Novel and legacy per- and polyfluoroalkyl substances (PFASs) in a farmland environment: Soil distribution and biomonitoring with plant leaves and locusts.

The occurrence of legacy and novel per- and polyfluoroalkyl substances (PFASs) in multiple matrices from a farmland environment was investigated in the Beijing-Tianjin-Hebei core area of northern China. PFASs were ubiquitously detected in farmland soils, and the detection frequency of 6:2 chlorinated polyfluoroalkyl ether sulfonic acid (6:2 Cl-PFESA) was higher than that of perfluorooctane sulfonic acid (98% vs. 83%). Long-chain PFASs, including 6:2 Cl-PFESA, showed a centered distribution pattern around the metropolis of Tianjin, probably due to the local intensive industrial activity, while trifluoroacetic acid (TFA) showed a decreasing trend from the coast to the inland area. Other than soil, TFA was also found at higher levels than other longer-chain PFASs in dust, maize (Zea mays), poplar (Populus alba) leaf and locust (Locusta migratoria manilens) samples. Both poplar leaves and locusts can be used as promising biomonitoring targets for PFASs in farmland environments, and their accumulation potential corresponds with protein and lipid contents. Apart from being exposed to PFASs via food intake, locusts were likely exposed via uptake from soil and precipitated dust in farmland environments. The biomonitoring of locusts may be more relevant to insectivores, which is important to conducting a comprehensive ecological risk assessment of farmland environments.

Artificial Sweeteners in Pig Feed: A Worldwide Survey and Case Study in Pig Farms in Tianjin, China.

Some artificial sweeteners (ASs) are used in pig feeds, although little is known on this regard. An investigation was conducted by determining seven common ASs in pig feed, manure, wastewater, compost, and soil from 16 pig farms in Tianjin, China. Saccharin (SAC) was predominant in feed (1.41-326 mg/kg) and manure samples (1.06-401 mg/kg). The annual mass loads of ASs in pig feeds were estimated at 5.69-119, 4.92-149, and 1.29-35 kg per 103 piglets, hogs, and sows, respectively. The annual emission of ASs via biowaste (i.e., manure) was estimated at 3.58-85.2, 0.04-26.2, and 0.08-9.97 kg per 103 capita for the three dominant ASs, i.e., SAC, neotame (NEO), and cyclamate (CYC). On a global scale, SAC was also widely detected at concentrations of 0.01-326 mg/kg in pig feed from China, Switzerland, Japan, Chile, and the United States, suggesting the worldwide use of ASs in pig feed. NEO and CYC were found in 41% and 30% of the feed samples, respectively, at concentrations of 0.05-70 mg/kg, whereas other ASs were barely found with rather lower concentrations. The annual mass loads of ASs consumed via pig feed consumption were estimated at 2400 tons worldwide. Thus, pig farming is an important source of ASs to the environment.

Occurrence of organophosphate flame retardants in farmland soils from Northern China: Primary source analysis and risk assessment.

Ninety-eight soil samples were collected from farmland soils from Beijing-Tianjin-Hebei core area, Northern China, where agricultural lands were subjected to contamination from intense urban and industrial activities. Twelve organophosphates flame retardants (OPFRs) were analyzed with total soil concentrations ranging from 0.543 µg/kg to 54.9 µg/kg. Chlorinated OPFRs were dominating at mean level of 3.64 µg/kg and Tris(2-chloroisopropyl) phosphate contributed the most (mean 3.36 ±â€¯5.61 µg/kg, 98.0%). Tris(2-ethylhexyl) phosphate was fully detected at levels of 0.041-1.95 µg/kg. Generally, tris(2-butoxyethyl) phosphate and triphenyl phosphate contributed the most to alkyl- (53.6%) and aryl-OPFRs (54.3%), respectively. The levels of ∑OPFRs close to the core urban areas were significantly higher than those from background sites. The occurrence and fate of OPFRs in soil were significantly associated with total organic carbon content and mostly with fine soil particles (<0.005 mm), and a transfer potential from the atmosphere was predicted with logKSA values. Comparable soil levels with poly brominated diphenyl ethers s in other studies suggested that the contamination of OPFRs occurred in farmland soil with an increasing trend but currently showed no significant environmental risk based on risk quotient estimation (<1). This investigation warrants further study on behaviors of OPFRs in a soil system and a continual monitoring for their risk assessment.

Uptake mechanisms of perfluoroalkyl acids with different carbon chain lengths (C2-C8) by wheat (Triticum acstivnm L.).

Organic compounds could be taken up by plants via different pathways, depending on chemical properties and biological species, which is important for the risk assessment and risk control. To investigate the transport pathways of perfluoroalkyl acids (PFAAs) by wheat (Triticum acstivnm L.), the uptake of five perfluoroalkyl carboxylic acids (PFCAs): TFA (C2), PFPrA (C3), PFBA (C4), PFHxA (C6), PFOA (C8), and a perfluoroalkyl sulfonic acid: PFOS (C8)) were studied using hydroponic experiments. Various inhibitors including a metabolic inhibitor (Na3VO4), two anion channel blockers (9-AC, DIDS), and two aquaporin inhibitors (AgNO3, glycerol) were examined. The wheat root and shoot showed different concentration trends with the carbon chain length of PFAAs. The uptake of TFA was inhibited by Na3VO4 and 9-AC whereas PFPrA was inhibited by Na3VO4, AgNO3 and 9-AC. For the other four PFAAs, only Na3VO4 was effective. These results together with the result of concentration-dependent uptake, which followed the Michaelis-Menten model, indicate that the uptake of PFAAs by wheat is mainly an energy-dependent active process mediated by carriers. For the ultra-short chain PFCAs (C2 and C3), aquaporins and anion channels may also be involved. A competition between TFA and PFPrA was determined during the plant uptake but no competition was observed between these two shorter chain analogues with other analogues, neither between PFBA and PFHxA, PFBA and PFBS, PFOA and PFOS.

Occurrence and enantiomer profiles of ß-blockers in wastewater and a receiving water body and adjacent soil in Tianjin, China.

A total of 58 samples were collected from hospitals, municipal wastewater treatment plants (WWTPs), a receiving water body (Dagu Drainage Canal, DDC), and adjacent farmland in Tianjin City, China, in May and November 2013 and were analyzed for five common ß-blockers (atenolol, sotalol, metoprolol, propranolol, and nadolol) to elucidate their source, occurrence and fate in a typical city in China. The profiles of the enantiomers of the ß-blockers in some samples were examined. Sotalol, metoprolol and propranolol were frequently detected, atenolol was less frequently detected, and nadolol was mostly not detected. Generally, the concentrations in hospital wastewaters occurred from

Environmental exposure of anthropogenic micropollutants in the Prut River at the Romanian-Moldavian border: a snapshot in the lower Danube river basin.

The Prut River, the second longest tributary of the Danube river, was investigated for a wide range of anthropogenic organic pollutants to fill the data gap on environmental contamination in eastern European surface waters. In this study, the occurrence of a wide range of organic pollutants was measured along the transboundary Prut River, between Sculeni and Branza in 2010-2012. Using two different analytical methods, gas chromatography coupled to mass spectrometry and liquid chromatography coupled to high-resolution mass spectrometry, over 300 compounds were screened for and 88 compounds were determined in the Prut River. In general, the chemicals occurred at low levels. At the last sampling site upstream of the confluence with the Danube river at Branza, the highest average concentrations (≥ 100 ng L-1) were determined for the artificial sweetener acesulfame, the pharmaceuticals metformin, 4-acetamidoantipyrene, and 4,4,5,8-tetramethylchroman-2-ol, the antioxidants 2,4-di-tert-butylphenol, 3-tert-butyl-4-hydroxyanisol, and 3,5-di-tert-butyl-4-hydroxy-toluene, the personal care products HHCB (galaxolide), 4-phenyl-benzophenone, and octyl dimethyl-p-aminobenzoic acid, the industrial chemical diphenylsulfone, and the sterol cholesterol. Low concentrations of agricultural pesticides occurred in the catchment. At Branza, the total accumulated load of all measured compounds was calculated to be almost 19 kg day-1. In comparison to the Rhine River, the loads in the Prut, determined with same LC-HRMS method for the same set of analytes, were two orders of magnitude lower. Discharge of wastewater without proper treatment from the city of Iasi in the Jijia catchment (Romania) as well as from the city of Cahul (Moldova) revealed a distinct increase in concentrations and loads in the Prut at Frasinesti and Branza. Thus, an implementation of wastewater treatment capacities in the Prut River basin would considerably reduce the loads of micropollutants from urban point sources.

Multimedia Distribution and Transfer of Per- and Polyfluoroalkyl Substances (PFASs) Surrounding Two Fluorochemical Manufacturing Facilities in Fuxin, China.

Industrial facilities can be point sources of per- and polyfluoroalkyl substances (PFASs) emission to the surrounding environment. In this study, 25 neutral and ionizable PFASs were analyzed in 94 multimedia samples including air, rain, outdoor settled dust, soil, plant leaves, river water, surface sediment, and shallow groundwater from two fluorochemical manufacturing parks (FMPs) in Fuxin, China, to elucidate the multimedia distribution and transfer pattern of PFASs from a point source. The concentrations of individual PFASs in air, outdoor settled dust, and surface river water decreased exponentially as the distance increases from the FMPs, whereas the concentrations of short-chain (C2-C4) perfluoroalkyl carboxylic acids (PFCAs) remained high (3000 ng/L) in the surface water 38 km away. At FMPs, air concentrations of fluorotelomer alcohols and iodides were found dominant with levels of up to 7900 pg/m3 and 920 pg/m3, respectively. Trifluoroacetic acid was directly released from FMPs and occurred in all the environmental matrices at levels 1-2 orders of magnitude higher than other PFCAs. Higher air-water concentration ratios of short-chain PFCAs (C2-C4) suggested their transfer tendency from air to water. Both short-chain (C2) and long-chain (>C6) PFCAs have greater sediment-water distribution coefficients and deposit dust-air coefficients, which have great influences on the long-range transport potential of different analogues.

Per- and Polyfluoroalkyl Substances (PFASs) in Indoor Air and Dust from Homes and Various Microenvironments in China: Implications for Human Exposure.

A newly developed solid-phase extraction cartridge composed of mixed sorbents was optimized for collection of both neutral and ionizable per- and polyfluoroalkyl substances (PFASs) in indoor air. Eighty-one indoor air samples and 29 indoor dust samples were collected from rooms of homes and hotels, textile shops, and cinemas in Tianjin, China. Fluorotelomer alcohols (FTOHs) were the predominant PFASs found in air (250-82 300 pg/m3) and hotel dust (24.8-678 ng/g). Polyfluoroalkyl phosphoric acid diesters were found at lower levels of nd-125 pg/m3 in air and 0.32-183 ng/g in dust. Perfluoroalkyl carboxylic acids (PFCAs) were dominant ionizable PFASs in air samples (121-20 600 pg/m3) with C4-C7 PFCAs contributing to 54% ± 17% of the profiles, suggesting an ongoing shift to short-chain PFASs. Long-chain PFCAs (C > 7) were strongly correlated and the intermediate metabolite of FTOHs, fluorotelomer unsaturated carboxylic acids, occurred in all the air samples at concentrations up to 413 pg/m3, suggesting the transformation of precursors such as FTOHs in indoor environment. Daily intake of ∑PFASs via air inhalation and dust ingestion was estimated at 1.04-14.1 ng/kg bw/d and 0.10-8.17 ng/kg bw/d, respectively, demonstrating that inhalation of air with fine suspended particles was a more important direct exposure pathway than dust ingestion for PFASs to adults.

Environmental context and magnitude of disturbance influence trait-mediated community responses to wastewater in streams.

Human land uses and population growth represent major global threats to biodiversity and ecosystem services. Understanding how biological communities respond to multiple drivers of human-induced environmental change is fundamental for conserving ecosystems and remediating degraded habitats. Here, we used a replicated 'real-world experiment' to study the responses of invertebrate communities to wastewater perturbations across a land-use intensity gradient in 12 Swiss streams. We used different taxonomy and trait-based community descriptors to establish the most sensitive indicators detecting impacts and to help elucidate potential causal mechanisms of change. First, we predicted that streams in catchments adversely impacted by human land-uses would be less impaired by wastewater inputs because their invertebrate communities should be dominated by pollution-tolerant taxa ('environmental context'). Second, we predicted that the negative effects of wastewater on stream invertebrate communities should be larger in streams that receive proportionally more wastewater ('magnitude of disturbance'). In support of the 'environmental context' hypothesis, we found that change in the Saprobic Index (a trait-based indicator of tolerance to organic pollution) was associated with upstream community composition; communities in catchments with intensive agricultural land uses (e.g., arable cropping and pasture) were generally more resistant to eutrophication associated with wastewater inputs. We also found support for the 'magnitude of disturbance' hypothesis. The SPEAR Index (a trait-based indicator of sensitivity to pesticides) was more sensitive to the relative input of effluent, suggesting that toxic influences of wastewater scale with dilution. Whilst freshwater pollution continues to be a major environmental problem, our findings highlight that the same anthropogenic pressure (i.e., inputs of wastewater) may induce different ecological responses depending on the environmental context and community metrics used. Thus, remediation strategies aiming to improve stream ecological status (e.g., rehabilitating degraded reaches) need to consider upstream anthropogenic influences and the most appropriate indicators of restoration success.

Occurrence and point source characterization of perfluoroalkyl acids in sewage sludge.

The occurrence and levels of perfluoroalkyl acids (PFAAs) emitted from specific pollution sources into the aquatic environment in Switzerland were studied using digested sewage sludges from 45 wastewater treatment plants in catchments containing a wide range of potential industrial emitters. Concentrations of individual PFAAs show a high spatial and temporal variability, which infers different contributions from industrial technologies and activities. Perfluorooctane sulfonic acid (PFOS) was generally the predominant PFAA with concentrations varying between 4 and 2440µgkg(-1) (median 75µgkg(-1)). Elevated emissions were especially observed in catchments capturing discharges from metal plating industries (median 82µgkg(-1)), aqueous firefighting foams (median 215µgkg(-1)) and landfill leachates (median 107µgkg(-1)). Some elevated perfluoroalkyl carboxylic acids (PFCAs) levels could be attributed to emissions from textile finishing industries with concentrations up to 233µgkg(-1) in sewage sludge. Assuming sorption to sludge for PFOS and PFCAs of 15% and 2%, respectively, concentrations in wastewater effluents up to the low µgL(-1) level were estimated. Even if wastewater may be expected to be diluted between 10 and 100 times by the receiving waters, elevated concentrations may be reached at specific locations. Although sewage sludge is a minor compartment for PFAAs in WWTPs, these investigations are helpful for the identification of hot-spots from industrial emitters as well as to estimate monthly average concentrations in wastewater.

Perfluoroalkyl compounds in municipal WWTPs in Tianjin, China--concentrations, distribution and mass flow.

BACKGROUNDS: Perfluorinated compounds (PFCs) have drawn much attention due to their environmental persistence, ubiquitous existence, and bioaccumulation potential. Wastewater treatment plants (WWTPs) are fundamental utilities in cities, playing an important role in preventing water pollution by lowering pollution load in waste waters. However, some of the emerging organic pollutants, like PFCs cannot be efficiently removed by traditional biological technologies in WWTPs, and some even increase in effluents compared to influents due to the incomplete degradation of precursors. Hence, WWTPs are considered to be a main point source in cities for PFCs that enter the aquatic environment. However, the mass flow of PFCs from WWTPs has seldom been analyzed for a whole city. Hence, in the present study, 11 PFCs including series of perfluoroalkyl carboxylic acids (PFCAs, C4-C12) and two perfluoroalkyl sulfonates (PFASs, C6 and C8) were measured in WWTP influents and effluents and sludge samples from six municipal WWTPs in Tianjin, China. Generation and dissipation of the target PFCs during wastewater treatment process and their mass flow in effluents were discussed. RESULTS: All the target PFCs were detected in the six WWTPs, and the total PFC concentration in different WWTPs was highly influenced by the population density and commercial activities of the corresponding catchments. Perfluorooctanoic acid (PFOA) was the predominant PFC in water phase, with concentrations ranging from 20 to 170 ng/L in influents and from 30 to 145 ng/L in effluents. Concentrations of perfluoroalkyl sulfonates decreased substantially in the effluent compared to the influent, which could be attributed to the sorption onto sludge, whereas concentrations of PFOA and some other PFCAs increased in the effluent in some WWTPs due to their weaker sorption onto solids and the incomplete degradation of precursors. Perfluorooctane sulfonic acid (PFOS) was the predominant PFC in sludge samples followed by PFOA, and their concentrations ranged from 42 to 169 g/kg and from 12 to 68 g/kg, respectively. Sludge-wastewater distribution coefficients (log K(d)) ranged from 0.62 to 3.87 L/kg, increasing with carbon chain length of the homologues. The mass flow of some PFCs in the effluent was calculated, and the total mass flow from all the six municipal WWTPs in Tianjin was 26, 47, and 3.5 kg/year for perfluorohexanoic acid, PFOA, and PFOS, respectively.

Identification of perfluoroalkyl acid sources in Swiss surface waters with the help of the artificial sweetener acesulfame.

Anthropogenic perfluorinated compounds (PFCs), especially the perfluoroalkyl acids (PFAAs) are ubiquitously found in surface waters around the globe. Emissions from households, industries and also atmospheric transport/deposition are discussed as the possible sources. In this study, these sources are evaluated using Switzerland as the study area. Forty-four surface water locations in different rivers and an Alpine lake were investigated for 14 PFAAs, four precursors and acesulfame, an artificial sweetener used as a population marker. Concentrations of individual PFAAs were generally low, between 0.02 and 10 ng/L. Correlation analysis showed that some PFAAs concentrations correlated well with population and less with catchment area, indicating that emissions from population, i.e., from consumer products, is the most important source to surface waters in Switzerland. The correlation with the population marker acesulfame confirmed this observation but highlighted also a few elevated PFAA levels, some of which could be attributed to industrial emissions.

Long-chain perfluorinated chemicals in digested sewage sludges in Switzerland.

This study focused on the occurrence of long-chain perfluorinated chemicals (PFCs) in anaerobically stabilized sewage sludges from 20 municipal WWTPs using current and historic samples to evaluate the levels of PFCs and to identify the relative importance of commercial and industrial sources. A quantitative analytical method was developed based on solvent extraction of the analytes and a LC-MS/MS system. For total perfluoralkyl carboxylates (PFCAs), the concentrations ranged from 14 to 50 µg/kg dry matter. Concentrations of perfluorooctane sulfonic acid (PFOS) ranged from 15 to 600 µg/kg dry matter. In three WWTPs, the PFOS levels were six to nine times higher than the average values measured in the other plants. These elevated PFOS concentrations did not correlate with higher levels of PFCAs, indicating specific additional local sources for PFOS at these WWTPs. Average concentrations in selected samples from the years 1993, 2002, and 2008 did not change significantly.

[Analysis of perfluorinated compounds in sludge by liquid extraction and high performance liquid chromatography-tandem mass spectrometry].

Perfluorinated compounds are emerging persistent organic pollutants. Wastewater treatment plants are reported to be one of their primary sources. However, a standard analytical method for sludge samples has not been set up. A novel and rapid analytical method based on the liquid extraction, followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was set up for 7 perfluorocarboxylic acids (PFCAs) and their precursors, 6:2 and 8:2 unsaturated flourotelomer carboxylic acids (FTUCAs), and 2 perfluoroalkyl sulfonates (PFASs) and their precursors, 5 derivates of sulfonamide in sludge. The parameters of methanol extraction, including pH, sonication temperature and time, and eluent volume were optimized. The extraction method was optimized as neutral extraction under sonication at 40 degrees C for 10 min, and it was successfully used for the analysis of perfluorinated compounds in the sludge samples. The linear calibration curves were obtained in the ranges of 0.1-20 microg/L for PFCAs and 6: 2/8: 2 FTUCA and 0.25-50 microg/L for PFASs and their precusors with linear correlation coefficients larger than 0.99. The recoveries of the target compounds ranged from 74% to 141% (except for FTUCAs) and the limits of quantification ranged from 0.6 to 30 microg/kg (dry weight). The use of internal standards can well correct the ion suppression (or enhancement) induced by co-eluting components present in the sample extracts, and improve the quantitative accuracy.

Determination of biocides and pesticides by on-line solid phase extraction coupled with mass spectrometry and their behaviour in wastewater and surface water.

This study focused on the input of hydrophilic biocides into the aquatic environment and on the efficiency of their removal in conventional wastewater treatment by a mass flux analysis. A fully automated method consisting of on-line solid phase extraction coupled to LC-ESI-MS/MS was developed and validated for the simultaneous trace determination of different biocidal compounds (1,2-benzisothiazoline-3-one (BIT), 3-Iodo-2-propynylbutyl-carbamate (IPBC), irgarol 1051 and 2-N-octyl-4-isothiazolinone (octhilinone, OIT), carbendazim, diazinon, diuron, isoproturon, mecoprop, terbutryn and terbutylazine) and pharmaceuticals (diclofenac and sulfamethoxazole) in wastewater and surface water. In the tertiary effluent, the highest average concentrations were determined for mecoprop (1010 ng/L) which was at comparable levels as the pharmaceuticals diclofenac (690 ng/L) and sulfamethoxazole (140 ng/L) but 1-2 orders of magnitude higher than the other biocidal compounds. Average eliminations for all compounds were usually below 50%. During rain events, increased residual amounts of biocidal contaminants are discharged to receiving surface waters.

Comparison of two extraction methods for the analysis of per- and polyfluorinated chemicals in digested sewage sludge.

A rapid and reliable analytical method, based on ion-pair extraction, clean-up on Envicarb cartridge and detection by liquid chromatography-tandem mass spectrometry (LC-MS/MS), was developed for determination of 17 per- and polyfluorinated chemicals (PFCs) in digested sewage sludge. Envicarb cartridge and six labeled internal standards were selected for the elimination/reduction and correction of matrix effects, respectively. As a result, the matrix effect for perfluorooctane sulfonamides (FOSAs) and perfluorocarboxylic acids (PFCAs) with carbon chain length from C6 to C14 was lowered to a range of -14% to +28%. However, the matrix effect for other analytes was still great mainly due to the absence of appropriate internal standard. Mean recoveries of the target analytes based on matrix spikes, at different spike levels (10-300ng/g), ranged from 70% to 169%. Relative standard deviations (RSDs) were in the range of 2-20% at different spike levels. The limit of quantification (LOQ) ranged between 0.6 and 30ng/g. The method was successfully applied to several sewage sludge samples from wastewater treatment plants nearby Zürich, Switzerland. In addition, by comparing the accuracy and precision of ion-pair extraction method and methanol extraction method, we further demonstrated that the ion-pair extraction method can be used for the analysis of PFCs in sludge samples. To our knowledge, this is the first study to extract the PFCs in sewage sludge with ion-pair method and to find unsaturated fluorotelomer carboxylic acids (FTUCAs) in sewage sludge.

Environmental risk assessment of human pharmaceuticals in the European Union: A case study with the ß-blocker atenolol.

ß-Adrenergic receptor blockers (ß-blockers) are applied to treat high blood pressure, ischemic heart disease, and heart rhythm disturbances. Due to their widespread use and limited human metabolism, ß-blockers are widely detected in sewage effluents and surface waters. ß-Adrenergic receptors have been characterized in fish and other aquatic animals, so it can be expected that physiological processes regulated by these receptors in wild animals may be affected by the presence of ß-blockers. Because ecotoxicological data on ß-blockers are scarce, it was decided to choose the ß-blocker atenolol as a case study pharmaceutical within the project ERAPharm. A starting point for the assessment of potential environmental risks was the European guideline on the environmental risk assessment of medicinal products for human use. In Phase I of the risk assessment, the initial predicted environmental concentration (PEC) of atenolol in surface water (500 ng L−1) exceeded the action limit of 10 ng L−1. Thus, a Phase II risk assessment was conducted showing acceptable risks for surface water, for groundwater, and for aquatic microorganisms. Furthermore, atenolol showed a low potential for bioaccumulation as indicated by its low lipophilicity (log KOW = 0.16), a low potential for exposure of the terrestrial compartment via sludge (log KOC = 2.17), and a low affinity for sorption to the sediment. Thus, the risk assessment according to Phase II-Tier A did not reveal any unacceptable risk for atenolol. Beyond the requirements of the guideline, additional data on effects and fate were generated within ERAPharm. A 2-generation reproduction test with the waterflea Daphnia magna resulted in the most sensitive no-observed-effect concentration (NOEC) of 1.8 mg L−1. However, even with this NOEC, a risk quotient of 0.003 was calculated, which is still well below the risk threshold limit of 1. Additional studies confirm the outcome of the environmental risk assessment according to EMEA/CHMP (2006). However, atenolol should not be considered as representative for other ß-blockers, such as metoprolol, oxprenolol, and propranolol, some of which show significantly different physicochemical characteristics and varying toxicological profiles in mammalian studies.

Fate of beta-blocker human pharmaceuticals in surface water: comparison of measured and simulated concentrations in the Glatt Valley Watershed, Switzerland.

This study focused on the occurrence and fate of four beta-blockers (atenolol, sotalol, metoprolol, propranolol) in wastewater and surface water. Measured concentrations were compared with predicted concentrations using an implementation of the geo-referenced model GREAT-ER for the Glatt Valley Watershed (Switzerland). Particularly, the question was addressed how measured and simulated data could complement each other for the exposure assessment of human pharmaceuticals and other micropollutants entering surface water through wastewater treatment plants (WWTP). Concentrations in the Glatt River ranged from

Recent levels of organochlorine pesticides and polychlorinated biphenyls in sediments of the sewer system in Hanoi, Vietnam.

The occurrence, temporal trend, sources and toxicity of PCBs and organochlorine pesticides were investigated in sediment samples from the sewer system of Hanoi City, including the rivers Nhue, To Lich, Lu, Set, Kim Nguu and the Yen So Lake. In general, the concentrations of the pollutants followed the order DDTs>PCBs>HCHs (beta-HCH)>HCB. However, the pollution pattern was different for the DDTs and PCBs when the sampling locations were individually evaluated. The concentrations of the DDTs, PCBs, HCHs, and HCB ranged from 4.4 to 1100, 1.3 to 384, <0.2 to 36 and <0.2 to 22 ng/g d.w., respectively. These levels are higher than at any other location in Vietnam. Compared to measurements from 1997, the DDTs, PCBs, beta-HCH and HCB levels show an increasing trend with DDT/DDE ratios, indicating very recent inputs into the environment although these persistent compounds are banned in Vietnam since 1995.