Field uptake rates of hydrophobic organic contaminants by semipermeable membrane devices: environmental monitoring considerations

The uptake rates of selected hydrophobic organic contaminants (HOCs) by semipermeable membrane devices (SPMDs)--a polyethylene layflat containing the lipid triolein--were investigated under natural conditions. SPMDs were exposed in three sampling sites (industrial, urban, and agricultural areas) in the Tajo River (Toledo, Spain) for 5, 11 and 20 d. The organochlorine compounds 4,4'-DDT, 4,4'-DDE, alpha-HCH, gamma-HCH, pentachlorobenzene, hexachlorobenzene, and polychlorinated biphenyls (PCBs), and the 16 priority pollutant polycyclic aromatic hydrocarbons (PAHs) were detected in the SPMDs deployed in the three sampling sites. A linear uptake rate was found for DDTs and for 4-Cl- and 5-Cl-substituted PCB congeners in all sampling sites. Concentrations of HCHs (80.3 ng g(-1) SPMD for alpha-HCH and 109 ng g(-1) SPMD for gamma-HCH after 20 d of exposure) increased according to a linear uptake rate in the SPMDs deployed in the sampling site located in the agricultural area. Likewise, a marked increase of total PAH concentration (up to 300 ng g(-1) SPMD after 20 d of exposure) was solely found in the sampling site situated near a thermoelectric power station. Examination of individual PAHs revealed that PAHs with log K(OW) between 4.2 and 5.7 displayed a linear uptake rate over the 20 d of exposure. Water concentrations (ng L(-1)) of HCB (0.80-2.48), lindane (1.30-11.5), 4,4'-DDT (0.61-2.02), 4,4'-DDE (6.89-11.6) and total PAHs (12.0-26.7) estimated by a linear uptake kinetic model were found to be high in comparison with other polluted aquatic systems, and similar to concentrations in other Spanish rivers. Our results suggest that SPMD kinetic uptake studies in the natural environment are recommended for identifying point-pollution sources, and that shorter times of SPMD exposure (approximately 1 week) are desirable to minimize one of the main problems of field SPMD deployment, i.e., the biofouling, which negatively affects the estimation of the dissolved HOC concentrations.     

Uptake of some selected aquatic pollutants in semipermeable membrane devices (SPMDs) and the polar organic chemical integrative sampler (POCIS)

The uptake characteristics of semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCISs) were examined for mono, di and tributyltin, triphenyltin, pyrene, benzo[a]pyrene, 4-tert-butylphenol, 4-n-nonylphenol, PCBs 77 and 153, PBDE 47, lindane, triclosan and DDT. Exposure in a flow through system continued for 28 days with samplers removed every 7 days in order to study the relevant uptake kinetics. Uptake remained linear for POCISs with sampling rates (Rs) of up to 0.2 L d(-1). For SPMDs uptake varied from linear to approaching equilibrium with Rs values of up to 14 L d(-1). 7 out of 9 results for SPMDs could be explained by an empirical model (nonylphenol and lindane were exceptions). None of the four organo-tin compounds studied were detected in POCISs and only tributyltin was accumulated significantly by SPMDs. The establishment of these sampling rates allows the calculation of time weighted water concentrations for several important contaminants. Using presented methods, sampling rates and exposure conditions, theoretical detection limits for selected compounds by SPMDs were between 11-68 pg L(-1), which is well below the environment quality standard proposed for those compounds that are included in the European Water Framework Directive.     

Investigation of hydrophobic contaminants in an urban slough system using passive sampling – insights from sampling rate calculations

Semipermeable membrane devices (SPMDs) were deployed in the Columbia Slough, near Portland, Oregon, on three separate occasions to measure the spatial and seasonal distribution of dissolved polycyclic aromatic hydrocarbons (PAHs) and organochlorine compounds (OCs) in the slough. Concentrations of PAHs and OCs in SPMDs showed spatial and seasonal differences among sites and indicated that unusually high flows in the spring of 2006 diluted the concentrations of many of the target contaminants. However, the same PAHs - pyrene, fluoranthene, and the alkylated homologues of phenanthrene, anthracene, and fluorene - and OCs - polychlorinated biphenyls, pentachloroanisole, chlorpyrifos, dieldrin, and the metabolites of dichlorodiphenyltrichloroethane (DDT) - predominated throughout the system during all three deployment periods. The data suggest that storm washoff may be a predominant source of PAHs in the slough but that OCs are ubiquitous, entering the slough by a variety of pathways. Comparison of SPMDs deployed on the stream bed with SPMDs deployed in the overlying water column suggests that even for the very hydrophobic compounds investigated, bed sediments may not be a predominant source in this system. Perdeuterated phenanthrene (phenanthrene-d (10)). spiked at a rate of 2 microg per SPMD, was shown to be a reliable performance reference compound (PRC) under the conditions of these deployments. Post-deployment concentrations of the PRC revealed differences in sampling conditions among sites and between seasons, but indicate that for SPMDs deployed throughout the main slough channel, differences in sampling rates were small enough to make site-to-site comparisons of SPMD concentrations straightforward.     

Monitoring of organotin compounds in seawater using semipermeable membrane devices (SPMDs)--tentative results

The impact of anthropogenic pollutants on the marine ecosystem is related to the concentrations experienced by the biota in the seawater and the resulting concentration in the organism. Results from monitoring of pollutants in water samples provide snapshots that can be high or low depending on a wide range of variables. To provide more integrated information, semipermeable membrane devices, SPMDs, have been used to monitor different organic pollutants. In this survey, SPMDs were used to monitor organotin compounds in the marine environment. Time-integrated sampling using SPMDs and direct water sampling was carried out at six stations in the inner Oslofjord, Norway. The sample work-up procedure for both water and SPMDs was based on direct derivatisation using NaBEt4 and simultaneous extraction with an organic solvent. Analysis was performed using a gas chromatograph equipped with an atomic emission detector. The results show that SPMDs do accumulate organotin compounds from the water phase. Both tributyl- (TBT) and dibutyltin were detected in all of the analysed membranes while no monobutyltin was found. Levels found in SPMDs range from < 1 to 220 ng Sn SPMD(-1). Water concentrations range from 0.4 to 10 ng Sn L(-1). An investigation of relative levels of TBT showed a similar concentration gradient in the inner Oslofjord using either direct water sampling or passive sampling by SPMDs. As the membranes are able to accumulate the organotins from the water it will be possible to locate lower concentrations than with direct analyses of water samples.     

Persistent organic pollutants in European background air: derivation of temporal and latitudinal trends

Data are presented for polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyls ethers (PBDEs) and selected organochlorine compounds (OCs) in passive air samplers (PAS) along a rural/remote latitudinal transect from southern UK to northern Norway during 2002-2004. This study is part of an ongoing campaign, using semi-permeable membrane devices (SPMDs) as PAS over two year intervals since 1994. Data for PCBs, selected OCs and PBDEs are compared with that from previous campaigns. Absolute sequestered amounts of selected PCB congeners have decreased in a first order fashion between 1994-2004, with an average atmospheric clearance rate of 4.1 +/- 0.6 years and continue to fractionate with latitude. HCB has also declined between 1998-2004, with a clearance rate of 6 +/- 2.4 years. Data on DDT and its breakdown products indicate little fresh release in Europe. Comparison of PBDEs in 2000-02 and 2002-04 indicates site differences, generally with increases at UK sites and decreases in Norway. BDE-28, 47 and 49 decreased with increasing latitude (p < 0.04), while the other congeners did not show any significant latitudinal dependence. Transect data are presented for PAHs the first time. Three- and 4-ringed compounds dominated the mixture present in the SPMD. The PAH composition of the SPMDs at site 3 was compared to the average composition taken by active sampling at the same site. SPMD performance for sampling PAHs leaves many uncertainties, but they can be successfully used to semiquantitatively detect PAHs in the atmosphere. Fluorene and phenanthrene increased with latitude (p > 0.05), while 1-methylphenanthere, fluoranthene, benzo[b]fluoranthene and indeno[123-cd]pyrene decreased. Results are discussed in terms of sources, long-range atmospheric transport, global fractionation and clearance processes.     

Assessment of bioavailable fraction of POPS in surface water bodies in Johannesburg City,South Africa,using passive samplers: an initial assessment

In this study, the semipermeable membrane device (SPMD) passive samplers were used to determine freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in selected water bodies situated in and around Johannesburg City, South Africa. The devices were deployed for 14 days at each sampling site in spring and summer of 2011. Time weighted average (TWA) concentrations of the water-borne contaminants were calculated from the amounts of analytes accumulated in the passive samplers. In the area of interest, concentrations of analytes in water ranged from 33.5 to 126.8 ng l^?1 for PAHs, from 20.9 to 120.9 pg l^?1 for PCBs and from 0.2 to 36.9 ng l^?1 for OCPs. Chlorinated pesticides were mainly composed of hexachlorocyclohexanes (HCHs) (0.15–36.9 ng l^?1) and dichlorodiphenyltrichloromethane (DDT) with its metabolites (0.03–0.55 ng l^?1). By applying diagnostic ratios of certain PAHs, identification of possible sources of the contaminants in the various sampling sites was performed. These ratios were generally inclined towards pyrogenic sources of pollution by PAHs in all study sites except in the Centurion River (CR), Centurion Lake (CL) and Airport River (AUP) that indicated petrogenic origins. This study highlights further need to map up the temporal and spatial variations of these POPs using passive samplers.     

利用Triolein-半渗透膜采样技术测定淮河水中的有毒有机污染物

利用 Triolein 半渗透膜采样技术 ( Triolein SPMD)采集了淮河信阳、淮南断面水样 ,测定了采样器中多氯联苯、多环芳烃、取代苯等有毒有机污染物浓度。污染物在 SPMD酯中高浓度富集 ,使其定性和定量更加容易和准确。根据SPMD酯 水分配平衡理论 ,进一步估算得到目标污染物在水中的平均浓度。本研究证明 Triolein SPMD技术可用于水中多氯联苯、多环芳烃、取代苯等污染物的采集和定量分析 ,可在我国的优先污染物监测、控制工作中发挥作用。     

Development of an integrative passive sampler for the monitoring of organic water pollutants

The development of convenient and competitive devices and methods for monitoring of organic pollutants in the aquatic environment is of increasing interest. An integrative passive sampling system has been developed which consists of a solid poly(dimethylsiloxane) (PDMS) material (tube or rod), acting as hydrophobic organic receiving phase, enclosed in a water-filled or an air-filled low-density polyethylene (LDPE) membrane tubing. These samplers enable the direct analysis of the pollutants accumulated during exposure in the receiving phase by thermodesorption-GC/MS, avoiding expensive sample preparation and cleanups. The capabilities of these sampling devices were studied for the sampling of 20 persistent organic pollutants (chlorobenzenes, hexachlorocyclohexanes, p,p'-DDE, PAHs, and PCBs) in laboratory exposure experiments. For the three sampler designs investigated the uptake of all target analytes was integrative over exposure periods up to 9 days (except PCB 101). The determined sampling rates range from 4 to 1340 microl h(-1) for the water-filled samplers and from 20 to 6360 microl h(-1) for the air-filled ones, respectively. The sampling rate of the analytes is dependent on their molecular weight, partition between water and sampler media (PDMS, polyethylene, water, air) and also of the sampler design. The passive samplers enable the estimation of time-weighted average (TWA) concentration of water pollutants in the lower ng l(-1) to pg l(-1) range.     

Assessment of the Usefulness of Semipermeable Membrane Devices for Long-Term Watershed Monitoring in an Urban Slough System

Semipermeable membrane devices (SPMDs) were deployed at eight sites within the Buffalo Slough, near Portland, Oregon, to (1) measure the spatial and seasonal distribution of dissolved polycyclic aromatic hydrocarbon (PAH) and organochlorine (OC) compounds in the slough, (2) assess the usefulness of SPMDs as a tool for investigating and monitoring hydrophobic compounds throughout the Columbia Slough system, and (3) evaluate the utility of SPMDs as a tool for measuring the long-term effects of watershed improvement activities. Data from the SPMDs revealed clear spatial and seasonal differences in water quality within the slough and indicate that for hydrophobic compounds, this time-integrated passive-sampling technique is a useful tool for long-term watershed monitoring. In addition, the data suggest that a spiking rate of 2–5 μg/SPMD of permeability/performance reference compounds, including at least one compound that is not susceptible to photodegradation, may be optimum for the conditions encountered here.     

Novel integrative passive samplers for the long-term monitoring of semivolatile organic air pollutants

Two types of passive sampler were developed for the long-term monitoring of semivolatile organic compounds (SOCs) in air. They consist of poly(dimethylsiloxane) (PDMS)-coated stir bars (type A) or silicone tubing (type B), acting as a solid receiving medium, enclosed in a heat-sealed low-density polyethylene (LDPE) membrane. These samplers combine the advantages of integrative passive sampling with those of analysing accumulated analytes by thermodesorption-GC-MS, whilst avoiding the use of solvents and expensive sample preparation and cleanup steps. The performance of these samplers was investigated for the integrative sampling of SOCs, including alpha- and gamma-hexachlorocyclohexanes, hexachlorobenzene, 2,4,4'-trichlorobiphenyl, 2,2',5,5'-tetrachlorobiphenyl and fluoranthene, in laboratory exposure experiments under controlled conditions. For both types of sampler, the uptake of all the analytes investigated was linear over an exposure period of 15 days. The sampling rates calculated ranged from 70 to 320 ml h(-1) (sampler A) and 630 to 4300 ml h(-1) (sampler B). The passive samplers are able to detect low time-weighted average air concentrations in the pg m(-3) range. The small, robust and inexpensive sampling devices were tested successfully for the long-term air monitoring of semivolatile organic pollutants in a polluted area over an exposure period of up to 28 days.     

半渗透膜采样技术监测城市污水处理流程中的难降解有毒有机污染物

应用新型半透膜采样技术（ＳＰＭＤ）,监测某城市污水处理流程中８个点污水中两类难降解有毒有机污染物多氯联苯（ＰＣＢ）和多环芳烃（ＰＡＨ）,同时同地采集水样,气相色谱质谱联机,选择性离子扫描方式对各ＰＣＢ异构体和ＰＡＨ定性定量。与水样液液萃取相比,ＳＰＭＤ采样技术显著提高了分析的准确度。根据测定的采样器中污染物浓度,推算采样期间该点污水中的平均浓度,与瞬间水样分析结果符合程度较好。半透膜采样方法可用于污水处理工艺流程中多氯联苯和多环芳烃污染物的定性和半定量监测     

Exposure Assessment to Mercury Vapor in Chloralkali Industry

The aim of the study was to develop a sampling method aimed at individual sampling of mercury vapor and subsequent individualexposure assessment of the worker. Hopcalite available fromInowrocawskie Zakady Chemiczne (in Poland) was founduseful for mercury vapor sampling in active and passive individual samplers. However the sampling rate determined forpassive sampler in steady-state laboratory chamber cannot be usedunder fluctuating conditions of mercury vapor concentration andair movement typical for field measurement. In order to check comparativeness of passive and active sampling methods, sampleswere taken in the same time and individual samplers fixed toworker's clothes were used. Mercury vapor concentration wasmeasured at two chloralkali industries in Poland and the resultswere presented. Excessive exposure in both industries wasconfirmed by finding elevated mercury concentration in urinesamples from the workers.     

A passive sampler for hydrogen sulfide

The silver nitrate/fluorescein mercuric acetate fluorimetric method for the measurement of atmospheric hydrogen sulfide has been adapted to passive sampling. Standard samplers have been tested and used in both indoor and outdoor environments. Sampler performance was not dependent on construction materials or sunlight intensity and gave similar results to active sampling. Two case studies were carried out, one in the Horniman Museum and its associated storage and study building, London, UK, and the other in the vicinity of a pulp and paper mill and geothermal area North Island, New Zealand. The detection limit of the samplers (50 ppt average for a one-week exposure) provides the opportunity to make measurements in a variety of locations provided exposure times are sufficiently long, i.e., up to one month in areas of low hydrogen sulfide concentration.     

The role of hydrodynamics, matrix and sampling duration in passive sampling of polar compounds with Empore SDB-RPS disks

There is an increasing need to monitor concentrations of polar organic contaminants in the aquatic environment. Integrative passive samplers can be used to assess time weighted average aqueous concentrations, provided calibration data are available and sampling rates are known. The sampling rate depends on environmental factors, such as temperature and water flow rate. Here we introduce an apparatus to investigate the sampling properties of passive samplers using river-like flow conditions and ambient environmental matrices: river water and treated sewage effluent. As a model sampler we selected Empore SDB-RPS disks in a Chemcatcher housing. The disks were exposed for 1 to 8 days at flow rates between 0.03 and 0.4 m s(-1). Samples were analysed using a bioassay for estrogenic activity and by LC-MS-MS target analysis of the pharmaceuticals sulfamethoxazole, carbamazepine and clarithromycin. In order to assess sampling rates of SDB disks, we also measured aqueous concentrations of the pharmaceuticals. Sampling rates increased with increasing flow rate and this relationship was not affected by the environmental matrix. However, SDB disks were only sampling in the integrative mode at low flow rates <0.1 m s(-1) and/or for short sampling times. The duration of linear uptake was particularly short for sulfamethoxazole (1 day) and longer for clarithromycin (5 days). At 0.03 m s(-1) and 12-14 degrees C, the sampling rate of SDB disks was 0.09 L day(-1) for clarithromycin, 0.14 L day(-1) for sulfamethoxazole and 0.25 L day(-1) for carbamazepine. The results show that under controlled conditions, SDB disks can be effectively used as passive sampling devices.     

Assessment of pumped mercury vapour adsorption tubes as passive samplers using a micro-exposure chamber

Mercury vapour adsorption tubes manufactured for pumped sampling and analysis have been evaluated for their performance as passive samplers. This has been done by exposing these tubes in a novel micro-exposure chamber. The uptake rates of these tubes have been found to be low (approximately 0.215 ml min(-1)) as compared to bespoke passive samplers for mercury vapour (typically in excess of 50 ml min(-1)). The measured uptake rates were shown to vary significantly between tubes and this was attributed to the variability in the air-sorbent interface and the proportion of the cross sectional area removed by the crimp in the quartz tubes used to secure the sorbent material. As a result of this variability the uptake rate of each tube must be determined using the micro-exposure chamber prior to deployment. Results have shown that the uptake rate determined in the micro-exposure chamber is invariant of concentration, and therefore these uptakes rates may be determined at a high mercury vapour concentration for many tubes at once in less than one hour. The uptake rate of the adsorption tubes under these conditions may be determined with a precision of 5%. Measurements made on a limited field trial in indoor and outdoor ambient air have shown that these tubes give results in acceptable agreement with more traditional pumped sampling methods, although longer sampling periods are required in order to reduce the uncertainty of the measurement, which is currently approximately 30%.     

Continuous, intermittent and passive sampling of airborne VOCs

Long sampling periods are often advantageous or required for measuring air quality and characterizing exposures. However, sampling periods exceeding 8 to 24 h using thermally desorbable adsorbent tube (TDT) samplers for the measurement of airborne volatile organic compounds (VOCs) face several challenges, including maintaining stable and low flow rates, and avoiding breakthrough of the adsorbent. These problems may be avoided using intermittent sampling; however, the literature contains few if any reports that have evaluated this technique in environmental, occupational or other applications. The purpose of this study is to evaluate continuous, intermittent and passive sampling methods using both laboratory and real-world tests. Laboratory tests compared continuous and intermittent (active) samplers in a controlled dynamic test gas generation system. Field tests used side-by-side active and passive samplers in an office, home workshop and four smokers' homes. All samples were analyzed for a wide range of VOCs by GC-MS. In most instances, intermittent sampling yielded better reproducibility (duplicate precision of 10 +/- 6%) than continuous low-flow sampling (18 +/- 5%), in part due to difficulty maintaining low flows. Concentrations obtained using intermittent sampling agreed with those for continuous sampling, with downward biases resulting primarily from errors in flow rate measurements. In the field, more VOC species were detected using active rather than passive sampling. Passive measurements were 12% lower than continuous measurements, a difference attributed to declining uptake rates at higher concentrations over the 3 to 4 d sampling period. Overall, most measurements obtained using the three sampling methods agreed within 20% for a wide range of concentrations (0.1 to 230 microg m(-3)). Both passive and intermittent sampling approaches are suitable for long sampling periods, but intermittent sampling provides greater flexibility with respect to sampling period, and permits the use of multi-bed adsorbents that can capture a wider range of VOCs.     

Low-flow active and passive sampling of VOCs using thermal desorption tubes: theory and application at an offset printing facility

While air sampling techniques using adsorbent-based collection, thermal desorption and chromatographic analysis have found a niche in ambient air sampling, occupational applications have been more limited. This paper evaluates the use of thermal desorption techniques for low flow active and passive sampling configurations which allow conveniently long duration sampling in occupational settings and other high concentration environments. The use of an orifice enables flows as low as 0.5 ml min(-1) and sampling periods up to several days without significant biases. A model is used to predict sampling rates of a passive sampler encompassing an orifice, a void space, glass wool, and the adsorbent. Laboratory and field tests conducted at a commercial offset printing facility, which contained a variety of volatile organic compounds (primarily aromatic but also a few chlorinated and terpene compounds at levels from 1 to 67,000 microg m(-3)), are used to evaluate the approach. Tenax GR and Carbosieve SIII, both singly and together, were employed as adsorbents. Side-by-side tests comparing high flow, low flow and passive samplers show excellent agreement and high linearity (r = 0.95) for concentrations spanning nearly five orders of magnitude. Active samplers were tested at flows as low as 0.5 ml min(-1), compared to typical flows up to 40 ml min(-1). Passive samplers demonstrated a linear range and agreement with predictions for adsorbate loadings from approximately 1 ng to nearly 10 microg. Using a chemical mass balance receptor model, concentrations in the facility were apportioned to solvents, inks and other indoor and outdoor sources. Overall, the use of low flow active and passive sampling approaches employing thermal desorption techniques provides good performance and tremendous flexibility that facilitates use in many applications, including workplace settings.     

Personal exposures and microenvironmental concentrations of particles and bioaerosols

The aim of this study was to compare the personal exposure to particles and bioaerosols with that measured by stationary samplers in the main microenvironments, i.e., the home and the workplace. A random sample of 81 elementary school teachers was selected from the 823 teachers working for two councils in eastern Finland for the winter time measurement period. Bioaerosol and other particles were collected on filters by button samplers using personal sampling and microenvironmental measurements in homes and workplaces. The 24-hour sampling period was repeated twice for each teacher. Particle mass, absorption coefficient of the filter and the concentration of viable and total microorganisms were analyzed from each filter. In this paper, the study design, quality assurance principles and results of particle and bioaerosol exposure are described. The results show that particle mass concentrations, absorption coefficient and fungi were higher in personal exposure samples than in home and workplace samples. Furthermore, these concentrations were usually lower in the home than in the workplace. Bacterial concentrations were highest in heavily populated workplaces, while the viable fungi concentrations were lowest in workplaces. The fungi and bacteria results showed high variation, which emphasises the importance of quality assurance (duplicates and field blanks) in the microbial field measurements. Our results indicate that personal exposure measurements of bioaerosols in indoor environments are feasible and supplement the information obtained by stationary samplers.     

Hydrology-linked spatial distribution of pesticides in a fjord system in Greenland

A pilot study is presented evaluating selected chlorinated pesticides as chemical tracers for water masses in a sub-Arctic fjord system (Godth?bsfjord, western Greenland). Polyoxymethylene (POM) based passive water samplers were deployed during summer-autumn 2010. The levels of the analysed chlorinated pesticides in the fjord surface waters were found to be low compared to earlier studies. α-Hexachlorocyclohexane (α-HCH) and hexachlorobenzene (HCB) were the predominant contaminants. However, these two compounds have higher levels in oceanic water compared to freshwater influenced fjord waters. These chemicals can thus be considered as indicators for direct atmospheric long-range transport, while the organochlorine pesticides like trans-, cis-chlordane, trans-nonachlor and oxychlordane that are detected in the inner parts of the fjord are indicators for potential freshwater sources such as rivers and glacial meltwater runoff (secondary sources). The average values were 50 pg L(-1) for HCB and 11 pg L(-1) for α-HCH. These concentrations are comparable to levels in fjords in Svalbard (Norwegian Arctic), but lower than in open and/or ice covered oceans in the Canadian Arctic. Two air samplers were deployed for the identification of direct atmospheric contributions. Local contamination sources do not contribute significantly. The study demonstrated the value of passive water sampling devices for comprehensive hydrological characterization of Arctic coastal waters.     

Occurrence of PAHs and PCBs in the Alna River, Oslo (Norway)

Thirty two polychlorinated biphenyl congeners (PCBs), hexachlorobenzene (HCB) and pentachlorobenzene (PeCB) were analysed in passive sampler extracts from surface water-exposed semipermeable membrane devices (SPMDs) and in bed sediment samples from a small urban watercourse, the River Alna (Oslo, Norway). Performance reference compound-corrected data from the passive samplers deployed at three sites along the river were used to track PCB contamination in the overlying water. SPMDs were able to detect an increase in dissolved PCB concentrations at the site furthest downstream that was corroborated by bed sediment concentrations. In comparison, no major increase in concentration of HCB, PeCB or PAHs could be observed. Comparison of passive sampling-based overlying water concentrations with total concentrations measured in bed sediments supports the possibility of further PCB sources upstream of the study area. Diagnostic PAH ratios (from SPMDs) and PCB congener pattern (from sediments) were used in an attempt to identify possible contaminant sources to the Alna River. Selected PAH diagnostic ratios support a multiple emission source scenario and demonstrate the complexity of identifying specific sources of these compounds to surface waters. PCB congener patterns in sediments from all three sites tend to indicate a source of highly chlorinated PCBs (of the Archlor 1260 type) and either a source of lower chlorinated PCBs or the less-likely occurrence of dechlorination in sediment. Information collected during the present screening study also confirms the Alna River as a continuous source of PCBs to the Oslofjord.