators Full text
2012
Alvarenga, Paula | Palma, Patricia | de Varennes, Amarilis | Cunha-Queda, Ana C.
This study is a contribution towards a risk assessment of the São Domingos Mine area (Portugal), integrating information from: soil physicochemical characteristics, pseudo-total and bioavailable trace elements (As, Cd, Cr, Cu, Ni, Pb and Zn), ecotoxicological evaluation, and microbial indicators. The bioassays using soil eluates (seed germination, luminescent inhibition of Vibrio fischeri and Daphnia magna immobilization) confirmed the soil toxicity categorization obtained with the bioassays using soil (plant growth tests, Eisenia fetida mortality and avoidance behaviour). However, the soil identified as the most toxic using bioassays, was different from the expected when considering the results from pseudo-total and effective bioavailable trace elements. Taking in consideration the observations, it is highly recommended to complement the results from environmental chemistry with results from bioassays, in order to provide a more complete and relevant information on the bioavailability of contaminants and to characterize the risk of contaminated soils.
Show more [+] Less [-]Long-term biological monitoring of environmental quality around a solid waste landfill assessed with lichens Full text
2012
Paoli, L. | Corsini, A. | Bigagli, V. | Vannini, J. | Bruscoli, C. | Loppi, S.
The diversity of epiphytic lichens and the accumulation of selected trace elements in the lichen Flavoparmelia caperata L. (Hale) were used as indicators of pollution around a landfill in central Italy along 14 years of waste management. Lichens revealed an increased deposition for some elements (i.e., Cd, Cr, Fe and Ni) and a decrease of the lichen diversity at sites facing the landfill after an enlargement of the dumping area. However, the results allowed to exclude a significant increase in heavy metal depositions in the surrounding area and suggested that successful waste management may be associated with environmental quality. It is concluded that lichen monitoring might provide essential information to enhance the implementation of ecological impact assessment, supporting industrial regulatory procedures, also when waste management is concerned.
Show more [+] Less [-]Use of a Bayesian isotope mixing model to estimate proportional contributions of multiple nitrate sources in surface water Full text
2012
Xue, Dongmei | De Baets, Bernard | Van Cleemput, Oswald | Hennessy, Carmel | Berglund, Michael | Boeckx, Pascal
To identify different NO₃ ⁻ sources in surface water and to estimate their proportional contribution to the nitrate mixture in surface water, a dual isotope and a Bayesian isotope mixing model have been applied for six different surface waters affected by agriculture, greenhouses in an agricultural area, and households. Annual mean δ¹⁵N–NO₃ ⁻ were between 8.0 and 19.4‰, while annual mean δ¹⁸O–NO₃ ⁻ were given by 4.5–30.7‰. SIAR was used to estimate the proportional contribution of five potential NO₃ ⁻ sources (NO₃ ⁻ in precipitation, NO₃ ⁻ fertilizer, NH₄ ⁺ in fertilizer and rain, soil N, and manure and sewage). SIAR showed that “manure and sewage” contributed highest, “soil N”, “NO₃ ⁻ fertilizer” and “NH₄ ⁺ in fertilizer and rain” contributed middle, and “NO₃ ⁻ in precipitation” contributed least. The SIAR output can be considered as a “fingerprint” for the NO₃ ⁻ source contributions. However, the wide range of isotope values observed in surface water and of the NO₃ ⁻ sources limit its applicability.
Show more [+] Less [-]Factors regulating the bioavailability of methylmercury to breeding rusty blackbirds in northeastern wetlands Full text
2012
Edmonds, Samuel Trower | O'Driscoll, Nelson J. | Hillier, N Kirk | Atwood, Jonathan L. | Evers, David C.
Rusty blackbirds are undergoing rapid population decline and have elevated Hg concentrations while breeding in the Acadian ecoregion of North America. Factors regulating the bioavailability of methyl-Hg (MeHg) within this population's habitat were determined using water, invertebrates, and blood from adult rusty blackbirds collected for Hg-speciation, along with additional water column parameters: MeHg and THg, dissolved organic carbon, pH, dissolved oxygen, conductivity, redox potential, and temperature. Both DO₂ and pH were negatively related to biota MeHg, while water MeHg concentrations were positively related. Both invertebrate MeHg concentration and %MeHg increased with trophic level. Invertebrate MeHg concentrations were among the greatest reported when compared with those reported elsewhere for wetlands and waterbodies—often several times greater for similar taxa—while percent MeHg of THg were similar. An environment with high bioavailability of MeHg in combination with a high trophic position best explains elevated Hg concentrations for this species regional population.
Show more [+] Less [-]Polybrominated diphenyl ethers (PBDEs) in sediments of the coastal East China Sea: Occurrence, distribution and mass inventory Full text
2012
Li, Yuanyuan | Lin, Tian | Chen, Yingjun | Hu, Limin | Guo, Zhigang | Zhang, Gan
Polybrominated diphenyl ethers (PBDEs) of sixty-three sediment samples from the coastal East China Sea (ECS), extending ∼1000 km from the Yangtze River Estuary to the south, were measured. The levels of BDE-209 and ∑PBDE₇ (sum of BDE-28, 47, 99, 100, 153, 154, 183) were 0.3–44.6 ng/g (dry weight) and nd-8.0 ng/g, respectively. BDE-209 was the predominant congener, followed by BDE-99/100. This was consistent with the historical and current usage of PBDE mixtures in China. The compositions and distribution of PBDEs suggest that the PBDEs in this area could be mainly from the coastal electronic waste dismantling/recycling and Yangtze River input. The poor correlations between TOC, grain size of sediments with PBDEs imply that the PBDE distribution is more related to their land-based inputs rather than the sediment characters in the area. The coastal ECS is an important sink of PBDEs (7.5 t/yr) in the world.
Show more [+] Less [-]Environmental risks of trace elements associated with long-term phosphate fertilizers applications: A review Full text
2012
Jiao, Wentao | Chen, Weiping | Chang, Andrew C. | Page, Albert L.
Application of phosphate fertilizer can be a significant contributor of potentially hazardous trace elements such as arsenic, cadmium, and lead in croplands. These trace elements have the potential to accumulate in soils and be transferred through the food chain. We articulated the environmental risks of trace elements associated with long-term phosphate fertilizer applications by combining data from the literature and results from model simulations. Results illustrate that under normal cropping practice, the impact of phosphate fertilizers applications on trace element accumulation in receiving soils has been limited and localized. Their plant uptake varied greatly depending on the fertilizer application rates, soil and plant characteristics. This has led to a great deal of uncertainty in characterizing soil distribution coefficients, Kd, and plant uptake factors, PUF, two of the most used parameters in assessing the risks of accumulations. Therefore, the risks may be more appropriately assessed based on the probabilistic distributions of Kd and PUF.
Show more [+] Less [-]The impact of organochlorines cycling in the cryosphere on their global distribution and fate – 1. Sea ice Full text
2012
Guglielmo, Francesca | Stemmler, Irene | Lammel, Gerhard
Global fate and transport of γ-HCH and DDT was studied using a global multicompartment chemistry-transport model, MPI-MCTM, with and without a dynamic sea ice compartment. The MPI-MCTM is based on coupled ocean and atmosphere general circulation models. Sea ice hosts 7–9% of the burden of the surface ocean. Without cycling in sea ice the geographic distributions are shifted from land to sea. This shift of burdens exceeds the sea ice burden by a factor of ≈8 for γ-HCH and by a factor of ≈15 for DDT. As regional scale seasonal sea ice melting may double surface ocean contamination, a neglect of cycling in sea ice (in an otherwise unchanged model climate) would underestimate ocean exposure in high latitudes. Furthermore, it would lead to overestimates of the residence times in ocean by 40% and 33% and of the total environmental residence times, τₒᵥₑᵣₐₗₗ, of γ-HCH and DDT by 1.6% and 0.6%, respectively.
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