In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility. High density traffic resulted in elevated metal concentrations on vegetation, which were related to distance from road and plant species.

Guidelines provided by the OECD and EPPO allow the use of single-species tests performed in greenhouses to assess the risk of herbicides to non-target terrestrial plant communities in the field. The present study was undertaken to investigate the use of greenhouse data to determine effects of herbicides with a different mode of action on the biomass, seed production and emergence of field-grown plants. In addition, a single species approach was compared with a mixed species approach. Effects on the biomass of greenhouse and field-grown plants were found to be related at different effect levels, indicating that it might be possible to translate results from greenhouse studies to field situations. However, the use of single-species tests may not be valid. The response of a single plant species to sublethal herbicide dosages differed to the response of the same species grown in a mixture with other species. The use of single-species greenhouse tests in the ecological risk assessment of crop protection products may only be valid for single species in the field, not for vegetations.

Hexanitrohexaazaisowurtzitane (CL-20) is an emerging explosive that may replace the currently used explosives such as RDX and HMX, but little is known about its fate in soil. The present study was conducted to determine degradation products of CL-20 in two sandy soils under abiotic and biotic anaerobic conditions. Biotic degradation was prevalent in the slightly acidic VT soil, which contained a greater organic C content, while the slightly alkaline SAC soil favored hydrolysis. CL-20 degradation was accompanied by the formation of formate, glyoxal, nitrite, ammonium, and nitrous oxide. Biotic degradation of CL-20 occurred through the formation of its denitrohydrogenated derivative (m/z 393 Da) while hydrolysis occurred through the formation of a ring cleavage product (m/z 156 Da) that was tentatively identified as CH2N-C(N-NO2)-CHN-CHO or its isomer N(NO2)CH-CHN-CO-CHNH. Due to their chemical specificity, these two intermediates may be considered as markers of in situ attenuation of CL-20 in soil. Two key intermediates of CL-20 degradation are potential markers of its natural attenuation in soil.

A multi-trophic, multi-exposure phase assessment approach was applied to characterize the toxicity of sediments collected from two rivers in Guiyu, China, an e-waste recycling centre. Elutriate toxicity tests (bacterium Vibrio fischeri and microalga Selenastrum capricornutum) and whole sediment toxicity test (crustacean Heterocypris incongruens) showed that most sediments exhibited acute toxicity, due to elevated heavy metals and PAHs levels, and low pH caused by uncontrolled acid discharge. The survival rates of crustaceans were negatively (p < 0.05) correlated with total PAHs in sediments (411-1755 mg kg⁻¹); EC50s of V. fischeri on the elutriates were significantly correlated with elutriate pH (p < 0.01). Significant (p < 0.05) correlations between the induction of hepatic metallothionein in tilapia (Oreochromis mossambicus) and metal concentrations (Cu, Zn, Pb) in sediments were also observed, when fish were fed with diets containing sediment. The results showed that uncontrolled e-waste recycling activities may bring adverse effects to local aquatic ecosystem. Toxicity tests using different trophic organisms provided important information, supplementing chemical analyses.

Molluscs are sensitive species to the toxic effects of organotin compounds, particularly to masculinisation. Both tributyltin (TBT) and triphenyltin (TPT) have been recently shown to bind to mollusc retinoid X receptor (RXR). If RXR is involved in lipid homeostasis, exposure to TPT would have an immediate effect on endogenous lipids. To test this hypothesis, the ramshorn snail Marisa cornuarietis was exposed to environmentally relevant concentrations of TPT (30, 125, 500 ng/L as Sn) in a semi-static water regime for 7 days. Percentage of lipids and total fatty acid content decreased significantly in TPT-exposed females while the activity of peroxisomal acyl-CoA oxidase, involved in fatty acid catabolism, increased. In addition, fatty acid profiles (carbon chain length and unsaturation degree) were significantly altered in exposed females but not in males. This work highlights the ability of TPT to disrupt lipid metabolism in M. cornuarietis at environmentally realistic concentrations and the higher susceptibility of females in comparison to males. Short-term exposure to the fungicide TPT disrupts lipid metabolism in M. cornuarietis at environmentally realistic concentrations.

Chlordecone was applied between 1972 and 1993 in banana fields of the French West Indies. This resulted in long-term pollution of soils and contamination of waters, aquatic biota, and crops. To assess pollution level and duration according to soil type, WISORCH, a leaching model based on first-order desorption kinetics, was developed and run. Its input parameters are soil organic carbon content (SOC) and SOC/water partitioning coefficient (Koc). It accounts for current chlordecone soil contents and drainage water concentrations. The model was valid for andosol, which indicates that neither physico-chemical nor microbial degradation occurred. Dilution by previous deep tillages makes soil scrapping unrealistic. Lixiviation appeared the main way to reduce pollution. Besides the SOC and rainfall increases, Koc increased from nitisol to ferralsol and then andosol while lixiviation efficiency decreased. Consequently, pollution is bound to last for several decades for nitisol, centuries for ferralsol, and half a millennium for andosol. Soil and water contamination by chlordecone will persist for several centuries in the French West Indies, because the only decontamination is through leaching by drainage water.

To determine background values of the 252 chemical compounds listed in Dutch legislation, a survey was designed with the aim of estimating percentiles of the cumulative frequency distributions and areal fractions exceeding the former, legislative reference values. Sampling locations were selected by probability sampling, so that in estimating the target quantities no model assumptions on the spatial variation were required, and valid estimates could be obtained by design-based inference. Strata in random sampling were formed by overlaying an aggregated soil map and land use map. For most of the heavy metals the areal fraction with concentrations in the topsoil (0-10 cm) exceeding the reference value was smaller than the allowable maximum of 5%. For these compounds a background value was determined smaller than the reference value. Exceptions were V, Co, Ba and Cu, for which a background value was defined (slightly) larger than the reference value. Legislative background values can be best derived by probability sampling and design-based estimation.

A natural experiment indicated that a link between the presence and concentration of four elements, copper, lead, nickel, and zinc in the influent to two wastewater reclamation plants to the presence and concentrations of the same four elements in the tap water of residential properties. There were 36 populations of results that were assessed for the normality of their distribution, the difference in their median concentrations, the similarity in the ratios of their median concentrations, and the correlations of the concentrations. The results of this study suggest that brass corrosion is the major source of these four elements in the water reclamation plants influent and that there are two distinct populations of brass sources, those in the early stages of dezincification where the release of the non-copper elements is dominant and those in the later stages where the release of copper dominates and the type of brass that is corroding. Statistical analysis of residential tap waters and water reclamation plant influent showed that metals found in both came from brass corrosion.

The present study investigates the concentrations and patterns of organochlorine pesticides (OCPs) and their metabolites in liver and plasma of two ringed seal populations (Phoca hispida): lower contaminated Svalbard population and more contaminated Baltic Sea population. Among OCPs, p,p'-DDE and sum-chlordanes were the highest in concentration. With increasing hepatic contaminant concentrations and activities of xenobiotic-metabolizing enzymes, the concentrations of 3-methylsulfonyl-p,p'-DDE and the concentration ratios of pentachlorophenol/hexachlorobenzene increased, and the toxaphene pattern shifted more towards persistent Parlar-26 and -50 and less towards more biodegradable Parlar-44. Relative concentrations of the chlordane metabolites, oxychlordane and -heptachlorepoxide, to sum-chlordanes were higher in the seals from Svalbard compared to the seals from the Baltic, while the trend was opposite for cis- and trans-nonachlor. The observed differences in the OCP patterns in the seals from the two populations are probably related to the catalytic activity of xenobiotic-metabolizing enzymes, and also to differences in dietary exposure. Contrasting patterns of organochlorine pesticides in two ringed seal populations.

Remediation programmes are considered to be complete when human risk-based criteria are met. However, these targets are often unsatisfied with the ecological parameters that may be important with regard to future soil use. Five soil subsamples, collecting along a pilot-scale soil column after electrokinetic treatment, were studied, from which about 42.0%-93.3% soil Cu had been successfully removed. A series of biological assays including soil microbial biomass carbon, basal soil respiration, soil urease activity, earthworm assays, and seed assays were used to evaluate their ecological risks. The results showed that the bioassay data from the treatment variants did not supposedly reflecting the decreased soil Cu concentrations after the electrokinetic treatment, but were highly correlated with some soil physicochemical characteristics. It suggests that bioassays are necessary to assess the ecotoxicity of soil after electrokinetic treatment.