Atmospheric concentrations and deposition fluxes of PCDD/F and PCB have been evaluated over a 1-year period in a Mediterranean coastal lagoon (Etang de Thau, France). Indicative PBDE air concentrations in the hot season are also reported in this work. ∑2,3,7,8-PCDD/Fs and ∑18PCBs (gas+particulate) air concentrations ranged from 67 to 1700fgm⁻³ and from 13 to 95pgm⁻³, respectively whereas ∑8PBDEs (gas+particulate) summer time levels varied from 158 to 230pgm⁻³. The PCDD/F and PCB atmospheric occurrence over Thau lagoon and subsequent inputs to the surface waters are determined by an assemble of factors, being the seasonality of atmospheric concentration, the air mass origin and meteorological conditions important drivers. Total (wet+dry) ∑2,3,7,8-PCDD/Fs and ∑18PCBs deposition fluxes to Thau Lagoon waters are 117 and 715pgm⁻²d⁻¹, respectively.

Critical loads are widely used in the effects-based assessment of emission reduction policies. While the impacts of acidification have diminished, there is increasing concern regarding the effects of nitrogen deposition on terrestrial ecosystems. In this context much attention has been focussed on empirical critical loads as well as simulations with linked geochemistry–vegetation models. Surprisingly little attention has been paid to adapt the widely used simple mass balance approach. This approach has the well-established benefit of easy regional applicability, while incorporating specified critical chemical criteria to protect specified receptors. As plant occurrence/biodiversity is related to both the nutrient and acidity status of an ecosystem, a single abiotic factor (chemical criterion) is not sufficient. Rather than an upper limit for deposition (i.e., critical load), linked nutrient nitrogen and acidity chemical criteria for plant occurrence result in an ‘optimal’ nitrogen and sulphur deposition envelope.

An urban soil chronosequence in downtown Detroit, MI was studied to determine the effects of time on pedogenesis and heavy metal sequestration. The soils developed in fill derived from mixed sandy and clayey diamicton parent materials on a level late Pleistocene lakebed plain under grass vegetation in a humid-temperate (mesic) climate. The chronosequence is comprised of soils in vacant lots (12 and 44 years old) and parks (96 and 120 years old), all located within 100m of a roadway. An A-horizon 16cm thick with 2% organic matter has developed after only 12 years of pedogenesis. The 12 year-old soil shows accelerated weathering of iron (e.g. nails) and cement artifacts attributed to corrosion by excess soluble salts of uncertain origin. Carbonate and Fe-oxide are immobilizing agents for heavy metals, hence it is recommended that drywall, plaster, cement and iron artifacts be left in soils at brownfield sites for their ameliorating effects.

Metal (Cr, Co, Cu, Zn, Cd, Pb, Ni) and metalloid (As) accumulation was studied in roadside soil and wild rat (Rattus sp.) samples from near a Pb–Zn mine (Kabwe, Zambia) and the capital city of Zambia (Lusaka). The concentrations of the seven metals and As in the soil samples and Pb in the rat tissue samples were quantified using atomic absorption spectroscopy. The concentrations of Pb, Zn, Cu, Cd, and As in Kabwe soil were much higher than benchmark values. Geographic Information System analysis indicated the source of metal pollution was mining and smelting activity. Interestingly, the area south of the mine was more highly contaminated even though the prevailing wind flow was westward. Wild rats from Kabwe had much higher tissue concentrations of Pb than those from Lusaka. Their body weight and renal Pb levels were negatively correlated, which suggests that mining activity might affect terrestrial animals in Kabwe.

International audience | In situ denitrification walls and biofilters made of wood chips are being implemented as innovative technologies for the removal of nitrates in tile drainage water from farms to reduce pollution of surface waters and the hypoxia problem in the Gulf of Mexico. Although fairly effective in removing nitrates, not much is known about the effectiveness of the biofilters in removal of herbicides, pesticides, and antibiotics in the drainage water. Using weathered wood chips obtained from an in situ denitrification wall, four common pollutants tested sorbed strongly to wood chips in the following order: enrofloxacin > monensin A > atrazine > sulfamethazine. Of the four chemicals tested, enrofloxacin was found to desorb the least by water extraction. The apparent hysteresis index for atrazine was found to be lower than that for enrofloxacin and sulfamethazine indicating greater sorption–desorption hysteresis for atrazine than enrofloxacin and sulfamethazine. Consecutive steps of water desorption and organic solvent extraction indicated that more than 65% of the sorbed atrazine, 70% of sulfamethazine, 90% of enrofloxacin, and 80% of monensin A were retained in wood chips. Results of this study showed that wood chip denitrification walls or biofilters have an added benefit in retaining herbicides and antibiotics and therefore can act as a barrier to reduce pollution of surface water and groundwater.

International audience | We present here the effects of ambient ozone (O3)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O3 treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O3 (NFA+). Stable carbon isotope discrimination (Δ) and derived time-integrated ci/ca ratios were reduced after an accumulated ozone exposure over a threshold of 40 ppb (AOT40) value from April to September of around 20,000 ppb·h. An AOT40 of above 67,000 ppb·h induced reductions in ribulose-1, 5-biphosphate carboxylase/oxygenase activity, aboveground C and needle N and K concentrations, the C/N ratio, Ca concentrations in twigs under 3 mm, and the aerial biomass, as well as increases in needle P concentrations and phosphoenolpyruvate carboxylase (PEPC) activity and the N and K concentrations in twigs under 3 mm. Macronutrients losses, the limitations placed on carbon uptake, and increases in catabolic processes may be the causes of carbon gain diminution in leaves which was reflected as a reduction in aboveground biomass at tree level. Stimulation of PEPC activity, the consequent decreased Δ, and compensation processes in nutrient distribution may increase O3 tolerance and might be interpreted as part of Aleppo pine acclimation response to O3.

The present work deals with the characterization of selected heavy metals (Ti, V, Cr, Mn, Cu, Mo, Pb, Ni, Cd and As) in PM10 collected in 2008 in three urban areas of Cantabria (Northern Spain) which are influenced by industrial activities. Ternary plots were used to identify the main tracers at the studied sites. Pollutant roses of these tracers were used as tools which give information about the location of the most important emission sources due to the characteristic wind patterns in Cantabria. Pollutant roses showed a significant contribution of the local industry to trace metal levels at the selected urban sites. | The authors would like to thank the financial support of CTM 2006-00317 project (MEC) and the Government of Cantabria (“Actions for improving the air quality and its diagnosis in Cantabria”) for their funding. We would like to express our gratitude to the Regional Environmental Ministry of Cantabria Government who kindly provided the dataset from ALM sampling point.

International audience | Composting may enhance bioremediation of PAH-contaminated soils by providing organic substrates that stimulate the growth of potential microbial degraders. However, the influence of added organic matter (OM) together with the microbial activities on the dissipation of PAHs has not yet been fully assessed. Materials and methods An in-vessel composting-bioremediation experiment of a contaminated soil amended with fresh wastes was carried out. Four different experimental conditions were tested in triplicate during 60 days using laboratory-scale reactors: treatment S (100%soil),W(100%wastes), SW(soil/ wastemixture), and SWB(soil/wastemixture with inoculation of degrading microorganisms). Results and discussion A dry mass loss of 35±5% was observed in treatments with organic wastes during composting in all the treatments except treatment S. The dissipation of the 16 USEPA-listed PAHs was largely enhanced from no significant change to 50.5±14.8% (for SW)/63.7±10.0% (for SWB).More obvious dissipation was observed when fresh wastes were added at the beginning of composting to the contaminated soil, without significant difference between the inoculated and non-inoculated treatments. Phospholipid fatty acid (PLFA) profiling showed that fungi and G-bacteria dominated at the beginning of experiment and were probably involved in PAH dissipation. Subsequently, greater relative abundances of G+bacteria were observed as PAH dissipation slowed down. Conclusions The results suggest that improving the composting process with optimal organic compositions may be a feasible remediation strategy in PAH-contaminated soils through stimulation of active microbial populations.