The O₃ uptake in 17 adult trees of six urban species was evaluated by the sap flow-based approach under free atmospheric conditions. The results showed very large species differences in ground area scaled whole-tree ozone uptake ( [Formula: see text] ), with estimates ranging from 0.61 ± 0.07 nmol m⁻² s⁻¹ in Robinia pseudoacacia to 4.80 ± 1.04 nmol m⁻² s⁻¹ in Magnolia liliiflora. However, average [Formula: see text] by deciduous foliages was not significantly higher than that by evergreen ones (3.13 vs 2.21 nmol m⁻² s⁻¹, p = 0.160). Species of high canopy conductance for O₃ ( [Formula: see text] ) took up more O₃ than those of low [Formula: see text] , but that their sensitivity to vapour pressure deficit (D) were also higher, and their [Formula: see text] decreased faster with increasing D, regardless of species. The responses of [Formula: see text] to D and total radiation led to the relative high flux of O₃ uptake, indicating high ozone risk for urban tree species.

Foliar δ³⁴S values of three soil-growing plant species (Platanus Orientalis L., Osmanthus fragrans L. and Cinnamomum camphora) have been analyzed to indicate atmospheric sulfur. The foliar δ³⁴S values of the three plant species averaged −3.11±1.94‰, similar to those of both soil sulfur (−3.73±1.04‰) and rainwater sulfate (−3.07±2.74‰). This may indicate that little isotopic fractionation had taken place in the process of sulfur uptake by root or leaves. The δ³⁴S values changed little in the transition from mature leaves to old/senescing leaves for both the plane tree and the osmanthus tree, suggestive of little isotope effect during sulfur redistribution in plant tissues. Significantly linear correlation between δ³⁴S values of leaves and rainwater sulfate for the plane and osmanthus trees allowed the tracing of temporal variations of atmospheric sulfur by means of foliar sulfur isotope, while foliage δ³⁴S values of the camphor is not an effective indicator of atmospheric sulfur.

Great efforts have been made in China to retrofit and upgrade the existing municipal wastewater treatment plants (WWTPs) for enhanced removal of organic substrates and in particular nutrients. However, the removal of trace recalcitrant or hazardous organic chemicals, e.g. steroid estrogens, one group of typical endocrine disrupting chemicals, has long been overlooked. The extensive investigations on estrogen removal rates in global and Chinese WWTPs and the estrogen biodegradation kinetics results in batch laboratory experiments are reviewed in this study. The effects of estrogen initial concentration and nitrifying activated sludge are highlighted. Challenges existing in current estrogen studies are pointed out, which are relevant for researches on fate and behavior of similar down-the-drain chemicals in both Chinese and global WWTPs.

Since early 1980s, chemical pollution has become a serious environmental problem in rapidly developing China. This study reviewed the policy and legal framework for monitoring and management of chemical pollutants in China, with reference to the relevant experience in other jurisdictions. Although efforts in environmental monitoring of chemical contamination have been substantially increased over the last decade, China is lagging behind in terms of nationwide monitoring of chemical contamination in human population, and standardization of sampling and analytical protocols. While actively participating in various international treaties and conventions related to pollution control, China also has a very comprehensive set of environmental laws and policies. These include the newly enacted legislation on the control of new chemicals (i.e., China REACH) and the development of a set of National Environmental Standards. In addition to environmental education, these new measures will further enhance the control of chemical pollutants and facilitate effective law enforcement.

Transfer of aqueous methylmercury (MeHg) to primary consumers in aquatic foodwebs is poorly understood despite its importance for bioaccumulation of MeHg. We studied bioaccumulation of MeHg in simple aquatic food chains of two humic boreal streams in relation to streamwater chemistry, food web characteristics and dietary fatty acid (FA) biomarkers. Transfer of aqueous MeHg into primary consumers was similar in both streams, resulting in higher MeHg in consumers in the MeHg-rich stream. Trophic enrichment of MeHg and dietary retention of FA biomarkers was the same in both streams, suggesting that exposure to aqueous MeHg at the base of the food chain determined levels of MeHg in biota. In addition, contents of dietary biomarkers suggested that ingestion of algae reduced MeHg bioaccumulation, while ingestion of bacteria stimulated MeHg uptake. Dietary uptake of bacteria could thus be an important pathway for MeHg-transfer at the bottom of food chains in humic streams.

Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24–36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species.

Urban soils and vegetation contain large pools of carbon (C) and nitrogen (N) and may sequester these elements at considerable rates; however, there have been no systematic studies of the composition of soils beneath the impervious surfaces that dominate urban areas. This has made it impossible to reliably estimate the net impact of urbanization on terrestrial C and N pools. In this study, we compared open area and impervious-covered soils in New York City and found that the C and N content of the soil (0–15 cm) under impervious surfaces was 66% and 95% lower, respectively. Analysis of extracellular enzyme activities in the soils suggests that recalcitrant compounds dominate the organic matter pool under impervious surfaces. If the differences between impervious-covered and open area soils represent a loss of C and N from urban ecosystems, the magnitude of these losses could offset sequestration in other parts of the urban landscape.

Polycyclic aromatic hydrocarbon (PAH) extracts of fine particles (PM₂.₅) collected from combustion of seven wood species and briquettes were tested for mutagenic activities using Ames test with Salmonella typhimurium TA98 and TA100. The woods were Pinus pinaster (maritime pine), Eucalyptus globulus (eucalypt), Quercus suber (cork oak), Acacia longifolia (golden wattle), Quercus faginea (Portuguese oak), Olea europea (olive), and Quercus ilex rotundifolia (Holm oak). Burning experiments were done using woodstove and fireplace, hot start and cold start conditions. A mutagenic response was recorded for all species except golden wattle, maritime pine, and briquettes. The mutagenic extracts were not correlated with high emission factors of carcinogenic PAHs. These extracts were obtained both from two burning appliances and start-up conditions. However, fireplace seemed to favour the occurrence of mutagenic emissions. The negative result recorded for golden wattle was interesting, in an ecological point of view, since after confirmation, this invasive species, can be recommended for domestic use.

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.

A very high ozone episode with observed hourly values above 350 μg m⁻³ occurred in July 2005 at the Lamas d’Olo air quality monitoring station, located in a mountainous area in the north of Portugal. Aiming to identify the origin and formation of this ozone-rich episode, a statistical analysis and a modelling approach were applied. A cross-spectrum analysis in the frequency domain and a synoptic analysis of the meteorological and air quality time series were performed. In order to go further in this analysis, a numerical modelling approach was applied. The results indicate that the transport of ozone and its precursors is the main responsible for the high ozone concentrations. Together with the local mountain breeze and subsidence conditions, the sea-breeze circulation transporting pollutants from the coastal urban and industrialized areas that reach the site during late afternoon turn out to be the driving forces for the ozone peaks.