Kinetics and equilibrium properties of the biosorption of Cu2+ by algae

The purpose of this study was to examine the kinetics and equilibrium properties of freshwater algae with Cu²⁺. This was a model system to explore using algae as biosensors for water quality. Methods included making luminescence measurements (fluorescence) and copper ion-selective electrode (CuISE) measurements vs. time to obtain kinetic data. Results were analyzed using a pseudo-first-order model to calculate the rate constants of Cu²⁺ uptake by algae: k _p(Cu?Calgae)?=?0.0025?±?0.0006?s^?1 by CuISE and k _p(Cu?Calgae)?=?0.0034?±?0.0011?s^?1 by luminescence. The binding constant of Cu?Calgae, K _Cu?Calgae, was 1.62?±?0.07?×?10⁷?M^?1. Fluorescence results analyzed using the Stern?CVolmer relationship indicate that algae have two types of binding sites of which only one appears to affect quenching. The fluorescence-based method was found to be able to detect the reaction of algae with Cu²⁺ quickly and at a detection limit of 0.1?mg?L^?1.     

Pedogenesis, geochemical forms of heavy metals, and artifact weathering in an urban soil chronosequence, Detroit, Michigan

An urban soil chronosequence in downtown Detroit, MI was studied to determine the effects of time on pedogenesis and heavy metal sequestration. The soils developed in fill derived from mixed sandy and clayey diamicton parent materials on a level late Pleistocene lakebed plain under grass vegetation in a humid-temperate (mesic) climate. The chronosequence is comprised of soils in vacant lots (12 and 44 years old) and parks (96 and 120 years old), all located within 100 m of a roadway. An A-horizon 16 cm thick with 2% organic matter has developed after only 12 years of pedogenesis. The 12 year-old soil shows accelerated weathering of iron (e.g. nails) and cement artifacts attributed to corrosion by excess soluble salts of uncertain origin. Carbonate and Fe-oxide are immobilizing agents for heavy metals, hence it is recommended that drywall, plaster, cement and iron artifacts be left in soils at brownfield sites for their ameliorating effects.     

Soil intervention as a strategy for lead exposure prevention: the New Orleans lead-safe childcare playground project

The feasibility of reducing children's exposure to lead (Pb) polluted soil in New Orleans is tested. Childcare centers (median = 48 children) are often located in former residences. The extent of soil Pb was determined by selecting centers in both the core and outlying areas. The initial 558 mg/kg median soil Pb (range 14-3692 mg/kg) decreased to median 4.1 mg/kg (range 2.2-26.1 mg/kg) after intervention with geotextile covered by 15 cm of river alluvium. Pb loading decreased from a median of 4887 μg/m(2) (454 μg/ft(2)) range 603-56650 μg/m(2) (56-5263 μg/ft(2)) to a median of 398 μg/m(2) (37 μg/ft(2)) range 86-980 μg/m(2) (8-91 μg/ft(2)). Multi-Response Permutation Procedures indicate similar (P-values = 0.160-0.231) soil Pb at childcare centers compared to soil Pb of nearby residential communities. At ～$100 per child, soil Pb and surface loading were reduced within hours, advancing an upstream intervention conceptualization about Pb exposure prevention.     

Open Air Laboratories (OPAL): a community-driven research programme

OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an inter-disciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public.     

An ethical dimension to sustainable restoration and long-term management of contaminated areas

Experience after the Chernobyl accident has shown that restoration strategies need to consider a wide range of different issues to ensure the long-term sustainability of large and varied contaminated areas. Thus, the criteria by which we evaluate countermeasures need to be extended from simple cost-benefit effectiveness and radiological protection standards to a more integrated, holistic approach, including social and ethical aspects. Within the STRATEGY project, the applicability of many countermeasures is being critically assessed using a wide range of criteria. Attention is being given to issues such as practicability, feasibility, capacity and environmental side-effects, as well as social factors such as public perceptions of risk, communication of information and the need for dialogue and consultation with affected communities, and ethical aspects such as informed consent and the fair distribution of costs and doses. Although such socio-ethical factors are now the subject of a substantial field of research, there has been little attempt to integrate them in a practical context for decision makers. Within this paper, we specifically consider the ethical aspects of restoration strategies and suggest practical means by which these can be taken into account in the decision making process, introducing a value matrix. The paper covers two critical areas: evaluation of individual countermeasures, and use of the matrix to ensure transparent and systematic consideration of values in selection of a restoration strategy.     

Assessment of perceived injury risks and priorities among truck drivers and trucking companies in Washington State

Problem

The trucking industry experiences one of the highest work-related injury rates. Little work has been conducted previously in the United States to assess the hazards, needs, and injury prevention priorities in trucking. Method: Two separate industry-wide surveys of 359 trucking companies and 397 commercial truck drivers were conducted in Washington State. Results: Trucking companies and drivers both ranked musculoskeletal and slip, trip, fall injuries as the top two priorities. Controlling heavy lifting, using appropriate equipment, and addressing slippery surfaces were frequently listed as solutions. There appears to be a gap in safety climate perception between workers and employers. However, driver and company priorities agreed with industry workers' compensation claims. There is room for safety program management improvement in the industry. The study findings detail opportunities for prioritizing and reducing injuries. Impact on Industry: This information can be used to focus and design interventions for the prevention of work-related injuries while improving industry competitiveness.     

Riparian vegetation dynamics and evapotranspiration in the riparian corridor in the delta of the Colorado River, Mexico

Like other great desert rivers, the Colorado River in the United States and Mexico is highly regulated to provide water for human use. No water is officially allotted to support the natural ecosystems in the delta of the river in Mexico. However, precipitation is inherently variable in this watershed, and from 1981-2004, 15% of the mean annual flow of the Lower Colorado River has entered the riparian corridor below the last diversion point for water in Mexico. These flows include flood releases from US dams and much smaller administrative spills released back to the river from irrigators in the US and Mexico. These flows have germinated new cohorts of native cottonwood and willow trees and have established an active aquatic ecosystem in the riparian corridor in Mexico. We used ground and remote-sensing methods to determine the composition and fractional cover of the vegetation in the riparian corridor, its annual water consumption, and the sources of water that support the ecosystem. The study covered the period 2000-2004, a flood year followed by 4 dry years. The riparian corridor occupies 30,000ha between flood control levees in Mexico. Annual evapotranspiration (ET), estimated by Moderate Resolution Imaging Spectrometer (MODIS) satellite imagery calibrated against moisture flux tower data, was about 1.1myr(-1) and was fairly constant throughout the study period despite a paucity of surface flows 2001-2004. Total ET averaged 3.4x10(8)m(3)yr(-1), about 15% of Colorado River water entering Mexico from the US Surface flows could have played only a small part in supporting these high ET losses. We conclude that the riparian ET is supported mainly by the shallow regional aquifer, derived from agricultural return flows, that approaches the surface in the riparian zone. Nevertheless, surface flows are important in germinating cohorts of native trees, in washing salts from the soil and aquifer, and in providing aquatic habitat, thereby enriching the habitat value of the riparian corridor for birds and other wildlife. Conservation and water management strategies to enhance the delta habitats are discussed in light of the findings.     

Building community resilience: can everyone enjoy a good life?

Initiatives to reduce community carbon emissions and foster sustainable lifestyles have had varying degrees of success. There is now a need for a re-energised, concerted and joined-up approach that places environmental issues in a wider context – one that improves quality of life while building community resilience. This involves enhancing the capacity of neighbourhoods to recover, respond and adapt to environmental and socio-economic changes. This paper examines the experience gained in a participatory action research (PAR) study to build community resilience, where facilitators supported residents to take ownership of their own agendas. The New Earswick Good Life Initiative (GLI) was an 18-month project undertaken in a low-income suburb of York (UK). A range of approaches were used to identify activities which had the most potential to nurture resilience and foster a shift towards greater environmental sustainability. The GLI highlighted how the introduction of new ideas not only need to be locally relevant but also requires care and time in order for them to embed within community. Altering the way a community manages its environment involves transforming social relationships, strengthening institutions and influencing local power balances. Furthermore, it is necessary to build social capital, knowledge, leadership skills and support social networks to allow communities to effectively engage with relevant local and national policies. Only by providing opportunities to develop these resilient attributes can increased local responsibility be successful. The paper concludes by providing guidance on strengthening community resilience and delivering pro-environmental behaviour change.     

A critical review of hydrological data collection for assessing preservation risk for urban waterlogged archaeology: A case study from the City of York, UK

Environmental change caused by urban development, possibly augmented by climate change, may result in accelerated decay of in situ archaeological resources. Damage may be related to changes in hydrological processes. Such archaeological resources have to be considered in environmental planning. In this paper we highlight the need for improved hydrological data from urban archaeological sites using the case study of the City of York, UK, arguably one of the most well studied and well preserved urban archaeological environments globally. We suggest that the quality of hydrological data collected during routine surveys and experimental work must be improved and standardised in order for us to produce reliable archaeological risk models for urban sites.     

Mercury (Hg) and lead (Pb) in interior and exterior New Orleans house paint films

Pre-1992, latex paint was formulated with mercury (Hg) as phenylmercuric acetate (PMA). Hg vaporizes reducing its content, and lead (Pb) is stable and remains unchanged. The objective of this study is to describe the content of Hg and Pb in existing paint coatings. Forty paint chip samples were collected from both interior and exterior surfaces of homes in metropolitan New Orleans and analyzed for Hg and Pb. The median Hg in exterior paints is 26.9 mg kg(-1) (0.8-214.0) compared with 7.1 mg kg(-1) (0.03-39.2) for interior paints. The median Pb content is 76603 mg kg(-1) (464-317151) and 416 mg kg(-1) (24-63313) respectively, for exterior and interior paints. The Spearman correlation coefficients for Hg and Pb are -0.312 (P=0.13) and -0.471 (P=0.07) respectively, in exterior and interior samples. Hg and Pb vary independently with each other in paint films. Median Hg in exterior paints is four times larger than for interior paints. Median Pb in exterior paints is 184 times larger than interior paints. The Pb and Hg content in exterior and interior paint chips are significantly different (Mann-Whitney Rank Sum Test, P0.001 and P=0.006, respectively). Only 1 of the 25 exterior paints contained less than the current 5000 mg kg(-1) US standard for Pb, the criteria for exemption from the power-sanding restrictions of the New Orleans Lead Ordinance. Prior to banning PMA in paint, Hg poisonings presented as acrodynia were reported for children living in homes freshly painted with latex paint. Because of the affinity of Hg and Pb for sulfur-containing amino acid proteins, their presence in paint coatings poses an increased hazard when released as dust.