Archives of Environmental Contamination and Toxicology, 1995
The death of buzzards (Buteo buteo) found in fodder and sugar beet fields treated with granular c... more The death of buzzards (Buteo buteo) found in fodder and sugar beet fields treated with granular carbofuran was investigated. To determine if there was a causal relationship between carbofuran treatment and bird mortality, earthworms of a specific fodder beet field as well as the crop contents of dead buzzards were analyzed for carbofuran contamination. Earthworms of the fodder beet field contained carbofuran concentrations up to 3.2 mg/kg, while remains of earthworms and carbofuran were detected in all buzzard crop contents. The carbofuran concentrations found in the earthworms as well as in the crops of the buzzards corroborate the suspicion that the buzzards found on fodder and sugar beet fields treated with granular carbofuran had died of secondary poisoning with carbofuran via contaminated earthworms. 1Carbofuran = 2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcar-
Chlorinated paraffins (CPs) are toxic, bioaccumulative, persistent, and ubiquitously present in t... more Chlorinated paraffins (CPs) are toxic, bioaccumulative, persistent, and ubiquitously present in the environment. CPs were analyzed in humus and needle samples, which were taken within the Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants (MONARPOP) at sampling sites of 7 different altitude profiles in the Alps. Gas chromatography combined with electron ionization tandem mass spectrometry (EI-MS/MS) was used for the determination of total CPs (sum of short, medium and long chain CPs). CPs were found in all samples; the concentrations varied between 7 and 199 ng g À1 dry weight (dw) and within 26 and 460 ng g À1 dw in humus and needle samples, respectively. A clear vertical tendency within the individual altitude profiles could not be ascertained. Within all altitude profiles, elevated concentrations were observed in humus samples taken between 700 and 900 m and between 1300 and 1500 m. In the needle samples no similar correlation could be observed due to higher variation of the data.
Persistent organic pollutants (POPs) are ubiquitous contaminants of environmental and human healt... more Persistent organic pollutants (POPs) are ubiquitous contaminants of environmental and human health relevance, but their emissions into the environment are still poorly known. In this study, concentrations of selected POPs were measured in ambient air in Zurich, Switzerland, and interpreted with a multimedia mass balance model. The aim of the combination of measurements and modeling was to backcalculate atmospheric emission rates of POPs. Measurements were performed in summer 2010 and winter 2011 and target analytes included polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Estimated emissions were higher in summer than in winter. Emission estimates for Zurich can be extrapolated to annual averages for Switzerland of 312 kg·a −1 (39 mg·capita −1 ·a −1 ), 53 kg·a −1 (7 mg·capita −1 ·a −1 ), and 3 kg·a −1 (0.4 mg·capita −1 ·a −1 , 94 g WHO98-TEQ·a −1 , 65 g I-TEQ·a −1 ) for the six indicator PCBs (iPCBs), the twelve coplanar dioxin-like PCBs (dlPCBs), and the 17 2,3,7,8-chlorosubstituted PCDD/Fs, respectively. The emission rates of iPCBs are in agreement with existing emission inventories, whereas for PCDD/Fs the emissions are five times higher than the estimates from the Swiss national emission inventory. Emissions of dlPCBs in Switzerland are presented here for the first time. Our study also provides the first seasonally resolved emission rates of POPs, which were determined with our combined measurement and modeling approach. These findings highlight the relevance of ongoing sources of POPs, even decades after regulations aiming to reduce or eliminate sources were established.
Short-chain chlorinated paraffins (SCCPs) are of concern due to their potential for adverse healt... more Short-chain chlorinated paraffins (SCCPs) are of concern due to their potential for adverse health effects, bioaccumulation, persistence, and long-range transport. Data on concentrations of SCCPs in urban areas and underlying emissions are still scarce. In this study, we investigated the levels and spatial distribution of SCCPs in air, based on two separate, spatially resolved sampling campaigns in the city of Zurich, Switzerland. SCCP concentrations in air ranged from 1.8 to 17 ng·m(-3) (spring 2011) and 1.1 to 42 ng·m(-3) (spring 2013) with medians of 4.3 and 2.7 ng·m(-3), respectively. Both data sets show that atmospheric SCCP levels in Zurich can vary substantially and may be influenced by a number of localized sources within this urban area. Additionally, continuous measurements of atmospheric concentrations performed at one representative sampling site in the city center from 2011 to 2013 showed strong seasonal variations with high SCCP concentrations in summer and lower level...
Cave, South Africa. The artefact is the only known tool so far discovered during the controlled e... more Cave, South Africa. The artefact is the only known tool so far discovered during the controlled excavations conducted at this site over the last decade, and was recovered from decalcified sediments near the stratigraphic interface of two breccia units, making it difficult to assign it with confidence to either. The morphology of the handaxe indicates a middle-late Acheulean industry, and preliminary electron spin resonance and palaeomagnetic dating suggest an age of greater than 780 000 years.
Melting glaciers may represent a secondary source of chemical pollutants that have previously bee... more Melting glaciers may represent a secondary source of chemical pollutants that have previously been incorporated and stored in the ice. Of particular concern are persistent organic pollutants (POPs), such as the insecticide dichlorodiphenyl trichloroethane (DDT) and industrial chemicals like polychlorinated biphenyls (PCBs), which are hazardous environmental contaminants due to their persistent, bioaccumulative and toxic properties. They were introduced in the
HBCDs (hexabromocyclododecanes) are used as flame retardants for plastics such as rigid insulatio... more HBCDs (hexabromocyclododecanes) are used as flame retardants for plastics such as rigid insulation panels, electric housings, and for textile back coatings. The world-wide market demand for HBCDs was estimated to 16700 tons in 2001 1 . Commercial HBCD is a mixture of isomers of 1,2,5,6,9,10-hexabromocyclododecane. Commonly three isomers, denoted as α-, β-, and γ-HBCD 2,3 , are reported. HBCDs have not shown any acute toxicity below their water solubility for fish, daphnia and algae 2 . However, physiological effects at the cell level were reported 4,5 . Data on chronic effects are rather scarce and the implications of the high bioaccumulation factor (log BCF 4 2,6 ) of HBCDs are not known, yet. The European Union is currently undertaking a risk assessment for HBCDs under its existing substances regulation 793/93/EEC. Very limited data are available on environmental concentrations of HBCDs. Studies from Sweden reported lipid based concentrations of HBCDs between < 50 and 8000 ng/g lipid weight (lw) in fish and guillemot eggs . No information on the isomer distribution was given. This paper reports α-, β-, and γ-HBCD concentrations in Whitefish samples from six Swiss lakes. The advantages of different analytical techniques (LC/MS versus GC/MS) as well as the implications of the results are discussed. To our knowledge, this is the first report on individual concentrations of α-, β-, and γ-HBCD in environmental samples.
Water science and technology : a journal of the International Association on Water Pollution Research, 2007
There is increasing concern about diffuse pollution of aquatic systems by biocides used in urban ... more There is increasing concern about diffuse pollution of aquatic systems by biocides used in urban areas. We investigated sources and pathways of biocides significant for the pollution of storm water runoff. Main sources seem to be building envelopes, i.e. facades (paints, plasters) and roof sealing membranes. First results from a defined urban catchment drained by a separated sewer system without any agricultural activities reveal a substantial occurrence. Even after the first flush, concentrations of terbutryn, carbendazim, mecoprop as well as Irgarol 1051 and its metabolite exceeded the Swiss water quality standard of 0.1 microg/L. In laboratory experiments, leaching of mecoprop used as a root protection agent in bitumen sheets for roof waterproofing was determined. The concentrations differed in 16 different sheets two orders of magnitude, depending on the product composition. Using optimized products, it is expected to be the most efficient and sustainable way to reduce the envir...
SUMMARY: A yearly amount of 9.3×106t compost and digestate derived from separately collected orga... more SUMMARY: A yearly amount of 9.3×106t compost and digestate derived from separately collected organic waste is produced in the 25 European Union member states. The improvement of soil properties is a major benefit of compost application. However, little is known about the occurrence of organic pollutants in compost. In the present study, polyaromatic hydrocarbons (PAHs), ortho substituted and dioxin-like polychlorinated
Levels, mass fluxes, and time trends of polybrominated diphenyl ethers (PBDEs) and polychlorinate... more Levels, mass fluxes, and time trends of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in Lake Thun, a peri-Alpine lake, are investigated. We present measurements of PBDEs and PCBs in air, lake water, lake sediment, and tributary water. These measurements are combined with a multimedia fate model, based on site-specific environmental parameters from the lake catchment. Measured loadings of PBDEs and PCBs in air and tributaries were used to drive the model. The model satisfactorily reproduces PBDE and PCB congener patterns in water and sediment, but it tends to yield concentrations in water below the measurements and concentrations in sediment exceeding the measurements. A sensitivity analysis reveals that partitioning of PBDEs and PCBs between the aqueous dissolved phase and suspended particulate matter in the water column strongly affects the model results, in particular the concentrations in water and sediment. For lower-brominated PBDEs, approximately 70% and 30% of input into the lake stems from atmospheric deposition and from tributaries, respectively. For heavier PBDEs and all PCBs, rivers appear to deliver the major load (64-92%). Waste water effluents are of minor importance. 50-90% of the total input is buried in the permanent sediment. Sediment burial makes PBDEs and PCBs less available for recycling in the environment, and reduces concentrations in the outflowing river. If use of deca-BDE increases in the future, levels in Lake Thun will follow the same trend. If the use and resulting environmental emissions decrease, concentrations in water will rapidly decline, according to our calculations, while sediment levels will decrease at a considerably slower rate.
Chemikalien zu rekonstruieren. In Gletscherseen steigt die Konzentration persistenter organischer... more Chemikalien zu rekonstruieren. In Gletscherseen steigt die Konzentration persistenter organischer Schadstoffe, die längst verboten sind.
In Europe, 9.3 x 10(6) t(dry weight (dw)) of compost and digestate are produced per year. Most of... more In Europe, 9.3 x 10(6) t(dry weight (dw)) of compost and digestate are produced per year. Most of this is applied to agricultural land, which can lead to considerable inputs of organic pollutants, such as polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) to soil. This paper presents an inventory of the pollutant situation in source-separated composts, digestates and presswater in Switzerland by a detailed analysis of over 70 samples. PCB concentrations ( summation PCB 28, 52, 101, 118, 138, 153, 180) were significantly higher in urban (median: 30 microg kg(-1)dw, n = 52) than in rural samples (median: 14 microg kg(-1)dw, n = 16). Together with low concentrations in general, this points to aerial deposition on compost input material as the major contamination pathway. Enantiomeric fractions of atropisometric PCB were close to racemic. Median PAH concentration was 3010 microg kg(-1)dw( summation 15PAH, n = 69), and one quarter of the samples exhibited concentrations above the relevant Swiss guide value for compost (4000 microg kg(-1)dw). The levels were influenced by the treatment process (digestate &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; compost), the season of input material collection (spring-summer &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; winter &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; autumn), the particle size (coarse-grained &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; fine-grained), and maturity (mature &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; less mature). The main source of PAH in compost was pyrogenic, probably influenced mainly by liquid fossil fuel combustion and some asphalt abrasion, as suggested by multiple linear regression. This study, together with a companion paper reporting on other organic contaminates including emerging compound classes, provides a starting point for a better risk-benefit estimation of the application of compost and digestate to agricultural soil in Switzerland.
Atmospheric particulate matter (PM1) was collected at an urban and a rural site in Switzerland du... more Atmospheric particulate matter (PM1) was collected at an urban and a rural site in Switzerland during a hibernal high air pollution episode and was investigated for estrogenicity using an estrogen-sensitive reporter gene assay (ER-CALUX). All samples that were tested induced estrogen receptor-mediated gene expression in T47D human breast adenocarcinoma cells. Observed estrogenic activities corresponded to 17b-estradiol (E2) CALUX equivalent concentrations ranging from 2 to 23 ng E2-CEQ per gram of PM1 (particulate matter of £ 1 mm aerodynamic diameter) and from 0.07 to 1.25 pg E2-CEQ per m 3 of sampled air. There was a strong correlation between the PM1 estrogenicity of the urban and rural sites (r = 0.92). Five hydroxylated polycyclic aromatic hydrocarbons (hydroxy-PAHs), which show structural similarities to E2, were assessed for their estrogenic activity. The following order of estrogenic potency was found: 2-hydroxychrysene > 2-hydroxyphenanthrene > 1-hydroxypyrene > 2-hydroxynaphthalene > 1-hydroxynaphthalene. Three of these hydroxy-PAHs, namely 2-hydroxyphenanthrene, 2-hydroxynaphthalene and 1-hydroxynaphthalene, were detected in all PM1 extracts. However, they contributed only 0.01-0.2% to the overall estrogenic activity. Hence, mainly other estrogenic compounds not yet identified by chemical analysis must be responsible for the observed activity. The temporal trend of PM1 estrogenicity at the urban and rural site, respectively, was compared with the time course of several air pollutants (NO 2 , NO, SO 2 , O 3 , CO) and meteorological parameters (temperature, humidity, air pressure, solar irradiation, wind velocity). However, specific emission sources and formation processes of atmospheric xenoestrogens could not be elucidated. This study showed that ambient particulate matter contains compounds that are able to interact with estrogen receptors in vitro and potentially also interfere with estrogenregulated pathways in vivo.
Diesel exhaust contains several genotoxic compounds that may or may not penetrate diesel particul... more Diesel exhaust contains several genotoxic compounds that may or may not penetrate diesel particulate filters (DPFs). Furthermore, the DPF-supported combustion of soot and adsorbed compounds may lead to the formation of additional pollutants. Herein, we compare the impact of 14 different DPFs on emissions of known genotoxic compounds. During a four year period, these DPFs were tested on a heavy duty diesel engine, operated in the ISO 8178/4 C1 cycle. Integral samples, including gas-phase and particle-bound matter were taken. All DPFs were efficient wall-flow filters with solid particulate number filtration efficiencies η > 98%. On the basis of their CO, NO, and NO 2 emission characteristics, two different filter families were distinguished. DPFs with high oxidation potential (hox, n ) 8) converted CO and NO besides hydrocarbons, whereas low oxidation potential DPFs (lox, n ) 6) did not support CO and NO oxidation but still converted hydrocarbons. Lox-DPFs reduced NO 2 from 1.0 ( 0.3 (engine-out) to 0.42 ( 0.11 g/kWh (η ) 0.59), whereas hox-DPFs induced a NO 2 formation up to 3.3 ( 0.7 g/kWh (η ) -2.16). Emissions of genotoxic PAHs decreased for both filter families. Conversion efficiencies varied for individual PAHs and were lower for lox-(η ) 0.31-0.87) than for hox-DPFs (η ) 0.75-0.98). Certain nitro-PAHs were formed indicating that nitration is an important step along PAH oxidation. For example, 1-nitronaphthalene emissions increased from 11 to 17 to 21 µg/L without, with lox-, and hox-DPFs respectively, whereas 2-nitronaphthalene emissions decreased from 25 to 19 to 4.7 µg/L. In contrast to our expectations, the nitration potential of lox-DPFs was higher than the one of hox-DPFs, despite the intense NO 2 formation of the latter. The filters converted most genotoxic PAHs and nitro-PAHs and most soot particles, acting as carriers for these compounds. Hox-DPF exhaust remains oxidizing and therefore is expected to support atmospheric oxidation reactions, whereas lox-DPF exhaust is reducing and consuming oxidants such as ozone, when mixed with ambient air.
The environmental safety of decabromodiphenyl ether (BDE-209), a widely used flame retardant, has... more The environmental safety of decabromodiphenyl ether (BDE-209), a widely used flame retardant, has been the topic of controversial discussions during the past several years. Degradation of BDE-209 into lower brominated diphenyl ether congeners, exhibiting a higher bioaccumulation potential, has been a critical issue. Here, we report on the degradation of BDE-209 and the formation of octa- and nonabromodiphenyl ether congeners under anaerobic conditions. Sewage sludge collected from a mesophilic digester was used as the inoculum and incubated up to 238 days with and without a set of five primers. Following Soxhlet extraction and a liquid chromatography cleanup procedure, parent compounds and debromination products were analyzed by GC/HRMS. In experiments with primers, concentrations of BDE-209 decreased by 30% within 238 days. This corresponds to a pseudo-first-order degradation rate constant of 1 x 10(-3) d(-1). Without primers, the degradation rate constant was 50% lower. Formation of two nonabromodiphenyl ether and six octabromodiphenyl ether congeners proved that BDE-209 underwent reductive debromination in these experiments. Debromination occurred at the para and the meta positions, whereas debromination at the ortho position was not statistically significant. All three nonabromodiphenyl ether congeners (BDE-206, BDE-207, and BDE-208) were found to undergo reductive debromination as well. No significant change of the BDE-209 concentration and no formation of lower brominated congeners was observed in sterile control experiments. To our knowledge, this is the first report demonstrating microbially mediated reductive debromination of BDE-209 under anaerobic conditions.
In October 2000, joint sealants containing polychlorinated biphenyls (PCB) were discovered in var... more In October 2000, joint sealants containing polychlorinated biphenyls (PCB) were discovered in various public buildings in Switzerland. Triggered by this event, a nationwide comprehensive study was initiated by the Swiss Agency for the Environment, Forests, and Landscape, and 1348 samples of joint sealants as well as 160 indoor air samples from concrete buildings erected between 1950 and 1980 were analyzed. Out of 1348 samples, 646 (48%) contained PCB. In 279 (21%) samples, PCB concentrations of 10 g/kg and more were detected, and concentrations of 100 g/kg of PCB or more were found in 129 (9.6%) samples. These data indicate that PCB were widely used as plasticizers in joint sealants in Switzerland. In buildings constructed between 1966 and 1971, one-third of all joint sealants investigated contained more than 10 g/kg of PCB. PCB concentrations exceeding the limit of 0.050 g/kg above which material is required to be treated as PCB bulk product waste were reached by 568 samples (42%). PCB with a chlorine content between 45 and 55%, corresponding to mixtures such as Clophen A50, Aroclor 1248, and Aroclor 1254, were encountered in 316 samples (70%). In 42 cases (26%) where joint sealants containing PCB were present, clearly elevated PCB indoor air concentrations above 1 µg/m 3 were encountered. In eight cases (5%), levels were higher than 3 µg/m 3 . The Swiss tentative guideline value of 6 µg/m 3 (based on a daily exposure of 8 h) for PCB in indoor air was exceeded in one case (0.6%). On the basis of this work, representing the first largescale nationwide analysis of the issue of PCB-contaminated joint sealants, we estimate that there are still 50-150 t of PCB present in these materials, acting as diffuse sources. They are distributed over many hundreds of buildings all over the country and represent a significant but frequently overlooked inventory of PCB. In light of the Stockholm Convention on persistent organic pollutants that entered into force last year, reduction of the release of PCB from these widely used materials is an important issue to be addressed.
Chronology of brominated fame retardants (BFRs), a class of currentlywidely used chemicals, was c... more Chronology of brominated fame retardants (BFRs), a class of currentlywidely used chemicals, was compared to the respective historical profiles of legacy organochlorine compounds in three dated sediment cores from a prealpine lake (Lake Thun, Switzerland). Concentrations of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) started to increase in the 1980s-1990s. In the more recent sediment layers, PBDEs still had steady or increasing concentrations, whereas for HBCDs one sediment core revealed a decreasing trend. In contrast to the contemporary BFRs, concentrations of legacy organochlorines, such as polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and dichlorodiphenyl trichloroethane (DDT), peaked in deeper sediment layers deposited some decades ago. Measurements of atmospheric deposition and evaluation of wastewater discharges pointtoward deposition on the lake surface as a relevant input pathway and wastewater as a minor source of POPs in Lake Thun. The effect of the environmental awareness and the regulations taken in the 1970s to reduce environmental pollution of organochlorines is well reflected in the analyzed sediment cores. The sediment burden closely follows estimated time trends of consumption and emission of PCBs and DDT. The current residues in sediment of BFRs are still lower than the historical peak levels of organochlorines. However, current atmospheric deposition of BFRs is similar to deposition of PCBs. Considering the high amount of BFRs presently stocked in the anthroposphere in flame proofed materials, further measures to reduce emissions during BFRs life cycle are recommended to prevent high environmental pollution as it occurred for the organochlorine compounds.
Archives of Environmental Contamination and Toxicology, 1995
The death of buzzards (Buteo buteo) found in fodder and sugar beet fields treated with granular c... more The death of buzzards (Buteo buteo) found in fodder and sugar beet fields treated with granular carbofuran was investigated. To determine if there was a causal relationship between carbofuran treatment and bird mortality, earthworms of a specific fodder beet field as well as the crop contents of dead buzzards were analyzed for carbofuran contamination. Earthworms of the fodder beet field contained carbofuran concentrations up to 3.2 mg/kg, while remains of earthworms and carbofuran were detected in all buzzard crop contents. The carbofuran concentrations found in the earthworms as well as in the crops of the buzzards corroborate the suspicion that the buzzards found on fodder and sugar beet fields treated with granular carbofuran had died of secondary poisoning with carbofuran via contaminated earthworms. 1Carbofuran = 2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcar-
Chlorinated paraffins (CPs) are toxic, bioaccumulative, persistent, and ubiquitously present in t... more Chlorinated paraffins (CPs) are toxic, bioaccumulative, persistent, and ubiquitously present in the environment. CPs were analyzed in humus and needle samples, which were taken within the Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants (MONARPOP) at sampling sites of 7 different altitude profiles in the Alps. Gas chromatography combined with electron ionization tandem mass spectrometry (EI-MS/MS) was used for the determination of total CPs (sum of short, medium and long chain CPs). CPs were found in all samples; the concentrations varied between 7 and 199 ng g À1 dry weight (dw) and within 26 and 460 ng g À1 dw in humus and needle samples, respectively. A clear vertical tendency within the individual altitude profiles could not be ascertained. Within all altitude profiles, elevated concentrations were observed in humus samples taken between 700 and 900 m and between 1300 and 1500 m. In the needle samples no similar correlation could be observed due to higher variation of the data.
Persistent organic pollutants (POPs) are ubiquitous contaminants of environmental and human healt... more Persistent organic pollutants (POPs) are ubiquitous contaminants of environmental and human health relevance, but their emissions into the environment are still poorly known. In this study, concentrations of selected POPs were measured in ambient air in Zurich, Switzerland, and interpreted with a multimedia mass balance model. The aim of the combination of measurements and modeling was to backcalculate atmospheric emission rates of POPs. Measurements were performed in summer 2010 and winter 2011 and target analytes included polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Estimated emissions were higher in summer than in winter. Emission estimates for Zurich can be extrapolated to annual averages for Switzerland of 312 kg·a −1 (39 mg·capita −1 ·a −1 ), 53 kg·a −1 (7 mg·capita −1 ·a −1 ), and 3 kg·a −1 (0.4 mg·capita −1 ·a −1 , 94 g WHO98-TEQ·a −1 , 65 g I-TEQ·a −1 ) for the six indicator PCBs (iPCBs), the twelve coplanar dioxin-like PCBs (dlPCBs), and the 17 2,3,7,8-chlorosubstituted PCDD/Fs, respectively. The emission rates of iPCBs are in agreement with existing emission inventories, whereas for PCDD/Fs the emissions are five times higher than the estimates from the Swiss national emission inventory. Emissions of dlPCBs in Switzerland are presented here for the first time. Our study also provides the first seasonally resolved emission rates of POPs, which were determined with our combined measurement and modeling approach. These findings highlight the relevance of ongoing sources of POPs, even decades after regulations aiming to reduce or eliminate sources were established.
Short-chain chlorinated paraffins (SCCPs) are of concern due to their potential for adverse healt... more Short-chain chlorinated paraffins (SCCPs) are of concern due to their potential for adverse health effects, bioaccumulation, persistence, and long-range transport. Data on concentrations of SCCPs in urban areas and underlying emissions are still scarce. In this study, we investigated the levels and spatial distribution of SCCPs in air, based on two separate, spatially resolved sampling campaigns in the city of Zurich, Switzerland. SCCP concentrations in air ranged from 1.8 to 17 ng·m(-3) (spring 2011) and 1.1 to 42 ng·m(-3) (spring 2013) with medians of 4.3 and 2.7 ng·m(-3), respectively. Both data sets show that atmospheric SCCP levels in Zurich can vary substantially and may be influenced by a number of localized sources within this urban area. Additionally, continuous measurements of atmospheric concentrations performed at one representative sampling site in the city center from 2011 to 2013 showed strong seasonal variations with high SCCP concentrations in summer and lower level...
Cave, South Africa. The artefact is the only known tool so far discovered during the controlled e... more Cave, South Africa. The artefact is the only known tool so far discovered during the controlled excavations conducted at this site over the last decade, and was recovered from decalcified sediments near the stratigraphic interface of two breccia units, making it difficult to assign it with confidence to either. The morphology of the handaxe indicates a middle-late Acheulean industry, and preliminary electron spin resonance and palaeomagnetic dating suggest an age of greater than 780 000 years.
Melting glaciers may represent a secondary source of chemical pollutants that have previously bee... more Melting glaciers may represent a secondary source of chemical pollutants that have previously been incorporated and stored in the ice. Of particular concern are persistent organic pollutants (POPs), such as the insecticide dichlorodiphenyl trichloroethane (DDT) and industrial chemicals like polychlorinated biphenyls (PCBs), which are hazardous environmental contaminants due to their persistent, bioaccumulative and toxic properties. They were introduced in the
HBCDs (hexabromocyclododecanes) are used as flame retardants for plastics such as rigid insulatio... more HBCDs (hexabromocyclododecanes) are used as flame retardants for plastics such as rigid insulation panels, electric housings, and for textile back coatings. The world-wide market demand for HBCDs was estimated to 16700 tons in 2001 1 . Commercial HBCD is a mixture of isomers of 1,2,5,6,9,10-hexabromocyclododecane. Commonly three isomers, denoted as α-, β-, and γ-HBCD 2,3 , are reported. HBCDs have not shown any acute toxicity below their water solubility for fish, daphnia and algae 2 . However, physiological effects at the cell level were reported 4,5 . Data on chronic effects are rather scarce and the implications of the high bioaccumulation factor (log BCF 4 2,6 ) of HBCDs are not known, yet. The European Union is currently undertaking a risk assessment for HBCDs under its existing substances regulation 793/93/EEC. Very limited data are available on environmental concentrations of HBCDs. Studies from Sweden reported lipid based concentrations of HBCDs between < 50 and 8000 ng/g lipid weight (lw) in fish and guillemot eggs . No information on the isomer distribution was given. This paper reports α-, β-, and γ-HBCD concentrations in Whitefish samples from six Swiss lakes. The advantages of different analytical techniques (LC/MS versus GC/MS) as well as the implications of the results are discussed. To our knowledge, this is the first report on individual concentrations of α-, β-, and γ-HBCD in environmental samples.
Water science and technology : a journal of the International Association on Water Pollution Research, 2007
There is increasing concern about diffuse pollution of aquatic systems by biocides used in urban ... more There is increasing concern about diffuse pollution of aquatic systems by biocides used in urban areas. We investigated sources and pathways of biocides significant for the pollution of storm water runoff. Main sources seem to be building envelopes, i.e. facades (paints, plasters) and roof sealing membranes. First results from a defined urban catchment drained by a separated sewer system without any agricultural activities reveal a substantial occurrence. Even after the first flush, concentrations of terbutryn, carbendazim, mecoprop as well as Irgarol 1051 and its metabolite exceeded the Swiss water quality standard of 0.1 microg/L. In laboratory experiments, leaching of mecoprop used as a root protection agent in bitumen sheets for roof waterproofing was determined. The concentrations differed in 16 different sheets two orders of magnitude, depending on the product composition. Using optimized products, it is expected to be the most efficient and sustainable way to reduce the envir...
SUMMARY: A yearly amount of 9.3×106t compost and digestate derived from separately collected orga... more SUMMARY: A yearly amount of 9.3×106t compost and digestate derived from separately collected organic waste is produced in the 25 European Union member states. The improvement of soil properties is a major benefit of compost application. However, little is known about the occurrence of organic pollutants in compost. In the present study, polyaromatic hydrocarbons (PAHs), ortho substituted and dioxin-like polychlorinated
Levels, mass fluxes, and time trends of polybrominated diphenyl ethers (PBDEs) and polychlorinate... more Levels, mass fluxes, and time trends of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in Lake Thun, a peri-Alpine lake, are investigated. We present measurements of PBDEs and PCBs in air, lake water, lake sediment, and tributary water. These measurements are combined with a multimedia fate model, based on site-specific environmental parameters from the lake catchment. Measured loadings of PBDEs and PCBs in air and tributaries were used to drive the model. The model satisfactorily reproduces PBDE and PCB congener patterns in water and sediment, but it tends to yield concentrations in water below the measurements and concentrations in sediment exceeding the measurements. A sensitivity analysis reveals that partitioning of PBDEs and PCBs between the aqueous dissolved phase and suspended particulate matter in the water column strongly affects the model results, in particular the concentrations in water and sediment. For lower-brominated PBDEs, approximately 70% and 30% of input into the lake stems from atmospheric deposition and from tributaries, respectively. For heavier PBDEs and all PCBs, rivers appear to deliver the major load (64-92%). Waste water effluents are of minor importance. 50-90% of the total input is buried in the permanent sediment. Sediment burial makes PBDEs and PCBs less available for recycling in the environment, and reduces concentrations in the outflowing river. If use of deca-BDE increases in the future, levels in Lake Thun will follow the same trend. If the use and resulting environmental emissions decrease, concentrations in water will rapidly decline, according to our calculations, while sediment levels will decrease at a considerably slower rate.
Chemikalien zu rekonstruieren. In Gletscherseen steigt die Konzentration persistenter organischer... more Chemikalien zu rekonstruieren. In Gletscherseen steigt die Konzentration persistenter organischer Schadstoffe, die längst verboten sind.
In Europe, 9.3 x 10(6) t(dry weight (dw)) of compost and digestate are produced per year. Most of... more In Europe, 9.3 x 10(6) t(dry weight (dw)) of compost and digestate are produced per year. Most of this is applied to agricultural land, which can lead to considerable inputs of organic pollutants, such as polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) to soil. This paper presents an inventory of the pollutant situation in source-separated composts, digestates and presswater in Switzerland by a detailed analysis of over 70 samples. PCB concentrations ( summation PCB 28, 52, 101, 118, 138, 153, 180) were significantly higher in urban (median: 30 microg kg(-1)dw, n = 52) than in rural samples (median: 14 microg kg(-1)dw, n = 16). Together with low concentrations in general, this points to aerial deposition on compost input material as the major contamination pathway. Enantiomeric fractions of atropisometric PCB were close to racemic. Median PAH concentration was 3010 microg kg(-1)dw( summation 15PAH, n = 69), and one quarter of the samples exhibited concentrations above the relevant Swiss guide value for compost (4000 microg kg(-1)dw). The levels were influenced by the treatment process (digestate &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; compost), the season of input material collection (spring-summer &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; winter &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; autumn), the particle size (coarse-grained &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; fine-grained), and maturity (mature &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; less mature). The main source of PAH in compost was pyrogenic, probably influenced mainly by liquid fossil fuel combustion and some asphalt abrasion, as suggested by multiple linear regression. This study, together with a companion paper reporting on other organic contaminates including emerging compound classes, provides a starting point for a better risk-benefit estimation of the application of compost and digestate to agricultural soil in Switzerland.
Atmospheric particulate matter (PM1) was collected at an urban and a rural site in Switzerland du... more Atmospheric particulate matter (PM1) was collected at an urban and a rural site in Switzerland during a hibernal high air pollution episode and was investigated for estrogenicity using an estrogen-sensitive reporter gene assay (ER-CALUX). All samples that were tested induced estrogen receptor-mediated gene expression in T47D human breast adenocarcinoma cells. Observed estrogenic activities corresponded to 17b-estradiol (E2) CALUX equivalent concentrations ranging from 2 to 23 ng E2-CEQ per gram of PM1 (particulate matter of £ 1 mm aerodynamic diameter) and from 0.07 to 1.25 pg E2-CEQ per m 3 of sampled air. There was a strong correlation between the PM1 estrogenicity of the urban and rural sites (r = 0.92). Five hydroxylated polycyclic aromatic hydrocarbons (hydroxy-PAHs), which show structural similarities to E2, were assessed for their estrogenic activity. The following order of estrogenic potency was found: 2-hydroxychrysene > 2-hydroxyphenanthrene > 1-hydroxypyrene > 2-hydroxynaphthalene > 1-hydroxynaphthalene. Three of these hydroxy-PAHs, namely 2-hydroxyphenanthrene, 2-hydroxynaphthalene and 1-hydroxynaphthalene, were detected in all PM1 extracts. However, they contributed only 0.01-0.2% to the overall estrogenic activity. Hence, mainly other estrogenic compounds not yet identified by chemical analysis must be responsible for the observed activity. The temporal trend of PM1 estrogenicity at the urban and rural site, respectively, was compared with the time course of several air pollutants (NO 2 , NO, SO 2 , O 3 , CO) and meteorological parameters (temperature, humidity, air pressure, solar irradiation, wind velocity). However, specific emission sources and formation processes of atmospheric xenoestrogens could not be elucidated. This study showed that ambient particulate matter contains compounds that are able to interact with estrogen receptors in vitro and potentially also interfere with estrogenregulated pathways in vivo.
Diesel exhaust contains several genotoxic compounds that may or may not penetrate diesel particul... more Diesel exhaust contains several genotoxic compounds that may or may not penetrate diesel particulate filters (DPFs). Furthermore, the DPF-supported combustion of soot and adsorbed compounds may lead to the formation of additional pollutants. Herein, we compare the impact of 14 different DPFs on emissions of known genotoxic compounds. During a four year period, these DPFs were tested on a heavy duty diesel engine, operated in the ISO 8178/4 C1 cycle. Integral samples, including gas-phase and particle-bound matter were taken. All DPFs were efficient wall-flow filters with solid particulate number filtration efficiencies η > 98%. On the basis of their CO, NO, and NO 2 emission characteristics, two different filter families were distinguished. DPFs with high oxidation potential (hox, n ) 8) converted CO and NO besides hydrocarbons, whereas low oxidation potential DPFs (lox, n ) 6) did not support CO and NO oxidation but still converted hydrocarbons. Lox-DPFs reduced NO 2 from 1.0 ( 0.3 (engine-out) to 0.42 ( 0.11 g/kWh (η ) 0.59), whereas hox-DPFs induced a NO 2 formation up to 3.3 ( 0.7 g/kWh (η ) -2.16). Emissions of genotoxic PAHs decreased for both filter families. Conversion efficiencies varied for individual PAHs and were lower for lox-(η ) 0.31-0.87) than for hox-DPFs (η ) 0.75-0.98). Certain nitro-PAHs were formed indicating that nitration is an important step along PAH oxidation. For example, 1-nitronaphthalene emissions increased from 11 to 17 to 21 µg/L without, with lox-, and hox-DPFs respectively, whereas 2-nitronaphthalene emissions decreased from 25 to 19 to 4.7 µg/L. In contrast to our expectations, the nitration potential of lox-DPFs was higher than the one of hox-DPFs, despite the intense NO 2 formation of the latter. The filters converted most genotoxic PAHs and nitro-PAHs and most soot particles, acting as carriers for these compounds. Hox-DPF exhaust remains oxidizing and therefore is expected to support atmospheric oxidation reactions, whereas lox-DPF exhaust is reducing and consuming oxidants such as ozone, when mixed with ambient air.
The environmental safety of decabromodiphenyl ether (BDE-209), a widely used flame retardant, has... more The environmental safety of decabromodiphenyl ether (BDE-209), a widely used flame retardant, has been the topic of controversial discussions during the past several years. Degradation of BDE-209 into lower brominated diphenyl ether congeners, exhibiting a higher bioaccumulation potential, has been a critical issue. Here, we report on the degradation of BDE-209 and the formation of octa- and nonabromodiphenyl ether congeners under anaerobic conditions. Sewage sludge collected from a mesophilic digester was used as the inoculum and incubated up to 238 days with and without a set of five primers. Following Soxhlet extraction and a liquid chromatography cleanup procedure, parent compounds and debromination products were analyzed by GC/HRMS. In experiments with primers, concentrations of BDE-209 decreased by 30% within 238 days. This corresponds to a pseudo-first-order degradation rate constant of 1 x 10(-3) d(-1). Without primers, the degradation rate constant was 50% lower. Formation of two nonabromodiphenyl ether and six octabromodiphenyl ether congeners proved that BDE-209 underwent reductive debromination in these experiments. Debromination occurred at the para and the meta positions, whereas debromination at the ortho position was not statistically significant. All three nonabromodiphenyl ether congeners (BDE-206, BDE-207, and BDE-208) were found to undergo reductive debromination as well. No significant change of the BDE-209 concentration and no formation of lower brominated congeners was observed in sterile control experiments. To our knowledge, this is the first report demonstrating microbially mediated reductive debromination of BDE-209 under anaerobic conditions.
In October 2000, joint sealants containing polychlorinated biphenyls (PCB) were discovered in var... more In October 2000, joint sealants containing polychlorinated biphenyls (PCB) were discovered in various public buildings in Switzerland. Triggered by this event, a nationwide comprehensive study was initiated by the Swiss Agency for the Environment, Forests, and Landscape, and 1348 samples of joint sealants as well as 160 indoor air samples from concrete buildings erected between 1950 and 1980 were analyzed. Out of 1348 samples, 646 (48%) contained PCB. In 279 (21%) samples, PCB concentrations of 10 g/kg and more were detected, and concentrations of 100 g/kg of PCB or more were found in 129 (9.6%) samples. These data indicate that PCB were widely used as plasticizers in joint sealants in Switzerland. In buildings constructed between 1966 and 1971, one-third of all joint sealants investigated contained more than 10 g/kg of PCB. PCB concentrations exceeding the limit of 0.050 g/kg above which material is required to be treated as PCB bulk product waste were reached by 568 samples (42%). PCB with a chlorine content between 45 and 55%, corresponding to mixtures such as Clophen A50, Aroclor 1248, and Aroclor 1254, were encountered in 316 samples (70%). In 42 cases (26%) where joint sealants containing PCB were present, clearly elevated PCB indoor air concentrations above 1 µg/m 3 were encountered. In eight cases (5%), levels were higher than 3 µg/m 3 . The Swiss tentative guideline value of 6 µg/m 3 (based on a daily exposure of 8 h) for PCB in indoor air was exceeded in one case (0.6%). On the basis of this work, representing the first largescale nationwide analysis of the issue of PCB-contaminated joint sealants, we estimate that there are still 50-150 t of PCB present in these materials, acting as diffuse sources. They are distributed over many hundreds of buildings all over the country and represent a significant but frequently overlooked inventory of PCB. In light of the Stockholm Convention on persistent organic pollutants that entered into force last year, reduction of the release of PCB from these widely used materials is an important issue to be addressed.
Chronology of brominated fame retardants (BFRs), a class of currentlywidely used chemicals, was c... more Chronology of brominated fame retardants (BFRs), a class of currentlywidely used chemicals, was compared to the respective historical profiles of legacy organochlorine compounds in three dated sediment cores from a prealpine lake (Lake Thun, Switzerland). Concentrations of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) started to increase in the 1980s-1990s. In the more recent sediment layers, PBDEs still had steady or increasing concentrations, whereas for HBCDs one sediment core revealed a decreasing trend. In contrast to the contemporary BFRs, concentrations of legacy organochlorines, such as polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and dichlorodiphenyl trichloroethane (DDT), peaked in deeper sediment layers deposited some decades ago. Measurements of atmospheric deposition and evaluation of wastewater discharges pointtoward deposition on the lake surface as a relevant input pathway and wastewater as a minor source of POPs in Lake Thun. The effect of the environmental awareness and the regulations taken in the 1970s to reduce environmental pollution of organochlorines is well reflected in the analyzed sediment cores. The sediment burden closely follows estimated time trends of consumption and emission of PCBs and DDT. The current residues in sediment of BFRs are still lower than the historical peak levels of organochlorines. However, current atmospheric deposition of BFRs is similar to deposition of PCBs. Considering the high amount of BFRs presently stocked in the anthroposphere in flame proofed materials, further measures to reduce emissions during BFRs life cycle are recommended to prevent high environmental pollution as it occurred for the organochlorine compounds.
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Papers by Peter Schmid