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Tokyo Bay and locations of sampling stations (coordinates given by Sakurai et al. (2010)). The nominal position of station 7 was changed to 35.5600 °N, 139.8433 °E (approximately 2km northeast of its previous position) after the May 2007 sampling.
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We estimated inflow rates of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) to Tokyo Bay, Japan, between February 2004 and February 2011 by a receptor-oriented approach based on quarterly samplings of the bay water. Temporal trends in these inflow rates are an important basis for evaluating changes in PFOS and PFOA emissions in the T...
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In this study, an analytical method for the routine determination of nine perfluorinated compounds (PFCs), using ultra performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (UPLC-QTOF-MS), was developed, validated, and used for their assay in surface water and sediments. The method yielded good linearity with a...
Citations
... These synthetic chemicals are widely distributed globally irrespective of a country's economic and industrial development (Kurwadkar et al. 2022) with global emission estimates of 2, 610 to 21, 400 tonnes of PFAS with 4-14 carbon from 1951 to 2015 . The buildup of these substances in different environmental media has been considered as concerns due to its inherent resistance to ecological and metabolic degradation, bioaccumulation tendencies, and other accompanying hazards (Abunada et al. 2020;Cousins et al. 2020;Sakurai et al. 2016;Suja et al. 2009;Vedagiri et al. 2018). Because of these concerns, the Stockholm Convention Conference of Parties included perfluorooctane sulfonate (PFOS) in Annex B (restricted production, uses, import and export) since August 2009 (The Conference of the Parties 2009). ...
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are organic chemicals which pose concerns in the environment due to their persistence and bioaccumulative properties. This study used Assessment Factors and Species Sensitivities Distributions to derive specific thresholds to protect the ecosystem in the Laguna Lake, Philippines from risks posed by the toxicity of PFOS and PFOA using available ecotoxicity data for local species. For Assessment Factor method, the U.S. Environmental Protection Agency guideline for the narrative Tier II criteria was suitable based on the available toxicity data with calculated maximum concentration threshold for PFOS and PFOA of 0.51 and 0.75 mg L-1, respectively, and continuous maximum concentration values of 0.06 and 0.08 mg L-1, respectively. For the methods using Species Sensitivity Distribution (SSD), PFOS and PFOA thresholds extrapolated using factors for small datasets were 0.046 and 0.088 mg L-1, respectively. Lastly, PFOS and PFOA Hazardous Concentration (HC5) extrapolated from the weighted average SSD model estimates were 0.061 and 0.078 mg L-1, respectively. The results can serve as the first regulatory and risk assessment basis for aquatic ecosystem protection against risks posed by emerging contaminants in the lake.
... Although the production of some long-chain PFAAs has been banned in most countries, PFAAs are still detected in various environmental media even in polar regions all over the world due to water-soluble PFAAs long-distance migration and bioaccumulation, and even migration to remote areas through ocean currents and marine aerosols (Giesy and Kannan, 2002;MacInnis et al., 2017;Boisvert et al., 2019). In recent years, there have been extensive international studies on PFAAs in various water environments, which mainly focused on the occurrence of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) at a particular study site (Buck et al., 2011;Wang et al., 2015b;Lindim et al., 2016;Sakurai et al., 2016), while only a few studies focused on global geospatial trends of PFAAs in coastal water (Liu et al., 2019;Muir and Miaz, 2021). For example, in 2012, Kunacheva et al. (2012) sampled and analyzed major water bodies around the world, and found that the concentrations of PFOA and PFOS ranged from 0.20 − 1630 ng/L and ND − 70.0 ng/L, respectively, with high concentrations mainly detected in North America, Europe, and Asia. ...
Perfluoroalkyl acids (PFAAs) have been ubiquitously distributed in water environment worldwide for a long time, especially in the estuaries and coastal areas. In this study, the distribution characteristics of 12 PFAAs in 91 main river estuaries along the entire coast of China were analyzed for the first time, and the riverine PFAAs fluxes into the coastal marine environment were estimated. Based on a mini-review, the PFAAs pollution in the coast of China at a global scale was evaluated, which was intended to reveal the overall level of PFAAs and to provide a science basis for strengthening environmental management along the coast of China. The results showed that perfluorooctanoic acid (PFOA), perfluorobutanoic acid (PFBA), and perfluorobutane sulfonic acid (PFBS) were dominant in the whole coastal region, which indicated the usage of PFAAs was changing from long-chain PFAAs to short-chain substitutes in China. With regard to the spatial distribution, the high PFAAs concentrations were found in the coastal areas of south Bohai Sea, Shandong Province from the north while those in the south were generally lower when taking the Qinling Mountain and Huaihe River as a dividing line. The estimated PFAAs riverine mass loading in the whole coastal region was 131 tons per year, and the discharge flux of the Yangtze River accounted for more than half (73.5 tons). In comparison with global data, PFAAs concentrations in the coast of China was at a moderate level, and the detected hotspots of high levels were strongly influenced by fluorochemical industries. However, the mass loading of PFAAs was diversified due to geographical differences and abundant river discharges.
... On dry weight basis (Fig. 2a-d), the ΣMS concentrations tended to be higher downstream of the Arakawa River (R-43), Sumida River (R-38), and Edogawa River (branch, R-34) than in the upstream and mid-locations, that are affected by both domestic and industrial discharges. The northwestern inner Tokyo Bay, which receives these rivers, is affected highly by MSs, similar to other anthropogenic pollutants (Sakurai et al., 2016). The elevated concentrations of MSs in estuarine sediments indicate that rivers were the major route for MS loading to Tokyo Bay, together with the STP effluents located in the inner Tokyo Bay. ...
We investigated the spatial distribution, mass profiles, and benthic risk assessment of a wide range of methylsiloxanes (MSs), including 7 cyclic MSs (CMSs; D3–D9; the number refers to the number of SiO bonds), 13 linear MSs (LMSs; L3–L15), and 15 modified and other MSs (MMSs) in sediments from the Tokyo Bay catchment basin, Japan. We observed widespread distribution of MSs (ΣCMS, ΣLMS, and ΣMMS) in the sediment samples, with concentrations of 1.0–6180 ng/g dry weight (dw), 1.8–10,100 ng/g dw, and < 0.31–210 ng/g dw, respectively. Our study is the first to measure various MMSs modified with hydrogen, vinyl, or phenyl groups; however, only methyltris(trimethylsiloxy)silane and phenyltris(trimethylsiloxy)silane were detected with high occurrence frequency. Notably, no elevated concentrations of MSs were observed downstream of silicone manufacturers, whereas the sediment was characterized by a specific D4/D5 ratio. With the Si-based mass profiles in extractable organosilicon (EOSi), the measured CMSs, LMSs, and MMSs accounted for 5.4%, 7.8%, and 0.2%, respectively. Unidentified EOSi (unknown fraction) constituted a major proportion of the EOSi in the sediment, with a mean of 87%, suggesting that the organosilicon environmental emissions were more than the measured MSs. In risk assessment of the adverse effects of D4, D5, and D6 in sediment on benthic organisms, the respective distributions indicated no overlap between the 95th percentile field sediment concentration and the 5th percentile chronic sediment no-effect concentration in organic carbon-normalized concentration. Although the hazard quotient compared with the predicted no-effect concentration for D5 and D6 exceeded the threshold level (hazard quotient ≥1), the results of probabilistic risk assessment for the three CMSs were not high enough to indicate a threat to benthic organisms in the study area.
... In Japan, PFOS and its salt was listed under the Chemical Substance Control Law. Since then, concentrations in aquatic environments of the compounds have gradually decreased (Sakurai et al. 2016). However, increases in the concentrations of other PFAAs such as perfluoro nonanoic acid (PFNA) have been reported (Zushi et al. 2011). ...
Perfluoroalkyls acids (PFAAs) have been emitted in the environment either as manufacturing by products or through degradation of its precursors. Development of efficient identification and quantification of PFAAs in different environmental media is important for environmental and human health risk assessments. In this study, different extraction methods were developed to determine nine (9) different PFAAs in seawater and seawater sandworm Perinereis wilsoni. P. wilsoni extracted using two methods: manual extraction and accelerated solvent extraction (ASE). Solid phase extraction method was used for the clean-up and preconcentration of PFAAs from the marine water samples. High-performace liquid chromatography–tandem mass spectrometry was used to analyze PFAAs concentrations in the samples. Percent recoveries of surrogate (SUR) in marine water samples were between 52 to 72% (blank), 52 to 88% (1 ng), and 56 to 79% (10 ng). Manual extraction of sandworm resulted in 57 to 93% recovery of SUR compounds. ASE extraction gave higher recoveries of SUR compounds (62 to 92%). The developed analytical methods for seawater and sandworm extraction can assure production of good quality PFAAs data.
... In addition to the studies carried out in Japan, Korea, and China, PFAS contamination was reported in multiple parts of Asia including India, Bangladesh, Vietnam, Singapore, Thailand, Malaysia, and many others (Duong et al., 2015;Habibullah-Al-Mamun et al., 2016;Kim et al., 2012;Lam et al., 2017;Nguyen et al., 2011;Sakurai et al., 2016;Sharma et al., 2016;Yeung et al., 2009). Sharma et al. (2016) reported that dominance of short-chain PFAS in Ganges River, India indicated the effect of PFOS substitution with short chain PFAS over time. ...
Per and poly-fluoroalkyl substances (PFAS) have been recognized as contaminants of emerging concerns by the United States Environmental Protection Agency (US EPA) due to their environmental impact. Several advisory guidelines were proposed worldwide aimed at limiting their occurrences in the aquatic environments, especially for perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). This review paper aims to provide a holistic review in the emerging area of PFAS research by summarizing the spatiotemporal variations in PFAS concentrations in surface water systems globally, highlighting the possible trends of occurrences of PFAS, and presenting potential human health impacts as a result of PFAS exposure through surface water matrices. From the data analysis in this study, occurrences of PFOA and PFOS in many surface water matrices were observed to be several folds higher than the US EPA health advisory level of 70 ng/L for lifetime exposure from drinking water. Direct discharge and atmospheric deposition were identified as primary sources of PFAS in surface water and cryosphere, respectively. While global efforts focused on limiting usages of long-chain PFAS such as PFOS and PFOA, the practices of using short-chain PFAS such as perfluorobutanoic acid (PFBA) and perfluorobutane sulfonic acid (PFBS) and PFAS alternatives increased substantially. These compounds are also potentially associated with adverse impacts on human health, animals and biota.
... However, future temporal trends of external loads are likely to decline in line with the phasing out of PFOA and PFOS (Wang et al., 2014). In fact, decaying trends during the last years have been reported in SFB effluents, as well as in other areas where PFAS regulations have been set up Land et al., 2018;Remucal, 2019;Sakurai et al., 2016 Despite showing decaying trends, it is important to remark that the width of uncertainty bands and their associated time scale to reach nearly-stable concentrations in sediment and fish could change given the fact that the most sensitive model parameter (t1/2Sj) in this exercise was estimated (see section 4.1). As some authors have recognized, this parameter is highly influenced by sediment composition (Ferrey et al., 2012;Venkatesan and Halden, 2014). ...
We present a model to predict the long-term distribution and concentrations of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in estuaries comprising multiple intercommunicated sub-embayments. To that end, a mass balance model including rate constants and time-varying water inputs was designed to calculate levels of these compounds in water and sediment for every sub-embayment. Subsequently, outflows and tidal water exchanges were used to interconnect the different regions of the estuary. To calculate plausible risks to population, outputs of the model were used as inputs in a previously designed model to simulate concentrations of PFOA and PFOS in a sport fish species (Cymatogaster aggregata). The performance of the model was evaluated by applying it to the specific case of San Francisco Bay, (California, USA), using 2009 sediment and water sampled concentrations of PFOA and PFOS in North, Central and South regions. Concentrations of these compounds in the Bay displayed exponential decreasing trends, but with different shapes depending on region, compound, and compartment assessed. Nearly stable PFOA concentrations were reached after 50 years, while PFOS needed close to 500 years to stabilize in sediment and fish. Afterwards, concentrations stabilize between 4 and 23 pg/g in sediment, between 0.02 and 44 pg/L in water, and between 7 and 104 pg/g wet weight in fish, depending on compound and region. South Bay had the greatest final concentrations of pollutants, regardless of compartment. Fish consumption is safe for most scenarios, but due to model uncertainty, limitations in monthly intake could be established for North and South Bay catches.
... However, PFOA use is not yet banned in Jordan and the relevant authorities permit production, import and use of PFOA, PFOA salts and PFOA-related compounds (LAHA, 2019). It should be pointed out that the concentrations of PFOA in ZR were comparable to those found in rivers in Uganda, Kenya and Ghana (Dalahmeh et al., 2018;Essumang et al., 2017;Loos et al., 2009), but lower than those found in rivers in industrial countries in Europe and Japan (Becker et al., 2010;Gobelius et al., 2018;Loos et al., 2009;Sakurai et al., 2016) (Table 2). ...
The Zarqa river (ZR) in Jordan receives >300,000 m3 day -1 of wastewater effluent from Assamra wastewater treatment plant (WWTP) and is a major source of irrigation water for vegetable crops and fodder downstream. ZR water quality is therefore highly important and directly influences crop and soil quality in irrigated fields. This study investigated the occurrence and concentration of 20 per- and polyfluoroalkyl substances (PFASs) in Assamra wastewater, ZR water, soils and crop plants (alfalfa (Medicago sativa), mint (Mentha spicata) and lettuce (Lactuca sativa)) along the ZR flow path between Assamra WWTP and Jerash spring. The combined PFAS concentration (∑PFASs) in Assamra WWTP effluent (14-24 ng L-1) was comparable to that in influent (10-15 ng L-1), indicating poor removal of PFASs. The dominant PFAS in influent was perfluorodecanoate (PFDA), while perfluorooctanoate (PFOA) and perfluoropentanoate (PFPeA) dominated in effluent. ∑PFASs in an unaffected upstream tributary (Sukhna station) was 4.7-5.4 ng L-1. Farther downstream, ZR water contained 16-27 ng L-1, with PFPeA, PFOA and PFDA dominating, and these levels did not change along the flow path to Jerash spring. ∑PFASs in soil was generally low, 340 ± 150 pg g-1 dry weight (dw) in alfalfa soil (mainly PFOA and PFDA) and 710 ± 420 pg g-1 dw in mint soil and 970 ± 800 pg g-1 dw in lettuce soil (mainly linear perfluorooctane sulfonate (L-PFOS) in both cases). Soil-water partitioning coefficient (Kd) was generally low in all soils (range 24-62 L kg-1, 20-46 L kg-1 and 28 L kg-1 for PFOA, PFDA and L-PFHxS, respectively). No PFASs were detected in alfalfa and mint plants. Overall, this investigation demonstrated that PFAS contamination in wastewater, surface water and soil in the ZR basin is very low in a global comparison, and that there is no accumulation of PFASs in the food and feed crops studied.
... 33 Tokyo Bay is a large semienclosed marine environment with a surface area of approximately 992 km 2 and a mean depth of approximately 15-19 m. 34,35 It receives wastewater from a catchment inhabited by approximately 29 million people. 36 Approximately 8.7 million of these people live in Tokyo itself and the rest live in the surrounding area draining to the Bay. It is assumed that the entire population is served by good wastewater treatment. ...
... It is assumed that the entire population is served by good wastewater treatment. 33,36 It is also assumed that there is no degradation or volatilisation of cVMS compounds discharged to rivers before these rivers reach the Bay (although we recognise that, in reality, there are likely to be losses of cVMS compounds from some discharge points where rivers are distant from the Bay). The dimensions and properties for Tokyo Bay adopted in the QWASI modelling described here are shown in Table S2. ...
Multi-media fate and transport models (MFTMs) are invaluable tools in understanding and predicting the likely behaviour of organic pollutants in the environment. However, some parameters describing the properties of both the environmental system and the chemical pollutant under consideration are uncertain and or variable in space and time. Furthermore, model performance is often evaluated using sparse data sets on chemical concentrations in different media. This can result in equifinality - the phenomenon in which several different combinations of model parameters can result in similar predictions of environmental concentrations. We explore this idea for MFTMs for the first time using, as examples, three cyclic volatile methyl siloxanes (cVMS: D4, D5 and D6) and the QWASI lake model applied to Tokyo Bay. Monte Carlo simulation was employed with parameters selected from probability distributions representing estimated uncertainty in a large number of iterations. This generated distributions of predicted chemical concentrations in water (CW) and sediment (CS) which represent the aleatory uncertainty envelope but which also demonstrate significant equifinality. For all three compounds, the uncertainty implied in the CW was lower (coefficient of variation, CV, of the order of 20%) than for CS (CV ca. 45%), reflecting the propensity of cVMS compounds to sorb to sediment and the sensitivity of the model to KOC. Confidence intervals were particularly high for the persistence of D5 and D6 in sediment which both ranged between approximately 1.7 years and approximately 26 years for Tokyo Bay. Predicted concentration distributions matched observations well for D5 and D6 not for D4. Equifinality could be reduced by better constraining acceptable parameter sets using additional measured data from different environmental compartments.
... The Tokyo-Bay catchment basin, including Tokyo Metropolis and the surrounding metropolitan area, is the center of human activities in Japan. The catchment basin is densely inhabited and encompasses a wide variety of municipal, agricultural, and industrial activities, including an active fishery in the bay itself (Sakurai et al., 2016). ...
... The target area was constructed to include water systems that flowed into Tokyo Bay, i.e., the Tone, Ara, Tama, Tsurumi, Yourou, Obitsu, and Koito river systems, and a set of other smaller river systems ( Fig. 1). The main stream of the Tone River flows into the Pacific Ocean and not into Tokyo Bay, but the Tone River provides a considerable flow of water into the Tokyo Bay catchment basin via water intake and distributary outflow (Sakurai et al., 2016), and we therefore included the catchment basin of the Tone River in the target area. The catchments of these river systems were divided into unit catchments (average area,~10 km 2 ; see Section 2.4.1 for explanation). ...
We investigated the multimedia fate of decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) in the densely populated catchment basin of Tokyo Bay, Japan, by using a georeferenced multimedia model. We estimated the daily per person consumption rate of these compounds in Japan according to literature. Emissions to the atmosphere accounted for almost all of the emissions of these compounds to the environment. The majority of these compounds was predicted to be distributed in the atmosphere (about 60%) and sediment (about 40%). The advective flows in and out of the atmosphere over the Tokyo Bay catchment basin dominated the flows of these compounds. The sewerage systems contributed considerably to the transport and fate of D5 and D6 in water. They transported these compounds from households to discharge outlets of sewage treatment plants (STPs), which in turn accounted for approximately one quarter of the emission of these compounds to rivers and to Tokyo Bay. The wastewater treatment plants also effectively removed these compounds from the wastewater. The overall persistence of D5 and D6 in the catchment basin was estimated to be 3.8–9.5 days. The horizontal distributions of these compounds were similar among environmental compartments; high concentrations were generally observed in populated areas. A sensitivity analysis demonstrated that the D5 discharge rate to Tokyo Bay excluding the direct discharge from STPs and the D5 mass in the river compartment were sensitive to changes of the organic-carbon-water partition coefficient. Comparison with the concentrations in rivers measured recently in the target area showed that the model captured overall trends of low to high concentrations in rivers. However, there was some variability and a bias toward underprediction. The model provided a better fit to measurements for D5 than for D6. One potential factor contributing to the bias toward underprediction was underestimation of the consumption rates.
... PFOS showed statistically significant declining trends in several surface waters, namely; in Tokyo Bay between 2004 and 2006 [129], in marine and fresh waters on the west coast of South Korea between 2008 and 2012 [95] and in Bohai Bay on the east coast of China between 2011 and 2013 [140]. The other significant downward trends for PFOS were observed in a digested sewage sludge sampled in Hinwil in Switzerland between 1998 and 2008 [136], in a Snow core from the Devon ice cap [91] and in a sediment core in the Haihe River (core S6, dated 1952-2006) in China [149]. ...
... PFOA showed statistically significant downward trends in several different consumer products, whereas it showed significant increasing trends in food contact paper (Category H in Additional file 7, Figure S17) [108]. PFOA showed statistically significant declining trends in the same surface waters for which declining PFOS trends were also observed, namely; in Tokyo Bay between 2004 and 2006 [129], in marine and fresh waters on the west coast of Korea between 2008 and 2012 [95] and in Bohai Bay on the east coast of China between 2011 and 2013 [140]. Where change-points occur the magnitude is generally shown before and after the change-point, but where the trend is insignificant on both sides the magnitude is shown for the whole period only. ...
Background
There is a concern that continued emissions of man-made per- and polyfluoroalkyl substances (PFASs) may cause environmental and human health effects. Now widespread in human populations and in the environment, several PFASs are also present in remote regions of the world, but the environmental transport and fate of PFASs are not well understood. Phasing out the manufacture of some types of PFASs started in 2000 and further regulatory and voluntary actions have followed. The objective of this review is to understand the effects of these actions on global scale PFAS concentrations.
Methods
Searches for primary research studies reporting on temporal variations of PFAS concentrations were performed in bibliographic databases, on the internet, through stakeholder contacts and in review bibliographies. No time, document type, language or geographical constraints were applied in the searches. Relevant subjects included human and environmental samples. Two authors screened all retrieved articles. Dual screening of 10% of the articles was performed at title/abstract and full-text levels by all authors. Kappa tests were used to test consistency. Relevant articles were critically appraised by four reviewers, with double checking of 20% of the articles by a second reviewer. Meta-analysis of included temporal trends was considered but judged to not be appropriate. The trends were therefore discussed in a narrative synthesis.
Results
Available evidence suggests that human concentrations of perfluorooctane sulfonate (PFOS), perfluorodecane sulfonate (PFDS), and perfluorooctanoic acid (PFOA) generally are declining, while previously increasing concentrations of perfluorohexane sulfonate (PFHxS) have begun to level off. Rapid declines for PFOS-precursors (e.g. perfluorooctane sulfonamide, FOSA) have also been consistently observed in human studies. In contrast, limited data indicate that human concentrations of PFOS and PFOA are increasing in China where the production of these substances has increased. Human concentrations of longer-chained perfluoroalkyl carboxylic acids (PFCAs) with 9–14 carbon atoms are generally increasing or show insignificant trends with too low power to detect a trend. For abiotic and biological environmental samples there are no clear patterns of declining trends. Most substances show mixed results, and a majority of the trends are insignificant with low power to detect a trend.
Conclusions
For electrochemically derived PFASs, including PFOS and PFOA, most human studies in North America and Europe show consistent statistically significant declines. This contrasts with findings in wildlife and in abiotic environmental samples, suggesting that declining PFOS, PFOS-precursor and PFOA concentrations in humans likely resulted from removal of certain PFASs from commercial products including paper and board used in food packaging. Increasing concentrations of long-chain PFCAs in most matrices, and in most regions, is likely due to increased use of alternative PFASs. Continued temporal trend monitoring in the environment with well-designed studies with high statistical power are necessary to evaluate the effectiveness of past and continuing regulatory mitigation measures. For humans, more temporal trend studies are needed in regions where manufacturing is most intense, as the one human study available in China is much different than in North America or Europe.
