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Long-term biological monitoring of environmental quality around a solid waste landfill assessed with lichens
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.
显示更多 [+] 显示较少 [-]The impact of organochlorines cycling in the cryosphere on global distributions and fate – 2. Land ice and temporary snow cover
2012
Hofmann, Lorenz | 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 inclusion of land ice (in Antarctica and Greenland) or snow cover (dynamic). MPI-MCTM is based on coupled ocean and atmosphere general circulation models. After a decade of simulation 4.2% γ-HCH and 2.3% DDT are stored in land ice and snow. Neglection of land ice and snow in modelling would underestimate the total environmental residence time, τₒᵥ, of γ-HCH and overestimate τₒᵥ for DDT, both on the order of 1% and depending on actual compartmental distribution. Volatilisation of DDT from boreal, seasonally snow covered land is enhanced throughout the year, while volatilisation of γ-HCH is only enhanced during the snow-free season. Including land ice and snow cover in modelling matters in particular for the Arctic, where higher burdens are predicted to be stored.
显示更多 [+] 显示较少 [-]To what extent do molecular collisions arising from water vapour efflux impede stomatal O₃ influx?
2012
Uddling, Johan | Matyssek, Rainer | Pettersson, Jan B.C. | Wieser, Gerhard
Pre-requisite for reliable O₃ risk assessment for plants is determination of stomatal O₃ uptake. One unaddressed uncertainty in this context relates to transpiration-induced molecular collisions impeding stomatal O₃ influx. This study quantifies, through physical modelling, the error made when estimating stomatal O₃ flux without accounting for molecular collisions arising from transpiratory mass flow of gas out of the leaf. The analysis demonstrates that the error increases with increasing leaf-to-air water vapour mole fraction difference (Δw), being zero in water vapour saturated air and 4.2% overestimation at Δw of 0.05. Overestimation is approximately twice as large in empirical studies quantifying stomatal O₃ flux from measured leaf or canopy water flux, if neglecting both water vapour-dry air collisions (causing overestimation of leaf conductance) and collisions involving O₃. Correction for transpiration-induced molecular collisions is thus relevant for both empirical research and for large-scale modelling of stomatal O₃ flux across strong spatial Δw gradients.
显示更多 [+] 显示较少 [-]Effects of aging on the digestive solubilization of Cu from sediments
2012
Zhong, Huan | Kraemer, Lisa | Evans, Douglas
Solubilization of particulate Cu by different solutions, mimicking digestive fluids of deposit-feeders, was quantified in stable isotope ⁶⁵Cu-spiked sediments (with 3 days-2 months Cu-sediment contact time or aging). Copper solubilization generally decreased with prolonged aging. However, such decrease became less evident after 1 month and equilibrium of Cu in sediments could be reached after 2 months. Aging effects on Cu solubilization can be explained by the changes in Cu geochemical fractionation with aging: Cu generally transferred from more mobile phases (carbonate and Fe–Mn associated) to more refractory phases (organic associated and residual phase). Besides Cu geochemical fractionation, digestive fluid composition and different Cu solubilization pathways involved, as well as sedimentary organic content, could all affect the digestive solubilization of Cu and its change with aging. Our results emphasize the necessity of considering Cu aging in laboratory sediment toxicity experiments, and in risk assessment of Cu contaminated sediments.
显示更多 [+] 显示较少 [-]The contribution of waste water treatment plants to PBDEs in ambient air
2012
Martellini, Tania | Jones, K. C. (Kevin C.) | Sweetman, Andy | Giannoni, Martina | Pieri, Francesca | Cincinelli, Alessandra
Air samples were collected at different sites in and around two wastewater treatment plants (WWTPs) located in central Italy to determine the concentrations, compositional profiles and contribution to ambient levels of eight polybrominated diphenyl ethers (PBDEs). The investigated WWTPs were selected as they treat industrial wastewater produced by local textile industries along with municipal wastewater. PBDE concentrations within the WWTPs were higher than those measured at reference sites located 4 and 5km away with BDE-209 dominating the BDE congener composition in all air samples in 2008. Ambient PBDE concentrations measured in and around the WWTPs and estimates of emissions from aeration tanks suggest that WWTPs are sources of PBDEs to ambient air. Principal component analysis and Pearson correlations confirmed this result. The effect of distance from the plant and wind direction on atmospheric concentrations was also investigated. Although the primary fate of PBDEs in WWTPs will be partitioning to sewage sludge, this study suggests that plants can provide a measurable source of these compounds to local ambient air.
显示更多 [+] 显示较少 [-]Ozone deposition to an orange orchard: Partitioning between stomatal and non-stomatal sinks
2012
Fares, Silvano | Weber, Robin | Park, Jeong-Hoo | Gentner, Drew | Karlik, Jan | Goldstein, Allen H.
Orange trees are widely cultivated in regions with high concentrations of tropospheric ozone. Citrus absorb ozone through their stomata and emit volatile organic compounds (VOC), which, together with soil emissions of NO, contribute to non-stomatal ozone removal. In a Valencia orange orchard in Exeter, California, we used fast sensors and eddy covariance to characterize water and ozone fluxes. We also measured meteorological parameters necessary to model other important sinks of ozone deposition. We present changes in magnitude of these ozone deposition sinks over the year in response to environmental parameters. Within the plant canopy, the orchard constitutes a sink for ozone, with non-stomatal ozone deposition larger than stomatal uptake. In particular, soil deposition and reactions between ozone, VOC and NO represented the major sinks of ozone. This research aims to help the development of metrics for ozone-risk assessment and advance our understanding of citrus in biosphere-atmosphere exchange.
显示更多 [+] 显示较少 [-]Legacy and current-use flame retardants in house dust from Vancouver, Canada
2012
Shoeib, Mahiba | Harner, Tom | Webster, Glenys M. | Sverko, Ed | Cheng, Yu
Fifteen polybrominated diphenyl ethers (PBDEs) and eighteen non-PBDEs were measured in 116 dust samples collected from homes in Vancouver, Canada during 2007–2008 as part of the Chemicals Health and Pregnancy (CHirP) study. The highest concentrations of PBDEs in house dust were observed for BDE 209, with a median concentration of 1350 ng/g. This is about two times greater than the median concentration of the PentaBDE (represented by the most abundant compounds in this formulation, ΣBDE 47, 99 and 100). In the case of non-PBDE FRs, a detection frequency between 81% and 100% was observed for nine analytes including: HBCD, BTBPE, BEHTBP, EHTBB, HBB, PBTO, PBBe, ATE and DP. The high detection of new FRs in indoor environments reflects their ubiquitous presence in indoor environment due to regulation of the PBDEs. Exposure to FRs are estimated based on these data for adults and toddlers.
显示更多 [+] 显示较少 [-]Rapid recovery of stem increment in Norway spruce at reduced SO₂ levels in the Harz Mountains, Germany
2012
Hauck, Markus | Zimmermann, Jorma | Jacob, Mascha | Dulamsuren, Choimaa | Bade, Claudia | Ahrends, Bernd | Leuschner, Christoph
Tree-ring width of Picea abies was studied along an altitudinal gradient in the Harz Mountains, Germany, in an area heavily affected by SO₂-related forest decline in the second half of the 20th century. Spruce trees of exposed high-elevation forests had earlier been shown to have reduced radial growth at high atmospheric SO₂ levels. After the recent reduction of the SO₂ load due to clean air acts, we tested the hypothesis that stem growth recovered rapidly from the SO₂ impact. Our results from two formerly damaged high-elevation spruce stands support this hypothesis suggesting that the former SO₂-related spruce decline was primarily due to foliar damage and not to soil acidification, as the deacidification of the (still acidic) soil would cause a slow growth response. Increasing temperatures and deposited N accumulated in the topsoil are likely additional growth-promoting factors of spruce at high elevations after the shortfall of SO₂ pollution.
显示更多 [+] 显示较少 [-]Effect of different arbuscular mycorrhizal fungal isolates on growth and arsenic accumulation in Plantago lanceolata L
2012
Orłowska, Elżbieta | Godzik, Barbara | Turnau, Katarzyna
The role of indigenous and non-indigenous arbuscular mycorrhizal fungi (AMF) on As uptake by Plantago lanceolata L. growing on substrate originating from mine waste rich in As was assessed in a pot experiment. P. lanceolata inoculated with AMF had higher shoot and root biomass and lower concentrations of As in roots than the non-inoculated plants. There were significant differences in As concentration and uptake between different AMF isolates. Inoculation with the indigenous isolate resulted in increased transfer of As from roots to shoots; AMF from non-polluted area apparently restricted plants from absorbing As to the tissue; and plants inoculated with an AMF isolate from Zn–Pb waste showed strong As retainment within the roots. Staining with dithizone indicated that AMF might be actively involved in As accumulation. The mycorrhizal colonization affected also the concentration of Cd and Zn in roots and Pb concentration, both in shoots and roots.
显示更多 [+] 显示较少 [-]Spatial distribution and trends of total mercury in waters of the Great Lakes and connecting channels using an improved sampling technique
2012
Dove, A. | Hill, B. | Klawunn, P. | Waltho, J. | Backus, S. | McCrea, R.C.
Environment Canada recently developed a clean method suitable for sampling trace levels of metals in surface waters. The results of sampling for total mercury in the Laurentian Great Lakes between 2003 and 2009 give a unique basin-wide perspective of concentrations of this important contaminant and represent improved knowledge of mercury in the region. Results indicate that concentrations of total mercury in the offshore regions of the lakes were within a relatively narrow range from about 0.3 to 0.8 ng/L. The highest concentrations were observed in the western basin of Lake Erie and concentrations then declined towards the east. Compared to the offshore, higher levels were observed at some nearshore locations, particularly in lakes Erie and Ontario. The longer-term temporal record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease in equivalent water concentrations since 1986.
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