The Intermediate Dynamic Model for Metals (IDMM) is a model for prediction of the pools of metals (Ni, Cu, Zn, Cd, Pb) in topsoils of catchments resulting from deposition of metals from the atmosphere. We used the model to simulate soil metal pools from 1400 onwards in ten UK catchments comprising semi-natural habitats, and compared the results with present day observations of soil metal pools. Generally the model performed well in simulating present day pools, and further improvements were made to simulations of Ni, Cu, Zn and Cd by adjusting the strength of metal adsorption to the soils. Some discrepancies between observation and prediction for Pb appeared to be due either to underestimation of cumulative deposition, or to overestimation of the metal pool under ‘pristine’, pre-industrial conditions. The IDMM provides a potential basis for large scale assessment of metal dynamics in topsoils.

The availability of Pb and As in an historically contaminated orchard soil, after amendment with compost and aging in the field, was determined by single-step chemical extraction with 1.0 M ammonium acetate at pH 4.8, sequential extraction using the modified BCR test, and a redworm bioassay in the laboratory. The efficiency of soil Pb extraction by ammonium acetate was greater at higher total soil Pb but was reduced by compost amendment. Conversely, the extraction efficiency of total soil As increased with compost amendment, but was not sensitive to total soil As. The redworm bioassay indicated Pb (but not As) bioavailability to be reduced by soil amendment with compost, a result consistent with the ammonium acetate extraction test but not reflected in modified BCR test. Electron microprobe studies of the orchard soil revealed Pb and As to be spatially associated in discrete particles along with phosphorus and iron.

Although high PAH content and detection of PAH-degraders, the PAH biodegradation is limited in aged-contaminated soils due to low PAH availability (i.e., 1%). Here, we tried to experimentally increase the soil PAH availability by keeping both soil properties and contamination composition. Organic extract was first removed and then re-incorporated in the raw soil as fresh contaminants. Though drastic, this procedure only allowed a 6-time increase in the PAH availability suggesting that the organic constituents more than ageing were responsible for low availability. In the re-contaminated soil, the mineralization rate was twice more important, the proportion of 5–6 cycles PAH was higher indicating a preferential degradation of lower molecular weight PAH. The extraction treatment induced bacterial and fungal community structures modifications, Pseudomonas and Fusarium solani species were favoured, and the relative quantity of fungi increased. In re-contaminated soil the percentage of PAH-dioxygenase gene increased, with 10 times more Gram negative representatives.

Changes in ultrastructure and induction of Heat Shock Proteins 70 have been studied in Conocephalum conicum (Marchantiales) collected in different urban and country sites in Italy. These results were compared to the effects in vitro of exposition to different heavy metals for several days.At urban sites, cellular ultrastructure was modified, and heavy metals could be observed accumulating in cell walls. Simultaneously, a strong increment in Hsp70 was detected, compared with results observed on control specimens.When C. conicum was exposed to heavy metals in vitro, comparable effects as in polluted sites were observed: Cd and Pb accumulated mostly within parenchyma and, within cells, were absorbed to cell walls or concentrated in vacuoles. Moreover, severe alterations were observed in organelles. Concomitantly, a progressive accumulation of Hsp70 was detected following heavy metals exposition.These effects are discussed in order to describe the dose and time-dependent response to heavy metal stress in C. conicum.

We correlated mineralogical and particle characteristics of Zn-containing particles with Zn geoavailability, bioaccessibility, and bioavailability following gavage and intranasal (IN) administration in rats. We compared samples of Zn/Pb mine waste and five pulverized pure-phase Zn minerals (<38 μm). Particles were neutron-activated to produce radioactive 65Zn. We assessed geoavailability using sequential extractions and bioaccessibility using in vitro extraction tests simulating various pH and biological conditions. Zn in vivo bioavailability and in vitro bioaccessibility decreased as follows: mine waste > hydrozincite > hemimorphite > zincite ≈ smithsonite >> sphalerite. We found significant correlations among geoavailability, bioaccessibility and bioavailability. In particular, Zn bioavailability post-gavage and post-IN was significantly correlated with bioaccessibility in simulated phagolysosomal fluid and gastric fluid. These data indicate that solid phase speciation influences biological uptake of Zn and that in vitro tests can be used to predict Zn bioavailability in exposure assessment and effective remediation design.

It is generally accepted that urban vegetation improves air quality and thereby enhances the well-being of citizens. However, empirical evidence on the potential of urban trees to mitigate air pollution is meager, particularly in northern climates with a short growing season. We studied the ability of urban park/forest vegetation to remove air pollutants (NO2, anthropogenic VOCs and particle deposition) using passive samplers in two Finnish cities. Concentrations of each pollutant in August (summer; leaf-period) and March (winter, leaf-free period) were slightly but often insignificantly lower under tree canopies than in adjacent open areas, suggesting that the role of foliage in removing air pollutants is insignificant. Furthermore, vegetation-related environmental variables (canopy closure, number and size of trees, density of understorey vegetation) did not explain the variation in pollution concentrations. Our results suggest that the ability of urban vegetation to remove air pollutants is minor in northern climates.

This paper investigates the variations in levels of nitrogen dioxide, NO2, monitored over the decade 2001–2010, in Newcastle-upon-Tyne (UK) city centre, to develop fundamental understanding of the periods of persistence of levels of NO2 greater than 40 μg m−3 (∼21 ppb) defined as air pollution event duration. The appropriateness of the hazard theory as a mechanism to understand failure rate of the duration of poor air pollution events was explored. The results revealed two types of air quality events. The longer duration air quality events (between 24 and 68 h) were associated with the “extreme-weather” conditions and were responsible for a small number of extremely long air pollution duration events. These created bias in the results and therefore the analysis was restricted specifically to the ‘normal-weather’ related air pollution event durations, conforming to a geometric distribution. This novel approach shows promise as a mechanism to monitor and investigate year on year trends observed in air quality data.

Natural gas is the largest source of anthropogenic emissions of methane (CH4) in the United States. To assess pipeline emissions across a major city, we mapped CH4 leaks across all 785 road miles in the city of Boston using a cavity-ring-down mobile CH4 analyzer. We identified 3356 CH4 leaks with concentrations exceeding up to 15 times the global background level. Separately, we measured δ13CH4 isotopic signatures from a subset of these leaks. The δ13CH4 signatures (mean = −42.8‰ ± 1.3‰ s.e.; n = 32) strongly indicate a fossil fuel source rather than a biogenic source for most of the leaks; natural gas sampled across the city had average δ13CH4 values of −36.8‰ (±0.7‰ s.e., n = 10), whereas CH4 collected from landfill sites, wetlands, and sewer systems had δ13CH4 signatures ∼20‰ lighter (μ = −57.8‰, ±1.6‰ s.e., n = 8). Repairing leaky natural gas distribution systems will reduce greenhouse gas emissions, increase consumer health and safety, and save money.

We measured Dechlorane Plus (DP) and its dechlorinated analogs in the blood and milk from women living in e-waste recycling sites in Wenling of Taizhou region, China (n = 49). Both syn-DP and anti-DP were detected in all samples. Another compound, Cl11-DP, was detected in 45% and 84% of milk and serum samples, respectively. DP levels in blood and milk from residents living in the local environment >20 yrs (R20 group) were significantly higher than those living in Taizhou <3 yrs (R3 group) (p < 0.05). The milk/serum partition coefficient from the same women was approximately 0.43 and 0.47 for syn-DP and anti-DP, respectively. A similar value in milk compared with anti-DP/∑DPs (fanti) in serum suggested that stereoselective DP bio-accumulation did not occur during the DP transport from blood to milk. This result indicate that DP can bio-accumulate in blood and milk with the low milk/serum partition coefficient and similar blood and milk stereoselective bio-accumulation profiles.

The influence of biochar (5%) on the loss, partitioning and bioaccessibility of 14C-isoproturon (14C-IPU) was evaluated. Results indicated that biochar had a dramatic effect upon 14C-IPU partitioning: 14C-IPU extractability (0.01 M CaCl2) in biochar-amended treatments was reduced to <2% while, 14C-IPU extractability in biochar free treatments decreased with ageing from 90% to 40%. A partitioning model was constructed to derive an effective partition coefficient for biochar:water (KBW of 7.82 × 104 L kg−1). This was two orders of magnitude greater than the apparent Kfoc value of the soil organic carbon:water (631 L kg−1). 14C-radiorespirometry assays indicated high competence of microorganisms to mineralise 14C-IPU in the absence of biochar (40.3 ± 0.9%). Where biochar was present 14C-IPU mineralisation never exceeded 2%. These results indicate reduced herbicide bioaccessibility. Increasing IPU application to ×10 its recommended dose was ineffective at redressing IPU sequestration and its low bioaccessibility.