Using synchrotron- and electron microscope-based X-ray microanalyses, the distribution and speciation of Zn and Pb were examined in situ in two earthworm species (Dendrodrilus rubidus and Lumbricus rubellus) living in heavily-polluted soils. Main findings: (i) Zn spectra in ingested soil and in tissues more closely resembled Zn3(PO4)2 than ZnS; (ii) Zn speciation in tissues gave a best fit for Zn to the inner shell of 4 oxygens at 1.94 Å (or nitrogens at 1.96 Å); (iii) the best fit for Pb in tissue was with a shell of oxygens at 2.18 Å and a shell of sulphurs at 2.67 Å; (iv) a component of the Zn and much of the Pb detectable in gut contents was co-distributed with S; (v) Zn and Pb display ‘soft’ acid affinities in soil, but ‘hard’ acid affinities in tissue. This is the first metal characterisation study conducted on an invertebrate quench-frozen in the field.

The dissolution of ZnO nanoparticles (nano-ZnO) plays an important role in the toxicity of nano-ZnO to the aquatic organisms. The effects of water chemistry such as pH, ionic components, and dissolved organic matter (DOM) on the dissolution of nano-ZnO and its toxicity to Escherichia coli (E. coli) were investigated in synthetic and natural water samples. The results showed that the toxicity of nano-ZnO to E. coli depended on not only free Zn2+ but also the coexisting cations which could reduce the toxicity of Zn2+. Increasing solution pH, HPO42−, and DOM reduced the concentration of free Zn2+ released from nano-ZnO, and thus lowered the toxicity of nano-ZnO. In addition, both Ca2+ and Mg2+ dramatically reduced the toxicity of Zn2+ to E. coli. These results highlight the importance of water chemistry on the toxicity evaluation of nano-ZnO in natural waters.

For many years, extended-spectrum-beta-lactamase (ESBL) producing bacteria were a problem mainly located in medical facilities. Within the last decade however, ESBL-producing bacteria have started spreading into the community and the environment. In this study, ESBL-producing Escherichia coli from sewage sludge were collected, analysed and compared to ESBL-E. coli from human urinary tract infections (UTIs). The dominant ESBL-gene-family in both sample groups was blaCTX-M, which is the most prevalent ESBL-gene-family in human infection. Still, the distribution of ESBL genes and the frequency of additional antibiotic resistances differed in the two sample sets. Nevertheless, phenotyping did not divide isolates of the two sources into separate groups, suggesting similar strains in both sample sets. We speculate that an exchange is taking place between the ESBL E. coli populations in infected humans and sewage sludge, most likely by the entry of ESBL E. coli from UTIs into the sewage system.

A recently developed modified polar organic chemical integrative sampler (POCIS) provides a means for monitoring perfluorinated chemicals (PFCs) in water. However, changes in external flow rates may alter POCIS sampling behaviour and consequently affect estimated water concentrations of analytes. In this work, uptake kinetics of selected PFCs, over 15 days, were investigated. A flow-through channel system was employed with spiked river water at flow rates between 0.02 and 0.34 m s−1. PFC sampling rates (Rs) (0.09–0.29 L d−1 depending on analyte and flow rate) increased from the lowest to highest flow rate employed for some PFCs (MW ≤ 464) but not for others (MW ≥ 500). Rs's for some of these smaller PFCs were increasingly less sensitive to flow rate as this increased within the range investigated. This device shows promise as a sampling tool to support monitoring efforts for PFCs in a range of flow rate conditions.

Urban particulate air pollution is a serious health issue. Trees within cities can remove fine particles from the atmosphere and consequently improve air quality and human health. Tree effects on PM2.5 concentrations and human health are modeled for 10 U.S. cities. The total amount of PM2.5 removed annually by trees varied from 4.7 tonnes in Syracuse to 64.5 tonnes in Atlanta, with annual values varying from $1.1 million in Syracuse to $60.1 million in New York City. Most of these values were from the effects of reducing human mortality. Mortality reductions were typically around 1 person yr−1 per city, but were as high as 7.6 people yr−1 in New York City. Average annual percent air quality improvement ranged between 0.05% in San Francisco and 0.24% in Atlanta. Understanding the impact of urban trees on air quality can lead to improved urban forest management strategies to sustain human health in cities.

Passive air samplers were deployed to collect both gas and particulate phase polycyclic aromatic hydrocarbons in Taiyuan between 2009 and 2010. Annual average concentrations of BaP equivalent concentration (B[a]Peq) in background, rural and urban areas were 2.90 ± 0.29, 23.2 ± 30.8 and 27.4 ± 28.1 ng/m3, respectively, with higher concentration in the winter than in other seasons. The median B[a]Peq concentrations of annual inhalation exposure were estimated to be in the range of 103–347 ng/d for all population groups in rural as well as in urban areas. The median values of incremental lifetime cancer risk (ILCR) induced by whole year inhalation exposure for all groups were basically larger than 10−6, with higher values in winter than in other seasons and in urban than in rural area. In the same season and area, the ILCR of adults was larger than other age groups and that of females was a little higher than males.

An estimated 229 000 m3 of coal fly ash remains in the river system after dredging to clean-up the 2008 Tennessee Valley Authority (TVA) spill in Kingston, Tennessee. The ash is heterogeneous with clear, orange and black spheres and non-spherical amorphous particles. Combustion produces iron oxides that allow low field magnetic susceptibility (χLF) and percent frequency dependent susceptibility (χFD%) to be used to discriminate between coal fly ash and sediments native to the watershed. Riverbed samples with χLF greater than 3.0 × 10−6 m3/kg, have greater than 15% ash measured by optical point counting. χLF is positively correlated with total ash, allowing ash detection in riverbed sediments and at depth in cores. The ratio of ash sphere composition is altered by river transport introducing variability in χLF. Measurement of χLF is inexpensive, non-destructive, and a reliable analytical tool for monitoring the fate of coal ash in this fluvial environment.

We set up a free-air ozone (O3) exposure system for determining the photosynthetic responses of Siebold's beech (Fagus crenata) and oak (Quercus mongolica var. crispula) to O3 under field conditions. Ten-year-old saplings of beech and oak were exposed to an elevated O3 concentration (60 nmol mol−1) during daytime from 6 August to 11 November 2011. Ozone significantly reduced the net photosynthetic rate in leaves of both species in October, by 46% for beech and 15% for oak. In beech there were significant decreases in maximum rate of carboxylation, maximum rate of electron transport in photosynthesis, nitrogen content and photosynthetic nitrogen use efficiency, but not in oak. Stomatal limitation of photosynthesis was unaffected by O3. We therefore concluded photosynthesis in beech is more sensitive to O3 than that in oak, and the O3-induced reduction of photosynthetic activity in beech was due not to stomatal closure, but to biochemical limitation.

Phytotoxicity results are reviewed for oils, dispersants and dispersed oils. The phytotoxicity database consists largely of results from a patchwork of reactive research conducted after oil spills to marine waters. Toxicity information is available for at least 41 crude oils and 56 dispersants. As many as 107 response parameters have been monitored for 85 species of unicellular and multicellular algae, 28 wetland plants, 13 mangroves and 9 seagrasses. Effect concentrations have varied by as much as six orders of magnitude due to experimental diversity. This diversity restricts phytotoxicity predictions and identification of sensitive species, life stages and response parameters. As a result, evidence-based risk assessments for most aquatic plants and petrochemicals and dispersants are not supported by the current toxicity database. A proactive and experimentally-consistent approach is recommended to provide threshold toxic effect concentrations for sensitive life stages of aquatic plants inhabiting diverse ecosystems.

Although urbanisation is a major cause of land-use change worldwide, towns and cities remain relatively understudied ecosystems. Research into urban ecosystem service provision is still an emerging field, yet evidence is accumulating rapidly to suggest that the biological carbon stores in cities are more substantial than previously assumed. However, as more vegetation carbon densities are derived, substantial variability between these estimates is becoming apparent. Here, we review procedural differences evident in the literature, which may be drivers of variation in carbon storage assessments. Additionally, we quantify the impact that some of these different approaches may have when extrapolating carbon figures derived from surveys up to a city-wide scale. To understand how/why carbon stocks vary within and between cities, researchers need to use more uniform methods to estimate stores and relate this quantitatively to standardised ‘urbanisation’ metrics, in order to facilitate comparisons.