60 research outputs found
Bioaccumulation, ecological effects and monitoring of PFAS in aquatic ecosystems
No full textAbstract: Per- and polyfluoroalkyl substances (PFAS) have become a major environmental concern due to their persistence, bioaccumulation potential, and toxicity. Originally valued for their exceptional chemical stability and widespread industrial applications, PFAS are now recognized as pervasive pollutants that pose significant ecological and human health risks. Despite increasing regulatory attention, knowledge gaps remain regarding their environmental distribution, bioavailability, and impact on aquatic ecosystems. This thesis investigates PFAS contamination across diverse aquatic environments, aiming to enhance understanding of their bioaccumulation pathways, ecological effects, and implications for regulatory frameworks. By examining PFAS distribution in marine, estuarine, and freshwater systems, this research highlights key factors influencing their presence in biota. In marine species from the Belgian North Sea, PFOS emerged as the dominant compound detected in liver and muscle tissues. Elevated concentrations in certain fish and crustaceans raised concerns over both ecological risks and potential human health hazards from seafood consumption. In the Scheldt River, a crucial industrial and ecological corridor, legacy PFAS were found to be evenly distributed, while alternative compounds were concentrated near industrial sites, reflecting recent emissions. Stable isotope analysis provided valuable insights into how habitat use and feeding preferences of fish and invertebrates influence PFAS bioaccumulation. The findings revealed that pelagic species, which primarily feed in the water column, predominantly accumulated water-soluble alternative PFAS, while benthic species, which inhabit and feed near the sediment, showed higher concentrations of sediment-associated legacy compounds. To improve biomonitoring strategies, this study explored the use of Asian clams and zebra mussels as active biomonitors, demonstrating their ability to accumulate PFAS even when these substances remained undetected in water and sediment samples. Biomarker analysis suggested that PFAS exposure could induce oxidative stress, potentially affecting organism health. Expanding the investigation to small freshwater systems, the study linked PFAS bioaccumulation in invertebrates to declines in ecological water quality. By estimating threshold body burdens beyond which ecological integrity is compromised, this work provides critical insights to protect aquatic organisms at the community level. The findings underscore the widespread bioaccumulation of PFAS, reinforcing the need for enhanced monitoring programs and regulatory measures. By integrating ecotoxicological research with field-based biomonitoring, this research contributes to the scientific foundation necessary for developing more effective mitigation strategies, ultimately supporting the protection of aquatic biodiversity and the long-term sustainability of water resources
Toxicity of Perfluoralkyl Substances (PFASs) to terrestrial invertebrates and songbirds
No full textAbstract: Environmental pollution is coeval with the appearance of humans and the global impact of environmental pollution has been reported for multiple contaminants. However, still little is known about the recently produced and detected perfluoroalkylated substances (PFAS). PFAS are chemicals which have been detected globally as a result of their production and use in multiple consumer products. They are highly persistent and bioaccumulative and hence end up in all compartments of the ecosystem in which they may cause detrimental effects. During my PhD, we investigated the exposure of PFAS on terrestrial invertebrates and songbirds along a distance gradient from a well-known fluorochemical hotspot near Antwerp. In addition, we determined their accumulation and potential effects on reproduction and oxidative status in songbirds. Furthermore, the transfer throughout the food chain was investigated in order to understand the exposure pathways of PFAS. Finally, we examined the role of soil physicochemical properties on the sorption of PFAS to the soil and hence the bioavailability to biota
Distribution of perfluorinated compounds (PFASs) in the aquatic environment of the industrially polluted Vaal River, South Africa
No full textAbstract: Perfluorinated alkyl substances (PFASs) are highly persistent chemicals, which have a bioaccumulative potential and can be found in wildlife around the world. Although multiple studies have been performed on PFASs pollution of the aquatic environment, little is known on PFASs pollution on the African continent and their possible risks for human health. In the present study, we examined the distribution of 15 PFASs in fish, invertebrates, sediment and water, collected at three sites, representing a gradient of industrial and mining pollution, along the Vaal River, South Africa. Furthermore, possible risks for human health through consumption of contaminated fish were examined. Perfluorooctane sulfonate (PFOS) was the most dominant PFAS measured in biota, whereas perfluoropentanoic acid (PFPeA) was measured in higher concentrations in water. Mean PFAS concentrations in water ranged from <LOQ to 38.5 ng/L. PFAS concentrations in water decreased along the gradient and were similar or lower compared to other studies in Europe, Asia and America. PFAS measurements in sediment were <LOQ, with the exception of PFOS at Thabela Thabeng (2.36 ng/g dry weight (dw)). Average 11PFAS concentrations in biota increased along the gradient and ranged from <LOQ to 34.5 ng/g wet weight (ww) in invertebrates, <LOQ to 289 ng/g ww in liver and <LOQ to 34.0 ng/g ww in muscle tissue. Although PFOS concentrations were relatively high compared to literature, concentrations of other PFASs were rather low. A potential risk for humans through consumption of PFAS-contaminated fish was assessed. Tolerable daily intake values (grams of fish that can be eaten daily without risking health effects) were much lower than the average South African fish consumption per day, implying a potential risk for human health through consumption of PFAS contaminated fish
Temporal trends in PFAS concentrations in livers of a terrestrial raptor (common buzzard; Buteo buteo) collected in Belgium during the period 2000\u20132005 and in 2021
No full textAbstract: Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals that have been globally distributed. Biological time series data suggest variation in temporal PFAS concentrations due to regulations and the phase-out of multiple PFAS analytes. Nonetheless, biomonitoring temporal trends of PFAS concentrations in raptors has only been done sporadically in Europe at a national scale. In the present study, we examined the concentrations of 28 PFAS in livers of common buzzard (Buteo buteo) collected in Belgium in the period 2000\u20132005 and in 2021. Despite the regulations and phase-out, the \u3a3PFAS concentrations remained similar in the livers over the past 20 years. However, over time the abundance of perfluorooctane sulfonate (PFOS), dominant in livers collected in 2000\u20132005, to the \u3a3PFAS concentration decreased from 46% to 27%, whereas the abundance of perfluorotetradecanoic acid (PFTeDA), dominant in 2021, increased from 19% to 43%. The PFOS concentrations in the present study did not exceed the Toxicity Reference Values (TRVs), which were determined in liver on the characteristics of an avian top predator. The absence of temporal changes in PFAS concentrations is hypothesized to be due to a lagged response in environmental concentrations compared to atmospheric concentrations
Monitoring van KRW chemische stoffen in biota uit waterlopen van vier Nederlandse Waterschappen
No full textAbstract: Micropolluenten in het aquatische milieu kunnen een sterke druk uitoefenen op het aquatisch ecosysteem. Zeker in hoge geaccumuleerde concentraties kunnen ze schadelijk zijn voor waterorganismen en zelfs een risico vormen voor menselijke gezondheid bij bijvoorbeeld consumptie van vis. Ieder lidstaat van de Europese Unie wordt door de Europese Kaderrichtlijn Water (KRW) aangezet om bepaalde chemische stoffen in het aquatische milieu te monitoren en te vergelijken met de milieukwaliteitsnormen. De meeste van die stoffen worden gemeten water en/of sediment. Sommige stoffen zijn echter heel slecht oplosbaar in water (hydrofoob) en daardoor niet of moeilijk meetbaar in water. De Europese Commissie heeft daarom een aantal prioritaire stoffen vastgelegd waarvoor biotanormen werden geformuleerd en die dus in aquatische biota gemeten moeten worden. Deze dienen in vis gemeten te worden, behalve de PAK\u2019s die in zoetwaterbivalven of kreeftachtigen moeten worden gemeten
Stadsparkvijver als pilootproject voor veilige herinfiltratie van PFAS-houdend bemalingswater
No full textAbstract: Het herinfiltratieproject Den Bell/Stadsparkvijver is strategisch belangrijk om verschillende redenen. De vijver in het Stadspark had het afgelopen decennium bijzonder sterk te lijden onder de verschillende bemalingen in de omgeving en viel in bepaalde periodes zelfs droog. Vanaf de zomer van 2021 raakte het herinfiltratieproject echter ernstig gehypothekeerd door de vaststelling van per- en polyfluoroalkylstoffen (PFAS) in het bemalingswater van Den Bell. Het voorstel van deze studie is om rond het herinfiltratieproject Den Bell/stadsparkvijver een pilootproject op te zetten dat de mogelijkheden van fytoremedi\uebring en sorptie in een stedelijke context onderzoekt, en waarbij het duurzaam voeden van de vijver meer gewaarborgd wordt. Het aanvoeren van het bemalingswater lijkt uit de resultaten van het huidige rapport wel degelijk een invloed te hebben op de PFAS concentraties die zich bevinden in de verschillende matrices die werden gemeten tijdens het project. Desondanks blijkt er uit de huidige resultaten geen directe invloed te zijn op de MMIF, maar het wordt toch aanbevolen om deze waterkwaliteit te blijven opvolgen aangezien de duur van het project slechts beperkt was, en er dus mogelijks onvoldoende tijd was om reeds een effect te kunnen hebben op de waterkwaliteit, en dus de aanwezige biota. Aangezien de MMIF gedurende het hele project tussen de 0.55-0.6 lag, is het nodig om na te gaan hoe deze kwaliteit kan worden verbeterd (evt. met monitoring van andere polluenten en nutri\uebnten). Verder zou fytoremediatie een mogelijke oplossing kunnen bieden bij het verlagen van de PFAS-concentraties in de vijver. Uit de huidige studie bleek dat riet minder polluenten accumuleert in vergelijking met watermunt, waardoor watermunt een betere optie lijkt te zijn om in te zetten bij fytoremediatie. Hierbij is het belangrijk dat het plant-afval na het oogsten op een correcte manier wordt afgevoerd, om te voorkomen dat deze polluenten opnieuw in het milieu terecht zouden komen. Eventuele andere pistes (bv. floating wetlands, andere vegetatie) zouden ook nog verder onderzocht kunnen worden, om na te gaan of zo het fytoremediatiepotentieel in de vijver nog kan toenemen, aangezien watermunt slechts ondiep zal wortelen
Aquatic macroinvertebrate community responses to pollution of perfluoroalkyl substances (PFAS) : can we define threshold body burdens?
No full textAbstract: The pollution of per- and polyfluorinated alkyl substances (PFAS) in aquatic environments is a worldwide concern of which the ecological impact is still not well understood. Especially field-based effect studies in aquatic ecosystems are generally lacking, creating a knowledge gap that goes along with monitoring and regulatory challenges. Therefore, this study examined if bioaccumulated PFAS concentrations could be related to ecological responses assessed by changes in the macroinvertebrate community structure. In addition, threshold body burdens that are protective of ecological damage were estimated. Aquatic macroinvertebrates were sampled in 30 streams across Flanders (Belgium) and 28 PFAS target analytes were measured in three resident taxa (Gammarus sp., Asellus sp. and Chironomus sp.) and translocated zebra mussels (Dreissena polymorpha). The macroinvertebrate community structure was assessed by calculating the Multimetric Macroinvertebrate Index Flanders (MMIF). Primarily long-chain perfluorinated carboxylic acids (PFCAs) were detected in both resident taxa (passive biomonitoring) and zebra mussels (active biomonitoring). Based on a 90th quantile regression model, safe threshold body burdens could be calculated for PFTeDA (7.1 ng/g ww) and \u3a3PFAS (2264 ng/g ww) in Gammarus sp. and for PFOA (5.5 ng/g ww), PFDoDA (1.7 ng/g ww), PFTrDA (0.51 ng/g ww), PFTeDA (2.4 ng/g ww), PFOS (644 ng/g ww) and \u3a3PFAS (133 ng/g ww) in zebra mussel. An additional threshold value was calculated for most compounds and species using the 95th percentile method. However, although these estimated thresholds are pertinent and indicative, regulatory applicability requires further lines of evidence and validation. Nevertheless, this study offers first-time evidence of associations between accumulated PFAS concentrations in invertebrates and a reduced ecological water quality in terms of macroinvertebrate community structure and highlights the potential of Gammarus sp. and zebra mussels to serve as reliable PFAS biomonitoring species
Do concentrations of perfluoroalkylated acids (PFAAs) in isopods reflect concentrations in soil and songbirds? A study using a distance gradient from a fluorochemical plant
No full textAbstract: Perfluoroalkylated acids (PFAAs) are persistent chemicals that have been detected globally in the environment and in wildlife. Although it is known that PFAAs sorb to solid matrices, little is known on PFAA concentrations in soils. PFAA pollution has often been studied in aquatic invertebrates. However, this has rarely been done on terrestrial species. In the present study, we examined whether the concentrations of 15 PFAAs in isopods (Oniscidae), collected at a fluorochemical plant and in four other areas, representing a gradient in distance from the pollution source (1\u202fkm to 11\u202fkm), were related to those in the soil and in eggs of a songbird, the great tit (Parus major), collected in the same areas. Additionally, we examined the effect of physicochemical properties such as total organic carbon (TOC) and clay content on the relationship between the concentrations in soil and isopods. Finally, we examined the composition profile in the soil and isopods. Mean PFOS and PFOA concentrations of 1700\u202fng/g dw and 24\u202fng/g dw were detected in the soil at the plant. PFOS and PFPeA were the dominant PFAAs in isopods and were detected at mean concentrations of 253 and 108\u202fng/g ww, respectively. The great tit eggs showed elevated mean PFOS concentrations of 55,970\u202fng/g ww. In most cases, PFAA concentrations decreased with increasing distance from the plant. As PFAA concentrations in isopods were correlated with concentrations in the soils, isopods could serve as a bioindicator for PFAA concentrations in soils. Additionally, there were indications that isopods could also serve as a bioindicator for PFAA concentrations in eggs of great tits. However, these indications were only the case at two locations, showing the need to further monitor the possibilities of using isopods as a bioindicator for PFAA concentrations in song bird eggs. Capsule Elevated PFAA concentrations in isopods reflected concentrations in songbird eggs and in soil, indicating that trophic transfer of PFAAs from soil, via isopods, to songbirds might play a role in the PFAA exposure of terrestrial songbirds
Are Feathers of a Songbird Model Species (The Great Tit, Parus major) Suitable for Monitoring Perfluoroalkyl Acids (PFAAs) in Blood Plasma?
No full textAbstract: Feathers have been shown to be useful in the biomonitoring of environmental contaminants, such as 20 metals and persistent organic pollutants. However, little is known regarding the levels of perfluoroalkyl 21 acids (PFAAs) in feathers and the applicability of these structures for the biomonitoring of these 22 compounds. In the present study, we report the extent to which feathers are suitable for monitoring PFAA 23 concentrations in the blood plasma of an insectivorous songbird model species, the great tit (Parus major), 24 settled at and in the vicinity of a fluorochemical plant in Antwerp, Belgium. For most of the target analytes 25 (out of the 15 investigated), the feather PFAA concentrations near the plant are the highest ever reported 26 in free-living birds. As PFAA concentrations did not differ in the adjacent sites, no pollution gradient with 27 distance from the plant was observed. In addition, the PFAA concentrations were not associated with the 28 age and sex of the birds. Perfluorooctanoic acid (PFOA) concentrations were significantly higher in P. 29 major feathers than in blood plasma, but for most other PFAAs, these differences were not observed. The 30 concentrations of perfluorooctane sulfonate (PFOS) and PFOA in P. major feathers and plasma were 31 significantly and positively correlated when combining data from all sites but often not at individual sites. 32 This result was likely caused by lower sample sizes at the individual sites and the use of matrices that 33 represent different time periods. Our results suggest that P. major feathers cannot be used to estimate 34 PFOA and PFOS concentrations in blood plasma, except when there is a great deal of variation in pollutant 35 concentrations among sites/individual birds. Both matrices represent different time frames, providing 36 complementary information on environmental PFAA concentrations, as illustrated by the observation that 37 more PFAA compounds could be detected in P. major feathers than in blood plasma
Per- and polyfluoroalkyl substances (PFAS) in homegrown crops : accumulation and human risk assessment
No full textAbstract: Homegrown crops can present a significant exposure source of per- and polyfluoroalkyl substances (PFAS) to humans. Field studies studying PFAS accumulation in multiple vegetable food categories and examining the potential influence of soil characteristics on vegetable bioavailability under realistic exposure conditions are very scarce. Crop PFAS accumulation depends on a complex combination of factors. The physicochemical differences among the numerous PFAS makes risk assessment very challenging. Thus, simplification of this complexity into key factors that govern crop PFAS accumulation is critical. This study analyzed 29 targeted legacy, precursor and emerging PFAS in the vertical soil profile (0\u201345 cm depth), rainwater and edible crop parts of 88 private gardens, at different distances from a major fluorochemical plant. Gardens closer to the plant site showed higher soil concentrations which could be linked with historical and recent industrial emissions. Most compounds showed little variation along the soil depth profile, regardless of the distance from the plant site, which could be due to gardening practices. Annual crops consistently accumulated higher sum PFAS concentrations than perennials. Highest concentrations were observed in vegetables, followed by fruits and walnuts. Single soil-crop relationships were weak, which indicated that other factors (e.g., porewater) may be better measures of bioavailability in homegrown crop accumulation. Regression models, which additionally considered soil characteristics showed limited predictive power (all R2 64 35%), possibly due to low variability in crop concentrations. Human intake estimations revealed that the PFAS exposure risk via crop consumption was similar nearby and remotely from the plant site, although the contribution to the overall dietary exposure can be relatively large. The tolerable weekly intake was frequently exceeded with respect to fruit and vegetable consumption, thus potential health risks cannot be ruled out
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