Dynamic spatiotemporal changes of per- and polyfluoroalkyl substances (PFAS) in soil and eggs of private gardens at different distances from a fluorochemical plant.

Homegrown food serves as an important human exposure source of per- and polyfluoroalkyl substances (PFAS), yet little is known about their spatiotemporal distribution within and among private gardens. This knowledge is essential for more accurate site-specific risk assessment, identification of new sources and evaluating the effectiveness of regulations. The present study evaluated spatiotemporal changes of legacy and emerging PFAS in surface soil from vegetable gardens (N = 78) and chicken enclosures (N = 102), as well as in homegrown eggs (N = 134) of private gardens, across the Province of Antwerp (Belgium). Hereby, the potential influence of the wind orientation and distance towards a major fluorochemical plant was examined. The ∑short-chain PFAS and precursor concentrations were higher in vegetable garden soil (8.68 ng/g dry weight (dw)) compared to chicken enclosure soil (4.43 ng/g dw) and homegrown eggs (0.77 ng/g wet weight (ww)), while long-chain sulfonates and C11-14 carboxylates showed the opposite trend. Short-term (2018/2019-2022) changes were mostly absent in vegetable garden soil, while changes in chicken enclosure soils oriented S-SW nearby (<4 km) the fluorochemical plant were characterized by a local, high-concentration plume. Moreover, soil from chicken enclosures oriented SE and remotely from the plant site was characterized by a widespread, diffuse but relatively low-concentration plume. Long-term data (2010-2022) suggest that phaseout and regulatory measures have been effective, as PFOS concentrations nearby the fluorochemical plant in soil and eggs have declined from 25.8 to 2.86 ng/g dw and from 528 to 39.4 ng/g ww, respectively. However, PFOS and PFOA concentrations have remained largely stable within this timeframe in gardens remotely from the plant site, warranting further rapid regulation and remediation measures. Future monitoring efforts are needed to allow long-term comparison for multiple PFAS and better distinction from potential confounding variables, such as variable emission outputs and variability in wind patterns.

Aquatic macroinvertebrate community responses to pollution of perfluoroalkyl substances (PFAS): Can we define threshold body burdens?

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 ΣPFAS (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 ΣPFAS (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.

Assessing the trophic ecology and migration on the exposure of cape petrels and Wilson's storm petrels from Antarctica to perfluoroalkylated substances, trace and major elements.

Chemical pollution is a global concern as contaminants are transported and reach even the remote regions of Antarctica. Seabirds serve as important sentinels of pollution due to their high trophic position and wide distribution. This study examines the influence of migration and trophic ecology on the exposure of two Antarctic seabirds, Wilson's storm petrel (Oceanites oceanicus - Ooc), and Cape petrel (Daption capense - Dca), to chemical elements and perfluoroalkyl substances (PFAS). Our methodology involved assessing the concentration of these pollutants in feather samples obtained from carcasses, offering a practical means for monitoring contamination. Trace and major element concentrations were comparable in both species, suggesting that migratory patterns have a minimal impact on exposure levels. However, Ooc had higher concentration of PFAS compared to Dca (mean, ng g-1dry weight, PFOA: Ooc:0.710, Dca:0.170; PFTrDA: Ooc:0.550, Dca:0.360, and PFTeDA: Ooc:1.01, Dca:0.190), indicating that migration to the more polluted Northern Hemisphere significantly affects PFAS exposure. Furthermore, while no strong associations were found between either trace elements or PFAS and the three stable isotopes (δ13C, δ15N, and δ34S), a negative association was observed between PFUnDA and δ15N, hinting at potential biodilution. The research concludes that the migratory patterns of these seabird species affect their PFAS exposure, underscoring the critical need for further exploration and understanding of these relationships to better inform conservation strategies.

Are Chinese mitten crabs (Eriocheir sinensis) suitable as biomonitor or bioindicator of per- and polyfluoroalkyl substances (PFAS) pollution?

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment. In Flanders, the bioaccumulation in aquatic organisms is currently being monitored using European perch and European eel. Since both are native species, there is an ethical need to search for other suitable biomonitors. This study aims to investigate whether the invasive Chinese mitten crab could be used in biomonitoring programs by assessing PFAS accumulation in hepatopancreas, muscle tissue, and carapace. Furthermore, we correlated accumulated concentrations to those in the local abiotic environment. Concentrations in the crabs (highest average ∑PFAS concentration of 688 ± 505 ng/g ww) were often higher than those in crab species from other regions across the globe, confirming that Flanders is highly polluted with PFAS. Concentrations in the crabs did not reflect those in the abiotic environment. This implies that biomonitoring is necessary to investigate the impact of PFAS pollution on organisms in aquatic ecosystems, as important data is missing when only the abiotic environment is monitored. The accumulation profiles differed between the invasive crab and the native European perch and European eel, potentially due to a different ecology and trophic position. Since all three species provide complementary information on the PFAS pollution, a multi-species approach in biomonitoring is recommended. Overall, our results show that the crabs can be used as biomonitor, but more information is necessary to confirm their suitability as bioindicator.

Prediction of perfluoroalkyl acids (PFAAs) in homegrown eggs: Insights into abiotic and biotic factors affecting bioavailability and derivation of potential remediation measures.

Homegrown eggs from free-ranging laying hens often contain elevated concentrations of perfluoroalkyl acids (PFAAs). However, it is unclear which factors contribute to these relatively large exposure risk scenarios. Moreover, existing bioavailability and modeling concepts of conventional organic pollutants cannot be generalized to PFAAs due to their different physicochemical soil interactions. Therefore, there is an urgent need for empirical models, based on real-world data, to provide insights into how (a)biotic factors affect the bioavailability to eggs. To this end, 17 targeted analytes were analyzed in abiotic (i.e. rainwater, soil; both N = 101) matrices and homegrown eggs (N = 101), which were sampled in 101 private gardens across Flanders (Belgium) in 2019, 2021 and 2022. Various soil characteristics were measured to evaluate their role in affecting PFAA bioavailability to the eggs. Finally, PFAAs were measured in potential feed sources (i.e. homegrown vegetable and earthworm pools; respectively N = 49 and N = 34) of the laying hens to evaluate their contribution to the egg burden. Modeling suggested that soil was a major exposure source to laying hens, accounting for 16-55% of the total variation in egg concentrations for dominant PFAAs. Moreover, concentrations in vegetables and earthworms for PFBA and PFOS, respectively, were significantly positively related with corresponding egg concentrations. Predictive models based on soil concentrations, total organic carbon (TOC), pH, clay content and exchangeable cations were successfully developed for major PFAAs, providing possibilities for time- and cost-effective risk assessment of PFAAs in homegrown eggs. Among other soil characteristics, TOC and clay content were related with lower and higher egg concentrations for most PFAAs, respectively. This suggests that bioavailability of PFAAs to the eggs is driven by complex physicochemical interactions of PFAAs with TOC and clay. Finally, remediation measures were formulated that are readily applicable to lower PFAA exposure via homegrown eggs.

Growth Hormones in Broad Bean (Vicia faba L.) and Radish (Raphanus raphanistrum subsp. sativus L.) Are Associated with Accumulated Concentrations of Perfluoroalkyl Substances.

In this study, we grew radish (Raphanus raphanistrum subsp. sativus L.) and broad beans (Vicia faba L.) in a greenhouse on soils spiked with a mixture of 15 per- and polyfluoroalkyl substances (PFASs) and investigated the association between accumulated ∑PFAS concentrations, growth, and hormone levels. Short-chained PFASs dominated aboveground tissues, whereas long-chained PFASs were most abundant in the plant roots. Our results showed that the presence or absence of exodermal Casparian strips, as well as the hydrophobicity and anion exchange capacities of PFASs, could explain the translocation of PFASs within plants. Significant associations found between accumulated PFAS concentrations and levels of gibberellins (GA1 and GA15), methionine, and indole-3-acetic acid (IAA) imply potential effects of PFASs on plant development and growth. This study provides the first evidence of associations between PFAS accumulation in plants and growth hormone levels, possibly leading to growth reduction of the apical dome and effects on the cell cycle in pericycle cells and methionine metabolism in plants.

Protecting public health and the environment: towards a general ban on cellulose acetate cigarette filters in the European Union.

After the establishment of a causal relationship between tobacco use and cancer in the 1950s, cellulose acetate filters were introduced with the claim to reduce the adverse health impact of unfiltered cigarettes. Often perceived to be more pleasant and healthy, filters encouraged smoking. However, filtered cigarettes are more deeply inhaled to obtain the same nicotine demand while altered combustion releases more tobacco-specific nitrosamines. The increasing use of cigarette filter ventilation is associated with a sharp rise in lung adenocarcinomas in recent decades. While not preventing adverse health effects, a global environmental problem has been created due to the non-biodegradable filter litter, causing ecotoxicological effects and the spread of microplastics. Recently, the Belgian Superior Health Council advised policymakers to ban cigarette filters as single-use plastics at both national and European levels. This article outlines the arguments used to justify this plea (human health and environment), the expected effects of a filter ban, as well as the public reception and reactions of the tobacco industry. The specific context of the European Union is discussed including the revision of the Single-Use Plastics Directive, affording a new opportunity to ban plastic filters. This perspective article aims to fuel the momentum and cooperation among member states for this purpose.

Assessment of poly- and perfluoroalkyl substances (PFAS) in commercially available drinking straws using targeted and suspect screening approaches.

Many food contact materials (FCMs) and reusable plastics in the food industry contain poly- and perfluoroalkyl substances (PFAS), a group of synthetic pollutants that are known to be potentially harmful for wildlife, humans, and the environment. PFAS may migrate from FCMs to food consumed by humans. As a replacement for plastics, often paper and other plant-based materials are used in commercial settings. This also applies to drinking straws, where plant-based and other presumably eco-friendly straws are increasingly used to reduce plastic pollution. In order to make these materials water-repellent, PFAS are added during manufacturing but can also already be present early in the supply chain due to the use of contaminated raw materials. In the present study, we examined the PFAS concentrations in 39 different brands of straws, made from five materials (i.e. paper, bamboo, glass, stainless steel, and plastic) commercially available on the Belgian market. We combined both targeted and suspect-screening approaches to evaluate a wide range of PFAS. PFAS were found to be present in almost all types of straws, except for those made of stainless steel. PFAS were more frequently detected in plant-based materials, such as paper and bamboo. We did not observe many differences between the types of materials, or the continents of origin. The presence of PFAS in plant-based straws shows that they are not necessarily biodegradable and that the use of such straws potentially contributes to human and environmental exposure of PFAS.

Associations between PFAS concentrations and the oxidative status in a free-living songbird (Parus major) near a fluorochemical facility.

For the past 7 decades, PFAS have been used in many different products and applications, which has led to a widespread contamination of these compounds. Nevertheless at present, little is known about the effects of these compounds on avian wildlife. Therefore, this study investigated associations between PFAS concentrations in the plasma and the oxidative status (i.e. non-enzymatic antioxidants and biomarkers of oxidative stress) in great tits at two sites near a fluorochemical manufacturing facility. Different PFAS were detected in the blood plasma with a mean ΣPFAS of 16062 pg/µL at the site closest to the facility. The PFAS profile in the plasma consisted mainly of PFOS, PFOA, PFDA and PFDoDA, where concentrations were higher for these compounds at the site closest to the plant. Our results show a clear link between PFAS and the antioxidant status of the birds; total antioxidant capacity and peroxidase activity were higher near the plant site, while the glutaredoxin activity was higher further away. Additionally, positive associations were found between PFDoDA and glutathione-S-transferase activity, between PFOS and glutathione-S-transferase activity, between PFDA and peroxidase activity, and between PFOS and peroxidase activity. Lastly, a negative association was found between plasma PFDA concentrations and the total polyphenol content. Interestingly, malondialdehyde levels did not differ between sites, suggesting lipid peroxidation was not affected. Although our results suggest that great tits with elevated PFAS concentrations did not suffer oxidative damage, the antioxidant defence responses were significantly triggered by PFAS exposure. This implies that the great tits have managed to defend themselves against the possible oxidative damage coming from PFAS contamination, although the upregulated antioxidant defences may have fitness costs. Further, experiments are needed to investigate the specific mechanisms by which PFAS induce oxidative stress in avian species.

Mixtures of sediment chemical contaminants at freshwater sampling sites across Europe with different contaminant burdens.

Extended chemical analyses of fluvial sediments were undertaken to establish the key pollutant pressures and mixtures present across nine European Union inland waterways. A wide range of chemical components and physical parameters were investigated including substances from the EU Priority List and Watch List. The data set was examined for key indicator compounds, however it was found that a wide range of pollution pressures were present in the different sediments including organic hydrocarbons, metal(loid)s, nutrients, polycyclic aromatic hydrocarbon (PAH), polychlorinated biphenyl (PCB) compounds, perfluoroalkyl and polyfluoroalkyl substances and pesticides, some of which exceeded regulatory guidance at different sampling points. The presence of such a wide range of compounds underpins the complex chemical composition of sediments that have acted as sinks for many decades absorbing contaminants from urban, industrial and agricultural sources. This dataset has been used to describe average overall toxicity of the sediments sampled, a calculation which was based on key components identified by Principal Component Analysis (PCA) and for those that had existing freshwater sediment regulatory values. A total of 33 components were used including PCBs, PAHs, metal(iod)s and pesticides. This analysis reflected the contamination of each site, with most indicating some level of toxicity during the sampling period. Watch List chemicals triclosan (TCS) and diclofenac (DIC) were also investigated; levels were relatively low, typically 10-100's ng L-1, however they were present at all sampling sites. The dataset is available as a resource for future chemical, and toxicological, sediment analysis comparisons.

Accumulation and effects of perfluoroalkyl substances in Arabidopsis thaliana in a temperature-dependent manner: an in vitro study.

The replacement of long-chained per- and polyfluoroalkyl substances (PFAS) with their short-chained homologues may have an impact on the accumulation in plants. The extent to which PFAS are absorbed by plants may differ among species and may depend on environmental factors, including temperature. The effect of an increased temperature on root uptake and translocation of PFAS in plants has been poorly studied. In addition, very few studies have examined toxicity of environmentally realistic PFAS concentrations to plants. Here, we investigated the bioaccumulation and tissue-distribution of fifteen PFAS in Arabidopsis thaliana L. grown in vitro at two different temperatures. Additionally, we examined the combined effects of temperature and PFAS accumulation on plant growth. Short-chained PFAS mainly accumulated in the leaves. The perfluorocarboxylic acid (PFCA) concentrations in roots and leaves, and the relative contribution of PFCAs to the ΣPFAS concentrations increased with carbon chain length regardless of temperature, with the exception of perfluorobutanoic acid (PFBA). An increased uptake of PFAS in leaves and roots at higher temperatures was observed for PFAS containing either eight or nine carbon atoms and could hence potentially result in higher risks for human intake. Leaf:root ratios of PFCAs followed a U-shaped pattern with carbon chain length, which is attributed to both hydrophobicity and anion exchange. Overall, no combined effects of realistic PFAS concentrations and temperature on the growth of A. thaliana were observed. PFAS exposure positively affected early root growth rates and root hair lengths, indicating a potential effect on factors involved in root hair morphogenesis. However, this effect on root growth rate became negligible later on in the exposure, and solely a temperature effect was observed after 6 days. Temperature also affected the leaf surface area. The underlying mechanisms on how PFAS stimulates root hair growth require further examination.

Transcriptomic effects of Perfluoralkyl acids on the adipose tissue of a songbird species at environmentally relevant concentrations.

Perfluoralkyl acids (PFAS) have been regarded as global pollutants for at least twenty years, with potentially negative physiological effects on multiple vertebrate species including humans. Here we analyze the effects of the administration of environmentally-relevant levels of PFAS on caged canaries (Serinus canaria) by using a combination of physiological, immunological, and transcriptomic analyses. This constitutes a completely new approach to understand the toxicity pathway of PFAS in birds. While we observed no effects on physiological and immunological parameters (e.g, body weight, fat index, cell-mediated immunity), the transcriptome of the pectoral fatty tissue showed changes compatible with the known effects of PFAS as obesogens in other vertebrates, particularly in mammals. First, transcripts related to the immunological response were affected (mainly enriched), including several key signaling pathways. Second, we found a repression of genes related to the peroxisome response and fatty acid metabolism. We interpret these results as indicative of the potential hazard of environmental concentrations of PFAS on the fat metabolism and the immunological system of birds, while exemplifying the ability of transcriptomic analyses of detecting early physiological responses to toxicants. As the potentially affected functions are essential for the survival of the animals during, for example, migration, our results underline the need for tight control of the exposure of natural populations of birds to these substances.

Effect of incubation time of three single extraction procedures on trace element extraction from sediment and soil.

The use of standard single-extraction procedures to evaluate the mobility and availability of trace elements is a common practice in most laboratories dealing with soil or sediment analysis. Most standard single-extraction procedures describe incubations last for 2 h. However, these were tested and validated for soil analysis. Applying them for sediment analysis without further investigation might be misleading and should be reviewed with care. This paper investigates the effect of incubation time on the extraction efficiency of three standard single-extracting reagents (0.01 M CaCl2, 1 M NH4NO3, and 0.05 M EDTA). Incubation experiments with sediment and soil samples lasting for 2 h, 10 h, and 10 d were performed. The results indicated that 2 h appears sufficient to reach equilibrium using CaCl2 or NH4NO3 for soil analysis; but when analyzing sediments, incubation for 10 d resulted in higher concentrations. Incubation experiments with 0.05 M EDTA showed that incubation for 2 h was enough to extract Cd from the soil sample, Mn and to a lesser extent Cd from the sediment samples; while for the other elements, incubation for 10 d yielded higher concentrations for both sample types compared to that obtained after 2 h and 10 h separately. Relative to the pseudo-total metal contents, more than 55% of all studied elements were extracted by using 0.05 M EDTA, indicating high bioavailable metal fraction.

Temporal trends in PFAS concentrations in livers of a terrestrial raptor (common buzzard; Buteo buteo) collected in Belgium during the period 2000-2005 and in 2021.

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 2000-2005 and in 2021. Despite the regulations and phase-out, the ΣPFAS 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 2000-2005, to the ΣPFAS 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.

PFAS accumulation in several terrestrial plant and invertebrate species reveals species-specific differences.

Despite the known persistence and bioaccumulation potential of perfluoroalkyl substances (PFAS), much uncertainty exists regarding their bioavailability in the terrestrial environment. Therefore, this study investigated the influence of soil characteristics and PFAS concentrations on the adsorption of PFAS to soil and their influence on the PFAS bioavailability to terrestrial plants and invertebrates. PFAS concentrations and profile were compared among different invertebrate and plant species and differences between leaves and fruits/nuts of the plant species were assessed. Soil concentrations were primarily affected by organic carbon content. The PFAS accumulation in biota was, except for PFOA concentrations in nettles, unrelated to the soil concentrations, as well as to the soil characteristics. The PFAS profiles in soil and invertebrates were mainly dominated by PFOA and PFOS, whereas short-chained PFAS were more abundant in plant tissues. Our results show that different invertebrate taxa accumulate different PFAS, likely due to dietary differences. Both long-chained and, to lesser extent, short-chained PFAS were observed in herbivorous invertebrate taxa, whereas the carnivorous invertebrates only accumulated long-chained PFAS. Correlations were observed between PFOA concentrations in herbivorous invertebrates and in the leaves of some plant species, whereas such relationships were absent for the carnivorous spiders. It is essential to continuously monitor PFAS exposure in terrestrial organisms, taking into account differences in bioaccumulation, and subsequent potential toxicity, among taxa, in order to protect the terrestrial ecosystem.

Trace element accumulation in different edible fish species from the Bolivian Amazon and the risk for human consumption.

Artisanal mining and erosion of metalbearing soils can contaminate aquatic ecosystems and affect the health of riparian human populations, through metal bio-accumulation processes and fish consumption. Concentrations of eight trace metals (Cd, Cr, Co, Cu, Pb, Hg, Ni, Zn) and a metalloid (As) were measured in the muscle tissue of different edible fish species collected from markets of two cities along the Beni River banks, in the Bolivian Amazon. Relationships between the size of fish belonging to different trophic levels (carnivores, omnivores, detritivores and herbivorous) from four different fishing zones were analyzed. The most relevant results corresponded to the detritivore group, whose members exhibited significant positive correlations between the fish size and the concentration of three metals (cadmium, cobalt and nickel). Furthermore, a 3 × 3 scenario-risk analysis was performed to assess local risk for human health. This was done by relating three different scenarios of local fish consumption collected from literature (maximum, average and minimum) and three different levels of trace element concentrations (95th, 50th and 5th percentile) derived from the present study and the Minimal Risk Levels suggested by the Agency for Toxic Substances and Disease Registry. Results of these calculations determined the amount of fish muscle per contaminant that could be consumed per day without risking human's health. Finally, Target Hazard Quotients were calculated for each trace element, aiming to indicate the potential exposure to each one and the concentration at which no adverse effects are expected. The obtained results made clear that mercury is the only trace element that represents an important health risk to humans within the studied region, considering most of the combinations in the 3 × 3 analysis. Chronic mercury intoxication could occur when consumption of fish in Riberalta or Rurrenabaque exceeded 83 g/day in females and 110 g/day in males.

Home-produced eggs: An important human exposure pathway of perfluoroalkylated substances (PFAS).

Humans are generally exposed to per- and polyfluoroalkyl substances (PFAS) through their diet. Whilst plenty of data are available on commercial food products, little information exists on the contribution of self-cultivated food, such as home-produced eggs (HPE), to the dietary PFAS intake in humans. The prevalence of 17 legacy and emerging PFAS in HPE (N = 70) from free-ranging laying hens was examined at 35 private gardens, situated within a 10 km radius from a fluorochemical plant in Antwerp (Belgium). Potential influences from housing conditions (feed type and number of individuals) and age of the chickens on the egg concentrations was examined, and possible human health risks were evaluated. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were detected in all samples. PFOS was the dominant compound and concentrations (range: 0.13-241 ng/g wet weight) steeply decreased with distance from the fluorochemical plant, while there was no clear distance trend for other PFAS. Laying hens receiving an obligate diet of kitchen leftovers, exhibited higher PFOS and PFOA concentrations in their eggs than hens feeding only on commercial food, suggesting that garden produce may be a relevant exposure pathway to both chickens and humans. The age of laying hens affected egg PFAS concentrations, with younger hens exhibiting significantly higher egg PFOA concentrations. Based on a modest human consumption scenario of two eggs per week, the European health guideline was exceeded in ≥67% of the locations for all age classes, both nearby and further away (till 10 km) from the plant site. These results indicate that PFAS exposure via HPE causes potential human health risks. Extensive analysis in other self-cultivated food items on a larger spatial scale is highly recommended, taking into account potential factors that may affect PFAS bioavailability to garden produce.

Perfluoroalkylated compounds in the eggs and feathers of resident and migratory seabirds from the Antarctic Peninsula.

In this study, we investigated factors that influence the differences in exposure of perfluoroalkyl acids (PFAAs) from eight species of Antarctic seabirds, including Pygoscelis penguins, Stercorarius maccormicki, and Macronectes giganteus. We analyzed the relationship between foraging ecology (based on δ13C, δ15N, and δ34S values) and PFAAs accumulated in eggs and breast feathers. Ten out of 15 targeted PFAAs were detected in eggs compared to eight in feathers. Mean ∑PFAA concentrations in feathers ranged from 0.47 in P. antarcticus to 17.4 ng/g dry weight (dw) in S. maccormicki. In eggs, ∑PFAA concentrations ranged from 3.51 in P. adeliae to 117 ng/g dw in S. maccormicki. The highest concentrations of most PFAAs were found in trans-equatorial migrators such as S. maccormicki, probably due their high trophic position and higher concentrations of PFAAs in the Northern Hemisphere compared to the Southern Hemisphere. Based on stable isotopes correlations, our results suggest that the trophic position (δ15N) and the foraging area (δ13C and δ34S) influence PFAAs concentrations in Antarctic seabirds. Our results point to the possibility that long-distance migratory birds may have as bio-vectors in the transport of pollutants, including PFCAs, in Antarctic environments, although this must be further confirmed in future studies using a mass balanced approach, such as extractable organofluorine (EOF).

Distribution of metals in water, sediment and fish tissue. Consequences for human health risks due to fish consumption in Lake Hawassa, Ethiopia.

Water pollution may be a serious environmental problem for Lake Hawassa, an important fishing and recreational site as well as a drinking-water source in Ethiopia. The present study aims at determining the distribution of metals and metalloids in the lake's water, sediment and fish tissues and assessing the resulting human health and ecological risks. Metals were detected in both abiotic and biotic samples. In water, only the Hg concentration was significantly different among sampling sites. The average concentration of As, Cd, Cr, Cu, Ni, Pb, and Zn in water were below the environmental quality thresholds, thus not having potentially adverse effect on aquatic life. In sediment, significant differences in metals concentration among sites were found for As, Cd, Pb, Co, Zn and Hg (p < 0.05). Exceedances of As, Cr, Cu, Hg, Ni and Zn were found in sediment, with Cr, Ni and Zn above the probable effect concentration and being potentially toxic to aquatic life. Fish stored more metals in their liver than in their muscle. The concentration of metals in carnivorous fish (Barbus intermedius) was not higher in muscle and liver than those in herbivores fish (Oreochromis niloticus). The Bioaccumulation Factor of Cr in all fish species muscle was >1. The Biota-Sediment Accumulation Factor of all metals in all fish species muscle were <1. Positive correlations among metals in water and correlations among metals in sediment were found, indicating a potential common pollution source. Positive correlation of total organic carbon with Cd, Co and Se and clay content with Pb, As and Hg was found and may imply that metals are easily adsorbed by the organic matter and fine sediment. With respect to the measured metals no potential health risk due to consumption of fish from Lake Hawassa was observed.

Trace element concentrations in caudal scutes from Crocodylus moreletii and Crocodylus acutus in Belize in relation to biological variables and land use.

Crocodylus moreletii (Morelet's crocodile) and Crocodylus acutus (American crocodile) are generalist, apex predators of subtropical aquatic habitats in Central America. As top predators, crocodiles may be exposed to high levels of micro pollutants, such as trace elements via bioaccumulation that enter the food web as a consequence of human activities. As such, the status of their population can be considered indicative of that of the entire ecosystem - i.e., crocodiles constitute as genuine indicator species. In this study, we report on the concentrations of trace elements found in the caudal scutes of 178 specimens of C. acutus and C. moreletii from Belize. Our objectives were three-fold: (1) to assess variation in trace element concentration between species, sexes, age classes and body index; (2) to identify areas with elevated exposure to trace elements by comparing concentrations in the scutes of crocodiles at various sites in Belize; and (3) to explore links between crocodile trace element load and local land use. All elements tested (Hg, Pb, Cd, As, Cu, Zn, Co) could be detected in at least some scutes. Many of the readings of As and Co were under or close to the detection limit and were not further analyzed. Relatively high Hg concentrations were observed in adults from Chiquibul Forest (median 3.170 µg/g) and Ambergris Caye (0.834 µg/g). Concentrations of Hg and Pb tended to be higher in adult animals than in juveniles, especially in C. acutus. On the other hand, concentrations of Cd, Cu and Zn were higher in juveniles than in subadult adult animals. Concentrations of Cu were higher in C. acutus than in C. moreletii, but otherwise no species-effects were found for the other trace elements. We found a negative correlation between Hg and Zn concentrations; correlations among Cd, Pb, Cu and Zn concentrations tended to be positive. In both juveniles and adults, animals with high concentrations of Zn had lower body-indices (a proxy for physiological condition). None of the other element concentrations correlated with the body-index. Specimens of C. acutus were more often sampled at coastal sites, while C. moreletii sampling points were typically closer to agricultural or forested areas. A canonical correlation analysis revealed a significant association between trace element load and habitat characteristics. Animals sampled inland, near submontane forests, contained higher levels of Hg, while animals sampled near agricultural, urban or lowland habitats tended to have higher concentrations of Cd, Pb, Cu and Zn. This study identifies the most prevalent trace element concentrations impacting Belizean watersheds while highlighting the exposure risk to non-essential trace elements in less-urbanised areas or protected areas.