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A study using risk-based geostatistical analysis aimed at improving remediation decisions at hazardous wastes sites is presented. The use of geostatistical analysis necessitates the identification of cancer risk for each sample taken. This sample-specific risk is utilized to produce maps of block-specific risk and links with models of site utilization to develop a quantity. The study shows the derivation of block-specific risk and shows how both this quantity and riskiness can be shown graphically to help in remediation decisions.

The failure of remedial measures at many of the hazardous waste sites (HWS) in the US indicates that consideration should be given to including ecological factors in design plans. There is urgent need to establish priorities according to comprehensive analysis and recording of the dangers from HWS, and for this reason site management work must be extended beyond its current boundaries. Ecological issues also need to be considered in relation to bioremediation, and should be made part of the remediation programmes which will be needed at many HWS, especially at western semiarid sites.

This paper demonstrates a maximum likelihood (ML)-based approach to derive representative ("best guess") contaminant concentrations from data with censored values (e.g., less than the detection limit). The method represents an advancement over existing techniques because it is capable of estimating the proportion of measurements that are true zeros and incorporating varying levels of censorship (e.g., sample specific detection limits, changes through time in method detection). The ability of the method to estimate the proportion of true zeros is validated using precipitation data. The stability and flexibility of the method are demonstrated with stochastic simulation, a sensitivity analysis, and unbiasedness analysis including varying numbers of significant digits. A key aspect of this paper is the application of the statistical analysis to real site rock core contaminant concentration data collected within a plume at two locations using high resolution depth-discrete sampling. Comparison of the representative values for concentrations at each location along the plume center-line shows a larger number of true zeros and generally lower concentrations at the downgradient location according to the conceptual site model, leading to improved estimates of attenuation with distance and/or time and associated confidence; this is not achievable using deterministic methods. The practical relevance of the proposed method is that it provides an improved basis for evaluating change (spatial, temporal, or both) in environmental systems. [ABSTRACT FROM AUTHOR]

This article presents information related to cleanup costs at waste sites. Most people agree that Superfund sites and other complex, multiparty, hazardous waste sites that pose risks to human health and the environment should be remediated. At a typical hazardous waste site, several categories of potentially responsible parties (PRPs) often face liability. Significant differences may exist within and among these classes of PRPs in terms of their contributions to and degree of responsibility for site conditions. Changes in site ownership and operations and disputes among identified PRPs often lead to disagreements.

Presents information on a study of organic compounds commonly found at hazardous waste sites for uptake by poplar trees. Background on the study; Materials and methods; Results and discussion.

In polluted environments, when microbial aerosols originate locally, species composition of the aerosols should reflect the polluted source. To test the connection between local environmental pollution and microbial aerosols near an urban waterfront, we characterized bacterial aerosols at Newtown Creek (NTC), a public waterway and Superfund site in a densely populated area of New York, NY, USA. Culturable bacterial aerosol fallout rate and surface water bacterial concentrations were at least an order of magnitude greater at NTC than at a neighboring, less polluted waterfront and a nonurban coastal site in Maine. The NTC culturable bacterial aerosol community was significantly different in taxonomic structure from previous urban and coastal aerosol studies, particularly in relative abundances of Actinobacteria and Proteobacteria. Twenty-four percent of the operational taxonomic units in the NTC overall (air + water) bacterial isolate library were most similar to bacterial 16S rRNA gene sequences previously described in terrestrial or aquatic environments contaminated with sewage, hydrocarbons, heavy metals, and other industrial waste. This study is the first to examine the community composition and local deposition of bacterial aerosols from an aquatic Superfund site. The findings have important implications for the use of aeration remediation in polluted aquatic environments and suggest a novel pathway of microbial exposure in densely populated urban communities containing contaminated soil and water. [ABSTRACT FROM AUTHOR]

Field and laboratory studies were carried out to understand the cause for steady increases in 129I concentrations emanating from radiological basins located on the Savannah River Site, South Carolina. The basins were closed in 1988 by adding limestone and slag and then capping with a low permeability engineered cover. Groundwater 129I concentrations in a well near the basins in 1993 were 200 pCi L-1 and are presently between 400 and 1000 pCi L-1. Iodine speciation in the plume contained wide ranges of iodide, iodate, and organo-iodine concentrations. First-order calculations based on a basin sediment desorption study indicate that the modest increase of 0.7 pH units detected in the study site groundwater over the last 17 years since closure of the basins may be sufficient to produce the observed increased groundwater 129I concentrations near the basins. Groundwater monitoring of the plume at the basins has shown that the migration of many of the high risk radionuclides originally present at this complex site has been attenuated. However, 129I continues to leave the source at a rate that may have been exacerbated by the initial remediation efforts. This study underscores the importance of identifying the appropriate in situ stabilization technologies for all source contaminants, especially if their geochemical behaviors differ. [ABSTRACT FROM AUTHOR]

The article focuses on the toxic waste dump called Love Canal, found in Niagara Falls, New York. The article comments on the history behind Love Canal creation by entrepreneur William T. Love and the dumping of toxic waste by Hooker Chemical, which would later be acquired by Occidental Chemical Corp. It mentions that the precise contents of the dumping are unknown, but includes benzene hexachloride, used in the pesticide lindane, chlorobenzene, used in the synthesis of DDT, and dioxin. It comments on the sale of Love Canal to the Niagara Falls school board, which used it for a school and playground and where chemical leaks soon occurred. It mentions the documented findings of increased rates of birth defects and miscarriages, and the government intervention in 1978.

Cement-based materials play an important role in multi-barrier concepts developed worldwide for the safe disposal of hazardous and radioactive wastes. Cement is used to condition and stabilize the waste materials and to construct the engineered barrier systems (container, backfill, and liner materials) of repositories for radioactive waste. In this study, Ni uptake by hardened cement paste has been investigated with the aim of improving our understanding of the immobilization process of heavy metals in cement on the molecular level. X-ray absorption spectroscopy (XAS) coupled with diffuse reflectance spectroscopy (DRS) techniques were used to determine the local environment of Ni in cement systems. The Ni-doped samples were prepared at two different water/cement ratios (0.4, 1.3) and different hydration times (1 hour to 1 year) using a sulfate-resisting Portland cement. The metal loadings and the metal salts added to the system were varied (50 up to 5000 mg/kg; NO3-, SO42-, Cl-). The XAS study showed that for all investigated systems Ni(II) is predominantly immobilized in a layered double hydroxide (LDH) phase, which was corroborated by DRS measurements. Only a minor extent of Ni(II) precipitates as Ni-hydroxides (α-Ni(OH)2 and β-Ni(OH)2). This finding suggests that Ni-Al LDH, rather than Ni-hydroxides, is the solubility-limiting phase in the Ni-doped cement system. [ABSTRACT FROM AUTHOR]

Discusses the use of meiofauna in the assessment of contaminated terrestrial sites. Sampling of communities present in a former explosives burning ground; Dominance of nematoda in the sites; Structures of the nematode communities.

Evaluates the action of the chemical [14C]pyrene in a creosote-contaminated soil undergoing remediation in a prepared bed system of a hazardous waste site. Use of the methyl isobutyl ketone humic fractionation procedure in evaluating the compound; Affinity of the added pyrene and transformation products.

Presents information on a method which can be used to estimate the probability of incorrectly delineating hazardous areas in a contaminated site, with emphasis on the simple indicator kringing (SIK) technique. Details on the spatial distribution of metal in the environment; Techniques used to assess soil contamination; Benefits of using the SIK technique.

The EPA has recently introduced new guidelines for setting data quality objectives, raising the possibility that risk standards could be used to ensure the hazardous waste sites are cleaned up quickly and efficiently. In addition, the EPA has issued the Superfund Accelerated Cleanup Model, which is intended to help speed up the remediation process by refocusing regulatory efforts on the identification of the principal causes of contamination at specific waste sites.

The potential use of natural shale and four synthetic organoclays as sorbent additives in containment barriers at hazardous wastes sites is studied.

The Dept. of Energy's Office of Environmental Management (EM) has announced plans to accelerate its nationwide cleanup of radioactive and hazardous wastes at its former nuclear weapons production sites and national laboratories. EM Asst. Undersecretary Alvin Alm aims to accomplish most of the cleanup of 130 sites by 2006 under his Ten-Year Plan. The EM will complete work at sites as soon as possible by building on the improvements introduced by former EM head Thomas Grumbly and by reducing risk and maintenance costs. Several government reports have criticized the office for its minimal cleanup accomplishments.

A study was conducted to assess whether the Hyde Park Dump near the Niagara River is still affecting th sediment of Lake Ontario 21 years after the dumpsite was closed down in 1975. Core burdens and concentration profile data show that the concentrations of three fluorinated compounds in the surficial sediments are still around 20% of their maximum. The high levels are attributed to the tandem of physical perturbations in the lake and continued migration of the compounds from the dumpsite.

Cyclodextrin is a cyclic oligosaccharide that increases the aqueous solubilities of several low-polarity organic compounds and enhances the transport and removal of those compounds from the soil. New studies show that cyclodextrin also has the capability to complex low-polarity organic compounds by modifying its structure under relevant environmental conditions. The hypothesis suggests that this complexation could be used to remediate sites contaminated by mixed wastes.

The leachate plume stretching 30m along the Grindsted Landfill in Denmark contains high concentration of pharmaceutical compounds from the landfill's groundwater downgradient. The kinds of pharmaceutical compounds have expanded from sulfonamides in the 1930s to barbiturates in the 1970s. However, a survey of the landfill revealed natural reduction in the concentration of pharmaceutical compounds despite the increased use of drugs because of rapid aerobic degradation, dilution and sorption. The attenuation prevents concentrations of pharmaceutical wastes from rising from 50m of the landfill.

A study was conducted to identify the parameters which influence redox-sensitive groundwater flow in a landfill leachate plume in Grindsted, Denmark. Analysis of trace metals present in the water indicated high methane production and reduction in iron, sulfate, manganese and nitrate in the plume. The landfill contained rich methanogenic and sulfate-reducing zones, while high aerobic activity was observed in areas far from the landfill. In between the two were areas called transition zones.

The leachate plume stretching 300m along the Grindsted Landfill in Denmark exhibited a natural reduction of organic compounds because of increased degradation. The groundwater was rich in organic compounds including benzene, toluene, ethylbenzene and xylenes. High aerobic activity in the surrounding areas of the plume significantly reduced amount of organic compounds from 60m of the plume. Pesticides were also absent within the immediate vicinity of the landfill because of active degradation.

Federal law requires states to locate suitable sites for the safe disposal of low-level radioactive wastes. However, the identification of suitable sites has been mired in controversy in recent years, leading to delays in the naming of new waste disposal sites and the closure of several established ones. One controversial issue that has cropped up has been the unwillingness of scientists to guarantee that sites can be kept safe for hundreds of years. Fortunately, the problem may yet be resolved as the understanding of what constitutes a good site improves and lessons from past mistakes are reviewed.

The article reports on the study conducted by a team from the State University of New York, Albany on the risk of diabetes for people living near hazardous waste sites. The team uses hospitalization data from 1993 to 2000 for adults residents in several New York zip codes. The results of their study indicates that 10% of the residents living near hazardous waste sites were more likely to be hospitalized for diabetes than people who are residing in clean environment. The risk of diabetes for exposure of hazardous wastes is due to organic pollutants.

The author opines regarding traditional practices used for ecological risk assessment (ERA) as employed by the U.S. Environmental Protection Agency (EPA) at Superfund sites. The process is said to involve presumed links between exposures and effects, the use of associated hazard quotients (HQ) to estimate observable effects, and the determination of cleanup levels needed to reach an acceptable HQs. Among many questions he raises about ERA, the author reports that the HQ is not a measure of risk and that ERAs are not estimates of probable risk. The author discusses an alternative ecological assessment scheme called Rodent Sperm Analysis RSA) patented by the U.S. Army Public Health Command.

As a proof of principle, a selected reaction monitoring (SRM) mass spectrometry-based methodology was applied to the simultaneous quantification of dozens of protein biomarkers in caged amphipods (Gammarus fossarum). We evaluated the suitability of the methodology to assess complex field contaminations through its application in the framework of a regional river monitoring network. Thanks to the high throughput acquisition of biomarker levels in G. fossarum exposed in four reference and 13 contaminated sites, we analyzed the individual responses of 38 peptides reporting for 25 proteins of interest in 170 organisms. Responses obtained in contaminated sites included inductions of vitellogenin-like proteins in male organisms, inductions of Na+K+/ATPases, and strong inhibitions of molt-related proteins such as chitinase and JHE-carboxylesterase. Proteins from detoxification and immunity processes were also found modulated in abundance. Summarizing, the results presented here show that the SRM strategy developed for multibiomarker measurement paves a very promising way to define multiple indicators of the health status of sentinel organisms for environmental hazard assessment. [ABSTRACT FROM AUTHOR]

Discusses the unifying framework model developed by the Superfund Basic Research Program for multidisciplinary and interdisciplinary research. Combination of scientific and engineering research efforts to address problems found at hazardous waste sites in the United States; Identification of areas of research; Creation of linkages to protect public health and enhance environmental quality.

Reports on the opposition of Oregon state and local officials against the listing of an industrial area in Portland, as a Superfund site. Efforts of the state to keep local control over the site's cleanup; Alternative cleanup plan for the site; Effects of Superfund listings to property value in the area.

The field-portable scanning spectrofluorometer (FPSS) is a new instrument developed by environmental scientists to analyze polyaromatic hydrocarbons (PAHs) and other high molecular organic compounds in the field. FPSS uses a synchronous scanning capability that takes advantage of the overlap between the emission and absorption spectra of a particular compound. Testing of a prototype instrument in the laboratory showed the significant correlation of FPSS data with GC-mass spectrometry results.

Reports on a study by G.B. Hamar and colleagues which measured blood volatile organic compound levels in 100 residents of an industrial area with two National Priorities List sites and a hazardous waste incinerator.

Details the report made by the US Agency for Toxic Substances and Disease Registry (ATSDR) linking birth defects and other disorders to e