Social justice and mobility in coastal Louisiana,USA

Regional Environmental Change - Louisiana faces extensive coastal land loss which threatens the livelihoods of marginalized populations. These groups have endured extreme disruptive events in the...     

Residues characterisation from the fluidised bed combustion of East London’s solid recovered fuel

Waste thermal treatment in Europe is moving towards the utilisation of the combustible output of mechanical, biological treatment (MBT) plants. The standardisation of solid recovered fuels (SRF) is expected to support this trend and increase the amount of the generated combustion residues. In this work, the residues and especially the fly ashes from the fluidised bed combustion (FBC) of East London’s NCV 3, Cl 2, and Hg 1 class SRF, are characterised. The following toxicity indicators have been studied: leachable chlorine, organochlorides expressed as pentachlorobenzene and hexachlorobenzene, and the heavy metals Cu, Cr, Cd, Zn, Ni, and Pb. Furthermore the mineralogical pattern of the ashes has been studied by means of XRD and SEM–EDS. The results suggest that these SRF derived ashes have significantly lower quantities of Cu, Cd, Pb, Zn, leachable Cl, and organochlorides when compared to other literature values from traditional waste thermal treatment applications. This fact highlights the importance of modern separation technologies employed in MBT plants for the removal of components rich in metals and chlorine from the combustible output fraction of SRF resulting to less hazardous residues.     

Safety margins for lead in the general population

The results of monitoring blood lead concentrations, the accepted biological indicator for lead in man, are examined against the three trigger values put forward in the UK, first as justifying environmental investigation (25 g 100 ml^-1), second as justifying health checks (35 g 100 ml^-1) and third as likely to give rise to obvious symptoms in a few individuals (50 g 100 ml^-1). Arguments for using the proportion or the number of individuals above a trigger value rather than the ratio of the mean blood lead concentration to the trigger value, the conventional safety margin, are presented. The numbers of individuals or proportions in the total population who are likely to be above the trigger values have been estimated and shown to be relatively small for all three. Factors likely to affect blood lead concentrations are examined against the possible effects of the changes, current and proposed, in the controls imposed on lead usage and on pathways. The qualitative changes expected are considered by groups-eg. smokers and drinkers, by regions, eg., those with lead-free drinking water as against those still with lead in their supplies, and for the general population eg. from the elimination of the soldered can for food and the reduction, and eventual elimination, of lead in petrol.Because the relationship between intake and blood concentration is non-linear in the UK, those with the highest existing blood lead concentrations in the general population must be expected to show the smallest relative reductions in blood lead for any small reduction in exposure. The analysis also concludes that those at highest risk will have to depend on their being identified individually and action taken on them and their immediate specific environment.     

GIS and aquaculture: Assessment of soft-shell clam sites

The 1992 collapse of the northern cod fishery at Newfoundland, Canada and the subsequent closure of a majority of the inshore ground fishery has placed a focus on the development of aquaculture within the province. In May 1995 Innovative Fisheries Inc. of St. John's, Newfoundland, conducted field studies to evaluate the soft-shell clam (edible bivalve molluscs) resources on three sand flats near Burgeo, Newfoundland. GIS can be used to examine issues regarding the development and management of the soft-shell clam beds. GIS can also be applied to examine the issue of ‘competing uses’ for the proposed soft-shell clam aquaculture site. The information presented in this study indicates that GIS is an important tool for the aquaculture industry. These systems can be used to monitor, quantify and evaluate the soft-shell beds near Burgeo. Management issues such as water quality, resource sustainability as well as the economic viability of the clam resource can be assessed within a GIS environment. The results of the analysis in this study suggest potential problems with faecal coliform contamination from local cottages. Finally, data collection for aquaculture site assessment is required if a resource is to be managed effectively. GIS applications provide insights into the quality of the physical environment as well as the sustainability of a resource. However, it is the aquaculture operators who ultimately make the final decisions.     

Toward a sustainable Iceland scallop fishery in Gilbert Bay,a marine protected area in the eastern Canada coastal zone

Iceland scallop (Chlamys islandica) stocks in the North Atlantic are usually pulse harvested, resulting in boom and bust local landings. We describe an adaptive management strategy for a sustainable harvest of Iceland scallops in Gilbert Bay, a Marine Protected Area (MPA) of coastal Labrador. The current management plan for the MPA closes pristine scallop habitat, a practice that under favourable ocean conditions may lead to local reseeding. The community-based co-management structure for the MPA utilizes the local ecological knowledge of fishermen. Scallop harvesters are participating in research on the present state of the resource. Currently scallops are smaller near the mouth of the bay where fishing effort has been concentrated historically. The cooperation of fishers in enforcing area closures and in monitoring the scallop harvest may lead to a sustainable scallop fishery.     

Integrated monitoring — Principles and practice

The concept of integrated monitoring is examined and defined. The different types and applications of monitoring in the United Kingdom are considered against the information they can provide. Two examples of integrated monitoring of health hazards in the UK are described. The relevance of the principles and the practice to the assessment of regional and global environmental problems is discussed and suggestions made for their review.The authors are with the Central Directorate on Environmental Pollution, Department of the Environment     

Comparison of coal/solid recovered fuel (SRF) with coal/refuse derived fuel (RDF) in a fluidized bed reactor

An experimental study was undertaken to compare the differences between municipal solid waste (MSW) derived solid recovered fuel (SRF) (complying with CEN standards) and refuse derived fuel (RDF). Both fuels were co-combusted with coal in a 50 kW fluidised bed combustor and the metal emissions were compared. Synthetic SRF was prepared in the laboratory by grinding major constituents of MSW such as paper, plastic, textile and wood. RDF was obtained from a local mechanical treatment plant. Heavy metal emissions in flue gas and ash samples from the (coal + 10% SRF) fuel mixture were found to be within the acceptable range and were generally lower than that obtained for coal + 10% RDF fuel mixture. The relative distribution of heavy metals in ash components and the flue gas stream shows the presence of a large fraction (up to 98%) of most of the metals in the ash (except Hg and As). Thermo-gravimetric (TG) analysis of SRF constituents was performed to understand the behaviour of fuel mixtures in the absence and presence of air. The results obtained from the experimental study will enhance the confidence of fuel users towards using MSW-derived SRF as an alternative fuel.     

Environmental sampling of volatile organic compounds during the 2018 Camp Fire in Northern California

Trace analysis of volatile organic compounds (VOCs) during wildfires is imperative for environmental and health risk assessment. The use of gas sampling devices mounted on unmanned aerial vehicles (UAVs) to chemically sample air during wildfires is of great interest because these devices move freely about their environment, allowing for more representative air samples and the ability to sample areas dangerous or unreachable by humans. This work presents chemical data from air samples obtained in Davis, CA during the most destructive wildfire in California's history - the 2018 Camp Fire – as well as the deployment of our sampling device during a controlled experimental fire while fixed to a UAV. The sampling mechanism was an in-house manufactured micro-gas preconcentrator (µPC) embedded onto a compact battery-operated sampler that was returned to the laboratory for chemical analysis. Compounds commonly observed in wildfires were detected during the Camp Fire using gas chromatography mass spectrometry (GC–MS), including BTEX (benzene, toluene, ethylbenzene, m+p-xylene, and o-xylene), benzaldehyde, 1,4-dichlorobenzene, naphthalene, 1,2,3-trimethylbenzene and 1-ethyl-3-methylbenzene. Concentrations of BTEX were calculated and we observed that benzene and toluene were highest with average concentrations of 4.7 and 15.1 µg/m³, respectively. Numerous fire-related compounds including BTEX and aldehydes such as octanal and nonanal were detected upon experimental fire ignition, even at a much smaller sampling time compared to samples taken during the Camp Fire. Analysis of the air samples taken both stationary during the Camp Fire and mobile during an experimental fire show the successful operation of our sampler in a fire environment.     

A simple method for preparing prometaphase chromosomes from amniotic fluid cell cultures

A simple method for preparing prometaphase chromosomes from amniotic fluid cell cultures is described. The technique is based upon several key steps including: (1) reduced colcemid concentration, (2) reduced exposure to trypsin-EDTA, and (3) maintaining cells in single suspension by adjusting cell concentration appropriately. Chromosomes with banding resolution up ot 800 bands per haploid set can be routinely produced. The described methodology is particularly useful in defining and establishing the clinical significance of subtle structural aberrations.