Zooming on light packaging waste differences by scanning electron microscopy

Environmental Science and Pollution Research - In the present paper, different types of pure and commercial plastic waste from different EU countries (UK, France, Italy, and Romania) were...     

Toxic effects of four sulphonylureas herbicides on soil microbial biomass

The effect of four triazinyl-sulfonylurea herbicides (cinosulfuron, prosulfuron, thifensulfuron methyl, triasulfuron) on soil microbial biomass, soil respiration, metabolic activity, metabolic quotient, and some enzymatic activities (acid and alkaline phosphatase, β-glucosidase, arylsulphatase, and fluorescein diacetate hydrolysis) were monitored under controlled conditions over 30 days. The herbicides were applied at the normal field dose (FD) and at ten-fold (10 FD) the field dose, in order to mimic a long term toxic effect. The measured soil microbial parameters showed that the FD had slight effects on soil microflora, while at 10 FD the tested herbicides exerted a stronger detrimental effect on soil microbial biomass and its biochemical activities.     

There is a limbo under the moon: what social interactions tell us about the floaters’ underworld

The ultimate and proximate causes of natal dispersal have been extensively investigated, but the behaviour of dispersers in relation to social interactions has been largely neglected. Here, we investigated the social organisation of floating individuals during their dispersal by analysing the behaviour of 40 radio-tagged eagle owls Bubo bubo during the wandering and stop phases of dispersal. Unexpectedly, eagle owl floaters mixed with conspecifics independently of their sex, age, phase of dispersal, birthplace, health status and habitat features, showing an ‘underworld’ of interactions characterised by the absence of obvious social organisation or short-term strategies. Non-breeding owls were not transient floaters that occurred at numerous sites for short periods of time but rather had fairly stable home ranges: they attempted to settle as soon as possible within well-defined home ranges. The spatial distribution pattern of floaters and high rates of home range overlap support the prediction that floating individuals are not spatially segregated, challenging the expectation that dominance by size, age and/or health status may determine the exclusive use of some portions of the dispersal area. Finally, (1) the short distances among conspecifics and the extensive home range overlaps allowed us to discard the possibility that neighbouring floaters represent a real cost during dispersal and (2) floater interactions showed a lack of clear mechanisms for avoidance of kin competition among offspring or inbreeding.     

Floater mortality within settlement areas can explain the Allee effect in breeding populations

The Allee effect (the positive relationship between population growth rate and population size) is a constraint of some animal populations at low numbers, which increases their likelihood of extinction because of a decrease in reproduction and/or survival. We were able to demonstrate that the Allee effect can be the result of a mortality increase affecting floaters (i.e. dispersing individuals able to enter as breeders in the reproductive population when a breeding territory or a potential mate – owner of a suitable breeding territory – becomes available). Previously, potential mechanisms underlying Allee effects were always related to the breeding portion of a population only. In contrast, our understanding of or solutions to population declines due to the Allee effects can reside elsewhere, away from breeding territories.     

Phytoremediation to increase the degradation of PCBs and PCDD/Fs

Phytoremediation is already regarded as an efficient technique to remove or degrade various pollutants in soils, water and sediments. However, hydrophobic organic molecules such as PAHs, PCBs and PCDD/Fs are much less responsive to bioremediation strategies than, for example, BTEX or LAS. PCDD/Fs and PCBs represent 3 prominent groups of persistent organic pollutants that share common chemical, toxicological and environmental properties. Their widespread presence in the environment may be explained by their chemical and biological stability. This review considers their fate and dissipation mechanisms. It is then possible to identify major sinks and to understand biological activities useful for remediation. Public health and economic priorities lead to the conclusion that alternative techniques to physical treatments are required. This review focuses on particular problems encountered in biodegradation and bioavailability of PCDD/Fs and PCBs. It highlights the potential and limitations of plants and micro-organisms as bioremediation agents and summarises how plants can be used to augment bacterial activity. Phytoremediation is shown to provide some new possibilities in reducing risks associated with dioxins and PCBs.     

Mapping knowledge investments in the aftermath of Hurricane Katrina: a new approach for assessing regulatory agency responses to environmental disaster

In the aftermath of large-scale disasters, the public's dependency on federal and state agencies for information about public safety and environmental risk is acute. While formal rules and procedures are in place to guide policy decisions in environmental risk assessment of spatially concentrated hazards such as regulated waste sites or vacant city lots, standard procedures for risk assessment seem potentially less well-suited for urban-scale disaster zones where environmental hazards may be widely dispersed and widely varying. In this paper we offer a new approach for the social assessment of regulatory science in response to large-scale disaster, illustrating our methodology through a socio-spatial analysis of the U.S. Environmental Protection Agency's (EPA) hazard assessment in New Orleans, Louisiana, following Hurricane Katrina in 2005. We find that the agency's commitment of epistemic resources or “knowledge investments” varied considerably across the flood-impacted portion of the city, concentrating in poorer and disproportionately African American neighborhoods previously known to be heavily contaminated. We address some of the study's social and policy implications, noting the multidimensionality and interactive nature of knowledge investments and the prospects for deepening and extending this approach through comparative research.