Metal uptake by woodlice in urban soils.

This study evaluated the uptake of bioavailable metal (Cd, Cr, Cu, Fe, Pb and Zn) by woodlice (Isopoda) collected from public open spaces in urban areas of Renfrewshire, Central West Scotland, UK. The species Oniscus asellus and Porcellio scaber were collected at 13 different locations together with associated surface soil samples. Soils were subject to sequential extraction to evaluate metal availability and analyzed by ICP-AES and flame AAS for Cd, Cr, Cu, Fe, Pb and Zn concentrations. The soil samples had metal concentrations typical of general urban environments and the potentially toxic elements were well below published guideline values for contaminated sites. The metal concentration showed differing inputs of natural and anthropogenic sources. Metals were bioconcentrated in the order Cu>Cd>Pb>Cr>Zn>Fe for O. asellus and Cu>Zn>Cd>Cr>Fe for P. scaber. Principal Component Analysis of soil geochemical properties and Isopoda metal concentration identified metal to metal variation in uptake. Multiple linear regression analysis was applied in order to investigate the metal uptake in relation to soil properties (total metal concentration, pH and organic matter (OM)). The results showed that factors affecting metal concentration were both species and site specific. The most available forms of metals were generally poorly related to metal accumulation by woodlice, with the only exception being for Cu, which was related to the exchangeable soil fraction. Soil conditions e.g. pH and OM, influenced metal association within the soil and OM played a significant role in restricting uptake of Cr and Pb in particular. For most of the metals studied, despite differences in the environmental availability of the metals, accumulation from ambient soil concentration is controlled by ecological and physiological factors influencing metal assimilation, storage and excretion and that the two biological species vary considerably in their regulation of individual metals.

Cobalt and secondary poisoning in the terrestrial food chain: data review and research gaps to support risk assessment.

Cobalt is a naturally occurring element found in rocks, soil, water, plants, and animals and has diverse industrial importance. It is cycled in surface environments through many natural processes (e.g. volcanic eruptions, weathering) and can be introduced through numerous anthropogenic activities (e.g. burning of coal or oil, or the production of cobalt alloys). The environmental behaviour of cobalt in terrestrial environment is relatively poorly studied and in particular where Co is used in industrial processes, the baseline information to support wider and long-term environmental impacts is widely dispersed. To support the adoption of new EU regulations on the risk assessment of chemicals, we review here the various aspects of the environmental chemistry, fate and transport of Co across environmental interfaces and discuss the toxicology and potential for bio magnification and food chain accumulation. The soil-to-plant transfer of Co appears to be viable route to expose lower trophic levels to biologically significant concentrations and Co is potentially accumulated in biomass and top soil. Evidence for further accumulation through soil-invertebrate transfer and to higher trophic levels is suggested by some studies but this is obscured by the relatively high variability of published transfer data. This variation is not due to one particular aspect of the transfer of Co in terrestrial environments. Influences are from the variability of geological sources within soil systems; the sensitivity of Co mobility to environmental factors (e.g. pH) and the variety of life strategies for metal elimination/use within biological species. Toxic effects of Co have been suggested for some soil-plant animal studies however, uncertainty in the extrapolation from laboratory to field is a major limitation.

The environmental behaviour of polychlorinated phenols and its relevance to cork forest ecosystems: a review.

Pentachlorophenol (PCP) has been used as a herbicide, biocide and preservative worldwide since the 1930s and as a result, extensive and prolonged contamination exists. The environmental impact increases when its many degradation products are taken into consideration. A number of chloroanisols and their related chlorophenols have been found in cork slabs collected from Portuguese oak tree forests before stopper manufacturing, and contamination by PCP and polychlorinated anisole (PCA) has been detected in Canadian forests. It is suggested that the use of polychlorinated phenols, in particular PCP, is thought to be a cause of the cork taint problem in wine, a major socio-economic impact not only for industry but on sensitive and highly biodiverse ecosystems. It also highlights particular issues relating to the regional regulation of potentially toxic chemicals and global economics world wide. To fully understand the impact of contamination sources, the mechanisms responsible for the fate and transport of PCP and its degradation products and assessment of their environmental behaviour is required. This review looks at the current state of knowledge of soil sorption, fate and bioavailability and identifies the challenges of degradation product identification and the contradictory evidence from field and laboratory observations. The need for a systematic evaluation of PCP contamination in relation to cork forest ecosystems and transfer of PCP between trophic levels is emphasised by discrepancies in bioaccumulation and toxicity. This is essential to enable long term management of not only transboundary contaminants, but also the sustainable management of socially and economically important forest ecosystems.