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Climate change is likely to have large effectson the Baltic Sea ecosystem. Simulations indicate 2–4 Cwarming and 50–80 % decrease in ice cover by 2100.Precipitation may increase *30 % in the north, causingincreased land runoff of allochthonous organic matter(AOM) and organic pollutants and decreased salinity.Coupled physical–biogeochemical models indicate that, inthe south, bottom-water anoxia may spread, reducing codrecruitment and increasing sediment phosphorus release,thus promoting cyanobacterial blooms. In the north,heterotrophic bacteria will be favored by AOM, whilephytoplankton production may be reduced. Extra trophiclevels in the food web may increase energy losses andconsequently reduce fish production. Future managementof the Baltic Sea must consider the effects of climatechange on the ecosystem dynamics and functions, as wellas the effects of anthropogenic nutrient and pollutant load.Monitoring should have a holistic approach, encompassingboth autotrophic (phytoplankton) and heterotrophic (e.g.,bacterial) processes.

The structural variation within the polychlorinated biphenyls (PCBs) was characterized by using principal component analysis (PCA). A multivariate model was evolved from 52 physicochemical descriptors including measured ultraviolet (UV) absorption spectra, calculated semiempirical parameters (AM1) and properties captured from the literature. Parameters calculated by using the AM1-Hamiltonian were e.g. heat of formation, dipole moments, ionization potential and the barrier of internal rotation. The UV spectra were measured and digitized in the range 200-300 nm. The multivariate model revealed that most of the information within the set of physicochemical parameters was related to molecular size. Descriptors depending on size were e.g. GC retention times, partition coefficients and a subset of semiempirically derived energy terms. Important also were parameters reflecting differences in substitution patterns and related to electronic and steric properties, such as UV absorption in the wavelength region 245-300 nm, the barrier of internal rotation and the ionization potential. The developed model describes the large variation in physicochemical characteristics within the PCBs. The importance of a broad chemical characterization is illustrated by a quantitative structure-activity relationship (QSAR) for the potency of inhibition of intercellular communication for 27 structurally diverse tetra- to heptachlorinated PCBs.

The ultraviolet absorption spectra of all 209 polychlorinated biphenyls (PCBs) were recorded in the range 200-300 nm and displayed two important absorption maxima, viz., the main-band, lambda(max) 200-225 nm, and the kappa-band, lambda(max) 245-265 nm. By utilising principal component analysis, substitution related spectral characteristics of the PCBs, underlying the main patterns of the spectra, were examined. Captured in the multivariate evaluation were e.g., the importance of chlorine atoms in ortho positions, determining the intensity and existence of the kappa-band, chlorine substitution in para-para position, and the total number of chlorine atoms. The measured UV-spectra of all 209 polychlorinated biphenyls provide important physico-chemical descriptors for use in future quantitative structure-activity and structure-property relationship (QSAR/QSPR) studies.

Polybrominated dibenzo-p-dioxins (PBDD) are emerging environmental pollutants with structural similarities to the highly characterized toxicants polychlorinated dibenzo-p-dioxins. The geographical and temporal variations of PBDD in biota samples from the Baltic Sea do not display features that are normally related to anthropogenic sources, and therefore the natural formation of PBDDs has been suggested. This study of the bromoperoxidase mediated oxidative coupling of 2,4,6-tribromophenol (an abundant substance that is naturally formed in marine systems) identified the formation of ppb-level yields of 1,3,6,8-tetrabromodibenzo-p-dioxin (1,3,6,8-TeBDD) through direct condensation. Additional TeBDDs (1,3,7,9-TeBDD, 1,2,4,7-TeBDD and/or 1,2,4,8-TeBDD) and tri-BDDs (1,3,7-TrBDD and 1,3,8-TrBDD) were frequently formed, but at lower yields. The formation of these TeBDDs probably proceeds via bromine shifts or Smiles rearrangements, while the TrBDDs may result from subsequent debromination processes. Since all of the congeners formed by oxidative coupling and subsequent reactions are also found in Baltic Sea biota, the results support the theory that PBDDs are formed from natural precursors.

Polybrominated dibenzo-p-dioxins (PBDD) are emerging environmental pollutants with structural similarities to the highly characterized toxicants polychlorinated dibenzo-p-dioxins. The geographical and temporal variations of PBDD in biota samples from the Baltic Sea do not display features that are normally related to anthropogenic sources such as incineration, and therefore the natural formation of PBDDs has been suggested. This study of the bromoperoxidase mediated oxidative coupling of 2,4,6-tribromophenol (an abundant substance that is naturally formed in marine systems) identified the formation of ppb-level yields of 1,3,6,8-tetrabromodibenzo-p-dioxin (1,3,6,8-TeBDD) through direct condensation. Additional TeBDDs (1,3,7,9-TeBDD, 1,2,4,7-TeBDD and/or 1,2,4,8-TeBDD) and tri-BDDs (1,3,7-TrBDD and 1,3,8-TrBDD) were frequently formed, but at lower yields. The formation of these TeBDDs probably proceeds via bromine shifts or Smiles rearrangements, while the TrBDDs may result from subsequent debromination processes. Since all of the congeners formed by oxidative coupling and subsequent reactions are also found in Baltic Sea biota, the results support the theory that PBDDs are formed from natural precursors.

High levels of polybrominated dibenzo-p-dioxins (PBDDs) have been found in Baltic Sea biota, where the toxic load owing to, for example, polychlorinated dibenzo-p-dioxins and other organic pollutants is already high. The levels and geographic pattern of PBDDs suggest biogenic rather than anthropogenic origin, and both biotic and abiotic formation pathways have been proposed. Photochemical formation from hydroxylated polybrominated diphenyl ethers (OH-PBDE) is a proposed pathway. for PBDDs in marine environments. Ultraviolet radiation-initiated transformations of OH-BDEs 47, 68, 85, 90, 99, and 123, which all are abundant in the environment, were investigated. It was shown that the most abundant PBDDs in the environment (1,3,7-triBDD and 1,3,8-triBDD) can be formed from the most abundant OH-BDEs (OH-BDE 47 and OH-BDE 68) at high rates and with percentage yields. In fact, most of the PBDDs that have been identified in the Baltic Sea environment were formed with high yield from the six studied OH-PBDE, through initial cyclization and subsequent debromination reactions. The high formation yields point to this route as an important source of PBDDs in biota. However, congeners showing relatively high retention in fish, specifically 1,3,6,8- and 1,3,7,9-tetraBDD, were not formed. These are likely formed by enzymatic coupling of brominated phenols.

High levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), mono- and non-ortho polychlorinated biphenyls (PCBs), and polybrominated dibenzo-p-dioxins (PBDDs) are found in fish from coastal areas in the Baltic Sea, which may cause ecotoxicological effects. To increase our understanding of the persistency of the emerging pollutants polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), fish feed was spiked with 21 PBDD/Fs, 17 PCDD/Fs, and 30 PCBs and fed to zebrafish. Concentrations in fish and eggs were examined during a six- or twelve-week uptake period, and a six-week elimination period. Steady-state was reached for 2, 3, 7, and/or 8-substituted tri- and tetra-BDD/Fs, with 2,3,7,8-tetra-BDD (2,3,7,8-TeBDD) being the most strongly retained. Steady-state was not reached for tetra- to hexa-CDDs. Non-2,3,7,8-congeners showed little of or no retention. Most PCBs had high retention and did not reach steady-state. Half-lives decreased in the order: PCBs > PCDD/Fs > PBDD/Fs. Concentrations of 2,3,7,8-penta- to octa-CDD/Fs decreased with their degree of chlorination suggesting that the rate-limiting factor for uptake is low bioavailability. Maternal transfer was observed for all retained compounds, with most transfer factors < 1, indicating that transfer rates are affected by the poor water solubility of the compounds. The limited retention of the major PBDD congeners found in Baltic Sea fish suggests that they are exposed to high or very high concentrations via either food or water.

SO₂ levels in the flue gas from a laboratory-scale fluidized bed reactor combusting artificial municipal solid waste (MSW) were varied (resulting in four different SO₂:HCl ratios 0, 0.2, 0.7 and 2.7 (by mass)) to study the effects of sulfur on the formation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzothiophenes (PCDTs). Sampling was performed simultaneously at three fixed points in the post-combustion zone with temperatures of 400, 300 and 200 °C, under normal combustion conditions and both during and after transient combustion conditions. The findings indicate that sulfur has a greater inhibitory effect on PCDF formation than on PCDD formation and that the PCDD/PCDF ratio in the flue gas depends on both the SO₂:HCl ratio in the flue gas and memory effects arising from transient combustion conditions. The results also indicate that the relative importance of different pathways shifts in the post-combustion zone; condensation products increasing with reductions in temperature and increases in residence time. However, these changes appear to depend on the SO₂:HCl ratio in the flue gas and combustion conditions. Sulfur seems to inhibit the chlorination of PCDFs. A tendency for increased SO₂ levels in the flue gas to increase levels of PCDTs was also detected, but the increases were much less significant than the reductions in PCDF levels.

This article aims to investigate the use and benefits of using comprehensive two-dimensional gas chromatography (GC x GC) and structure-activity relationship modeling for screening and prioritization of organic contaminants in complex matrices. The benefit of applying comprehensive screening techniques to samples with high organic contaminant content is primarily that compounds with diverse physicochemical properties can be analyzed simultaneously. Here, a heavily contaminated industrial area was surveyed for organic pollutants by analyzing soil, sediment, and surface water samples. The hazard of the pollutants were ranked using SARs. The water samples were liquid-liquid extracted using dichloromethane and directly analyzed by GC x GC-time-of-flight mass spectrometry (GC x GC-TofMS). Soil and sediment samples were extracted with dichloromethane in an ultrasonic bath and subjected to gel permeation chromatography to eliminate lipids and humic matter. The low molecular weight fraction was then analyzed with GC x GC-TofMS. More than 10,000 components were found in each sample, of which ca. 300 individual compounds were unambiguously identified using the National Institute of Standards and Technology mass spectra library and authentic reference standards. Alkanes, polycyclic aromatic hydrocarbons, and phthalates were generally the most abundant and were found in all matrices. In contrast, chlorinated compounds such as chlorophenols, biphenyls, and chlorinated pesticides were only detected in samples from a few hotspot regions. The toxicities of the most frequently detected compounds and of the compounds detected at the highest concentrations in samples from hotspot regions were estimated by ecological structure-activity relationships. The ratio of the measured concentration to the predicted toxicity level was then calculated for each compound and used for an initial risk assessment in order to prioritize compounds for further transport and fate modeling, complementary measurements, and more advanced risk assessments. The advantage of using of GC x GC-TofMS for preliminary screenings of contaminated areas was evaluated at a polluted area in northern Sweden. The area was found to carry organic pollutants such as polyaromatic hydrocarbons, aliphatic hydrocarbons, polychlorinated biphenyls, phthalic compounds, and many chlorinated pesticides. Preliminary risk assessments indicate which compounds to use for subsequent remediation experiments based on their availability on the site or toxicity.

The aim of this study was to compare the polycyclic aromatic hydrocarbon (PAH) contents in a number of complex samples, including soil samples from industrial sites, anti-skid sand, urban dust and ash samples from municipal solid waste incinerators. The samples were characterized by routine analysis of PAHs (gas chromatography–quadrupole mass spectrometry) and gas chromatography–time of flight mass spectrometry (GC–TOFMS). Classification of the samples by principal component analysis (PCA) according to their composition of PAHs revealed that samples associated with traffic and the municipal incinerator formed homogeneous clusters, while the PAH-contaminated soils clustered in separate groups. Using spectral data to resolve co-eluting chromatographic peaks, 962 peaks could be identified in the GC–TOFMS analysis of a pooled sample and 123–527 peaks in the individual samples. Many of the studied extracts included a unique set of chemicals, indicating that they had a much more diverse contamination profile than their PAH contents suggested. Compared to routine analysis, GC–TOFMS provided more detailed information about each sample and in this study a large number of alkylated PAHs were found to be associated with the corresponding unsubstituted PAHs. The possibility to filter peaks according to different criteria (e.g. to include only peaks that were detected in the analysis of another sample) was explored and used to identify unique as well as common compounds within samples. This procedure could prove to be valuable for obtaining relevant chemical data for use in conjunction with results from various biological test systems.

This study was designed to assess the availability of polycyclic aromatic hydrocarbons (PAHs) present at a gasworks site to different soil remediation techniques. The study examined the effect on PAH availability of using different organic solvents, the degree of pretreatment, and the extraction time. In total, 25 PAHs (with two to six fused rings) and five carbonyl derivatives were measured. The results indicated that the PAHs and their derivatives were bound loosely to the surface of the studied soil and that there were no significant kinetic boundaries associated with the extraction of the PAHs. Furthermore, it was concluded that the studied soil was not suitable for bioremediation, as the concentration of PAHs with low molecular weight were limited. However, pressurized liquid extraction (PLE) with methanol as the solvent extracted 97% of all PAHs and PAH-derivatives, indicating that extraction may be effective as part of a soil remediation technique for old gasworks soils.

In this study, we examined 31 samples of varying chemical composition, including samples of soils from gasworks, coke production sites, and sites where wood preservatives were heavily used; ash and soot from municipal solid waste incinerators; antiskid sand; and dust from areas with heavy road traffic. The samples were comprehensively chemically characterized, especially their polycyclic aromatic compound contents, using gas chromatography–time-of-flight mass spectrometry, whereas their biological effects were assessed using dehydrogenase activity, root growth (Hordeum vulgare), reproduction of springtails (Folsomia candida), algal growth (Desmodesmus subspicatus), germinability (Sinapis alba), Vibrio fischeri, DR-CALUX, and Ames Salmonella assays. The number of compounds detected in the samples ranged from 123 to 527. Using the multivariate regression technique of partial-least-squares projections to latent structures, it was possible to find individual compounds that exhibited strong correlations with the different biological responses. Some of the results, however, indicate that a broader chemical characterization may be needed to identify all the compounds that may cause the measured biological responses.

The aim of this study was to evaluate different techniques for assessing the availability of polycyclic aromatic hydrocarbons (PAHs) in soil. This was done by comparing the amounts (total and relative) taken up by the earthworm Eisenia fetida with the amounts extracted by solid-phase microextraction (SPME), semi-permeable membrane devices (SPMDs), leaching with various solvent mixtures, leaching using additives, and sequential leaching. Bioconcentration factors of PAHs in the earthworms based on equilibrium partitioning theory resulted in poor correlations to observed values. This was most notable for PAHs with high concentrations in the studied soil. Evaluation by principal component analysis (PCA) showed distinct differences between the evaluated techniques and, generally, there were larger proportions of carcinogenic PAHs (4–6 fused rings) in the earthworms. These results suggest that it may be difficult to develop a chemical method that is capable of mimicking biological uptake, and thus estimating the bioavailability of PAHs.

The total and relative amounts of PAHs extracted by abiotic techniques for assessing the bioavailability of PAHs was found to differ from the amounts taken up by Eisenia fetida.

Keywords: Bioavailability; Polycyclic aromatic hydrocarbons; Earthworms; Leaching; Hydroxypropyl-β-cyclodextrin; Solid-phase microextraction; Semi-permeable membrane device

Climate change is expected to alter global temperature and precipitation patterns resulting in complex environmental impacts. The proposed higher precipitation in northern Scandinavia would increase runoff from land, hence increase the inflow of terrestrial dissolved organic matter (tDOM) in coastal regions. This could promote heterotrophic bacterial production and shift the food web structure, by favoring the microbial food web. The altered climate is also expected to affect transport and availability of organic micropollutants (MPs), with downstream effects on exposure and accumulation in biota. This study aimed to assess climate-induced changes in a Bothnian Sea food web structure as well as bioaccumulation patterns of MPs. We performed a mesocosms-study, focusing on aquatic food webs with fish as top predator. Alongside increased temperature, mesocosm treatments included tDOM and MP addition. The tDOM addition affected nutrient availability and boosted both phytoplankton and heterotrophic bacteria in our fairly shallow mesocosms. The increased tDOM further benefitted flagellates, ciliates and mesozooplankton, while the temperature increase and MP addition had minor effect on those organism groups. Temperature, on the other hand, had a negative impact on fish growth and survival, whereas tDOM and MP addition only had minor impact on fish. Moreover, there were indications that bioaccumulation of MPs in fish either increased with tDOM addition or decreased at higher temperatures. If there was an impact on bioaccumulation, moderately lipophilic MPs (log Kow 3.6 - 4.6) were generally affected by tDOM addition and more lipophilic MPs (log Kow 3.8 to 6.4) were generally affected by increased temperature. This study suggest that both increased temperatures and addition of tDOM likely will affect bioaccumulation patterns of MPs in shallow coastal regions, albeit with counteracting effects.

Long-range atmospheric transport is a major pathway for delivering persistent organic pollutants to the oceans. Atmospheric deposition and volatilization of chlorinated pesticides and algae-produced bromoanisoles (BAs) were estimated for Bothnian Bay, northern Baltic Sea, based on air and water concentrations measured in 2011-2012. Pesticide fluxes were estimated using monthly air and water temperatures and assuming 4 months ice cover when no exchange occurs. Fluxes were predicted to increase by about 50 % under a 2069-2099 prediction scenario of higher temperatures and no ice. Total atmospheric loadings to Bothnian Bay and its catchment were derived from air-sea gas exchange and "bulk'' (precipitation ? dry particle) deposition, resulting in net gains of 53 and 46 kg year(-1) for endosulfans and hexachlorocyclohexanes, respectively, and net loss of 10 kg year(-1) for chlordanes. Volatilization of BAs releases bromine to the atmosphere and may limit their residence time in Bothnian Bay. This initial study provides baseline information for future investigations of climate change on biogeochemical cycles in the northern Baltic Sea and its catchment.

Halogenated natural products in biota of the Baltic Sea include bromoanisoles (BAs) and methoxylated bromodiphenyl ethers (MeO-BDEs). We identified biogenic 6-MeO-BDE47 and 2'-MeO-BDE68 in Baltic water and air for the first time using gas chromatography - high resolution mass spectrometry. Partial pressures in air were related to temperature by: log p/Pa=m/T(K)+b. We determined Henry's law constants (HLCs) of 2,4-dibromoanisole (2,4-DiBA) and 2,4,6-tribromoanisole (2,4,6-TriBA) from 5 to 30°C and revised our assessment of gas exchange in the northern Baltic. The new water/air fugacity ratios (FRs) were lower, but still indicated net volatilization in May-June for 2,4-DiBA and May - September for 2,4,6-TriBA. The net flux (negative) of BAs from Bothnian Bay (38,000km²) between May - September was revised from -1319 to -532kg. FRs of MeO-BDEs were >1, suggesting volatilization, although this is tentative due to uncertainties in their HLCs and binding to dissolved organic carbon.

Bromophenols produced by marine algae undergo O-methylation to form bromoanisoles (BAs), which are exchanged between water and air. BAs were determined in surface water of the northern Baltic Sea (Gulf of Bothnia, consisting of Bothnian Bay and Bothnian Sea) during 2011-2013 and on a transect of the entire Baltic in September 2013. The abundance decreased in the following order: 2,4,6-tribromoanisole (2,4,6-TBA) > 2,4-dibromoanisole (2,4-DBA) ≫ 2,6-dibromoanisole (2,6-DBA). Concentrations of 2,4-DBA and 2,4,6-TBA in September were higher in the southern than in the northern Baltic and correlated well with the higher salinity in the south. This suggests south-to-north advection and dilution with fresh riverine water enroute, and/or lower production in the north. The abundance in air over the northern Baltic also decreased in the following order: 2,4,6-TBA > 2,4-DBA. However, 2,6-DBA was estimated as a lower limit due to breakthrough from polyurethane foam traps used for sampling. Water/air fugacity ratios ranged from 3.4 to 7.6 for 2,4-DBA and from 18 to 94 for 2,4,6-TBA, indicating net volatilization. Flux estimates using the two-film model suggested that volatilization removes 980-1360 kg of total BAs from Bothnian Bay (38000 km(2)) between May and September. The release of bromine from outgassing of BAs could be up to 4-6% of bromine fluxes from previously reported volatilization of bromomethanes and bromochloromethanes.

Marine macroalgae are used worldwide for human consumption, animal feed, cosmetics and agriculture. In addition to beneficial nutrients, macroalgae contain halogenated natural products (HNPs), some of which have toxic properties similar to those of well-known anthropogenic contaminants. Sixteen species of red, green and brown macroalgae were collected in 2017–2018 from coastal waters of the northern Baltic Sea, Sweden Atlantic and Norway Atlantic, and analyzed for bromoanisoles (BAs) and methoxylated bromodiphenyl ethers (MeO-BDEs). Target compounds were quantified by gas chromatography-low resolution mass spectrometry (GC-LRMS), with qualitative confirmation in selected species by GC-high resolution mass spectrometry (GC-HRMS). Quantified compounds were 2,4-diBA, 2,4,6-triBA, 2′-MeO-BDE68, 6-MeO-BDE47, and two tribromo-MeO-BDEs and one tetrabromo-MeO-BDE with unknown bromine substituent positions. Semiquantitative results for pentabromo-MeO-BDEs were also obtained for a few species by GC-HRMS. Three extraction methods were compared; soaking in methanol, soaking in methanol–dichloromethane, and blending with mixed solvents. Extraction yields of BAs did not differ significantly (p > 0.05) with the three methods and the two soaking methods gave equivalent yields of MeO-BDEs. Extraction efficiencies of MeO-BDEs were significantly lower using the blend method (p < 0.05). For reasons of simplicity and efficiency, the soaking methods are preferred. Concentrations varied by orders of magnitude among species: ∑2BAs 57 to 57 700 and ∑5MeO-BDEs < 10 to 476 pg g−1 wet weight (ww). Macroalgae standing out with ∑2BAs >1000 pg g−1 ww were Ascophyllum nodosum, Ceramium tenuicorne, Ceramium virgatum, Fucus radicans, Fucus serratus, Fucus vesiculosus, Saccharina latissima, Laminaria digitata, and Acrosiphonia/Spongomorpha sp. Species A. nodosum, C. tenuicorne, Chara virgata, F. radicans and F. vesiculosus (Sweden Atlantic only) had ∑5MeO-BDEs >100 pg g−1ww. Profiles of individual compounds showed distinct differences among species and locations.

Thousands of halogenated natural products (HNPs) pervade the terrestrial and marine environment. HNPs are generated by biotic and abiotic processes and range in complexity from low molecular mass natural halocarbons (nHCs, mostly halomethanes and haloethanes) to compounds of higher molecular mass which often contain oxygen and/or nitrogen atoms in addition to halogens (hHNPs). nHCs have a key role in regulating tropospheric and stratospheric ozone, while some hHNPs bioaccumulate and have toxic properties similar those of anthropogenic-persistent organic pollutants (POPs). Both chemical classes have common sources: biosynthesis by marine bacteria, phytoplankton, macroalgae, and some invertebrate animals, and both may be similarly impacted by alteration of production and transport pathways in a changing climate. The nHCs scientific community is advanced in investigating sources, atmospheric and oceanic transport, and forecasting climate change impacts through modeling. By contrast, these activities are nascent or nonexistent for hHNPs. The goals of this paper are to (1) review production, sources, distribution, and transport pathways of nHCs and hHNPs through water and air, pointing out areas of commonality, (2) by analogy to nHCs, argue that climate change may alter these factors for hHNPs, and (3) suggest steps to improve linkage between nHCs and hHNPs science to better understand and predict climate change impacts.

Pressurized liquid extraction (PLE) has gained wide acceptance for the extraction of persistent organic pollutants (POPs) from various environmental and biological matrices. This extraction technique was developed to shorten the extraction step, since this is one of the most time-consuming steps in many analytical procedures. When POPs enter the food chain, as in a number of recent food crises, thousands of samples have to be analyzed in a short time to protect humans from severe POP exposure. In such cases, PLE provides a good alternative to conventional extraction techniques. This article gives an overview of a number of studies of the extraction of POPs from food and feed, using PLE. Of special interest are applications dealing with selective extraction procedures, where integrated clean-up strategies are utilized to combine extraction and clean-up or fractionation to simplify further the entire sample-preparation chain.

The consumption of pharmaceuticals worldwide coupled with modest removal efficiencies of sewage treatment plants have resulted in the presence of pharmaceuticals in aquatic systems globally. In this study, we investigated the environmental concentrations of a selection of 93 pharmaceuticals in 43 locations in the Baltic Sea and Skagerrak. The Baltic Sea is vulnerable to anthropogenic activities due to a long turnover time and a sensitive ecosystem in the brackish water. Thirty-nine of 93 pharmaceuticals were detected in at least one sample, with concentrations ranging between 0.01 and 80 ng/L. One of the pharmaceuticals investigated, the anti-epileptic drug carbamazepine, was widespread in coastal and offshore seawaters (present in 37 of 43 samples). In order to predict concentrations of pharmaceuticals in the sub-basins of the Baltic Sea, a mass balance-based grey box model was set up and the persistent, widely used carbamazepine was selected as the model substance. The model was based on hydrological and meteorological sub-basin characteristics, removal data from smaller watersheds and wastewater treatment plants, and statistics relating to population, consumption and excretion rate of carbamazepine in humans. The grey box model predicted average environmental concentrations of carbamazepine in sub-basins with no significant difference from the measured concentrations, amounting to 0.57–3.2 ng/L depending on sub-basin location. In the Baltic Sea, the removal rate of carbamazepine in seawater was estimated to be 6.2 10−9 s−1 based on a calculated half-life time of 3.5 years at 10 °C, which demonstrates the long response time of the environment to measures phasing out persistent or slowly degradable substances such as carbamazepine. Sampling, analysis and grey box modelling were all valuable in describing the presence and removal of carbamazepine in the Baltic Sea.

Little is known about the impact of emissions of micropollutants from small and large-scale sewage treatment plants (STPs) on drinking water source areas. We investigated a populated catchment that drains into Lake Malaren, which is the drinking water source for around 2 million people including the inhabitants of Stockholm, Sweden. To assess the persistence, mobility, bioavailability and bioaccumulation of 32 structurally diverse emerging organic contaminants, sediment, integrated passive and grab water samples were collected along the catchment of the River Fyris, Sweden. The samples were complemented with STP effluent and fish samples from one sampling event. Contaminants identified as persistent, mobile, and bioavailable were 4,6,6,7,8,8-hexamethyl-1,3,4,7-tetrahydrocyclopenta[g] isochromene (galaxolide), 2,4,7,9-tetramethyl-5-decyn-4,7-diol, tris(2-chloroethyl) phosphate, tris(1,3-dichloro-2-propyl) phosphate, and tris(1-chloro-2-propyl) phosphate. Galaxolide and 2,4,7,9-tetramethyl-5-decyn-4,7-diol were additionally found to be bioaccumulative, whereas n-butylbenzenesulfonamide was found to be only persistent and mobile. The total median mass flux of the persistent and mobile target analytes from Lake Ekoln into the drinking water source area of Lake Malaren was estimated to be 27 kg per year. Additionally, 10 contaminants were tentatively identified by non-target screening using NIST library searches and manual review. Two of those were confirmed by reference standards and further two contaminants, propylene glycol and rose acetate, were discharged from STPs and travelled far from the source. Attenuation of mass fluxes was highest in the summer and autumn seasons, suggesting the importance of biological degradation and photodegradation for the persistence of the studied compounds.

On-site sewage treatment facilities (OSSFs), which are used to reduce nutrient emissions in rural areas, were screened for anthropogenic compounds with two-dimensional gas chromatography–mass spectrometry (GC × GC–MS). The detected compounds were prioritized based on their persistence, bioaccumulation, ecotoxicity, removal efficiency, and concentrations. This comprehensive prioritization strategy, which was used for the first time on OSSF samples, ranked galaxolide, α-tocopheryl acetate, octocrylene, 2,4,7,9-tetramethyl-5-decyn-4,7-diol, several chlorinated organophosphorus flame retardants and linear alkyl benzenes as the most relevant compounds being emitted from OSSFs. Twenty-six target analytes were then selected for further removal efficiency analysis, including compounds from the priority list along with substances from the same chemical classes, and a few reference compounds. We found significantly better removal of two polar contaminants 2,4,7,9-tetramethyl-5-decyn-4,7-diol (p = 0.0003) and tris(2-butoxyethyl) phosphate (p = 0.005) in soil beds, a common type of OSSF in Sweden, compared with conventional sewage treatment plants. We also report median removal efficiencies in OSSFs for compounds not studied in this context before, viz. α-tocopheryl acetate (96%), benzophenone (83%), 2-(methylthio)benzothiazole (64%), 2,4,7,9-tetramethyl-5-decyn-4,7-diol (33%), and a range of organophosphorus flame retardants (19% to 98%). The environmental load of the top prioritized compounds in soil bed effluents were in the thousands of nanogram per liter range, viz. 2,4,7,9-tetramethyl-5-decyn-4,7-diol (3000 ng L^− 1), galaxolide (1400 ng L^− 1), octocrylene (1200 ng L^− 1), and α-tocopheryl acetate (660 ng L^− 1).

The removal of organic contaminants from wastewater using cost-efficient and easily accessible methods have been increasingly studied in recent years. Most studies have focused on municipal sewage treatment plants; however, our study investigated treatment with char-fortified filter beds for on-site sewage treatment facilities (OSSFs). OSSFs are commonly used in rural and semi-urban areas all over the world to treat wastewater to reduce eutrophication and water-related diseases. To screen for a wide range of organic contaminants in order to improve the understanding of wastewater treatment efficiency and molecular properties, samples were taken from an OSSF field study site that used three filter types: sand, char-fortified sand, and char-fortified gas concrete. First, we screened for organic contaminants with state-of-the-art gas chromatography and liquid chromatography mass spectrometry-based targeted and untargeted analysis and then we developed quantitative structure-property relationship models to find the key molecular features responsible for the removal of organic contaminants. We identified 74 compounds, of which 24 were confirmed with reference standards. Amongst these 74 compounds were plasticizers, UV stabilizers, fragrances, pesticides, surfactant and polymer impurities, pharmaceuticals and their metabolites, and many biogenic compounds. Sand filters that are sometimes used as a last treatment step in OSSFs can remove hydrophobic contaminants. The addition of biochar significantly increases the removal of these and a few hydrophilic compounds (Wilcoxon signed-rank test, α = 0.05). Gas concrete did not appear to be suitable for the removal of organic contaminants. This study showed that, besides hydrophobic effects, biodegradation is the most important removal pathway in long-term field applications. However, further improvements are necessary to remove very hydrophilic contaminants as they were not removed with sand and biochar-fortified sand.

This study is the first attempt to quantify environmental fluxes per capita of organic contaminants discharged from on-site sewage treatment facilities (OSSFs) in affected recipients. Five sites were monitored around the River Fyris in Sweden: three mainly affected by OSSFs and two mainly affected by municipal sewage treatment plants (STPs). Gas chromatography-mass spectrometry was used to determine environmental concentrations of 30 anthropogenic contaminants, including organophosphorus compounds, rubber and plastic additives, UV stabilizers, fragrances, surfactant ingredients and polycyclic aromatic hydrocarbons. Uni- and multivariate statistical analysis of the most frequently detected contaminants showed that median fluxes per capita of tris(1,3-dichloro-2-propyl) phosphate, tris(1-chloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, and n-butylbenzene sulfonamide were similar at OSSF and STP sites, but the mass fluxes per capita of tris-(2-butoxyethyl) phosphate, 2-(methylthio)benzothiazole, and galaxolide, were significantly lower (~2 to 3-fold) at OSSF sites than at STP sites (Mann-Whitney, α = 0.05). Differences between these sites were larger in samples collected in summer and autumn than in samples collected in winter. Deviations likely originated from differences in treatment technology and distances between source and sampling sites. Further studies are needed to characterize mass fluxes per capita of contaminants in waters that directly receive discharges from OSSFs.

We studied the degradation of technical toxaphene in anaerobic sewage sludge from a municipal waste water treatment plant. Chlorobornanes, chlorocamphenes and related compounds were rapidly degraded, with degradation rates in the order of decachloro>nonachloro>octochloro>heptachloro ≈ hexachloro compounds. The half-lives of individual congeners ranged from <1 day to several days. We also studied the degradation of technical toxaphene in previously sterilized sludge (control), and found it was slower than in the anaerobic sludge. The chlorobornanes that degraded most rapidly in the non-sterilized anaerobic sludge were those with gem chloro substitution on the 6-member carbon-ring, including the toxic congeners, Toxicant A and B. Non-gem chloro substituted congeners, like the biologically persistent P26 and P50, also degraded, but less rapidly. Toxaphene degradation in sewage sludge proceeded primarily via reductive dechlorination, leading to HxSed, HpSed, TC2 and other persistent metabolites. Enantioselective determinations indicated little, if any, enantioselectivity in the formation and/or degradation of these compounds. The isomer and enantiomer profiles of the hexa-, hepta-, and octachlorobornanes are similar to those observed in sediment from the Baltic Sea, suggesting that technical toxaphene is the source of these compounds and that its composition was changed via similar anaerobic degradation pathways.

Technical toxaphene and a 22-component Reference Mixture were analyzed using capillary gas chromatography with split/splitless injection (SSL) and on-column injection (OC). In both techniques, electron-capture, negative ionization mass spectrometry (ECNI-MS) was used for detection of chlorobornanes, chlorocamphenes and related compounds. Significant discrimination of highly chlorinated congeners was observed as a result of incomplete transfer of these compounds from the vaporizer to the analytical column when using SSL. This resulted in a much lower response for nona- and decachloro congeners than when using OC. In addition, several toxaphene components, especially the chlorobornanes with gem dichloro substitution on the six-member carbon ring, undergo thermal degradation when using SSL. Some of these congeners are major components of technical toxaphene, but generally are not present, except at low concentrations, in environmental and biological samples. Therefore, technical toxaphene may be discriminated and/or degraded differently than toxaphene compounds in environmental samples when using SSL. This results in significant bias of the quantitative data when using the technical material as a reference. OC suffers much less from these deficiencies and, therefore, is a preferable technique for toxaphene analysis.

Trace analysis of 2,3,7,8-polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and the 12 WHO-PCBs (four non-ortho and eight mono-ortho congeners that have been assigned toxic equivalence factors, TEFs, by the World Health Organisation) was conducted by comprehensive two-dimensional gas chromatography with a micro electron-capture detector (GC x GC-mu ECD). Four food matrices (fish oil from herring, spiked cows' milk, vegetable oil and an eel extract) were analysed by two GC x GC laboratories, and four GC-HRMS laboratories generated reference values. The two GC x GC laboratories used different column combinations for separating the target analytes. For the first dimension, non-polar DB-XLB and VF-1 columns were used, and for the second dimension, an LC-50 liquid crystalline column with unique selectivity for planar compounds. The congener-specific and total toxic equivalence (TEQ) data obtained using DB-XLB x LC-50 were in good agreement with results obtained by the GC-HRMS laboratories. The WHO-PCB data obtained with the VF-1 x LC-50 combination was also good, but the PCDD/F concentrations were sometimes overestimated due to matrix interferences. GC x GC-mu ECD using DB-XLB x LC-50 seems to fulfil the European Community requirements of a screening method for PCDD/F and WHO-PCB TEQ in food.

Principal component analysis (PCA) was applied for evaluating the selectivity of 22 GC columns for which complete retention data were available for the 136 tetra- to octa-chlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Because the hepta- and octa-homologues are easy to separate the PCA was focused on the 128 tetra- to hexa-CDD/Fs. The analysis showed that 21 of the 22 GC columns could be subdivided into four groups with different selectivity. Group I consists of columns with non-polar thermally stable phases (Restek 5Sil MS and Dioxin 2, SGE BPX-DXN, Supelco Equity-5, and Agilent DB-1, DB-5, DB-5ms, VF-5ms, VF-Xms and DB-XLB). Group II includes ionic liquid columns (Supelco SLB-IL61, SLB-IL111 and SLB-IL76) with very high polarity. Group III includes columns with high-percentage phenyl and cyanopropyl phases (Agilent DB-17 and DB-225, Quadrex CPS-1, Supelco SP-2331, and Agilent CP-Sil 88), and Group IV columns with shape selectivity (Dionex SB-Smectic and Restek LC-50, Supelco beta DEXcst, Agilent VF-Xms and DB-XLB). Thus, two columns appeared in both Group I and IV (Agilent VF-Xms and DB-XLB). The selectivity of the other column, Agilent DB-210, differs from those of these four groups. Partial least squares (PLS) regression was used to correlate the retention times of the tetra- to hexa-CDD/Fs on the 22 stationary phases with a set of physicochemical and structural descriptors to identify parameters that significantly influence the solute-stationary phase interactions. The most influential physicochemical parameters for the interaction were associated with molecular size (as reflects in the total energy, electron energy, core-core repulsion and standard entropy), solubility (aqueous solubility and n-octanol/water partition coefficient), charge distribution (molecular polarizability and dipolar moment), and reactivity (relative Gibbs free energy); and the most influential structural descriptors were related to these parameters, in particular, size and dipolar moment. Finally, the PCA and PLS analyses were complemented with linear regression analysis to identify the most orthogonal column combinations, which could be used in comprehensive two-dimensional gas chromatography (GC x GC) to enhance PCDD/F separation and congener profiling. (C) 2014 Elsevier B.V. All rights reserved.

The orders of elution of all 136 tetra- to octa-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined on six gas chromatography (GC) columns. Three of these columns had ionic liquid stationary phases (SLB-IL111, SLB-IL76 and SLB-IL61; Supelco), one a liquid crystal phase (LC-50; Restek), one a chiral phase (beta DEXcst; Restek) and one a low bleed non-polar phase (DB-XLB; J&W/Agilent). According to our results, the high polarity and multiple solvation interactions of the ionic liquid stationary phases offered superior resolving power to that achieved with previously evaluated columns. The SLB-IL61 and SLB-IL111 columns resolved or partially separated 106 and 100 congeners, respectively, of the 136 PCDD/Fs. The SLB-IL61 also resolved 15 and partially separated one of the seventeen 2,3,7,8-substituted PCDD/Fs. Additional congeners can be separated by complementary analyses using additional columns in a dual- or triple-column approach. For example, using a combination of the SLB-IL61 and SLB-IL111 columns all but 8 congeners would be separated, including all 2,3,7,8-substituted PCDD/Fs. Two more congeners would be separated using a combination of SLB-IL76 and a liquid crystal (SB-Smectic) column, but in this case the 2,3,7,8-TeCDF would not be resolved. Three-column combinations would give even better separation: the DB-17/Smectic/SLB-IL76 and DB-225/Smectic/SLB-IL111 combinations would separate all but 1 of the 136 PCDD/F congeners. Unfortunately, the smectic column is no longer in production. If only commercially available columns are considered, combinations of SLB-IL61 and SLB-IL111 with DB-XLB, LC-50, or DB-225 offer the best performance, with 4, 4, and 3 unresolved congeners, respectively. Moreover, in each of these cases, one of the congeners in each unresolved pair is resolved on at least one of the other columns and so a reasonable estimate of the unresolved congeners' concentrations can be obtained by subtraction. The profiling of all 136 PCDD/Fs is thus greatly facilitated by using ionic liquid columns or combinations including such columns. However, there is room for improvement in the technical performance of the evaluated ionic liquid columns: their long-term retention time stability was poor and some highly chlorinated and sterically hindered congeners underwent dehalogenation during separation.

(C) 2013 Elsevier B.V. All rights reserved.

This paper describes the development of methods for selective extraction of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from soils and sediments, using pressurized liquid extraction with in-cell clean-up (SPLE). Two binary solvent mixtures, viz. dichloromethane/n-heptane (DCM/Hp), and diethylether/n-heptane (DEE/Hp), were evaluated. The SPLE extraction conditions were optimized using central composite face (CCF) design. Three factors were investigated: extraction temperature (60-160°C), number of extraction cycles (1-3) and time per cycle (2-18min). The results showed that DCM/Hp (1/1, v/v) and DEE/Hp (1/2, v/v) were the best extraction solvent compositions and that the extraction temperature was a critical factor that needed careful optimization to achieve high extraction efficiency without co-extraction of sulfuric acid. Under the optimal conditions, the SPLE methods provided results with good accuracy and precision. For the sandy soil certified reference material (CRM-529) the quantification results ended up in the range 82-110% as compared to the concentrations obtained by a reference method based on Soxhlet extraction and external column clean-up. Furthermore, for a clay soil (CRM-530) and a sediment reference material (WMS-01), the accuracy (trueness) of the TEQ values were +11% (DCM/Hp) and +8% (DEE/Hp) for CRM-530, +8% and -7% for WMS-01, respectively. The individual congener concentrations also agreed well with the certified values. These findings show that SPLE is a promising method for combined extraction and clean-up of PCDD/Fs in soil/sediment samples.

Modular pressurized liquid extraction (M-PLE) procedures were developed for simultaneous extraction, clean-up and fractionation of polychlorinated dioxins and furans (PCDD/Fs) in soil, sediment and sludge samples. The procedures utilize two coupled extraction cells: an upstream cell filled with the sample and layers of silica and acid- and base-modified silica, and a downstream cell filled with activated carbon. The silica layers were added to remove polar or hydrolysable matrix components, and the carbon to perform planarity-based fractionation. Two solvent systems (dichloromethane–heptane, DCM–Hp and diethyl ether–heptane, DEE–Hp) and two activated carbon loads (1% and 3% carbon on Celite) were evaluated using certified reference materials (CRM-529 and WMS-01) and materials from previous inter-calibration studies. Using any of the four procedures, data statistically equivalent to the certified or reference values were obtained. The M-PLE procedure using DCM–Hp and 1% carbon sometimes extracted the reference materials more efficiently than the reference methods, while the DEE–Hp procedure extracted them equally efficient, offering an alternative with less environmental impact. The methods with 1% carbon on Celite produced sufficiently pure extracts for sample loads up to one gram, but for greater sample loads the higher carbon load (3% carbon on Celite) was required to avoid breakthrough of target analytes. The new streamlined procedures are fast, cost-efficient, involve relatively low environmental impact (in the case of DEE–Hp) and are well suited for high-throughput analysis of solid samples, e.g. in connection with environmental monitoring campaigns and major soil remediation efforts.

Background: Prioritisation of chemical pollutants is a major challenge for environmental managers and decision-makers alike, which is essential to help focus the limited resources available for monitoring and mitigation actions on the most relevant chemicals. This study extends the original NORMAN prioritisation scheme beyond target chemicals, presenting the integration of semi-quantitative data from retrospective suspect screening and expansion of existing exposure and risk indicators. The scheme utilises data retrieved automatically from the NORMAN Database System (NDS), including candidate substances for prioritisation, target and suspect screening data, ecotoxicological effect data, physico-chemical data and other properties. Two complementary workflows using target and suspect screening monitoring data are applied to first group the substances into six action categories and then rank the substances using exposure, hazard and risk indicators. The results from the ‘target’ and ‘suspect screening’ workflows can then be combined as multiple lines of evidence to support decision-making on regulatory and research actions.

Results: As a proof-of-concept, the new scheme was applied to a combined dataset of target and suspect screening data. To this end, > 65,000 substances on the NDS, of which 2579 substances supported by target wastewater monitoring data, were retrospectively screened in 84 effluent wastewater samples, totalling > 11 million data points. The final prioritisation results identified 677 substances as high priority for further actions, 7455 as medium priority and 326 with potentially lower priority for actions. Among the remaining substances, ca. 37,000 substances should be considered of medium priority with uncertainty, while it was not possible to conclude for 19,000 substances due to insufficient information from target monitoring and uncertainty in the identification from suspect screening. A high degree of agreement was observed between the categories assigned via target analysis and suspect screening-based prioritisation. Suspect screening was a valuable complementary approach to target analysis, helping to prioritise thousands of substances that are insufficiently investigated in current monitoring programmes.

Conclusions: This updated prioritisation workflow responds to the increasing use of suspect screening techniques. It can be adapted to different environmental compartments and can support regulatory obligations, including the identification of specific pollutants in river basins and the marine environments, as well as the confirmation of environmental occurrence levels predicted by modelling tools. Graphical Abstract: (Figure presented.)

A collaborative trial involving 16 participants from nine European countries was conducted within the NORMAN network in efforts to harmonise suspect and non-target screening of environmental contaminants in whole fish samples of bream (Abramis brama). Participants were provided with freeze-dried, homogenised fish samples from a contaminated and a reference site, extracts (spiked and non-spiked) and reference sample preparation protocols for liquid chromatography (LC) and gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS). Participants extracted fish samples using their in-house sample preparation method and/or the protocol provided. Participants correctly identified 9–69 % of spiked compounds using LC-HRMS and 20–60 % of spiked compounds using GC-HRMS. From the contaminated site, suspect screening with participants’ own suspect lists led to putative identification of on average ∼145 and ∼20 unique features per participant using LC-HRMS and GC-HRMS, respectively, while non-target screening identified on average ∼42 and ∼56 unique features per participant using LC-HRMS and GC-HRMS, respectively. Within the same sub-group of sample preparation method, only a few features were identified by at least two participants in suspect screening (16 features using LC-HRMS, 0 features using GC-HRMS) and non-target screening (0 features using LC-HRMS, 2 features using GC-HRMS). The compounds identified had log octanol/water partition coefficient (KOW) values from −9.9 to 16 and mass-to-charge ratios (m/z) of 68 to 761 (LC-HRMS and GC-HRMS). A significant linear trend was found between log KOW and m/z for the GC-HRMS data. Overall, these findings indicate that differences in screening results are mainly due to the data analysis workflows used by different participants. Further work is needed to harmonise the results obtained when applying suspect and non-target screening approaches to environmental biota samples.

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs, precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as well. Levels of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids (PFCAs and PFSAs), in 2015 the sum of polyfluoroalkyl phosphoric acid esters (PAPs) were 15-20 ng/g dry weight, the sum of fluorotelomer sulfonic acids (FTSAs) was 0.8-1.3 ng/g, and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2 ng/g. Persistent PFSAs and PFCAs were detected at 1.9-3.9 ng/g and 2.4-7.3 ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%, respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment. (C) 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.

Perch (Perca fluviatilis) has been used in biological effect monitoring in a program for integrated coastal fish monitoring at the reference site Kvadofjarden along the Swedish east coast, which is a site characterized by no or minor local anthropogenic influences. Using a set of physiological and biochemical endpoints (i.e., biomarkers), clear time trends for "early warning" signs of impaired health were noted in the perch from this site, possibly as a result of increased baseline pollution. The data sets also showed relatively large variations among years. To identify additional temporal variation in biological parameters, global mRNA expression studies using RNA sequencing was performed. Perch collected in 2010 and 2014 were selected, as they showed variations in several biomarkers, such as the activity of the detoxification enzyme CYP1A (EROD), the plasma levels of vitellogenin, markers for oxidative stress, white blood cells count and gonad sizes. The RNA sequencing study identified approximately 4800 genes with a significantly difference in mRNA expression levels. A gene ontology enrichment analysis showed that these differentially expressed genes were involved in biological processes such as complement activation, iron ion homeostasis and cholesterol biosynthetic process. In addition, differences in immune system parameters and responses to the exposure of toxic substances have now been verified in two different biological levels (mRNA and protein) in perch collected in 2010 and 2014. Markedly higher mRNA expression of the membrane transporter (MATE) and the detoxification enzyme COMT, together with higher concentrations of bioactive naturally produced brominated compounds, such as brominated indoles and carbazoles, seem to indicate that the perch collected in 2014 had been exposed to macro- and microalga blooming to a higher degree than did perch from 2010. These results and the differential mRNA expression between the 2 years in genes related to immune and oxidative stress parameters suggest that attention must be given to algae blooming when elucidating the well-being of the perch at Kvadofjarden and other Baltic coastal sites.

Biomass torrefaction for sustainable energy production has gained an increasing interest. However, there is a lack of information on the thermal formation of persistent organic pollutants such as dioxins in the torrefied solid product. In this paper, we investigated the applicability of pressurized liquid extraction (PLE) for simultaneous extraction of a number of polychlorinated planar aromatic compounds from torrefied wood. The targeted compounds included polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), naphthalenes (PCNs), benzenes (PCBz), phenols (PCPhs) and PAHs. PLE tests were conducted on torrefied and non-torrefied (i.e. raw) eucalyptus wood chips using 5 single solvents (n-hexane, toluene, dichloromethane, acetone and methanol) and a mixture of n-hexane/toluene (1:1, v/v). The performance of each solvent was evaluated in terms of recoveries of spiked internal standards and the amount of co-extracted sample matrix. High polarity solvents such as methanol and acetone resulted in poor recoveries from torrefied wood for most of the target compounds, probably due to the high co-extraction of thermally degraded lignocellulosic compounds. Raw wood was less solvent-dependent and comparable results were obtained for polar and non-polar solvents. Toluene showed the best performance of the investigated solvents, with average recoveries of 79 +/- 14% and 66 +/- 9% for raw and torrefied wood, respectively. The method was validated using pentachlorophenol-tainted spruce wood chips. The proposed PLE method was compared to the traditional Soxhlet method. Results show that PLE gave equivalent or better extraction for all target compounds.

A comprehensive screening of micropollutants was performed in wastewaters from on-site sewage treatment facilities (OSSFs) and urban wastewater treatment plants (WWTPs) in Sweden. A suspect screening approach, using high resolution mass spectrometry, was developed and used in combination with target analysis. With this strategy, a total number of 79 micropollutants were successfully identified, which belong to the groups of per- and polyfluoroalkyl substances (PFASs), pesticides, phosphorus-containing flame retardants (PFRs) and pharmaceuticals and personal care products (PPCPs). Results from this screening indicate that concentrations of micropollutants are similar in influents and effluents of OSSFs and WWTPs, respectively. Removal efficiencies of micropollutants were assessed in the OSSFs and compared with those observed in WWTPs. In general, removal of PFASs and PFRs was higher in package treatment OSSFs, which are based on biological treatments, while removal of PPCPs was more efficient in soil bed OSSFs. A novel comprehensive prioritization strategy was then developed to identify OSSF specific chemicals of environmental relevance. The strategy was based on the compound concentrations in the wastewater, removal efficiency, frequency of detection in OSSFs and on in silico based data for toxicity, persistency and bioaccumulation potential.

This review provides a summary of methods for treating soils contaminated with polychlorinated aromatic compounds, especially polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Unlike many other soil pollutants, PCDD/Fs bind tightly to the soil, which severely reduces the efficiency of most aqueous treatment procedures and leaves few realistic alternatives besides the traditional containment techniques (landfill, solidification/stabilization, and in situ vitrification). Incineration has long been, and still is, the most efficient destruction technique, with a removal efficiency of >99.9999%. However, supercritical water oxidation, base-catalyzed decomposition, steam distillation, and various extraction techniques, such as solvent and liquefied gas and subcritical water extraction, may provide removal efficiencies of >95%. Many of the alternative techniques are expected to be cheaper than incineration and may therefore be attractive for moderately polluted soils. However, some of them are at an early stage of development and need to be further tested before their true potential can be assessed.

Ten previously unidentified polybrominated dibenzo-p-dioxins (PBDDs) were identified or tentatively identified in samples of Baltic Sea sediment and biota. Five tetrabrominated dibenzo-p-dioxins (TeBDDs) were identified using authentic reference standards, including the four most abundant (previously denoted 4U1 through 4U3). In addition, five tribromodibenzo-p-dioxins (TrBDDs) were tentatively identified using retention times and analysis of TeBDD debromination products (including a moderately abundant compound previously denoted 3U1). An attempt was made to improve the gas chromatographic separation of the major TeBDDs, but with limited success. The data generated were used as basis for a discussion on the potential PBDD formation routes. No single formation pathway could explain the PBDD patterns found. Instead, a combination of a number of potential formation processes is suggested, including enzymatic and photolytic coupling of environmentally abundant bromophenols or hydroxyl diphenyl ethers (OH-PBDEs), and debromination of PBDDs to lesser brominated products.