Vertical profile of PCDD/Fs, dioxin-like PCBs, other PCBs, PAHs, chlorobenzenes, DDX, HCHs, organotin compounds and chlorinated ethers in dated sediment/soil cores from flood-plains of the river Elbe, Germany

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and other organic micropollutants were determined in dated sediment/soil cores collected from the flood-plain of the river Elbe near Pevestorf (PT), approximately 125 km upstream of Hamburg, and Heuckenlock (HL) in southeast of Hamburg. Concentrations of PCDD/Fs peaked sharply at PT in the 1950s and at HL at the end of the 1940s. Cluster analyses provide evidence that the region of Bitterfeld-Wolfen (about 350-400 km upstream of Hamburg) could be the source of the PCDD/F contamination existing in the cores PT and HL since the 1940s. Obviously it is caused by sediments of the river Elbe of a similar composition. Whereas the PCDD/Fs, HCHs (hexacyclohexane isomers), DDX (DDT, DDD, DDE), and tetrachlorinated ethers in PT and HL presumably originated predominantly from the Bitterfeld-Wolfen region, organotin compounds in HL and dichlorinated haloethers in HL during the 1940s and 1950s can probably largely be attributed to emissions from the Hamburg region. Although they are separated by a large distance, in both sediment cores PT and HL concentrations and composition patterns of most organic micropollutants analyzed widely match. Inductively it can be concluded that similar contaminations will be found in many of the river bank soils between the Bitterfeld-Wolfen region and Hamburg. Excavation of top soils may uncover highly contaminated materials. Since the dated sediment cores show the variation in contaminants in the Elbe sediments over a defined time period, it is possible to make an approximate assessment of the actual degree of contamination to be expected in areas where in previous decades contaminated dredged sediments from the Elbe and from the Port of Hamburg have been deposited on land and used for building plots or for agricultural purposes.     

Sorption of organic contaminants by biopolymers: role of polarity, structure and domain spatial arrangement

Sorption behavior of hydrophobic organic contaminants (HOCs) (i.e., pyrene, phenanthrene and naphthalene) by native and chemically modified biopolymers (lignin, chitin and cellulose) was examined. Lignins (native and treated) showed nonlinear sorption for all compounds studied, emphasizing their glassy character. Chitins and celluloses had linear isotherms for phenanthrene and naphthalene, illustrating the dominance of partitioning, while pyrene yielded nonlinear isotherms. Sorption capacity (K(oc)) of HOCs was negatively correlated with the polarity [(O+N)/C] of the biopolymers. Aromatic and alkyl+aromatic C percentages, rather than alkyl C content, demonstrated a better correlation with K(oc) values, indicating the importance of aromatic structures for HOC affinity. Hydrophobicity (K(ow))-normalized K(oc) values decreased sharply with increasing percentage of O-alkyl C versus total aliphatic C (O-alkyl C/total aliphatic C) or with polar C/(alkyl+aromatic C) ratio of the biopolymers until their values reached 80% and 4, respectively, illustrating the effect of surrounding polar groups on reducing affinity for HOCs. Overall, the results of this study highlight the role of spatial arrangement of domains within biopolymers in sorption of HOCs, and point to sorbent properties, such as functionality, polarity and structure, jointly regulating the sorption of HOCs in biopolymers.     

Estrogenic activity associated with organochlorine compounds in fish extracts from European mountain lakes

Fish muscle extracts from ten European mountain lakes were analyzed for organochlorine compounds (OCs) and estrogenic activity, the latter by a recombinant yeast assay based on the human estrogen receptor. Seventy percent of the samples showed estrogenic activity above detection limits and a subset of five samples showed estrogenic activities, equivalent to more than 10,000 pg/g of estradiol. These highly estrogenic samples occurred in two lakes, Velké Hin?ovo in the Tatra Mountains and Redon in the Pyrenees. Principal component analysis correlated estrogenic activity of muscle extracts to fish age and concentrations of the more chlorinated polychlorobiphenyls (PCBs). This is consistent with previously observed correlations of these PCBs with fish age. In addition, most fish with high estrogenic activity were found in lakes containing high OC levels in the sediments, which gives further ground to atmospheric deposition of anthropogenic pollutants as main process leading to the observed endocrine disruption effects.     

Nitrogen and metals in two regions in Central Europe: Significant differences in accumulation in mosses due to land use?

The study was conducted to test the hypothesis that the regional variability of nitrogen (N) and metal accumulations in terrestrial ecosystems are due to historical and recent ways of landuse. To this end, two regions of Central Europe were selected for investigation: the Weser-Ems Region (WER) and the Euro Region Nissa (ERN). They were assumed to have land use-specific accumulation profiles. Thus, the metal and N accumulations in both regions were examined by means of geostatistically based comparative moss analysis. The sampling and chemical analysis of mosses were conducted in accordance with the convenient guidelines and methods, respectively. The spatial representativity of the sampling sites was computed by means of a land classification which was calculated for Europe by means of classification trees and GIS-techniques. The differences of deposition loads were tested for statistical significance with regard to time and space. The measurement values corroborated the decline of metal accumulation observed since the beginning of the European Metals in Mosses Surveys in 1990. The metal loads of the mosses in the ERN exceeded those in the WER significantly. The opposite holds true for the N concentrations: those in the WER were significantly higher than those in the ERN. The reduction of emissions from power plants, factories and houses was strongly correlated with the decline of deposition and bioaccumulation of metals. As proved by the European Metals in Mosses Surveys, this tendency is due to successful environmental policies. But no such success could be verified by monitoring the accumulation of N in mosses.     

Speciation of organotins in polyvinyl chloride pipe via X-ray absorption spectroscopy and in leachates using GC-PFPD after derivatisation

Three different polyvinyl chloride (PVC) pipe types were subjected to de-ionized water exposures over the course of at least 180 days. Water exposed to the pipe was analyzed for organotin speciation and concentration. Organotin concentrations were the highest during the first 1-5 days. The species and concentrations of organotins leached varied by pipe type. Data were normalized by surface area in order to compare laboratory results with results from a residential pipe system. For one pipe type, the lowest non-zero concentrations from the laboratory tests overestimated organotin concentrations in solution when compared with water samples from the same pipe type in a residence. For organotin exposure estimates, a range of 0.1 ng m(-2) to 10 ng m(-2) could be used for mature pipes (e.g. in use for 1 year). These estimates should be refined with more field study, however, due to the high variation in organotin species and concentrations leached as a function of pipe type, accuracy within an order of magnitude may be optimal as, in many instances, the type of pipe installed or buried may be unknown. X-ray absorption spectroscopy (XAS) was used to identify organic and inorganic tin species in reference materials and the PVC samples. Monobutyl tin was identified as the primary organotin species in the pipes. Results from the XAS analyses also indicate that the technique shows promise for distinguishing between inorganic tin and organotins. Furthermore, organotins may be distinguished between mono-, di-, and tri-ligand species using XAS.     

Review of state of the art methods for measuring water in landfills

In recent years several types of sensors and measurement techniques have been developed for measuring the moisture content, water saturation, or the volumetric water content of landfilled wastes. In this work, we review several of the most promising techniques. The basic principles behind each technique are discussed and field applications of the techniques are presented, including cost estimates. For several sensors, previously unpublished data are given. Neutron probes, electrical resistivity (impedance) sensors, time domain reflectometry (TDR) sensors, and the partitioning gas tracer technique (PGTT) were field tested with results compared to gravimetric measurements or estimates of the volumetric water content or moisture content. Neutron probes were not able to accurately measure the volumetric water content, but could track changes in moisture conditions. Electrical resistivity and TDR sensors tended to provide biased estimates, with instrument-determined moisture contents larger than independent estimates. While the PGTT resulted in relatively accurate measurements, electrical resistivity and TDR sensors provide more rapid results and are better suited for tracking infiltration fronts. Fiber optic sensors and electrical resistivity tomography hold promise for measuring water distributions in situ, particularly during infiltration events, but have not been tested with independent measurements to quantify their accuracy. Additional work is recommended to advance the development of some of these instruments and to acquire an improved understanding of liquid movement in landfills by application of the most promising techniques in the field.     

Evaluation of methods for sorting CCA-treated wood

Construction and demolition (C&D) wood frequently contains treated wood including wood treated with chromated copper arsenate (CCA). Many recycling options for such wood require that the product be essentially free of preservative chemicals. The objectives of this study were to document the characteristics of the wood waste stream and to evaluate the effectiveness of sorting methods for identifying treated wood. Sorting methods evaluated included visual sorting and visual sorting augmented with the use of PAN indicator stain and/or hand-held X-ray fluorescence (XRF) units. Experiments were conducted on two types of construction and demolition (C&D) wood: source separated loads containing only C&D wood and wood hand-picked from commingled loads of general C&D waste. Results showed that 77% of the treated wood was CCA-treated. For uncontaminated piles (<1% treated wood) of source separated C&D wood, visual sorting was found to effectively remove the small amounts of treated wood present. For piles of source separated wood that were contaminated (approximately 50% treated wood), visual sorts were not accurate and benefited from augmented sorting using PAN indicator stain. The handheld XRF devices were found to be effective for sorting commingled C&D wood, as PAN indicator stain was not as effective due to the excessive amount of surface dirt associated with commingled wood waste. Visual sorting of source separated wood was estimated to cost between US$21 to US$96 per metric ton. These costs depended upon the amount of treated wood and whether or not augmentation with PAN indicator was necessary. Visual sorting augmented with hand-held XRF units was estimated at US$113 per metric ton. The bulk of these costs were associated with labor. Future efforts should focus on reducing labor costs by mounting automated XRF units on conveyor systems.     

Assessment of medical wastes management practice: a case study of the northern part of Jordan

This study includes a survey of the procedures available, techniques, and methods of handling and disposing of medical waste at medium (between 100 and 200 beds) to large (over 200 beds) size healthcare facilities located in Irbid city (a major city in the northern part of Jordan). A total of 14 healthcare facilities, including four hospitals and 10 clinical laboratories, serving a total population of about 1.5 million, were surveyed during the course of this research. This study took into consideration both the quantity and quality of the generated wastes to determine generation rates and physical properties. Results of the survey showed that healthcare facilities in Irbid city have less appropriate practices when it comes to the handling, storage, and disposal of wastes generated in comparison to the developed world. There are no defined methods for handling and disposal of these wastes, starting from the personnel responsible for collection through those who transport the wastes to the disposal site. Moreover, there are no specific regulations or guidelines for segregation or classification of these wastes. This means that wastes are mixed, for example, wastes coming from the kitchen with those generated by different departments. Also, more importantly, none of the sites surveyed could provide estimated quantities of waste generated by each department, based upon the known variables within the departments. Average generation rates of total medical wastes in the hospitals were estimated to be 6.10 kg/patient/day (3.49 kg/bed/day), 5.62 kg/patient/day (3.14 kg/bed/day), and 4.02 kg/patient/day (1.88 kg/bed/day) for public, maternity, and private hospitals, respectively. For medical laboratories, rates were found to be in the range of 0.053-0.065 kg/test-day for governmental laboratories, and 0.034-0.102 kg/test-day for private laboratories. Although, based on the type of waste, domestic or general waste makes up a large proportion of the waste volume, so that if such waste is not mixed with patient derived waste, it can be easily handled. However, based on infections, it is important for healthcare staff to take precautions in handling sharps and pathological wastes, which comprises only about 26% of the total infectious wastes. Statistical analysis was conducted to develop mathematical models to aid in the prediction of waste quantities generated by the hospitals studied, or similar sites in the city that are not included in this study. In these models, the number of patients, number of beds, and hospital type were determined to be significant factors on waste generation. Such models provide decision makers with tools to better manage their medical waste, given the dynamic conditions of their healthcare facilities.     

Evaluation of commercial landscaping mulch for possible contamination from CCA

Wood treated with chromated copper arsenate (CCA) is found in construction and demolition (C&D) debris, and a common use for wood recycled from C&D debris is the production of mulch. Given the high metals concentrations in CCA-treated wood, a small fraction of CCA-treated wood can increase the metal concentrations in the mulch above regulatory thresholds. The objective of this study was to determine the extent of contamination of CCA-treated wood in consumer landscaping mulch and to determine whether visual methods or rapid X-ray fluorescence (XRF) technology can be used to identify suspect mulch. Samples were collected throughout the State of Florida (USA) and evaluated both visually and chemically. Visual analysis focused on documenting wood-chip size distribution, whether the samples were artificially colored, and whether they contained plywood chips which is an indication that the sample was, in part, made from recycled C&D wood. Chemical analysis included measurements of total recoverable metals, leachable metals as per the standardized synthetic precipitation leaching procedure (SPLP), and XRF analysis. Visual identification methods, such as colorant addition or presence of plywood, were found effective to preliminarily screen suspect mulch. XRF analysis was found to be effective for identifying mulch containing higher than 75 mg/kg arsenic. For mulch samples that were not colored and did not contain evidence of C&D wood, none exceeded leachable metal concentrations of 50 microg/L and only 3% exceeded 10 mg/kg for recoverable metals. The majority of the colored mulch made from recycled C&D wood contained from 1% to 5% CCA-treated wood (15% maximum fraction) resulting in leachable metals in excess of 50 microg/L and total recoverable metals in excess of 10 mg/kg. The maximum arsenic concentration measured in the mulch samples evaluated was 230 mg/kg, which was above the Florida residential direct exposure regulatory guideline of 2.1 mg/kg.     

Behavior and stability of organic contaminant droplets in aqueous solutions

The behavior of several hydrophobic organic compounds (HOCs) in water at concentrations close to and above their maximum solubility values was studied. For this purpose, solutions of benzene, toluene, xylene, trichloroethylene (TCE) and a mixture of them were prepared in excess in freshwater and in saltwater, and solution stability was examined. High organic concentrations were found to remain stable in both freshwater and saltwater. In saltwater, for example, toluene and xylene concentrations remained as high as 14 and 26 times their solubilities, respectively, over a period of 6 days, while in freshwater, their concentrations remained 8 and 30 times their solubilities over the same period. This phenomenon is attributed to the presence of stable organic droplets, which were observed using optical microscopy. In addition, the transport of HOC droplets through sand is demonstrated, using an experimental system consisting of a saltwater source reservoir connected by a porous inactive sand layer to a freshwater collector reservoir.