Bioremediation of a former dry cleaner using potassium lactate

Chlorinated solvents were released to the surficial groundwater underneath a former dry cleaning building, resulting in a groundwater plume consisting of high concentrations of trichloroethene (TCE) and cis‐1,2‐dichloroethene (cis‐1,2‐DCE) and low concentrations of tetrachloroethene (PCE) and vinyl chloride. The initial remedial action included chemical oxidation via injection of 14,400 gallons of Fenton's Reagent in March 2002, and an additional 14,760 gallons in April 2002. A sharp reduction of contaminant concentrations in groundwater was observed the following month; however, rebound of contaminant concentrations was evident as early as October 2002. A source area of PCE‐impacted soils was excavated in June 2004. Following the excavation, Golder Associates Inc. (2007) implemented a biostimulation plan by injecting 55 gallons of potassium lactate (PURASAL® HiPure P) in September 2005, and again in February 2006. Comparing the preinjection and postinjection site conditions, the potassium lactate treatments were successful in accomplishing a 40 to 70 percent reduction in mass within four months following the second injection. Elevated vinyl chloride concentrations have persisted through both injection events; however, significant vinyl chloride reduction has been observed in one well with the highest total organic carbon (TOC) concentrations following each injection. © 2008 Wiley Periodicals, Inc.     

Arsenic speciation and mobility in surface water at Lucky Shot Gold Mine, Alaska

Historical mining in Alaska has created a legacy of approximately 6,830 abandoned mine sites which include adits, tailing piles and contaminated land that continue to impact surface and groundwater quality through run-off and leaching of potentially toxic metals, especially arsenic (As). One such site is the Lucky Shot Gold Mine in Hatcher Pass, south-central Alaska, which operated from 1920 until 1942, mining gold-bearing quartz veins hosted in a Cretaceous tonalite intrusion. Arsenopyrite (FeAsS) and pyrite (FeS₂) present in the quartz veins contribute to elevated As levels in water draining, abandoned mine adits. As future underground mining at Lucky Shot may further adversely impact water quality, baseline geochemical studies were undertaken to assess As mobility in the vicinity of the mine adits. Water samples were collected from streams, adits and boreholes around the mine and analysed for major and minor elements using inductively coupled plasma-mass spectrometry (ICP-MS) and for anions by ion chromatography (IC). Arsenic species separation was performed in the field to determine the ratio of inorganic As(III)/As(V) using anion-exchange chromatography, following established methods. It was determined that water draining the adits had elevated levels of As roughly seventy times the United States Environmental Protection Agency Drinking Water Standard of 10?μg?L^?1, although this was rapidly diluted downstream in Craigie Creek to <2?μg?L^?1. Adit and surface water pH was circum-neutral and displayed no characteristics of acid mine drainage. Despite being well oxygenated, As(III) is the dominant As species in adit water, accounting for close to 100?% of total As. The proportion of As(V) increases downstream of the adits, as some As(III) is oxidized, but the speciation enhances arsenic mobility at the site. The δ¹⁸O measurements indicate that the water in the system has a short residence time as it is very similar to meteoric water, supporting the observation that the predominance of As(III) in adit water results from the lack of thermodynamical equilibrium being attained and preferential absorbance of As(V).     

Understanding Conceptual Climate Change Meanings and Preferences of Multi-Actor Professional Leadership in New York

This article sets out to evaluate the range of meanings and preferences for the concepts of adaptation, resilience, mitigation and coping of a variety of professionals in New York who are undertaking leadership positions in developing climate change policies and practices. This article positions a normative set of simplified meanings for each of the aforementioned concepts based on a review of existing literature. Utilizing a survey, these normative meanings are evaluated by and between the: (a) concepts and meanings; (b) concepts and applications and (c) applications and preferences, as applied to various risk-based scenarios ranging from sea-level rise to heat waves. This survey tests the hypotheses that the respondents: (i) are unable to consistently match the concept of resiliency with the normative meanings or applications: and (ii) will not consistently show a preference for resilience applications or outcomes ahead of other concepts. The results of the survey confirm both hypotheses, which is demonstrative of the inadequacy of the current framework dominated by a narrowly defined framework for resilience. It is anticipated that the results of this article will advance an argument for the necessity to develop consistent meanings for concepts which bridge the scientific, policy and popular domains.     

Trisomy 18 and maternal serum and amniotic fluid alpha-fetoprotein

Maternal serum and amniotic fluid alpha-fetoprotein levels were studied retrospectively in a total of 58 pregnancies with trisomy 18. In those pregnancies uncomplicated by either fetal exomphalos or neural tube defect the midtrimester maternal serum alpha-fetoprotein (MSAFP) levels were markedly reduced, the median value for 38 such pregnancies being 0.6 multiples of the median (MoM). Trisomy 18 with exomphalos was associated with a higher median MSAFP, but still within the normal range: 1.1 MoM, (nine pregnancies); trisomy 18 with exomphalos and neural tube defect (NTD) was associated with grossly raised levels: median MSAFP was 4-5 MoM (three pregnancies). Amniotic fluid alpha-fetoprotein (AFAFP) levels were normal in uncomplicated trisomy 18 pregnancies: median AFAFP, for 19 pregnancies, was 1.1 MoM. Exomphalos alone, or together with neural tube defect, was associated with greatly elevated levels of AFAFP; for exomphalos alone median AFAFP was 9.59 MoM (four pregnancies), and for exomphalos with neural tube defect the median AFAFP was 23.95 Mom (three pregnancies). Screening with low and high MSAFP, routine ultrasound, and amniocentesis on all women aged 35 years or over, together might identify over 50 per cent of pregnancies with trisomy 18.     

Assessing potential risks to wildlife and sportsmen from exposure to dioxin in pulp and paper mill sludge spread on managed woodlands

Potential human and wildlife exposures to TCDD in landspread pulp and paper mill sludge in the State of Maine were evaluated by means of a human health and an ecological risk assessment methodology. The highest historical concentrations of TCDD reported for these sludges do not present a risk to American woodcock, selected as an indicator species for this analysis. Concentrations of TCDD as high as 50 ppt in soil are not likely to produce adverse effects in the embryonic/hatchling stage of the woodcock. This soil concentration of TCDD does not present a significant risk to sportsmen and their families that may consume birds which inhabit these sites.     

Mitochondrial DNA evidence for rapid colonisation of the Indo–West Pacific by the mudcrab Scylla serrata

Scylla serrata (Forskål, 1775) is widely distributed throughout mangrove habitats of the Indo-West Pacific (IWP) coastal waters. This study investigated the phylogeographic distribution of S. serrata mitochondrial DNA haplotypes sampled throughout the species range. Adults were sampled from three west Indian Ocean locations (N?=?21), five west Pacific sites (N?=?28) and three sites from northern and eastern Australia (N?=?76). Temperature-gradient gel-electrophoresis and sequencing of 549 base pairs of a mtDNA gene (cytochrome oxidase 1) identified 18 distinct haplotypes. Haplotypes cluster into two clades separated by ?2% sequence-divergence. One clade is widespread throughout the IWP, the other is strictly confined to northern Australia. Genealogical assessment of sequenced haplotypes suggests that the historical spread of S. serrata throughout the IWP has occurred rapidly and recently (<1 million years before present) from a west Pacific origin. The fact that many locations contain a single unique haplotype suggests limited contemporary gene flow between trans-oceanic sites, and that recent historical episodes of population founding and retraction have both determined and affected the current distribution of S. serrata populations. Contrary to that reported for other widespread species of IWP taxa, there is no pattern of regional separation of Indian from Pacific Ocean populations. However, results do suggest a vicariant separation of northern Australian crabs prior to the IWP radiation. We speculate that this separation may have resulted in the formation of a new species of Scylla.     

Microplastic contamination in Great Lakes fish

Freshwater ecosystems, generally adjacent to human population and more contaminated relative to adjacent marine ecosystems, are vulnerable to microplastic contamination. We sampled 7 species of fish from Lake Ontario and Lake Superior and assessed their gastrointestinal (GI) tracts to quantify ingested microplastics and other anthropogenic particles. A subset of the microparticles were chemically analyzed to confirm polymer types and anthropogenic origins. We documented the highest concentration of microplastics and other anthropogenic microparticles ever reported in bony fish. We found 12,442 anthropogenic microparticles across 212 fish (8 species) from nearshore Lake Ontario, 943 across 50 fish (1 species) from Humber River, and 3094 across 119 fish (7 species) from Lake Superior. Fish from Lake Ontario had the greatest mean abundance of anthropogenic microparticles in their GI tracts (59 particles/fish [SD 104]), with up to 915 microparticles in a single fish. Fish from Lake Superior contained a mean [SD] of 26 [74] particles/fish, and fish from Humber River contained 19 [14] particles/fish. Most particles were microfibers. Overall, ≥90% of particles were anthropogenic, of which 35-59% were microplastics. Polyethylene (24%), polyethylene terephthalate (20%), and polypropylene (18%) were the most common microplastics. Ingestion of anthropogenic particles was significantly different among species within Lake Ontario (p < 0.05), and the abundance of anthropogenic particles increased as fish length increased in Lake Ontario (ρ = 0.62). Although we cannot extrapolate the concentration of microplastics in the water and sediments of these fish, the relatively high abundance of microplastics in the GI tracts of fish suggests environmental exposure may be above threshold concentrations for risk.