| 1. |
- Abongo, D. A., et al.
(författare)
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Occurrence, abundance and distribution of benthic macroinvertebrates in the Nyando River catchment, Kenya
- 2015
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Ingår i: African Journal of Aquatic Science. - : NATL INQUIRY SERVICES CENTRE PTY LTD. - 1608-5914 .- 1727-9364. ; 40:4, s. 373-392
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Tidskriftsartikel (refereegranskat)abstract
- A baseline study was conducted of the occurrence of macroinvertebrates at 26 sites in the Nyando River catchment in 2005-2006. A total of 13 orders and 16 families of Arthropoda, Mollusca, Platyhelminthes and Annelida were collected, with the order Ephemeroptera being most abundant in the up- and mid-stream reaches, followed by Hemiptera and Plecoptera respectively. The downstream sections of the river were dominated by Hirudinea and tubificids, as the water quality deteriorated mainly due to local land use, raw sewage effluent discharge and annual floods. Insects and annelids were the main invertebrates found and the extent of pollution increased from mid-section (Site 15) downwards as the river flowed into the Winam Gulf. Stringent management measures are required to safeguard the environment and ecosystems of Lake Victoria.
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| 2. |
- Abong'o, Deborah, et al.
(författare)
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Impacts of pesticides on human health and environment in the River Nyando catchment, Kenya
- 2014
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Ingår i: International Journal of Humanities, Arts, Medicine and Sciences. - : Best Journals. - 2348-0521. ; 2:3, s. 1-14
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The population of the River Nyando catchment largely relies on rain fed agriculture for their subsistence.Important crops grown include cereals, cash crops fruits and vegetables. Farming is one of the contributors of pollution to Lake Victoria. Organophosphates and other banned organochlorine pesticides such as lindane, aldrin and dieldrin were used by farmers. The pesticides transport was by storm water run-off and air drift into the lake. Environmental risk assessment background information was collected through questionnaire and interviews of farmers to determine knowledge and safe use of pesticides. Fourteen pesticides were identified as commonly used of which four are toxic to bees and five to birds. The farmers identified declines in the number of pollinating insects, the disappearance of Red-billed Oxpecker (Buphagus erythrorthynchus) and wild bird’s fatalities. The general knowledge among farmers about chemicals risks, safety, and chronic illnesses was low. Activities that increases environmental awareness and safety of pesticides should be initiated by the agrochemical firms and government.
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| 3. |
- Abong'o, Deborah, et al.
(författare)
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Organochlorine pesticide residue levels in soil from the Nyando River catchment, Kenya
- 2015
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Ingår i: Africa Journal of Physical Sciences. - 2313-3317. ; 2:1, s. 18-32
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Tidskriftsartikel (refereegranskat)abstract
- Soil samples were collected from six locations representative of the Nyando River catchment area of the Lake Victoria over a period of two years. Sampling was done four times in the year in February, May, September and December 2005 and 2006 in farms where maize, tea, sugar cane, coffee, rice and vegetables have been grown over the years. This coincided with the effects of different seasons and farming activities on residue levels of the pesticides in use. The objective was to investigate levels and distribution of organochlorine pesticides that have either been banned or are restricted for use in Kenya. Organochlorine pesticides investigated were DDT, lindane, aldrin, dieldrin, heptachlor, endrin, endosulfan (both α- and β- isomers and endosulfan sulphate), the sum is called “total” or Σendosulfan and methoxychlor. Prior to the ban or restriction in use, these pesticides had found wide applications in public health for control of disease vectors and in agriculture for control of crop pests. The analysis revealed presence of all the targeted pesticides with the highest mean concentrations for methoxychlor 140 ± 1.5 μg/kg, Σendosulfan (30 ± 2.1 μg/kg), aldrin (18 ± 0.28 μg/kg), respectively. The results show the presence of these pesticides in soils in the basin and this could be impacting negatively on the ecosystem health of the area.
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| 4. |
- Andersson, Anna, et al.
(författare)
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Evaluating gas chromatography with a halogen-specific detector for the determination of disinfection by-products in drinking water
- 2019
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Ingår i: Environmental Science and Pollution Research. - : Springer Berlin/Heidelberg. - 0944-1344 .- 1614-7499. ; 26, s. 7305-7314
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Tidskriftsartikel (refereegranskat)abstract
- The occurrence of disinfection by-products (DBPs) in drinking water has become an issue of concern during the past decades. The DBPs pose health risks and are suspected to cause various cancer forms, be genotoxic and have negative developmental effects. The vast chemical diversity of DBPs makes comprehensive monitoring challenging. Only few of the DBPs are regulated and included in analytical protocols. In this study, a method for simultaneous measurement of 20 DBPs from five different structural classes (both regulated and non-regulated) was investigated and further developed for 11 DBPs using solid phase extraction and gas chromatography coupled with a halogen specific detector (XSD). The XSD was highly selective towards halogenated DBPs, providing chromatograms with little noise. The method allowed detection down to 0.05 µg/L and showed promising results for the simultaneous determination of a range of neutral DBP classes. Compounds from two classes of emerging DBPs, more cytotoxic than the “traditional” regulated DBPs, were successfully determined using this method. However, haloacetic acids (HAAs) should be analyzed separately as some HAA methyl esters may degrade giving false positives of trihalomethanes (THMs). The method was tested on real water samples from two municipal waterworks where the target DBP concentrations were found below the regulatory limits of Sweden.
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| 5. |
- Andersson, Anna, et al.
(författare)
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Molecular changes among non-volatile disinfection by-products between drinking water treatment and consumer taps
- 2021
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Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 7:12, s. 2335-2345
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Tidskriftsartikel (refereegranskat)abstract
- The formation of disinfection by-products (DBPs) during drinking water treatment has been associated with various health concerns but the total DBP exposure is still unknown. In this study, molecular level non-target analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to study non-volatile DBPs, and how their composition changes during water distribution in four drinking water treatment plants (DWTPs) in Sweden using different types of raw water and disinfection processes. The largest portion of tap water DBP compositions were detected also at the DWTPs, highlighting that these DBP formulae were rather stable and contribute to human DBP exposure. Yet the number of detected DBPs decreased 14-48% between drinking water treatment and consumer taps in the three plants in which no mixing of water from other DWTPs in the distribution system occurred showing active DBP processing in the water distribution network. While considerable amounts of bromine-containing DBPs were detected upon chemical disinfection in some DWTPs, few of them were detected in the tap water samples, likely due to debromination by hydrolytic reactions. The overall fewer non-volatile DBPs detected in tap waters, along with changed distribution among chlorine and bromine DBPs, demonstrate that DBP mixtures are highly dynamic and that DBP measurements at DWTPs do not adequately reflect exposure at the point-of-use. Clearly, more knowledge about changes of DBP mixtures through the distribution system is needed to improve DBP exposure assessments.
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| 6. |
- Andersson, Anna, et al.
(författare)
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Selective removal of natural organic matter during drinking water production changes the composition of disinfection by-products
- 2020
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Ingår i: Environmental Science. - : ROYAL SOC CHEMISTRY. - 2053-1400 .- 2053-1419. ; 6:3, s. 779-794
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Tidskriftsartikel (refereegranskat)abstract
- Disinfection by-products (DBPs) are potentially toxic compounds formed upon chemical disinfection of drinking water. Controlling the levels and characteristics of dissolved organic matter (DOM) as precursor material for DBPs is a major target to reduce DBP formation. A pilot-scale treatment including suspended ion exchange (SIX (R)), a ceramic microfilter (CeraMac (R)) with in-line coagulation and optional pre-ozonation followed by granular activated carbon (GAC) filtration was compared with a conventional full-scale treatment based on DOM removal and DBP formation using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), rapid fractionation, liquid chromatography organic carbon detection (LC-OCD), adsorbable organic halogens (AOX) and trihalomethane (THM) analysis. The new treatment combination showed different selectivity for DOM removal, compared to the conventional, leading to changes in composition of the DBPs formed. SIX (R) and GAC had the largest impacts on reducing AOX and THM formation potentials but the high adsorptive capacity of GAC affected the diversity of detected DBPs most. Chlorination and chloramination of pilot treated water with doses normally used in Sweden produced low levels of AOX compared to the full-scale treatment, but FT-ICR MS revealed an abundance of brominated DBP species in contrast with the conventional treatment, which were dominated by chlorinated DBPs. This finding was largely linked to the high DOM removal by the pilot treatment, causing an increased Br-/C ratio and a higher formation of HOBr. Potential increases in Br-DBPs are important to consider in minimizing health risks associated with DBPs, because of the supposed higher toxicity of Br-DBPs compared to Cl-DBPs.
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| 7. |
- Andersson, Anna, 1990-
(författare)
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Uncharted Waters : Non-target analysis of disinfection by-products in drinking water
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Disinfection by-products (DBPs) are potentially toxic compounds formed when drinking water is treated with disinfectants, such as chlorine or chloramine. A large proportion of the exposure to DBPs is still unknown and the health risks observed through epidemiological studies cannot be explained by DBPs known today. In this thesis, a part of the unknown DBP fraction is investigated, covering a wide range of non-volatile, chlorine/bromine-containing DBPs. The goals were to investigate how the compositions of these DBPs differ between water treatment plants, how their occurrence changes in the distribution system until reaching consumers and how new treatment techniques can reduce their formation and toxicity. To analyze unknown DBPs, a non-targeted approach adopting ultra-high-resolution mass spectrometry, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), was used, where the mass of molecules is measured with such accuracy that the elemental composition of individual DBPs can be calculated. A panel of bioassays was used to assess the combined toxic effects from these DBP mixtures. The results show that the formation of these DBPs to a large extent was specific to each water treatment plant and that local conditions influenced DBP formation, based on e.g., the abundance of organic material with certain chemical structures, bromide and disinfection procedure and agent (chlorine or chloramine). The DBPs were detected in both chlorinated and chloraminated water and in all tap water samples, demonstrating that they are part of human exposure. The number of DBP formulae decreased and the DBP composition changed between drinking water treatment and consumer taps, suggesting that DBP exposure to consumers is not necessarily resembling measurements at the treatment plants. Evaluation of new treatment techniques showed that suspended ion exchange and ozonation have potential to decrease the formation and toxic effects of DBPs and that the removal of organic matter can influence qualitative aspects of DBP formation, such as the proportions of chlorine-containing (less toxic) versus bromine-containing (more toxic) DBPs. Through increased knowledge about the role and relevance of non-volatile DBPs, this work can contribute to future monitoring and actions to reduce the health risks associated with DBPs in chlorinated or chloraminated drinking water.
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| 8. |
- Andersson, Anna, et al.
(författare)
-
Waterworks-specific composition of drinking water disinfection by-products
- 2019
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Ingår i: Environmental Science. - Cambridge : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; :5, s. 861-872
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Tidskriftsartikel (refereegranskat)abstract
- Reactions between chemical disinfectants and natural organic matter (NOM) upon drinking water treatment result in formation of potentially harmful disinfection by-products (DBPs). The diversity of DBPs formed is high and a large portion remains unknown. Previous studies have shown that non-volatile DBPs are important, as much of the total toxicity from DBPs has been related to this fraction. To further understand the composition and variation of DBPs associated with this fraction, non-target analysis with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to detect DBPs at four Swedish waterworks using different types of raw water and treatments. Samples were collected five times covering a full year. A common group of DBPs formed at all four waterworks was detected, suggesting a similar pool of DBP precursors in all raw waters that might be related to phenolic moieties. However, the largest proportion (64–92%) of the assigned chlorinated and brominated molecular formulae were unique, i.e. were solely found in one of the four waterworks. In contrast, the compositional variations of NOM in the raw waters and samples collected prior to chemical disinfection were rather limited.This indicated that waterworks-specific DBPs presumably originated from matrix effects at the point of disinfection, primarily explained by differences in bromide levels, disinfectants (chlorine versus chloramine) and different relative abundances of isomers among the NOM compositions studied. The large variation of observed DBPs in the toxicologically relevant non-volatile fraction indicates that non-targeted monitoring strategies might be valuable to ensure relevant DBP monitoring in the future.
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| 9. |
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| 10. |
- Ashiq, Muhammad Jamshaid, 1987-
(författare)
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The occurrence of disinfection by-products in four Swedish drinking waterworks
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Disinfection by-products (DBPs) are unwanted, potentially toxic compounds formed when drinking water is disinfected with chemical disinfectants such as chlorine or chloramine. The levels of DBPs produced depends on parameters, such as levels of natural organic matter (NOM) and the nature and concentration of chemical disinfectant used. In this thesis, the effects of two different types of chemical disinfectants, chlorine and chloramine, are investigated in terms of levels of DBP production. The goal was to investigate if chlorine disinfection produces similar levels and types of DBPs as in case of chloramination.Within the thesis work was also tested a method based on a gas chromatograph coupled with halogen selective detector (GC-XSD) to determine the known DBPs in the drinking water.The results show that the formation of DBPs at chlorine or chloramine disinfection were similar. Still, chloramine is preferably used because it produces less legally regulated DBPs.The GC-XSD worked well for the determination of DBPs in drinking water. Since XSD is very selective and specific towards halogens and easy to operate, therefore this setup not only a potential tool for routine DBPs monitoring at drinking water facilities, but it could also be used for the determination of unknow halogenated compounds.Through increased knowledge in the formation of DBPs and their determination with GC-XSD can contribute to the development of better methods to quantify known and identify unknow halogenated organic compounds in treated drinking water and reduce public exposure to potentially toxic halogenated organic compounds.
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| 11. |
- Bastviken, David, et al.
(författare)
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Chlorine cycling and fates of 36Cl in terrestrial environments
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Chlorine-36 (36Cl), a radioisotope of chlorine (Cl) with a half-life of 301,000 years, is present in some types of nuclear waste and is disposed in repositories for radioactive waste. As the release of 36Cl from such repositories to the near surface environment has to be taken into account it is of interest to predict possible fates of 36Cl under various conditions as a part of the safety assessments of repositories for radioactive waste. This report aims to summarize the state of the art knowledge on Cl cycling in terrestrial environments. The view on Cl cycling in terrestrial environments is changing due to recent research and it is clear that the chloride ion (Cl–) is more reactive than previously believed. We group the major findings in three categories below according to the amount of data in support of the findings.From the result presented in this report it is evident that:There is an ubiquitous and extensive natural chlorination of organic matter in terrestrial ecosystems.The abundance of naturally formed chlorinated organic compounds (Clorg) frequently exceeds the abundance of Cl–, particularly in soils. Thereby Clorg in many cases dominates the total Cl pool.This has important implications for Cl transport. When reaching surface soils Cl– will not be a suitable tracer of water and will instead enter other Cl pools (Clorg and biomass) that prolong residence times in the system.Cl– dominates import and export from terrestrial ecosystems while Clorg and biomass Cl can dominate the standing stock Cl within terrestrial ecosystems.Both Cl and Clorg pools have to be considered separately in future monitoring programs addressing Cl cycling.Further, there are also indications (in need of confirmation by additional studies) that:There is a rapid and large uptake of Cl– by organisms and an accumulation in green plant parts. A surprisingly large proportion of total catchment Cl (up to 60%) can be found in the terrestrial biomass.Emissions of total volatile organohalogens could be a significant export pathway of Cl from the systems.Some of the Clorg may be very persistent and resist degradation better than average organic matter. This may lead to selective preservation of some Clorg (with associated low bioavailability).There is a production of Clorg in tissues of e.g. plants and animals and Cl can accumulate aschlorinated fatty acids in organisms.Most other nevertheless important aspects are largely unknown due to lack of data. Key unknowns include:The development over time of major Cl pools and fluxes. As long as such data is lacking we cannot assess net changes over time.How the precesses behind chlorination, dechlorination and transport patterns in terrestrial systems are regulated and affected by environmental factors.The ecological roles of the chlorine cycling in general.The ecological role of the microbial chlorination in particular.The chlorine cycling in aquatic environments – including Cl– and Clorg pools in sediment and water, are largely missing.Given the limited present information available, and particularly the lack of data with a temporal dimension and the lack of process understanding, predictive models are challenging. We also summarize currently available methods to study Cl in the environment.
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| 12. |
- Benskin, Jonathan, et al.
(författare)
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Manufacturing Origin of Perfluorooctanoate (PFOA) in Atlantic and Canadian Arctic Seawater
- 2012
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 46:2, s. 677-685
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Tidskriftsartikel (refereegranskat)abstract
- The extent to which different manufacturing sources and long-range transport pathways contribute to perfluorooctanoate (PFOA) in the world’s oceans, particularly in remote locations, is widely debated. Here, the relative contribution of historic (i.e., electrochemically fluorinated) and contemporary (i.e., telomer) manufacturing sources was assessed for PFOA in various seawater samples by an established isomer profiling technique. The ratios of individual branched PFOA isomers were indistinguishable from those in authentic historic standards in 93% of the samples examined, indicating that marine processes had little influence on isomer profiles, and that isomer profiling is a valid source apportionment tool for seawater. Eastern Atlantic PFOA was largely (83−98%) of historic origin, but this decreased to only 33% close to the Eastern U.S. seaboard. Similarly, PFOA in the Norwegian Sea was near exclusively historic, but the relative contribution decreased to ∼50% near the Baltic Sea. Such observations of contemporary PFOA in coastal source regions coincided with elevated concentrations, suggesting that the continued production and use of PFOA is currently adding to the marine burden of this contaminant. In the Arctic, a spatial trend was observed whereby PFOA in seawater originating from the Atlantic was predominantly historic (up to 99%), whereas water in the Archipelago (i.e., from the Pacific) was predominantly of contemporary origin (as little as 17% historic). These data help to explain reported temporal and spatial trends from Arctic wildlife biomonitoring, and suggest that the dominant PFOA source(s) to the Pacific and Canadian Arctic Archipelago are either (a) from direct emissions of contemporary PFOA via manufacturing or use in Asia, or (b) from atmospheric transport and oxidation of contemporary PFOA-precursors.
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| 13. |
- Benskin, Jonathan P., et al.
(författare)
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Perfluoroalkyl Acids in the Atlantic and Canadian Arctic Oceans
- 2012
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Ingår i: Environmental Science and Technology. - : American Chemical Society. - 0013-936X .- 1520-5851. ; 46:11, s. 5815-5823
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Tidskriftsartikel (refereegranskat)abstract
- We report here on the spatial distribution of C-4, C-6, and C-8 perfluoroalkyl sulfonates, C-6-C-14 perfluoroalkyl carboxylates, and perfluorooctanesulfonamide in the Atlantic and Arctic Oceans, including previously unstudied coastal waters of North and South America, and the Canadian Arctic Archipelago. Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were typically the dominant perfluoroalkyl acids (PFAAs) in Atlantic water. In the midnorthwest Atlantic/Gulf Stream, sum PFAA concentrations (Sigma PFAAs) were low (77-190 pg/L) but increased rapidly upon crossing into U.S. coastal water (up to 5800 pg/L near Rhode Island). Sigma PFAAs in the northeast Atlantic were highest north of the Canary Islands (280-980 pg/L) and decreased with latitude. In the South Atlantic, concentrations increased near Rio de la Plata (Argentina/Uruguay; 350-540 pg/L Sigma PFAAs), possibly attributable to insecticides containing N-ethyl perfluorooctanesulfonamide, or proximity to Montevideo and Buenos Aires. In all other southern hemisphere locations, Sigma PFAAs were less than210 pg/L. PFOA/PFOS ratios were typically greater than= 1 in the northern hemisphere, similar to 1 near the equator, and less than= 1 in the southern hemisphere. In the Canadian Arctic, Sigma PFAAs ranged from 40 to 250 pg/L, with perfluoroheptanoate, PFOA, and PFOS among the PFAAs detected at the highest concentrations. PFOA/PFOS ratios (typically greater thangreater than1) decreased from Baffin Bay to the Amundsen Gulf; possibly attributable to increased atmospheric inputs. These data help validate global emissions models and contribute to understanding of long-range transport pathways and sources of PFAAs to remote regions.
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| 14. |
- Bidleman, Terry, 1942-, et al.
(författare)
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A review of halogenated natural products in Arctic, Subarctic and Nordic ecosystems
- 2019
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Ingår i: Emerging Contaminants. - : Elsevier. - 2405-6650 .- 2405-6642. ; 5, s. 89-115
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Tidskriftsartikel (refereegranskat)abstract
- Halogenated natural products (HNPs) are organic compounds containing bromine, chlorine, iodine, andrarely fluorine. HNPs comprise many classes of compounds, ranging in complexity from halocarbons tohigher molecular weight compounds, which often contain oxygen and/or nitrogen atoms in addition tohalogens. Many HNPs are biosynthesized by marine bacteria, macroalgae, phytoplankton, tunicates,corals, worms, sponges and other invertebrates. This paper reviews HNPs in Arctic, Subarctic and Nordicecosystems and is based on sections of Chapter 2.16 in the Arctic Monitoring and Assessment Program(AMAP) assessment Chemicals of Emerging Arctic Concern (AMAP, 2017) which deal with the highermolecular weight HNPs. Material is updated and expanded to include more Nordic examples. Much ofthe chapter is devoted to “bromophenolic” HNPs, viz bromophenols (BPs) and transformation productsbromoanisoles (BAs), hydroxylated and methoxylated bromodiphenyl ethers (OH-BDEs, MeO-BDEs) andpolybrominated dibenzo-p-dioxins (PBDDs), since these HNPs are most frequently reported. Othersdiscussed are 2,20-dimethoxy-3,30,5,50-tetrabromobiphenyl (2,20-dimethoxy-BB80), polyhalogenated 10-methyl-1,20-bipyrroles (PMBPs), polyhalogenated 1,10-dimethyl-2,20-bipyrroles (PDBPs), polyhalogenatedN-methylpyrroles (PMPs), polyhalogenated N-methylindoles (PMIs), bromoheptyl- and bromooctylpyrroles, (1R,2S,4R,5R,10E)-2-bromo-1-bromomethyl-1,4-dichloro-5-(20-chloroethenyl)-5-methylcyclohexane (mixed halogenated compound MHC-1), polybrominated hexahydroxanthene derivatives(PBHDs) and polyhalogenated carbazoles (PHCs). Aspects of HNPs covered are physicochemicalproperties, sources and production, transformation processes, concentrations and trends in the physicalenvironment and biota (marine and freshwater). Toxic properties of some HNPs and a discussion of howclimate change might affect HNPs production and distribution are also included. The review concludeswith a summary of research needs to better understand the role of HNPs as “chemicals of emergingArctic concern”.
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| 15. |
- Bidleman, Terry, et al.
(författare)
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Chapter 2: Properties, sources, global fate and transport
- 2013
-
Ingår i: Canadian Arctic Contaminants Assessment Report III 2013. - Ottawa : Northern Contaminants Program, Aboriginal Affairs and Northern Development Canada. - 9781100546520 ; , s. 19-146
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Bokkapitel (refereegranskat)abstract
- Part II of the second Canadian Arctic Contaminants Assessment Report (CACAR-II) began with a section on “Physicochemical Properties of Persistent Organic Pollutants”, which identified key physicochemical (pchem) properties, provided the rationale for their measurement or prediction and tabulated literature citations for chemicals that are of concern to the NCP (Bidleman et al. 2003). The section also discussed temperature dependence of pchem properties and their applications to describing partitioning in the physical environment.There is, and will continue to be, emphasis on predictive approaches to screening chemicals for persistence, bioaccumulation and toxic (PB&T)properties, as well as long-range atmospheric transport (LRAT) potential (Brown and Wania 2008, Czub et al. 2008, Fenner et al. 2005, Gouin andWania 2007, Howard and Muir 2010, Klasmeier et al. 2006, Matthies et al. 2009, Muir and Howard 2006). This has created the need for determining pchem properties of new and emerging chemicals of concern.Predicting gas exchange cycles of legacy persistent organic pollutants (POPs) and new and emerging chemicals of concern places a high demand on the accuracy of pchem properties, particularly the air/water partition coefficient, KAW. Hexachlorocyclohexanes (HCHs) in Arctic Ocean surface waters are close to air-water equilibrium, with excursions toward net volatilization or deposition that vary with location and season (Hargrave et al. 1993, Jantunen et al. 2008a, Lohmann et al. 2009, Su et al. 2006, Wong et al. 2011) while hexachlorobenzene (HCB) (Lohmann et al. 2009, Su et al. 2006, Wong et al. 2011) and some current use pesticides (CUPs) (Wong et al. 2011) are undergoing net deposition. The predicted Arctic Contamination Potential (ACP) for persistent organic chemicals is strongly influenced by ice cover due to its effect on air-water gas exchange (Meyer and Wania 2007).Many advances have taken place and numerous papers have been published since CACAR-II, which present new measurements and predictions of pchem properties. This section does not attempt to provide a comprehensive review of the field, or to compile pchem properties from the many studies. The approach taken is to highlight the reports which are most relevant to polar science, particularly in areas of improving reliability of pchem properties for POPs, improving experimental techniques and comparing predictive methods. The section ends with a discussion of polyparameter linear free energy relationships (pp-LFERs), which goes beyond partitioning descriptions based on single pchem properties by taking into account specific chemical interactions that can take place in airsurface and water-surface exchange processes. A detailed list of chemical names and nomenclature are provided in the Glossary.
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| 16. |
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| 17. |
- Bidleman, Terry, et al.
(författare)
-
Halogenated Natural Products
- 2017
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Ingår i: AMAP Assessment 2016: Chemicals of Emerging Arctic Concern. - Oslo, Norway : AMAP - Arctic Monitoring and Assessment Programme. - 9788279711049 ; , s. 243-267
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Bokkapitel (refereegranskat)
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| 18. |
- Blanck, Hans, 1950, et al.
(författare)
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A retrospective analysis of contamination and periphyton PICT patterns for the antifoulant irgarol 1051, around a small marina on the Swedish west coast
- 2009
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 58:2, s. 230-237
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Tidskriftsartikel (refereegranskat)abstract
- Irgarol is a triazine photosystem II (PSII) inhibitor that has been used in Sweden as an antifouling ingredient since the 1990´s. Early microcosm studies indicated that periphyton was sensitive to irgarol at concentrations regularly found in harbours and marinas. However, field studies of irgarol effects on the Swedish west coast in 1994, using the Pollution-Induced Community Tolerance (PICT) approach, failed to detect any effects of the toxicant in the field. A PICT study involves sampling of replicate communities in a gradient of contamination, and a comparison of their community tolerance levels, with an increase being an indication that sensitive species have been eliminated and replaced by more tolerant ones. Typically, short-term assays are used to quantify the community tolerance levels. Later PICT studies in the same area over a 10 year period demonstrate that irgarol tolerance levels have increased, although the contamination pattern has been stable. Our results support the hypothesis that that the PICT potential was low initially, due to a small differential sensitivity between the community members, and that a persistent selection pressure was required to favour and enrich irgarol tolerant species or genotypes.
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| 19. |
- Bornman, Riana, et al.
(författare)
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DDT in Brest Milk: Intake, Risk, Lactation Duration, and Effect of Gender.
- 2012
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Ingår i: Epidemiology. - : Ovid Technologies (Wolters Kluwer Health). - 1044-3983.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- DDT is annually applied indoors of every dwelling at 64-128 g DDT for malaria vector control. We studied 163 breast milk samples from three DDT-sprayed villages and one reference village in South Africa for the presence and levels of DDT. Mean ?DDT levels in breast milk from the DDT-sprayed villages were 18, 11, and 9.5 mg/kg mf (milk fat) (1.4 mg/kg mf reference village). Primipara mothers from DDT-sprayed villages had significantly higher levels ?DDT in their milk. The highest DDT level in breast milk ever reported from South Africa was detected (5.2 mg/l wm (whole milk) and 140 mg/kg mf). The Maximum Residue Limit (MRL) in milk and Provisional Tolerable Daily Intake (PTDI) for DDT by infants were significantly exceeded in DDT-sprayed villages (maximum exceeded the MRL 310 times, and the PTDI 99 times). The differences between villages indicated differences in exposure and uptake due to application, substrate, and/or culture. The duration of completed lactation was similar for all four villages and DDT exposure had no effect on the duration. There were indications (not significant) that first-born female infants drank milk with higher ?DDT levels than first-born male infants and vice versa for multipara male and female infants. These patterns were evident in each of the DDT-spayed villages, suggesting gender involvement on levels of DDT in breast milk. In view of the high levels recorded, effective measures to reduce DDT exposure are urgently needed, over and above the need to find suitable, safe, and sustainable alternatives.
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| 20. |
- Bornman, Riana, et al.
(författare)
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Household behavioural responses following successful IRS malaria control: Challenges for health education and intervention strategies.
- 2012
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Control of malaria remains one of the world’s chief current public health challenges, particularly in sub-Saharan Africa where malaria is still responsible for 10% of the total disease burden. Mothers, guardians and caregivers of children play a vital role in the prevention, early detection and management of malaria. The general and daily priorities of caregivers living in a malarial area are not well understood, particularly as they have to balance competing social, economic and health constraints. A better understanding of household behaviour with respect to health education is imperative for the reduction of malaria incidence and the success of malaria control strategies. The investigation compared the relative importance assigned by female caregivers in communities under a successful vertically-managed malaria control programme to malaria awareness on the one hand and to social and economic concerns on the other. We conducted interviews with 156 caregivers of children using both open-ended and closed fixed-answer questions. The adult female responsible for the day-to-day care of the children was interviewed 1) in two malarial villages subject to annual indoor residual spraying (IRS) a total of 120 persons (60 in each village), and 2) 36 in a reference non-sprayed village. The mean income was between 27-56% of the national mean, indicating a community under considerable pressure. Male parents were often absent due to work commitments. Unemployment, poverty, crime, and lack of clean water were the main, unprompted, threats, but malaria was volunteered by none. Only when malaria was prompted (caregivers had good knowledge of malaria), did its concern rise to 52% and 38% in the IRS-sprayed villages. Malaria was not a prominent conscious concern and this apparent discrepancy between actual daily and potential future threats significantly increases the difficulty of mobilising communities for preventive action regarding potential threats. Integrated Vector Management (IVM), a multi-sector (central or local government, together with communities) horizontal control program, may be particularly difficult to implement in communities such as these above. Any changes to this effective system will therefore have to take exceptional care not to impact on the effectiveness other than to improve it. Considerations should be given to study the needs requirements of the caregiver as a crucial component of rural community life as their ‘buy-in’ to any new measures will be crucial for success. Our findings should be considered in malaria control strategies, rural policy development, climate change adaptation, and communication strategies.
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| 21. |
- Bouwman, Henk, et al.
(författare)
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DDT : Fifty years since silent spring
- 2013
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Ingår i: Late lessons from early warnings. - Copenhagen : European Environment Agency. - 9789292133498 ; , s. 272-291
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- 'There was a strange stillness. The birds for example — where had they gone? Many people spoke about them, puzzled and disturbed. The feeding stations in the backyards were deserted. The few birds seen anywhere were moribund: they trembled violently and could not fly. It was a spring without voices ... only silence lay over the fields and woods and marsh.'The book Silent Spring by Rachel Carson is mainly about the impacts of chemicals (in particular in particular dichlorodiphenyltrichlorethane also known as DDT) on the environment and human health. Indeed, the close association between humans and birds remains very apt. Representing the only two warm-blooded groups of life on Earth, mammals and birds share the same environments and threats.Carson's claim that she lived in 'an era dominated by industry, in which the right to make a dollar at whatever cost is seldom challenged' still resonates strongly with the problems that societies face all over the world. One chapter heading, 'The obligation to endure', derived from the French biologist and philosopher Jean Rostand's famous observation that, 'the obligation to endure gives us the right to know'. United States President John F. Kennedy responded to the challenge posed by Carson by investigating DDT, leading to its complete ban in the US. The ban was followed by a range of institutions and regulations concerned with environmental issues in the US and elsewhere, driven by public demand for knowledge and protection.DDT was the primary tool used in the first global malaria eradication programme during the 1950s and 1960s. The insecticide is sprayed on the inner walls and ceilings of houses. Malaria has been successfully eliminated from many regions but remains endemic in large parts of the world. DDT remains one of the 12 insecticides — and the only organochlorine compound — currently recommended by the World Health Organization (WHO), and under the Stockholm Convention on Persistent Organic Pollutants, countries may continue to use DDT. Global annual use of DDT for disease vector control is estimated at more than 5 000 tonnes.It is clear that the social conscience awakened by Rachel Carson 50 years ago gave momentum to a groundswell of actions and interventions that are slowly but steadily making inroads at myriad levels. Chapter 17 of her book, 'The other road' reminds the reader of the opportunities that should have been seized much earlier. With more than 10 % of bird species worldwide now threatened in one way or another, it is clear that we missed early warnings or failed to act on them. Will we continue to miss signposts to 'other roads'? Are our obligations to endure met by our rights to know? As Carson said 50 years ago: 'The choice, after all, is ours to make.'
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| 22. |
- Bouwman, Hindrik, et al.
(författare)
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DDT and Malaria Prevention: Addressing the Paradox
- 2011
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 119:6, s. 744-747
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Tidskriftsartikel (refereegranskat)abstract
- Background: The debate regarding dichlorodiphenyltrichloroethane (DDT) in malaria prevention and human health is polarized and can be classified into three positions: anti-DDT, centrist-DDT, pro-DDT.Objective: We attempted to arrive at a synthesis by matching a series of questions on the use of DDT for indoor residual spraying (IRS) with literature and insights, and to identify options and opportunities.Discussion: Overall, community health is significantly improved through all available malaria control measures, which include IRS with DDT. Is DDT “good”? Yes, because it has saved many lives. Is DDT safe as used in IRS? Recent publications have increasingly raised concerns about the health implications of DDT. Therefore, an unqualified statement that DDT used in IRS is safe is untenable. Are inhabitants and applicators exposed? Yes, and to high levels. Should DDT be used? The fact that DDT is “good” because it saves lives, and “not safe” because it has health and environmental consequences, raises ethical issues. The evidence of adverse human health effects due to DDT is mounting. However, under certain circumstances, malaria control using DDT cannot yet be halted. Therefore, the continued use of DDT poses a paradox recognized by a centrist-DDT position. At the very least, it is now time to invoke precaution. Precautionary actions could include use and exposure reduction.Conclusions: There are situations where DDT will provide the best achievable health benefit, but maintaining that DDT is safe ignores the cumulative indications of many studies. In such situations, addressing the paradox from a centrist-DDT position and invoking precaution will help design choices for healthier lives.
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