Bisphenols, bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE) are commonly used as raw materials or additives in the production of several industrial and consumer products. However, information regarding the occurrence and distribution of these industrial chemicals in freshwater ecosystem is limited. In this study, four bisphenols, six BADGEs, and three BFDGEs were determined in abiotic and biotic samples collected from the Dongjiang River basin in southern China. Among the four bisphenols, BPA was widely present in all samples analyzed including surface water (median: 1.81 ng/L), sediment (3.1 ng/g dw), aquatic plants (3.69 ng/g dw), algae (7.57 ng/g dw), zooplankton (6.17 ng/g dw), and fish muscle (5.28 ng/g dw). Among the nine BADGEs and BFDGEs analyzed, BADGE, BADGE•H2O, BADGE·HCl·H2O and BADGE•2H2O was found in all sample types. Although the median concentration of BADGE•2H2O in surface water was below LOQ, this compound was found at median concentrations of 2.61, 3.59, 1.03, 1.69, and 49.8 ng/g dw in sediment, plants, algae, zooplankton, and fish muscle, respectively. Significant positive linear correlations were found among logarithmic transformed concentrations of BPA, BADGE, BADGE•H2O, BADGE•HCl•H2O, and BADGE•2H2O in sediment. The bioconcentration factor (logBCF) values of BADGE, BADGE•H2O, BADGE•HCl, BADGE•HCl•H2O, BADGE•2H2O, and BADGE•2HCl in fish, plants, algae, and zooplankton were > 3.3 L/kg (wet weight), indicating that these chemicals possess moderate bioaccumulation potential. The estimated daily total intake of bisphenols and BADGEs through fish consumption was 75.1 ng/kg bw/day for urban adult residents. The study provides baseline information on the occurrence of bisphenols, BADGEs, and BFDGEs in a freshwater ecosystem.

Increasingly rigorous data quality (DQ) evaluations and/or screening practices are being applied to environmental and ecotoxicological datasets. DQ is predominantly evaluated by scoring given data against preselected criteria. This study provides the first examination on the effectiveness of score-based DQ evaluation in providing statistically meaningful differentiation of measurements using fish bioconcentration factor (BCF) dataset as an illustration. This is achieved by inspecting how log BCF differs with the built-in overall-DQ and specific-DQ evaluations, and how it is influenced by interactive effects and hierarchy of DQ criteria. Approximately 80-90% of analyzable chemicals show no statistical difference in log BCF between low-quality (LQ) and high-quality (HQ) measurements in overall evaluation (n = 183) or in individual evaluation of 6 DQ criteria (n = 53 to 101). Further examination shows that log BCF may/may not change with different combinations or total number of criteria violations. Tree analysis and nodal structures of deviation in log BCF also reveal the absence of common structural dependence on the criteria violated. Finally, simple averaging of all measurements without DQ differentiation yields comparable log BCFs as those derived using strictly HQ data with ≤0.5 log unit difference in over 93% of the chemicals (n = 158) and no dependence on number of measurements, fraction of LQ measurements, or bioaccumulation potential of the chemicals. For accurate log BCF, DQ appears no more important than having more independent measurements irrespective of their individual DQ statuses. This work concludes by calling for: (i) re-documentation of experimental details in legacy environmental and ecotoxicological datasets, (ii) examination of other DQ-categorized datasets using the tests and tools applied here, and (ii) a thorough and systematic reflection on how DQ should be assessed for modeling, benchmarking, and other data-based analyses or applications.

The bioconcentration factor (BCF) is an important parameter that gives information regarding the ability of a contaminant to be taken up by organisms from the water. Per- and polyfluoroalkyl substances (PFAS) are widespread in the environment, causing concern regarding their impact on human health. Due to the lack of available bioaccumulation data for most compounds in the PFAS group, we developed a quantitative structure-property relationship (QSPR) model to predict the log BCF for fish (taxonomic class Teleostei), based on experimental data available for the most studied 33 representatives of this group of compounds. Furthermore, we implemented the developed model to predict log BCF for an external dataset of 2209 PFAS. Consequently, 1045 PFAS were found not to be bioaccumulative, 208 were classified as bioaccumulative, and 956 were predicted to be very bioaccumulative. Finally, we obtained the high correlation (R2 = 0.844) between the log BCFs obtained in laboratory and field studies for 13 PFAS. In silico analyses indicate that PFAS bioconcentration depends on the size (chain length - number of CF2 groups in alkyl tail/chain) of a molecule, as well as on the atomic distribution properties. In general, long-chain PFAS - above 8 and 6 carbon atoms for perfluorinated carboxylic acids (PFCAs)and perfluorinated sulfonic acids (PFSAs), respectively - tend to bioconcentrate more compared to the short-chain ones. In conclusion, predicting BCF on fish is possible for a wide range of fluorinated compounds, which can be further used for estimating PFAS behavior in the environment.

Per- and polyfluoroalkyl substances (PFAS) are a widespread and persistent class of contaminants posing significant environmental and human health concerns. Comprehensive understanding of the modes of action underlying toxicity among structurally diverse PFAS is mostly lacking. To address this need, we recently reported on our application of developing zebrafish to evaluate a large library of PFAS for developmental toxicity. In the present study, we prioritized 15 bioactive PFAS that induced significant morphological effects and performed RNA-sequencing to characterize early transcriptional responses at a single timepoint (48 h post fertilization) after early developmental exposures (8 h post fertilization). Internal concentrations of 5 of the 15 PFAS were measured from pooled whole fish samples across multiple timepoints between 24-120 h post fertilization, and additional temporal transcriptomics at several timepoints (48-96 h post fertilization) were conducted for Nafion byproduct 2. A broad range of differentially expressed gene counts were identified across the PFAS exposures. Most PFAS that elicited robust transcriptomic changes affected biological processes of the brain and nervous system development. While PFAS disrupted unique processes, we also found that similarities in some functional head groups of PFAS were associated with the disruption in expression of similar gene sets. Body burdens after early developmental exposures to select sulfonic acid PFAS, including Nafion byproduct 2, increased from the 24-96 h post fertilization sampling timepoints and were greater than those of sulfonamide PFAS of similar chain lengths. In parallel, the Nafion byproduct 2-induced transcriptional responses increased between 48 and 96 h post fertilization. PFAS characteristics based on toxicity, transcriptomic effects, and modes of action will contribute to further prioritization of PFAS structures for testing and informed hazard assessment.

The application of the 3Rs (Replacement, Reduction, and Refinement) in animal experimentation has recently concentrated its efforts on utilizing cellular systems to predict toxicity in organisms. In this context, while refining the data obtained from cell lines, this study assesses their bioaccumulation potential and various methods for extrapolating the in vitro metabolization rate constant to support modelled bioaccumulation assessments for fish and their limitations. For this purpose, the concentrations of the parent compound, phenanthrene, and its major metabolites within the cells and in the medium at various exposure times were quantified. A chemical distribution model (mass balance) was applied to calculate the concentrations of the cell-bioaccessible compounds (Cfree) based on the experimentally determined concentrations. An elevated matching was observed between the in vitro bioconcentration factor (BCF) and the in vivo BCFs reported in the literature for zebrafish liver cells (ZFL). This study demonstrates the importance of further investigating in vitro biotransformation kinetics. The results obtained with the approach developed here provide valuable information to enhance current models. Additionally, it underscores the potential of cell lines as a strategy for rapid, simple, and cost-effective predictions without the need for animal experimentation.

This research examined soil contamination and the uptake of potentially toxic elements (PTEs) by maize plants in mining communities. We collected 192 soil samples and 40 maize plant samples from two mining areas and a pristine site. We analyzed the physical properties and element content of the soil, including phosphorus, nitrogen, potassium, Fe, Zn, Co, Pb, Cd, Cr, and Ni. We also measured the elemental concentrations in the maize plants. The study found higher levels of Zn, Cu, and Pb at the mining sites compared to the control areas. The pollution factor (CF) indicated pollution with Cu > Pb > and > Zn at both mine sites. The pollution index (PLI) showed no pollution in the Nkalagu mine and control sites, but heavy and moderate pollution at the Ameka mine and control sites, respectively. The Ameka mine site was enriched with Zn. The bioaccumulation coefficient (BAC) was < 1 except for Zn at the Nkalagu mine and control site. The transfer factor for Fe and Zn from root to shoot was > 1. Pb was > 1 in all study areas except the Ameka mining areas. The results suggest remediation is needed for the two mine sites, especially at Ameka.

Field research on phthalate monoesters (MPEs) and their relationships with phthalate esters (PAEs) is limited, especially in wild fishes. Here, PAEs and MPEs were measured in surface water, sediment, and wild fish collected from a representative river basin with high economic development. Several metabolites of emerging plasticizers, such as mono(3,5,5-trimethyl-1-hexyl) phthalate and mono(6-oxo-2-propylheptyl) phthalate, have already existed in fish with high detection frequencies (95 % and 100 %). Monobutyl phthalate and mono(2-ethylhexyl) phthalate were the predominant MPEs in fish and natural environment (surface water and sediment), while bis(2-ethylhexyl) phthalate was the most abundant PAEs in all matrices. The total concentrations (median) of 9 PAEs and 16 MPEs were 5980 and 266 ng/L in water, 231 and 10.6 ng/g (dw) in sediment, and 209 and 32.5 ng/g (ww) in fish, respectively. The occurrence of MPEs was highly related to their parent PAEs, with similar spatial distribution characteristics in the aquatic environments. Moreover, municipal wastewater discharge was recognized as the main source of MPEs in the research area. Fish species can accumulate targeted chemicals, and it seems more MPEs were from the PAE degradation in fish other than the direct uptake of MPEs in water. Parent PAEs showed higher ecological risk than their corresponding metabolites.

The fruiting body of Neoboletus luridiformis (Scarletina bolete) mushroom was used to determine the level of bioconcentration and subsequent distribution of seventeen elements (Ag, Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Sr, and Zn). A two-centimeter-thick vertical section of the entire fruit body was divided into 101 partial sub-samples where the contents of the studied elements were determined using ICP OES. The actual distribution of the elements in the fruiting body profile was visualized using a GIS interpolation method resulting in distribution maps. The study provides valuable insights into the distribution patterns of 17 elements within the fruiting body of N. luridiformis. Based on the visualization of the elemental content, the determined elements can be divided into three categories. Elements accumulated primarily (i) in the cap (Al, Ag, Ca, Cd, Cu, Fe, K, Mg, Ni, and Zn), (ii) in the stipe (Ba, Mn, Na, Pb, and Se), and (iii) elements with non-specific distribution (Cr and Sr). Since such detailed information supported by graphical visualization has not been published to date, the information in this study will help to better understand the accumulation and distribution of elements within the fruiting bodies of wild as well as cultivated mushroom species.

Human activities have changed the natural rates at which metals are moved and accumulated in both land and water environments, resulting in negative impacts on local wildlife. In this study, concentrations of Cr, Ni, Cd, Pb, Cu, Mn, Co, and Zn were evaluated in water and riverbed sediment samples collected from the Verde River basin (VR), as well as in tissue samples from five native Loricariidae species. Sediment samples collected from the central section of the VR riverbed indicated the presence of metal concentrations, which were primarily attributed to scattered pollution sources linked to rural activities in the surrounding areas. The bioconcentration factor in the Loricariids liver presented the highest average values for Zn (1.27-58.21), Co (0.48-14.91) and Cu (1.15-11.14). The same pattern was observed in the muscle, but in a lower proportion. Regarding the bioaccumulation factor, Co (1.54-34.84), Cu (5.85-25.22) and Zn (0.64-18.08) attained the highest average values in the liver. The co-inertia analysis examined the spatial distribution of metal concentrations in riverbed sediments and in tissues of Loricariids from the upper, middle, and lower stretches of the river, including the river mouth. The analysis revealed varying patterns, with samples from some regions showing higher bioaccumulation levels. This suggests that riverbed sediments are a primary source of metal contamination in Loricariids from these areas. The pollution has had a significant impact on the bioaccumulation of metals in the VR\' Loricariids, which are good indicators of sediment-associated metal bioaccumulation. The metal concentrations recorded in both the riverbed sediments and Loricariids surpassed international and Brazilian limits set for aquatic health and safe human consumption. Given the importance of the Verde River in terms of its ecological, social, cultural, and economic roles, it is essential to implement biomonitoring and control measures to safeguard both terrestrial and aquatic resources.

In the European Medicines Agency (EMA) \"Guideline for Environmental Risk Assessment of Medicinal Products for Human Use,\" a fish bioconcentration factor (BCF) study is triggered in Phase I for pharmaceuticals having log Kow >4.5, to support Persistence, Bioaccumulation and Toxicity (PBT) screening, and in Phase II to assess secondary poisoning and bioaccumulation (\'B\') potential when log Kow ≥3. The standard sampling schedule outlined in OECD Test Guideline 305 (TG305) may require assessment of approximately 200 fish following exposure to low- and high-test concentrations and a negative control. We report experimental log Kow and BCF values for 64 human pharmaceuticals that were used to evaluate the current BCF testing trigger of log Kow ≥3, and whether a single BCF exposure concentration allows accurate classification of bioaccumulation potential. Our data support raising the BCF testing trigger to log Kow ≥4, and use of a single test concentration. The resulting reduction in the use of fish is consistent with the 3 R s principle and did not adversely affect classification accuracy. An assessment of potential risk of secondary poisoning was also conducted for three drugs classified as either B or vB, and no risks were identified.