On the fate of triclosan in humans

Triclosan is a chlorinated organic compound which, due to its antibacterial properties in vitro, has found widespread use in a variety of products such as textiles, plastics and healthcare products. Humans are directly and chronically exposed to triclosan via dermal and mucosal contact from soap and toothpaste, upon which triclosan is rapidly absorbed into the body. Owing to the hydroxyl group on triclosan and the quick phase II metabolism, the turnover of triclosan in the human body is relatively fast and the plasma half life is less than a day. Nevertheless, triclosan has been found in human blood plasma and milk. A cause for concern in this regard, is that in vitro and in vivo animal studies show that triclosan is able to exert adverse effects on hormone homeostasis and metabolic mechanisms, connected to a diverse array of possible toxicological endpoints. Before this work began, the information about the exposure to triclosan in humans was scarce. Furthermore, the methods for analyzing triclosan in human body fluids lacked sensitivity. There was a need to identify the main sources of triclosan in humans and to investigate the exposure to triclosan in different subgroups of human populations. Also, the fact that triclosan had been found in human plasma warranted further study to examine the transfer rate of triclosan from plasma to milk, and to elucidate if breast milk is a significant source of triclosan to infants. In addition, there was a clear need to study if the in vivo triclosan exposure in humans had an impact on cytochrome P450 3A4 enzyme activity and/or thyroid hormone homeostasis. The scope of this thesis was to contribute to filling these knowledge gaps. Study I describes a sensitive and precise method for the analysis of triclosan in human body fluids, enabling the study of background levels of triclosan. Study II showed that triclosan was omnipresent in plasma and milk from Swedish nursing mothers, and that the level of exposure was highly correlated to the use of triclosan containing personal care products. The transfer rate of triclosan from plasma to milk was low, and the risk of adverse effects from triclosan exposure of the breastfed infant via the milk was judged to be negligible. The results from Study III showed that, apart from some small gender and age variations, the exposure was quite homogenous among serum pools of different genders, ages, regional cohorts and sampling years from the Australian population. Study IV showed that the in vivo exposure to triclosan via toothpaste in humans is not likely to change cytochrome P450 3A4 enzyme activity and/or thyroid hormone homeostasis. While this work shows that there is widespread human exposure to triclosan as a result of the use of triclosan containing personal care products, more research is needed to assess potential negative effects thereof

Screening of platinum group elements and silver in the Swedish environment

Inom ramen för nationell miljöövervakning har en screeningundersökning genomförts avseende metallerna platina, palladium, rhodium och silver. Andra metaller såsom cerium och koppar ingick också i studien. Undersökningen syftade främst till: - Att beskriva förekomsten av platina, palladium, rhodium och silver i bakgrundsområden och i urbana områden i Sverige, genom analys av sediment, ytvatten, dagvatten, avloppsvatten, slam och fisk. - Att bedöma om halterna av dessa metaller är förhöjda i urbana miljöer relativt bakgrundsområden. - Att översiktligt bedöma om halterna förändrats under de senaste årtiondena. - Att bedöma human exponeringA screening environmental monitoring study was performed on platinum, palladium, rhodium and silver. Other metals such as cerium and copper was also included. The study is part of the national environmental monitoring program run by the Swedish EPA. The major goals of the study were: q To provide new data on the environmental levels of platinum groups elements and silver in urban and background areas in Sweden through analysis of sediments, surface water, stormwater, waste water, sludge and fish. q To assess whether levels are higher in urban areas compared to rural areas. q To assess whether there are indications of time trends. q To assess human exposure. The study consists of a national programme (60 samples) and three regional programs (14 samples). Major matrices were sediments and urine. There were no pronounced indications that background lakes were affected by anthropogenic emissions of Pt, Pd or Rh. For silver, sediment concentrations indicate a possible increase in background lakes over the last decade or two. Data is however too limited to state this as a general phenomenon. To elicudate possible emission sources analyses were performed on stormwater, urban runoff pond sediments, sewage sludge and waste water effluents. Platinum, Rh and Pd were enriched in stormwaters and runoff pond sediments, in agreement with road traffic as a major emission source of these metals. Data also consistently show that muncipal waste waters were enriched in Pt relative to the composition of stormwaters. The medical use of Pt is a suggested explanation. In ten recipients affected by urban emissions or road traffic, sediment levels of Pd, Pt, Rh and Ag were generally higher than background levels. The platinum group elements (PGE) profile in these sediments were compared to the profiles for waste water effluent and stormwaters, respectively. Although several of these recipients were recipients to municipal waste water treatment plants, most sediments show profiles similar to stormwater. This indicates that vehicle catalysts still is the major source of Pt, Pd and Rh to these recipients. Surface water and fish were also analysed from a few of these urban recipients. Palladium concentrations were detected in urban surface waters, but neither Pt, Rh nor Ag were detected. Fish (perch) from these sites did not display concentrations of Pd, Pt or Rh above the analytical reporting limit. Silver in these fish samples occurred in similar or lower concentrations than in the background lakes. To assess time trends, fish from background lakes sampled in 1985, 2000 and 2014 were analysed. Furthermore sediment from both background lakes and urban lakes were analysed at several depths, corresponding to at least the last 2-3 decades. Overall there were no indications of pronounced time trends. None of the PGEs were detected in human urine from 20 individuals, except for two observations of platinum. Silver was detected in ca 50% of the urine samples and levels were similar to a 15 year old study. The overall assessment of the data in this study is that neither Pt, Pd, Rh nor Ag give rise to a concern for ecotoxicological effects. It should though be considered that although some ecotoxicological data exist, effect criteria for the PGEs have not been established and the monitoring data presented are limited

Screening av organiska föroreningar i slambehandlad åkermark

Spridning av organiska miljögifter i åkermark från användning av slam från reningsverk somgödningsmedel har studerats i en screeningstudie åt Naturvårdsverket. Huvudsakliga syftet med utredningen är att: - Insamla miljödata på organiska föroreningar i jord och biota från åkermark gödslad med slam från reningsverk. - Utvärdera uppmätta halter av organiska föroreningar mot tidigare resultat och modelluppskattningar. Studien utgörs av ett nationellt program med totalt 48 prover. Prover insamlades från två fältförsök i Skåne: Igelösa och Petersborg, och två privata fält, Taxinge och ”Sörmland”. Huvudsaklig matris var jord (n=42), men även prover av slam (n=2), gröda (n=3) och mask (n=1) har ingått i studien. Undersökningen visar att PFOS, PBDE (47, 99, 100 and 209), galaxolid, tonalid och DEHP anrikas i jord behandlad med slam. Det finns även enstaka indikationer på att halter av DIDP, nonylfenol och TCPP kan öka, men dessa observationer är osäkra eftersom de inte är vanligt förekommande. Jämförelse mellan modellberäkningar och fältdata visar på bra överensstämmelse när det gäller PFOS och BDE-209 d.v.s. dessa ämnen ackumuleras i jorden över tid vid upprepad slambehandling. De ämnen som generellt inte detekteras, alkylfenoler, dibutylftalat och LAS, stämmer också bra överens med tidigare uppskattningar och mätresultat. I kärnor från höstvete provtaget vid Petersborg detekterades ingen av de analyserade organiska ämnena. Resultatet stödjer tidigare modellberäkningar och upptagsstudier: ackumulationen av många organiska ämnen från jord till gröda är begränsad. I mask från Taxingefältet påträffades PFOS och PBDE (47, 99 och 100) i detekterbara halter, vilket visar att dessa ämnen kan bioackumuleras i biota. Beräknade bioackumulationsfaktorer (BSAF) från jord till biota ligger i linje med tidigare resultat. Riskkarakteriseringen för jordekosystem och människor exponerade via intag av grödor visar att halter i jord efter lång tids gödsling med slam inte utgör en riskAn environmental screening study was performed on organic pollutants in arable land where municipal sewage sludge is used as fertiliser. The study is part of the national environmental monitoring program run by the Swedish EPA. The major goals of the study were to: q Provide data on environmental levels of organic contaminants in soil and biota from arable land amended with sewage sludge. q Evaluate measured field levels of organic contaminants against previous results and model predictions. The study consists of a national program with a total of 48 samples. Samples were collected from two experimental arable fields in Skåne: Igelösa and Petersborg, and two private farm fields, Taxinge and “Sörmland”. The three first fields represent long time sewage sludge addition and the last field a first time sludge addition. Major matrix was soil (n=42), but also samples of sewage sludge (n=2), crops (n=3) and earthworms (n=1) were studied. The following substance groups were studied in all matrices except of earthworms; phthalates, LAS, alkylphenols, antibacterial substances (triclosan, triclocarban), musk compounds, organophosphates, perfluoroalkyls (PFOS, PFOA) and brominated flame retardants (PBDE). Musk compounds, perfluoroalkyls and brominated flame retardants were studied in earthworms. The study shows that PFOS, PBDE (47, 99, 100 and 209), galaxolide, tonalide and DEHP are enriched in sludge amended soils, as compared to control soils. There are also single indications that concentrations of DIDP, nonylphenol and TCPP may increase, but these observations are uncertain as they are not generally observed. The results indicate that the concentrations of certain contaminants increase with increasing sludge addition rate and that the impact primarily, but not exclusively, is in the upper most soil layers (0-0,3 m). Simple mass balance demonstrates that single additions of sludge will for many substances result in soil concentrations so low (sub μg/kg dw) that they cannot be detected at the analytical reporting limits used. When comparing model predictions with the present field data, PFOS and BDE-209 behaves as expected, i.e. they accumulate in soil upon repeated applications of sludge over time. The general non-detects of alkylphenols, dibutylphthalate and LAS are also in agreement with predictions and earlier findings. The non-detects of organophosphates is difficult to evaluate because of relatively high analytical reporting limits compared to maximum expected levels. The general presence of galaxolide in the present sludge amended soils is however in contrast to model predictions. At three sites, galaxolide is enriched in amended soils relative to control fields. Whether galaxolide accumulates or not, following repeated applications, cannot be assessed from this data due to contradictory results. Earlier model predictions and degradation studies do, however, suggest that galaxolide should not accumulate but persist for about one year

Riskbedömning av fosforrika fraktioner vid återförseltill åker- och skogsmark samt vid anläggandeav etableringsskikt

Fosfor är en ändlig resurs och ett nationellt mål är att återföra fosfor från avloppet till jordbruksmarken. Det finns även andra fosforrika material som kan återföras till jordbruksmarken, och som i vissa fall redan gör det. Exempel på fosforrika material är slam från kommunala avloppsreningsverk, stallgödsel och rötat livsmedelsavfall. Till varierande grad innehåller dessa material oönskade och toxiska ämnen, dvs metaller och organiska föroreningar inklusive läkemedel. Fosforåterföring medför således en risk för att jordbruksmarken förorenas och att risker för hälsa eller miljö kan uppkomma. Fosforåterföring sker även vid skapande av växtetableringsskikt inom anläggningsarbeten, och det förekommer försök att gödsla skogsmark med slam. Denna utredning har med modellberäkningar utvärderat risker för långsiktig förorening av jordbruks- och skogsmark samt risker för att toxiska effekter på hälsa eller miljö kan uppkomma. Utredningen har även inkluderat bedömning av toxiska effekter på hälsa och miljö för ett etableringsskikt. Resultaten utgör underlag för Naturvårdsverkets arbete med att utforma en förordning för fosforåterföring, särskilt vad gäller behov och utformning av gränsvärden för oönskade ämnen. I samråd med Naturvårdsverket, Kemikalieinspektionen och Livsmedelsverket har 9 metaller och 18 organiska ämnen valts ut. Som komplettering av tidigare riskbedömning ingår dessutom LAS, DEHP, nonylfenol, oktylfenol, PAH och PBDE för ytvatten, samt för skogsmark och växtetableringsskikt

Triclosan in individual human milk samples from Australia

Triclosan is a chlorinated phenol ether that has been in widespread use as a broad-spectrum antibacterial agent for four decades. When compared to the limited international data available on human body burden of triclosan, results from a pooled blood study suggested that triclosan concentrations in Australia were a factor two higher than observed in Sweden. This study determined triclosan levels in individual human milk samples (n = 151) collected between 2002 and 2005 from primiparous Australian mothers. It provided the first report of population triclosan levels and individual variation in Australia and gave a measure of infant exposure via breast feeding. The distribution of triclosan concentration was positively skewed, with 7.2% of the samples below the LOQ 66% with a concentration of less than or equal to 1.0 ng g(-1) fresh weight and the remaining samples above 1 ng g(-1) reaching a maximum concentration of 19 ng g(-1) fresh weight. The mean and median triclosan concentrations were 1.3 +/- 2.7 ng g(-1) f.w. and 0.26 ng g(-1) f.w., respectively. The results of this study showed high variability in triclosan concentrations between individuals and no correlations with maternal age (p = 0.094), maternal weight (p = 0.971) or infant age at the time of sample collection (p = 0.621). A large number of samples contained low or non-quantifiable concentrations of triclosan and so, in Australia, ubiquitous background exposure due to environmental sources is low. This means that body burden can be influenced by an individual's use of triclosan containing product. Given that triclosan containing product use is continuing, it is important that monitoring in both humans and the environment is continued and that triclosan containing products are adequately labeled so that an individual can choose to avoid exposure. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved