Hexabromocyclododecane in sediments from riverine, port, and coastal areas of Kaohsiung, Taiwan: levels, spatial distribution, and potential ecological risk.

The widespread use of hexabromocyclododecane (HBCD), a brominated flame retardant, is a major public health concern because of the toxic, persistent, and bioaccumulative nature of HBCD. However, there is limited information available regarding the distribution and transportation of HBCD in sediments across various environmental settings, spanning from riverine to marine environments in the Kaohsiung area of Taiwan. In this study, we comprehensively investigated the level and distribution of and potential ecological risk posed by HBCD in surface sediments in the Kaohsiung area of Taiwan. In sediment samples from stations on the Love River and Kaohsiung Port area, the concentrations of HBCD ranged from 10.6 to 320.1 µg/kg dry weight (dw) and nondetectable (n.d.) to 58.4 µg/kg dw, respectively. The concentrations of HBCD in sediment collected from the M1, M2, and M3 sites, located in the Cijin coastal area, were 896.2 µg/kg dw, 3.2 µg/kg dw ( 1. The M1 site had the highest risk level (RQ = 5.27). These data suggest that domestic sewage and industrial wastewater discharge pose a potential risk to marine environments. Consequently, timely measures to control HBCD-related risks are required. Our study offers insight into the environmental effects of HBCD contamination of sediment and provides valuable information that can be used to guide environmental policy and safety measures.

Exploring specific biomarkers regarding neurobehavioral toxicity of lead dioxide nanoparticles in medaka fish in different water matrices.

Nano-scale lead dioxide (nPbO2) is an industrial metal oxide nanoparticle that can be also formed as a corrosion by-product from chlorination of Pb-containing plumbing materials. nPbO2 governs release of toxic lead ion in drinking water and receiving organisms; however, its modes of toxic action regarding neurobehavioral toxicity remain unclear. This study evaluated the toxicity mechanism of nPbO2 (10 and 20 mg/L) versus its released Pb(II)aq (100 µg/L) in terms of aqueous chemistry, bioavailability and neurobehavioral toxicity to medaka fish in different water matrices. In very hard water (VHW), dissolved salts enhanced the aggregation and sedimentation of nPbO2, resulting in higher bioavailability and altered locomotion of treated fish than those fish exposed to nPbO2 in soft water with humic acid (SW + HA). Transcriptomic results identified six differentially expressed genes with greater altered expression with nPbO2 than the control or Pb(II)aq exposure. With VHW exposure, nPbO2 caused greater altered expression of genes involved in cell adhesion (nlgn1 and epd), cell cytoskeleton (α1-tubulin), and relevant apoptosis (c-fos, birc5.1-a and casp3), as compared with SW + HA or Pb(II)aq exposure. This study provides novel molecular mechanistic insights into the neurobehavioral nanotoxicity using nPbO2 and medaka fish as surrogates, suggesting nPbO2 promotes neurobehavioral dysfunction, leading to adverse outcomes from gene alteration to the organismal level. The identified biomarkers responded specifically to the nPbO2-induced neurotoxicity in different water matrices can be used for evaluating toxicity risks of small metal oxide particulates on human or aquatic life under environmentally relevant exposures.

Distribution patterns and transportation behavior of alkylphenol polyethoxylate degradation metabolites among river, port area, and coastal water bodies of Kaohsiung City, Taiwan.

In this study, we conducted a comprehensive study of the distribution, transportation behavior and potential ecological risk of alkylphenol polyethoxylates (APnEOs) in the aquatic environments of Kaohsiung City, Taiwan because little information is available regarding the fate of APnEOs in the water bodies of a total environment. At Love River, APnEOs concentrations were much higher at upstream of interception stations L15 (27.33 ± 1.22 µg/L) and L16 (6.31 ± 0.14 µg/L) than at downstream of interception stations L1-L14 (0.69-2.54 µg/L). Additionally, the average ethoxy (EO) chain lengths of APnEOs at L15 and L16 were longer than at L1-L14. These observations were attributed to the sluice between L14 and L15 that intercepts and accumulates untreated sewage from upstream areas and to the infrastructure of the sewage system that prevents domestic sewage from flowing downstream in the river and to the Kaohsiung Port Area. At Kaohsiung Port Area, APnEO concentrations ranging from 0.63 to 6.50 µg/L were measured. The concentration range and average EO chain length of these APnEOs were similar to those of the downstream stretch of the river, which was attributed to the mixing efficiency of the Kaohsiung Port Area and Love River through tidal exchange. At Cijin Coastal Area, APnEO concentrations ranged from 0.14 to 18.77 µg/L. Notably, the APnEO concentration of surface waters was much higher than that of bottom waters. This observation was attributed to the sewage discharged from the ocean outfall buoying up to the surface instead of mixing with surrounding bottom waters. In potential ecological risk, 19 of 39 sampling points exceeded toxic equivalency of 1 µg/L, and approximately 48.7% of the sampling points would exceed the threshold. The result provides insight into the environmental implications of APnEOs contamination in aquatic environments and useful information for environmental policy and ecological risk assessments.

An environmentally friendly strategy for determining organic ultraviolet filters in seawater using liquid-phase microextraction with liquid chromatography-tandem mass spectrometry.

Benzophenone-3, benzophenone-8, and 4-methylbenzylidene camphor are used in sunscreens because they can protect the skin from UV radiation. The widespread use of organic UV filters may mean that they directly or indirectly enter seawater during recreational activities or through sewage discharge. In this study, a simple and efficient method using 1-octanol:isooctane (2:8, v/v) as an extraction solvent and liquid chromatography-electrospray tandem mass spectrometry was developed to measure trace levels of organic UV filters in seawater samples. This proposed method proved to be a highly sensitive, low-cost, and green analytical tool that requires minimal sample preparation. The method was validated and it exhibited favorable performance as well as acceptable accuracy (67 to 115%), precision (2.1 to 7.3%), coefficients of determination (0.9952 < R2 < 0.9987), sensitivity (limits of quantification [3.3 to 5.7 ng L-1]), and an acceptable matrix effect (87 to 99%). This methodology was successfully applied to analyze seawater taken from Kenting National Park located in the Hengchun Peninsula of southern Taiwan. Benzophenone-3 was detected at all sampling sites and at a higher concentration than the other organic UV filters. The highest concentration of benzophenone-3 was 514.6 ng L-1 in a sample collected from Baisha Beach.

Differential alteration in reproductive toxicity of medaka fish on exposure to nanoscale zerovalent iron and its oxidation products.

Nanoscale zerovalent iron (nZVI) is a redox-active nanomaterial commonly used in remediation of soil and groundwater pollution and wastewater treatment processes. A large quantity of nZVI (e.g., >100 mg/L) accidentally released from in situ sites to nearby oxygenized aquifers could be rapidly oxidized to iron oxides (e.g., Fe3O4 or Fe2O3) and ions (e.g., Fe2+), for acute hypoxia effects to aquatic life. However, we do not know the ecotoxicological fate of nZVI and its oxidation products at lower, environmentally concentrations in surface water receiving waterborne transportation or effluent discharge in terms of exposure to aquatic vertebrate species. This study assessed the causal effect on reproductive toxicity in medaka adults (Oryzias latipes) of carboxymethyl cellulose-stabilized nZVI (CMC-nZVI), Fe2+ and iron oxide nanoparticles (nFe3O4) with 21-day aqueous exposure at 5 and 20 mg/L (Fe-equivalent). Such concentrations did not significantly change the dissolved oxygen, oxidation-reduction potential or pH values in the 3 iron solutions during the fish exposure period. Neither CMC-nZVI nor Fe2+ treated adults showed altered daily egg production (fecundity) and oxidative stress responses in observed tissues, as compared to controls. However, the fecundity in nFe3O4 (20 mg/L)-treated pairs was significantly decreased, with increased incidence of abnormal immature oocytes in the ovary. As well, nFe3O4 treatment suppressed activities of the antioxidants superoxide dismutase and expression of glutathione peroxidase (gpx) in the brain and ovary. Although nFe3O4 or Fe2+ treatments inhibited mRNA expression of hepatic estrogen receptor (er-α) in females, plasma levels of sex hormones and (Na, K)-ATPase activity in gills of treated fish did not differ from controls for both sexes. Hence, oxidation products (e.g., nFe3O4) from nZVI at lower milligram-per-liter levels may be potent in inducing nanoparticle-specific reproductive toxicity in medaka fish by inducing oxidative stress in female gonads. MAIN FINDING: nZVI oxidation product nFe3O4 at lower mg/L induces nanoparticle-specific reproductive toxicity in medaka fish.

Determination of sulfamonomethoxine in tilapia (Oreochromis niloticus × Oreochromis mossambicus) by liquid chromatography-tandem mass spectrometry and its application pharmacokinetics study.

A precise and reliable analytical method to measure trace levels of sulfamonomethoxine (SMM) and N4-acetyl metabolite in tilapia samples using liquid chromatography-tandem mass spectrometry was developed. Optimized chromatographic separation was performed on C18 reversed-phase columns using gradient elution with methanol and 5 mmol/L of an ammonium acetate aqueous solution (adjusted to pH 3.5 using formic acid). This study investigated the pharmacokinetic properties and tissue distribution of SMM and its major metabolite N4-acetyl sulfamonomethoxine (AC-SMM) in tilapia after a single dose of 100 mg kg-1 body weight of orally administered SMM. Blood and tissues were collected between 0.5 and 192 h with 14 total sampling time points. SMM was rapidly absorbed, and extensively distributed in the bile and liver through systemic circulation. Enterohepatic circulation of SMM was observed in the tilapia body. Acetylation percentages were 45% (blood), 90% (liver), 62% (kidney), 98% (bile), and 52% (muscle). High concentrations of AC-SMM accumulated in the tilapia bile. At 192 h, AC-SMM concentration in the bile remained at 4710 µg kg-1. The ke value of AC-SMM (0.015 h-1) in the blood was lower than that of SMM (0.032 h-1). This study demonstrated effective residue monitoring and determined the pharmacokinetic properties of SMM and AC-SMM in tilapia.

Survey of selected personal care products in surface water of coral reefs in Kenting National Park, Taiwan.

Kenting National Park (KNP) located in the Hengchun Peninsula in southern Taiwan is a popular tourist spot, annually attracting millions of visitors, who engage in water sport and amusement activities. In this region, sewage is directly discharged into the marine environment. In this study, the concentrations of five organic UV filters [benzophenone (BP), 2,4-dihydroxy benzophenone (BP-1), 2-hydroxy-4-methoxy benzophenone (BP-3), 2,2'-dihydroxy-4-methoxy benzophenone (BP-8), and 4-methylbenzylidene camphor], five preservatives [methylparaben (MeP), ethylparaben, propylparaben (PrP), butylparaben, and benzylparaben], one disinfectant [triclosan (TCS)], and twenty-four detergent derivatives [nonylphenol (NP), nonylphenol ethoxylates (NP2EO-NP12EO), octylphenol (OP) and octylphenol ethoxylates OP2EO-OP12EO] were detected in seawater and river water samples collected from eight beaches in KNP and two major river estuaries in the Hengchun Peninsula. BP-3 was detected at all sampling sites and was higher in concentration than the other organic UV filters. The highest concentration of BP-3 was 1233 ng/L collected from Wanlitong Beach. MeP and PrP were the main preservative components in seawater. The highest total content of preservative agents was 164 ng/L collected from Houwan Beach. Moreover, NP was detected at all sampling sites, with the highest concentration found at Sail Rock Beach (26.5 ng/L). The highest concentration of OP was 113 ng/L in the Boli River estuary. The widespread use of personal care products (PCPs) has resulted in the release of their major ingredients into natural ecosystems. Therefore, the potential long-term effects of multi-PCPs at low concentration exposure to on the coral reef ecosystem in KNP must be considered and monitored.

A generic and rapid strategy for determining trace multiresidues of sulfonamides in aquatic products by using an improved QuEChERS method and liquid chromatography-electrospray quadrupole tandem mass spectrometry.

A rapid and efficient multiresidue method that involves using improved QuEChERS method and liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) was developed to measure trace levels of sulfonamides in fish tissue. This proposed method was proven to be a powerful, highly sensitive, and environmentally friendly analytical tool that requires minimal sample preparation. The typical MS/MS fragmentation patterns of the [M+H](+) were 156 m/z, 108 m/z, and 92 m/z. Separation was performed on HC-C18 columns with a gradient elution by using methanol -5mM ammonium acetate containing formic acid (pH 3.5). This method was validated and exhibited favorable performance as well as acceptable accuracy (80.2-93.5%), precision (3.82-8.71%), sensitivity (limits of detection (LODs) 0.43-1.22 µg kg(-1), limits of quantification (LOQs) 1.27-3.71 µg kg(-1); decision limit (CCα) 1.49-10.9 µg kg(-1), detection capability (CCß) 1.71-11.4 µg kg(-1)), and an acceptable matrix effect (-18.2-18.4%). This methodology has been successfully applied in analyzing various fish tissue from local markets.