Occurrence of methyl triclosan, a transformation product of the bactericide triclosan, in fish from various lakes in Switzerland

The bactericide triclosan and methyl triclosan, an environmental transformation product thereof, have been previously detected in lakes and a river in Switzerland. Both compounds are emitted via wastewater treatment plants (WWTPs), with methyl triclosan probably being formed by biological methylation. Passive sampling with semi-permeable membrane devices (SPMDs) showed the presence of methyl triclosan in some lakes, suggesting some potential for bioaccumulation of the compound. In this study, we report the presence of methyl triclosan in fish (white fish, Coregonus sp.; roach, Rutilus rutilus) from various lakes in Switzerland receiving inputs from WWTPs. Identification of the compound was based on mass spectral (MS) evidence including MS/MS data. The concentrations of methyl triclosan in the fish were up to 35 ng g(-1) on a wet weight basis and up to 365 ng g(-1) on a lipid basis with concentrations in a relatively narrow range for fish from the same lake (Thunersee, 4-6 ng g(-1); Zürichsee, 32-62 ng g(-1); Pf?ffikersee, 43-56 ng g(-1); Greifensee, 165-365 ng g(-1), lipid basis). No methyl triclosan (<1 ng g(-1), lipid basis) was detected in fish (lake trout, Salmo trutta) from a remote lake in Sweden (H?bberstj?rnen) and in fish (roach) from a small lake in Switzerland with no input from WWTPs (Hüttnersee, <2-<5 ng g(-1), lipid basis). The concentrations of methyl triclosan in fish correlated (r2 = 0.85) with the ratio of population in the watershed to water throughflow of the lakes (P/Q ratio), which is considered to be a measure for the domestic burden from WWTPs to a lake. Passive sampling with SPMDs confirmed the presence of methyltriclosan in lakes and a river (Zürichsee and Greifensee; Limmat) but not in a remote mountain lake (J?risee) and in Hüttnersee. The bioconcentration factor (BCF) of methyl triclosan estimated from the fish data and SPMD-derived water concentrations was in the order of 1-2.6 x 10(5) (lipid basis) and thus in the range of other persistent organic pollutants. SPMDs were found to be reliable for monitoring low concentrations of methyl triclosan in surface water. Methyl triclosan appears to be a suitable marker for WWTP-derived lipophilic contaminants in the aquatic environment and fish.     

Occurrence and fate of the cytostatic drugs cyclophosphamide and ifosfamide in wastewater and surface waters

The two oxazaphosphorine compounds cyclophosphamide and ifosfamide are important cytostatic drugs used in the chemotherapy of cancer and in the treatment of autoimmune diseases. Their mechanism of action, involving metabolic activation and unspecific alkylation of nucleophilic compounds, accounts for genotoxic effects described in the literature and is reason for environmental concern. The occurrence and fate of cyclophosphamide and ifosfamide were studied in wastewater treatment plants (WWTPs) and surface waters in Switzerland, using a highly sensitive analytical method based on solid-phase extraction and liquid chromatography tandem mass spectrometry. The compounds were detected in untreated and treated wastewater at concentrations of <0.3-11 ng/L, which corresponded well with concentrations predicted from consumption data and typical renal excretion rates. Weekly loads determined in influent and effluent wastewater were comparable and suggested a high persistence in WWTPs. Furthermore, no degradation was observed in activated sludge incubation experiments within 24 h at concentrations of approximately 100 ng/L. Processes that may be relevant for elimination in natural waterbodies were studied with a set of incubation experiments in the laboratory. After extrapolation to natural conditions in surface waters, a slow dark-chemical degradation (half-lives on the order of years) is the most important transformation process. Degradation by photochemically formed HO* radicals may be of some relevance only in shallow, clear, and nitrate-rich waterbodies but could be further exploited for elimination of these compounds by advanced oxidation processes, i.e., in a treatment of hospital wastewater. In surface waters, concentrations ranged from < or =50 to 170 pg/L and were thus several orders of magnitude lower than the levels at which acute ecotoxicological effects have been reported in the literature (mg/L range). However, due to a lack of studies on chronic effects on aquatic organisms and data on occurrence and effects of metabolites, a final risk assessment cannot be made.     

Occurrence of some organic UV filters in wastewater, in surface waters, and in fish from Swiss Lakes

Organic UV filters are used in personal care products such as sunscreen products, and in cosmetics, beauty creams, skin lotions, lipsticks, hair sprays, hair dyes, shampoos, and so forth. The compounds enter the aquatic environmentfrom showering, wash-off, washing (laundering), and so forth via wastewater treatment plants (WWTPs) ("indirect inputs") and from recreational activities such as swimming and bathing in lakes and rivers ("direct inputs"). In this study, we investigated the occurrence of four important organic UV filter compounds (benzophenone-3, BP-3; 4-methylbenzylidene camphor, 4-MBC; ethylhexyl methoxy cinnamate, EHMC; octocrylene, OC) in wastewater, and in water and fish from various Swiss lakes, using gas chromatographic/mass spectrometric analyses. All four UV filters were present in untreated wastewater (WWTP influent) with a maximum concentration of 19 microg L(-1) for EHMC. The data indicate a seasonal variation with influent loads higher in the warmer season (June 2002) than in the colder one (April 2002). The influent loads were in the order EHMC > 4-MBC approximately BP-3 > OC. The concentrations in treated wastewater (WWTP effluent) were considerably lower, indicating substantial elimination in the plants. 4-MBC was usually the most prevalent compound (maximum concentration, 2.7 microg L(-1)), followed by BP-3, EHMC, and OC. UV filters were also detected in Swiss midland lakes and a river (Limmat) receiving inputs from WWTPs and recreational activities. However, all concentrations were low (<2-35 ng L(-1)); no UV filters (<2 ng L(-1)) were detected in a remote mountain lake. Data from passive sampling using semipermeable membrane devices (SPMDs) supported the presence of these UV filters in the lakes and the river and suggested some potential for accumulation of these compounds in biota. SPMD-derived water concentrations increased in the order Greifensee < Zürichsee < Hüttnersee. This order is reversed from that observed for methyl triclosan, used as a chemical marker for WWTP-derived lipophilic contaminants in the lakes. This indicated inputs of UV filters from sources other than WWTPs to the lakes during summer,for example,inputs from recreational activities. Fish (white fish, Coregonus sp.; roach, Rutilus rutilus; perch, Perca fluviatilis) from these lakes contained low but detectable concentrations of UV filters, in particular, 4-MBC (up to 166 ng g(-1) on a lipid basis). 4-MBC concentrations relative to methyl triclosan were lower in fish than in SPMDs exposed in the same lakes, suggesting that 4-MBC is less bioaccumulated than expected or metabolized in fish. The lipid-based bioconcentration factor (BCF(L)) estimated from the fish (roach) data and SPMD-derived water concentrations was about 1-2.3 x 10(4) and thus approximately 1 order of magnitude lower than expected from its Kow value.     

Azole fungicides: occurrence and fate in wastewater and surface waters

The mode of action of azole compounds implies a potential to affect endocrine systems of different organisms and is reason for environmental concern. The occurrence and fate of nine agricultural azole fungicides, some of them also used as biocides, and four azole pharmaceuticals were studied in wastewater treatment plants (WWTPs) and lakes in Switzerland. Two pharmaceuticals (fluconazole, clotrimazole, 10-110 ng L(-1)) and two biocides (propiconazole, tebuconazole, 1-30 ng L(-1)) were consistently observed in WWTP influents. Loads determined in untreated and treated wastewater indicated thatfluconazole, propiconazole, and tebuconazole were largely unaffected by wastewater treatment, but clotrimazole was effectively eliminated (> 80%). Incubation studies with activated sludge showed no degradation for fluconazole and clotrimazole within 24 h, but strong sorption of clotrimazole to activated sludge. Slow degradation and some sorption were observed for tebuconazole and propiconazole (degradation half-lives, 2-3 d). In lakes, fluconazole, propiconazole, and tebuconazole were detected at low nanogram-per-liter levels. Concentrations of the pharmaceutical fluconazole correlated with the expected contamination by domestic wastewater, but not those of the biocides. Per capita loads of propiconazole and tebuconazole in lakes suggested additional inputs; for example, from agricultural use or urban runoff rainwater.     

Nicotine derivatives in wastewater and surface waters: application as chemical markers for domestic wastewater

Nicotine is extensively metabolized in the human body to a number of compounds, which may enter natural waters via discharge of domestic wastewater. However, little is known on exposure of and potential effects on the aquatic environment. In this study, two major urinary metabolites, cotinine and 3'-hydroxycotinine, as well as a further tobacco alkaloid, N-formylnornicotine, were measured in wastewater and water from Swiss lakes using an analytical procedure based on SPE and LC-MS/MS SRM with cotinine-d3 as internal standard (LOQs, 1.0-1.5 ng/L). Typical concentrations of cotinine and 3'-hydroxycotinine were approximately 1-10 microg/L in untreated wastewater, but clearly less in treated wastewater (approximately 0.01-0.6 microg/L), corresponding to elimination efficiencies of 90-99%. N-Formylnornicotine, however,was found at similar concentrations in untreated and treated wastewater (0.02-0.15 microg/L). Its apparent persistence during wastewater treatment was further confirmed by incubation experiments with activated sludge. In lakes, cotinine, 3'-hydroxycotinine, and N-formylnornicotine were detected at concentrations up to 15, 80, and 6 ng/L, respectively. Concentrations in lakes correlated with the expected anthropogenic burden by domestic wastewater (ratio population per water throughflow), demonstrating the suitability of these nicotine derivatives as hydrophilic, anthropogenic markers. In small receiving waters with significant wastewater discharges, concentrations of a few hundred ng/L may be expected. Possible ecotoxicological risks associated with such environmental concentrations, can, however, not be assessed at present as data on effects on aquatic organisms are very limited, in particular on long-term effects.     

Effect of scale on the behavior of atrazine in surface waters

Field runoff is an important transport mechanism by which agricultural pesticides, including atrazine, move into the hydrologic environment. Atrazine is chosen because it is widely used, is transported in runoff relatively easily, is widely observed in surface waters, and has relatively little loss in the stream network. Data on runoff of atrazine from experimental plot and field studies is combined with annual estimates of load in numerous streams and rivers, resulting in a data set with 408 observations that span 14 orders of magnitude in area. The load as a percent of use (LAPU) on an annual basis is the parameter that is compared among the studies. There is no difference in the mean or range of LAPU values for areas from the size of experimental field plots (> or = 0.000023 ha) and small watersheds (< 100,000 ha). The relatively invariant LAPU value observed across a large range of watershed areas implies that the characteristics of atrazine itself (application method and chemical properties) are important in determining the extent of runoff. The variable influences on the extent of runoff from individual watershed characteristics and weather events are superimposed on the relatively invariant LAPU value observed across the range of watershed areas. The results from this study establish the direct relevance for agricultural field plot studies to watershed studies across the full range of scale.     

Caffeine,an anthropogenic marker for wastewater comtamination of surface waters

The suitability of caffeine as a chemical marker for surface water pollution by domestic wastewaters was assessed in this study. Caffeine concentrations in influents and effluents of Swiss wastewater treatment plants (WWTPs, 7-73 and 0.03-9.5 microg/L, respectively) indicated an efficient elimination of 81-99.9%. Corresponding loads in untreated wastewater showed small variations when normalized forthe population discharging to the WWTPs (15.8 +/- 3.8 mg person(-1) d(-1)), reflecting a rather constant consumption. WWTP effluent loads were considerably lower (0.06 +/- 0.03 mg person(-1) d(-1)), apart from installations with low sludge age (< or = 5 d, loads up to 4.4 mg person(-1) d(-1)). Despite the efficient removal in most WWTPs, caffeine was ubiquitously found in Swiss lakes and rivers (6-250 ng/ L), except for remote mountain lakes (<2 ng/L; analytical procedure for wastewater and natural waters: SPE, GC-MS-SIM or GC-MS-MS-MRM, internal standard 13C3-labeled caffeine). Caffeine concentrations in lakes correlated with the anthropogenic burden by domestic wastewaters, demonstrating the suitability of caffeine as a marker. A mass balance for Greifensee revealed that approximately 1-4% of the wastewaters had been discharged without treatment, presumably on rainy days when the capacity of WWTPs had been exceeded. For Zürichsee, it could be shown that the monthly inputs of caffeine correlated with precipitation data. The depth- and seasonal-dependent concentrations in this lake were adequately rationalized by a numerical model considering flushing, biodegradation, and indirect photodegradation via HO. radicals as elimination processes and caffeine inputs as fitting variables.     

Occurrence of perfluoroalkyl compounds in surface waters from the North Pacific to the Arctic Ocean

Perfluoroalkyl compounds (PFCs) were determined in 22 surface water samples (39-76°N) and three sea ice core and snow samples (77-87°N) collected from North Pacific to the Arctic Ocean during the fourth Chinese Arctic Expedition in 2010. Geographically, the average concentration of ∑PFC in surface water samples were 560 ± 170 pg L(-1) for the Northwest Pacific Ocean, 500 ± 170 pg L(-1) for the Arctic Ocean, and 340 ± 130 pg L(-1) for the Bering Sea, respectively. The perfluoroalkyl carboxylates (PFCAs) were the dominant PFC class in the water samples, however, the spatial pattern of PFCs varied. The C(5), C(7) and C(8) PFCAs (i.e., perfluoropentanoate (PFPA), perfluoroheptanoate (PFHpA), and perfluorooctanoate (PFOA)) were the dominant PFCs in the Northwest Pacific Ocean while in the Bering Sea the PFPA dominated. The changing in the pattern and concentrations in Pacific Ocean indicate that the PFCs in surface water were influenced by sources from the East-Asian (such as Japan and China) and North American coast, and dilution effect during their transport to the Arctic. The presence of PFCs in the snow and ice core samples indicates an atmospheric deposition of PFCs in the Arctic. The elevated PFC concentration in the Arctic Ocean shows that the ice melting had an impact on the PFC levels and distribution. In addition, the C(4) and C(5) PFCAs (i.e., perfluorobutanoate (PFBA), PFPA) became the dominant PFCs in the Arctic Ocean indicating that PFBA is a marker for sea ice melting as the source of exposure.     

Strong hg(II) complexation in municipal wastewater effluent and surface waters

The speciation of mercury(II) in the aquatic environment is greatly affected by the presence of ligands capable of forming extremely strong complexes with Hg(II). In this study, a novel competitive ligand exchange (CLE) technique was used to characterize Hg(II)-complexing ligands in samples collected from three municipal wastewater treatment plants, a eutrophic lake, a creek located downstream of an abandoned mercury mine, and a model water containing dissolved Suwannee River humic acid. These samples contained 3.3-15.9 mg/L dissolved organic carbon and were amended with 1.0-1.7 nM Hg(II) for CLE analysis. Results indicated that all samples contained labile Hg(II)-complexing ligands with conditional stability constants similar to those of reduced sulfur-containing ligands. Two wastewater effluent samples also contained approximately 0.5 nM of ligands that formed extremely strong Hg(II) complexes that did not dissociate in the presence of competing ligands. The conditional stability constant of these extremely strong or nonlabile complexes (i.e., (c)K(HgL)) were estimated to be greater than 10(30), for the reaction Hg(2+) + L' = HgL. The third wastewater sample and the eutrophic lake sample contained lower concentrations, 0.07-0.09 nM, of nonlabile Hg(II)-complexing ligands. The results suggested that these extremely strong Hg(ll)-complexing ligands should account for most of the dissolved Hg(II) species in municipal wastewater effluent and may dominate Hg(II) speciation in effluent-receiving waters.     

Ab initio and in situ comparison of caffeine, triclosan, and triclocarban as indicators of sewage-derived microbes in surface waters

Three organic wastewater compounds (OWCs) were evaluated in theory and practice for their potential to trace sewage-derived microbial contaminants in surface waters. The underlying hypothesis was that hydrophobic OWCs outperform caffeine as a chemical tracer, due to their sorptive association with suspended microorganisms representing particulate organic carbon (POC). Modeling from first principles (ab initio) of OWC sorption to POC under environmental conditions suggested an increasing predictive power: caffeine (0.2% sorbed) < triclosan (9-60%; pH 6-9) < triclocarban (76%). Empirical evidence was obtained via analysis of surface water from three watersheds in a rural-to-urban gradient in Baltimore, MD. Mass spectrometric OWC detections were correlated to microbial plate counts for 40 monitoring sites along 14 streams, including multiple chronic sewage release sites and the local wastewater treatment plant. Consistent with ab initio calculations, correlation analyses of 104 observations for fecal coliforms, enterococci, and Escherichia coli in natural surface waters showed that the particle-active antimicrobials triclosan and triclocarban (R2 range, 0.45-0.55) were indeed superior to caffeine (0.16-0.37) for tracking of microbial indicators. It is concluded that chemical monitoring of microbial risks is more effective when using hydrophobic OWCs such as triclosan and triclocarban in place of, or in conjunction with, the traditional marker caffeine.     

Occurrence and fate of nitrosamines and nitrosamine precursors in wastewater-impacted surface waters using boron as a conservative tracer

Using boron as a conservative tracer of municipal wastewater effluents, a mass balance was developed to determine river flowrates that requires only wastewater discharge flowrates and boron concentrations in wastewater effluents and in the river upstream and downstream of these discharges. Furthermore, this method permits calculation of the percentage of the river deriving from wastewater. This method could be useful within river sections featuring no independent data regarding river discharge. We assessed the decay of nitrate and N-nitrosodimethylamine (NDMA) precursors within an engineered treatment wetland and, using our boron analysis technique to account for dilution, within the Quinnipiac River (CT). Although both decayed with several day half-lives, their slow decay indicates they can persist to impact downstream drinking water supplies. Concentrations of NDMA and N-nitrosomorpholine (NMOR) were measurable within the river, but concentrations of four other nitrosamines, their precursors, and NMOR precursors were not detectable.     

Behavior of the polycyclic musks HHCB and AHTN in lakes, two potential anthropogenic markers for domestic wastewater in surface waters

The synthetic polycyclic musks HHCB and AHTN are potential chemical markers for domestic wastewater contamination of surface waters. Understanding their environmental behavior is important to evaluate their suitability as markers. This study focuses on the quantification of the processes that lead to an elimination in lakes. Rate constants for all relevant processes were estimated based on laboratory studies and models previously described. In lake Zurich, during winter time, both compounds are eliminated primarily by outflowing water and due to losses to the atmosphere. In summer, direct photolysis represents the predominant elimination process for AHTN in the epilimnion of lake Zurich (quantum yield, 0.12), whereas for HHCB, photochemical degradation is still negligible. HHCB and AHTN were then measured in effluents of Swiss wastewater treatment plants (WWTPs), in remote and anthropogenically influenced Swiss surface waters, and in Mediterranean seawater using an analytical procedure based on SPE and GC-MS-SIM with D6-HHCB as internal standard (LODs for natural waters, 2 and 1 ng/L, respectively). In winter, concentrations of HHCB and AHTN in lakes (<2-47 and <1-18 ng/L, respectively) correlated with the anthropogenic burden by domestic wastewater (ratio population per water throughflow), demonstrating the suitability of these compounds as quantitative, source-specific markers. In summer, however, no such correlations were observed. Vertical concentration profiles in lake Zurich indicated significant losses in the epilimnion during summer, mainly for AHTN, and could be rationalized with a lake modeling program (MASASlight), considering measured, average loads from WWTP effluents (0.80 +/- 0.22 and 0.32 +/- 0.11 mg person(-1) d(-1) for HHCB and AHTN, respectively) and the estimated rate constants for elimination processes.     

Enantiomeric profiling of chiral drugs in wastewater and receiving waters

The aim of this paper is to discuss the enantiomer-specific fate of chiral drugs during wastewater treatment and in receiving waters. Several chiral drugs were studied: amphetamine-like drugs of abuse (amphetamine, methamphetamine, MDMA, MDA), ephedrines (ephedrine and pseudoephedrine), antidepressant venlafaxine, and beta-blocker atenolol. A monitoring program was undertaken in 7 WWTPs (utilizing mainly activated sludge and trickling filters technologies) and at 6 sampling points in receiving waters over the period of 9 months. The results revealed the enantiomer-specific fate of all studied drugs during both wastewater treatment and in the aqueous environment. The extent of stereoselectivity depended on several parameters including: type of chiral drug (high stereoselectivity was recorded for atenolol and MDMA), treatment technology used (activated sludge showed higher stereoselectivity than trickling filters), and season (higher stereoselectivity was observed in the aqueous environment over the spring/summer time).     

Occurrence and fate of carbamazepine,clofibric acid,diclofenac, ibuprofen,ketoprofen, and naproxen in surface waters

Although various single-concentration measurements of pharmaceuticals are available in the literature, detailed information on the variation over time of the concentration and the load in wastewater effluents and rivers and on the fate of these compounds in the aquatic environment are lacking. We measured the concentrations of six pharmaceuticals, carbamazepine, clofibric acid, diclofenac, ibuprofen, ketoprofen, and naproxen, in the effluents of three wastewater treatment plants (WWTPs), in two rivers and in the water column of Lake Greifensee (Switzerland) over a time period of three months. In WWTP effluents, the concentrations reached 0.95 microg/L for carbamazepine, 0.06 microg/L for clofibric acid, 0.99 microg/L for diclofenac, 1.3 microg/L for ibuprofen, 0.18 microg/L for ketoprofen, and 2.6 microg/L for naproxen. The relative importance in terms of loads was carbamazepine, followed by diclofenac, naproxen, ibuprofen, clofibric acid, and ketoprofen. An overall removal rate of all these pharmaceuticals was estimated in surface waters, under real-world conditions (in a lake), using field measurements and modeling. Carbamazepine and clofibric acid were fairly persistent. Phototransformation was identified as the main elimination process of diclofenac in the lake water during the study period. With a relatively high sorption coefficient to particles, ibuprofen might be eliminated by sedimentation. For ketoprofen and naproxen, biodegradation and phototransformation might be elimination processes. For the first time, quantitative data regarding removal rates were determined in surface waters under real-world conditions. All these findings are important data for a risk assessment of these compounds in surface waters.     

A photochemical source of methyl chloride in saline waters

It is shown experimentallythatthe methoxy group in simple lignin-like molecules can be the source of the methyl group in CH3Cl produced by a photochemical reaction in an aqueous solution of chloride. Terrestrially derived colored dissolved organic matter (CDOM) in river water also yields CH3Cl through a photochemical process in a chloride solution. CDOM extracted from subsurface ocean waters showed some ability to enhance photochemical production of CH3Cl while CDOM from surface water showed no effect. Reactions of the kind described in this paper may be contributors to the marine source of methyl chloride and possibly other alkyl halides.