Use of TIE techniques to characterize industrial effluents in the Pearl River Delta region

Environmental metabolomics uncovers oxidative stress, amino acid dysregulation, and energy impairment in Daphnia magna with exposure to industrial effluents

Anthropogenic activities are regarded as point sources of pollution entering freshwater bodies worldwide. With over 350,000 chemicals used in manufacturing, wastewater treatment and industrial effluents are comprised of complex mixtures of organic and inorganic pollutants of known and unknown origins. Consequently, their combined toxicity and mode of action are not well understood in aquatic organisms such as Daphnia magna. In this study, effluent samples from wastewater treatment and industrial sectors were used to examine molecular-level perturbations to the polar metabolic profile of D. magna. To determine if the industrial sector and/or the effluent chemistries played a role in the observed biochemical responses, Daphnia were acutely (48 h) exposed to undiluted (100%) and diluted (10, 25, and 50%) effluent samples. Endogenous metabolites were extracted from single daphnids and analyzed using targeted mass spectrometry-based metabolomics. The metabolic profile of Daphnia exposed to effluent samples resulted in significant separation compared to the unexposed controls. Linear regression analysis determined that no single pollutant detected in the effluents was significantly correlated with the responses of metabolites. Significant perturbations were uncovered across many classes of metabolites (amino acids, nucleosides, nucleotides, polyamines, and their derivatives) which serve as intermediates in keystone biochemical processes. The combined metabolic responses are consistent with oxidative stress, disruptions to energy metabolism, and protein dysregulation which were identified through biochemical pathway analysis. These results provide insight into the molecular processes driving stress responses in D. magna. Overall, we determined that the metabolic profile of Daphnia could not be predicted by the chemical composition of environmentally relevant mixtures. The findings of this study demonstrate the advantage of metabolomics in conjunction with chemical analyses to assess the interactions of industrial effluents. This work further demonstrates the ability of environmental metabolomics to characterize molecular-level perturbations in aquatic organisms exposed to complex chemical mixtures directly.

Acute toxicity assays using Danio rerio and Daphnia magna to assess hot-spring drainage in the Shibukuro and Tama Rivers (Akita, Japan)

We investigated the lethal toxicity of Shibukuro and Tama river water near the inflow of Tamagawa hot-spring water in Akita Prefecture, Japan. We first measured metal concentrations in both rivers. We detected iron, arsenic, and aluminum; the concentrations of each tended to decrease from upstream to downstream. We next examined the influence of river water on zebrafish Danio rerio and water flea Daphnia magna. We observed lethal effects in both species, with Daphnia magna more sensitive to toxicity than Danio rerio. For both species, the toxic effects of river water decreased with increasing distance downstream from the inflow of hot-spring water. Our results show that the metals discharged from Tamagawa hot spring have a negative effect on aquatic organisms.

Chemical characteristics and toxicological effects of leachates from plastics under simulated seawater and fish digest

In recent years, the ecological risks of plastics to marine environments and organisms have attracted increasing attention, especially the leachates from plastics. However, a comprehensive knowledge about the leaching characteristics and subsequent toxicological effects of leachates is still sparse. In this study, 15 different plastic products were immersed in simulated seawater and fish digest for 16 h. The leachates were analyzed through non-target and target analyses and their toxicological signatures were assessed by bioassays. In total, 240 additives were identified from the plastic leachates, among which plasticizers represented the most (16.7%), followed by antioxidants (8.7%) and flame retardants (7.1%). Approximately 40% of plastic leachates exhibited significant inhibitory effects on the bioluminescence using a recombinant luminescent assay. In addition, both the hyperactive and hypoactive behaviors were displayed in the larvae of marine medaka (Oryzias melastigma) exposed to some plastic leachates. In general, the number and amount of identified compounds under simulated fish digest were less than those under simulated seawater. However, the simulated fish digest leachates triggered higher toxicity. Redundancy analysis demonstrated that identified additives did not adequately explain the toxicological effects. Future research should focus on the identification of more additives in the plastic leachates and their potential ecological risks.

Effect of membrane filtration on the fate of polychlorinated biphenyls in wastewater treatment

The Spokane River is impacted by levels of polychlorinated biphenyls (PCBs) that have triggered fish consumption advisories and exceed water quality standards. Select wastewater treatment plants (WWTPs) on the river have been upgraded from secondary (biological) treatment to tertiary treatment in the form of membrane filtration to address phosphorus contamination. Because membrane filtration is effective at removing particles, it is likely to reduce PCB concentrations in the effluent as well. In this work, PCBs measured in the influents and effluent of several WWTPs discharging to the river were examined. Implementation of membrane filtration reduced PCB concentrations in the effluent (and therefore PCB loads to the river) by 33% at a facility that produces recycled and virgin paper and by ∼55% at municipal WWTPs, compared to secondary (activated sludge) treatment. Largest reductions in concentrations in effluent and loads were achieved for higher molecular weight (MW) PCB congeners (i.e. those with six or more chlorines), homologs, and formulations. The more modest reductions in effluent concentrations achieved at the paper WWTP may be due to the mix of PCBs in the wastewater there: it contained primarily the low MW Aroclor 1242 (presumably from carbonless copy paper) and PCB 11 (3,3'-dichlorobiphenyl) possibly from pigments. PCBs that appear to be associated with silicone products such as caulk, tubing, and o-rings are relatively more abundant in the effluent of some plants compared to the influent, suggesting that these congeners arise from contamination during sampling or from within the plant itself. At some WWTPs, this contamination accounts for nearly a third of PCBs measured in the effluent.

Chemical Characterization of Specific Micropollutants from Textile Industry Effluents in Fez City, Morocco

Textile industry is one of the most polluting industries in the world. It has a high importance in terms of its environment impact, since it consumes a considerably large amount of water and produces highly polluted discharge water. In this work, characterization of toxic organic compounds is proposed. Based on gas chromatography coupled to mass spectrometry (GC/MS) screening analysis, organic micropollutant diversity of textile effluents from a local textile processing factory was investigated. In the present work, physicochemical characterization of the studied textile effluents showed considerably high values of principal pollution parameters above the prescribed discharge water limits. Heavy metals like zinc (Zn), copper (Cu), iron (Fe), nickel (Ni), cadmium (Cd), chromium (Cr), and lead (Pb) were found to be present within the permissible limits. The results of GC/MS revealed the presence of various organic compounds belonging to a wide range of chemical classes. Main groups of chemical compounds detected in these effluents were aromatic carboxylic acids, alkanes, aromatic amines, phthalates, aliphatic carboxylic acids, and linear aliphatic alcohols. The results of this study allowed significant contributions to the chemical characterization of textile industry contaminants and identification of indicators that can be considered an important tool for assessment of the potential impact of textile activities to the contamination of aquatic environment and health hazard.

Endothelium-targeted deletion of the miR-15a/16-1 cluster ameliorates blood-brain barrier dysfunction in ischemic stroke

The blood-brain barrier (BBB) maintains a stable brain microenvironment. Breakdown of BBB integrity during cerebral ischemia initiates a devastating cascade of events that eventually leads to neuronal loss. MicroRNAs are small noncoding RNAs that suppress protein expression, and we previously showed that the miR-15a/16-1 cluster is involved in the pathogenesis of ischemic brain injury. Here, we demonstrated that when subjected to experimentally induced stroke, mice with an endothelial cell (EC)-selective deletion of miR-15a/16-1 had smaller brain infarcts, reduced BBB leakage, and decreased infiltration of peripheral immune cells. These mice also showed reduced infiltration of proinflammatory M1-type microglia/macrophage in the peri-infarct area without changes in the number of resolving M2-type cells. Stroke decreases claudin-5 abundance, and we found that EC-selective miR-15a/16-1 deletion enhanced claudin-5 mRNA and protein abundance in ischemic mouse brains. In cultured mouse brain microvascular ECs (mBMECs), the miR-15a/16-1 cluster directly bound to the 3' untranslated region (3'UTR) of Claudin-5, and lentivirus-mediated ablation of miR-15a/16-1 diminished oxygen-glucose deprivation (OGD)-induced down-regulation of claudin-5 mRNA and protein abundance and endothelial barrier dysfunction. These findings suggest that genetic deletion of endothelial miR-15a/16-1 suppresses BBB pathologies after ischemic stroke. Elucidating the molecular mechanisms of miR-15a/16-1-mediated BBB dysfunction may enable the discovery of new therapies for ischemic stroke.

Assessment of Biological Toxicity and Ecological Safety for Urban Black-Odor River Remediation

The judgment and assessment of remediation effect on urban black-odor river still depend on the physical-chemical parameters and lack in ecological safety effects. A set of combined biological toxicity tests were applied to evaluate the ecological effects of one urban black-odor river before and after the remediation. The special growth rate of Chlorella vulgaris and mortality rate of Daphnia magna were used to assess acute toxicity. The Salmonella Typhimurium/Reverse Mutation Assay was applied to test the mutagenicity. The tests by C. vulgaris growth showed that there was no inhibition before and after remediation by overlying water, in contrast promoted the growth of C. vulgaris. The tests by D. magna showed slight toxicity on site 3# before remediation and nontoxic after remediation. The mutagenicity of organic extracts from overlying water at all sampling sites were positive before remediation, but were eliminated after remediation except from 3 of 4 sites on TA98 strain. The addition of the liver microsomal S9 induced the positive mutagenicity on site 4# compared to S9 absence. The results clarified the applicable and the importance of the biological toxicity tests on assessing the remediation effect and potential ecological risk of urban black-odor river.

Bioensayos Ecotoxicológicos con la microalga Pseudokirchneriella subcapitata para medir el impacto de los metales en ecosistemas lóticos utilizando técnicas de microscopía confocal de fluorescencia

Un bioensayo ecotoxicológico rápido y sencillo permite una estimación confiable del estado de los ecosistemas lóticos de las cuencas de Camaná, Majes y Colca localizados en la Región en Arequipa-Perú en seis estaciones de muestreo (Taparza, Grande, Majes1, Majes2, Camaná1 y Camaná2), mediante la inhibición del crecimiento de la microalga Pseudokirchneriella subcapitata a las 24, 48 y 72 horas y la Concentración Efectiva Media (CE50), a las 72 horas en comparación con los Estándares peruanos de Calidad Ambiental (ECA) y las directrices de la calidad del agua de la Organización Mundial de la Salud (OMS). Se observó que en los puntos de muestreo de Majes1 y Majes2 se superaron los valores de coliformes termotolerantes al aluminio, manganeso, hierro y sólidos suspendidos totales (SST) comparados con los valores de ECA y directrices de calidad del agua de la OMS, con una CE50 categorizándolos como moderadamente tóxicos. En este artículo, se utilizaron técnicas de microscopía confocal de fluorescencia para observar el impacto de los estándares de la EQS y los de la OMS, proponiendo como modelo la aplicación de técnicas microscópicas, con amplias perspectivas para futuros estudios de ecotoxicidad por metales.

Pollutants released from the pulp paper industry: Aquatic toxicity and their health hazards

The pulp paper industries release wastewater containing very complex organic and inorganic pollutants. These pollutants are discharged mainly pulping and bleaching process during paper manufacturing. The main gaseous pollutants hydrogen sulfides, sodium sulfide, methyl mercaptan, sulfur, and chlorine dioxide is reported for chronic, respiratory disorder and irritation to skin, eyes and cardiac problem along with nausea and headache. The major inorganic pollutants include ferrous, copper, zinc, nickel, and magnesium, which is reported for neurotoxicity, toxic to juvenile channel catfish (Ictalurus punctatus) and Accumulation to gill > liver > ovary > muscle. The detected major organic and inorganic pollutants are hexadecanoic acids, octacosane, β-sitosterol trimethylsilyl ether, 1-tetradecane, 2-methoxy phenol, trichlorocatechol, tetrachlorocatechol, chlorophenols, chloroguaiacols, chlorosyringols, chlorocatechols, terpenes, methanol, phenol, alkylated phenols, decalone, benzoic acid, abietic acid, and dehydroabietic acid. Several of these compounds are reported as endocrine-disrupting chemicals (EDCs). Therefore, direct toxicity of effluent to the reproductive system in aquatic flora and fauna are reported. Several reports have highlighted reduced gonad size, change in secondary sexual character, delayed maturity and suppression of sex hormone in fish rainbow trout (Oncorhynchus mykiss) and mosquitofish (Gambusia holbrooki) further the in-vitro studies of organic compounds on fish, Salmonella typhimurium, Vibrio fischeri, and Saccharomyces have shown inhibition in growth and luminescence properties. The presence of organic and inorganic pollutants in pulp paper industry wastewater causes phytotoxicity chromosomal aberration in Allium cepa. Thus the manuscript has concluded that detected pollutants produced foul odors and cause hermaphroditism in fish, hepatotoxicity and mutagenic effect. In addition, the growth of coliform bacteria in River and other aquatic resources has been reported due to contamination of PPI effluent. The studies also highlighted the presence of tannins, chlorophenols, dioxins, furans, biocide, fatty acids, and resin acids along with chlorolignine compounds as persistent organic pollutants (POP), which needs special attention for pollution prevention of rivers, lakes and other aquatic resources.

Extended suspect screening strategy to identify characteristic toxicants in the discharge of a chemical industrial park based on toxicity to Daphnia magna

With an increasing amount of industrial wastewater being discharged and the numerous chemicals existed in, methods to identify toxicants in such complex matrices are urgently needed for source control and quality management. In vivo toxicity to Daphnia magna was evaluated in the effluent of a wastewater treatment plant (WWTP). An extended suspect screening strategy was performed by bioassay-directed fractionation, accompanied with suspect screening of 228 suspect chemicals in toxic fractions based on their mass characteristics and chromatography characteristics. A toxicity evaluation of the original samples, organic components extracted by solid-phase extraction (SPE) and the filtered samples showed that organic compounds extracted by SPE were the main toxic components. Four of the 26 fractions of the organic extracts exhibited a toxic unit (TU) > 1.0, with hydrophobic organic compounds contributing most to the toxicity. Twenty-eight of the 228 suspects were identified in four toxic fractions, with 53.6% of the suspects elucidated by spectrum interpretation based on mass characteristics and 53.8% more false positive suspects removed based on chromatography characteristics. Finally, 6 pollutants, including imazalil, prometryn, propiconazole, tebuconazole, buprofezin and diazinon, were further confirmed and explained 48.79% of the observed toxicity. With 2.48 times more of the toxicity explained and 90% of the labor saved, the extended suspect screening strategy enabled more efficient and reliable identification compared to traditional quantitative analysis and non-target screening, especially for identification of characteristic toxicants in complex environmental matrices.

Effect of low-purity Fenton reagents on toxicity of textile dyeing effluent to Daphnia magna

This study aimed to identify the source of toxicity in textile dyeing effluent collected from February to July 2016, using Daphnia magna as a test organism. Toxicity identification evaluation (TIE) procedures were used to identify the toxicants in textile dyeing effluent, and Jar testing to simulate the Fenton process was conducted to identify the source of toxicants. Textile dyeing effluent was acutely toxic to D. magna [from 1.5 to 9.7 toxic units (TU)] during the study period. TIE results showed that Zn derived from the Fenton process was a key toxicant in textile dyeing effluent. Additionally, Jar testing revealed that low-purity Fenton reagents (FeCl₂ and FeSO₄), which contained large amounts of Zn (89 838 and 610 mg L^-1, respectively), were the source of toxicity. Although we were unable to conclusively identify the residual toxicity (approx. 1.4 TU of 9.71 TU) attributable to unknown toxicants in textile dyeing effluent, the findings of this study suggest that careful operation of the Fenton treatment process could contribute to eliminating its unintended toxic effects on aquatic organisms.

Is A/A/O process effective in toxicity removal? Case study with coking wastewater

The anaerobic-anoxic-oxic (A/A/O) process is the commonly used biological wastewater treatment process, especially for the coking wastewater. However, limit is known about its ability in bio-toxicity removal from wastewater. In this study, we evaluated the performance of A/A/O process in bio-toxicity removal from the coking wastewater, using two test species (i.e. crustacean (Daphnia magna) and zebra fish (Danio rerio)) in respect of acute toxicity, oxidative damage and genotoxicity. Our results showed that the acute toxicity of raw influent was reduced gradually along with A/A/O process and the effluent presented no acute toxicity to Daphnia magna (D. magna) and zebra fish. The reactive oxygen species (ROS) level in D. magna and zebra fish was promoted by the effluent from each tank of A/A/O process, showing that coking wastewater induced oxidative damage. Herein, the oxidative damage to D. magna was mitigated in the oxic tank, while the toxicity to zebra fish was reduced in the anoxic tank. The comet assays showed that genotoxicity to zebra fish was removed stepwise by A/A/O process, although the final effluent still presented genotoxicity to zebra fish. Our results indicated that the A/A/O process was efficient in acute toxicity removal, but not so effective in the removal of other toxicity (e.g. oxidative damage and genotoxicity). Considering the potential risks of wastewater discharge, further advanced toxicity mitigation technology should be applied in the conventional biological treatment process, and the toxicity index should be introduced in the regulation system of wastewater discharge.

A new tool for assessing sediment quality based on the Weight of Evidence approach and grey TOPSIS

Sediment is an important part of an aquatic ecosystem, so it is essential to develop an effective sediment quality assessment tool. This study aims to develop a new sediment quality assessment tool using a Weight of Evidence approach in combination with the grey TOPSIS (Technique for Order Preference by Similarity, a mathematical calculation of multi-criteria decision analysis). This tool can analyze data from chemical analyses, laboratory toxicity tests and benthic community structure analyses to generate individual results from each line of evidence, and integrate data from these three lines of evidence to obtain an overall assessment through an Excel Visual Basic for Application program. The tool can compare the relative magnitude of risks among sites and rate each site with high, moderate, or low ecological risk, thus guiding us to take pertinent measures toward polluted sediment. A case study of the sediment of Dongjiang River basin, south China, demonstrated the successful application of this tool. It proved that this assessment tool can provide a comprehensive and accurate assessment of sediment quality and efficiently discriminate risks among different sites, suggesting it is a powerful tool for environment risk assessment.

Screening of multiple hormonal activities in water and sediment from the river Nile, Egypt, using in vitro bioassay and gonadal histology

In Egypt, until yet no records are available regarding possible multiple hormonal activities in the aquatic systems and especially in the river Nile. In this paper, in vitro yeast estrogen screen (YES) and yeast androgen screen (YAS) were used to assess (for the first time) the multiple hormonal activities in surface waters and sediments of the river Nile. This study aimed to determine whether river Nile water can cause changes in gonadal histology of Nile tilapia (Oreochromis niloticus niloticus). All water samples exhibited extremely low levels of estrogenicity. Estrogenicity was nearly not detected in any of the sediment samples. Unlike the estrogenicity, significant androgenic activities were recorded in the water and sediment samples along the course of the river Nile. The present study reports for the first time quantification anti-estrogenic and anti-androgenic activities with high levels in both water and sediment of the river Nile. The greatest anti-estrogenic and anti-androgenic activities were observed in samples from downstream river Nile. These results indicated that the anti-estrogenic and anti-androgenic activities along the Nile course were great and the pollution of the sites at downstream was more serious than the upstream sites due to industrial and anthropogenic activities at these sites. Good correlations were observed among some hormonal activities, suggesting coexistence of these contaminants in the environmental matrices. There were no signs of sexual disruption in any of the gonads analyzed from either male or female Nile tilapia, demonstrating that no hormonal activity present along the Nile course was sufficient to induce adverse effects on reproductive development. Further investigation is necessary to identify the compounds responsible for the hormonal activities in the river Nile and to examine effects of very low levels of hormonally active compounds on gonadal histology, as well as in the development of more sensitive biomarkers.

Reduction in toxicity of coking wastewater to aquatic organisms by vertical tubular biological reactor

We conducted a battery of toxicity tests using photo bacterium, algae, crustacean and fish to evaluate acute toxicity profile of coking wastewater, and to evaluate the performance of a novel wastewater treatment process, vertical tubular biological reactor (VTBR), in the removal of toxicity and certain chemical pollutants. A laboratory scale VTBR system was set up to treat industrial coking wastewater, and investigated both chemicals removal efficiency and acute bio-toxicity to aquatic organisms. The results showed that chemical oxygen demand (COD) and phenol reductions by VTBR were approximately 93% and 100%, respectively. VTBR also reduced the acute toxicity of coking wastewater significantly: Toxicity Unit (TU) decreased from 21.2 to 0.4 for Photobacterium phosphoreum, from 9.5 to 0.6 for Isochrysis galbana, from 31.9 to 1.3 for Daphnia magna, and from 30.0 to nearly 0 for Danio rerio. VTBR is an efficient treatment method for the removal of chemical pollutants and acute bio-toxicity from coking wastewater.

Estrogenic activity and identification of potential xenoestrogens in a coking wastewater treatment plant

In this study, the estrogenic activities in influent and effluents of coking wastewater from different treatment stages were studied using Yeast Estrogen Screen (YES) bioassays. Raw extracts were further fractioned to identify the potential xenoestrogens combined with YES bioassays and gas chromatography-mass spectrometry analysis. Influent, primary effluent, and anaerobic effluent showed high estrogenic activities, with potencies of 1136±269, 1417±320, and 959±69 ng/L of 17β-estradiol (E2) equivalent (EEQ), respectively. The potency of estrogenic activity was gradually removed through the treatment processes. In the final effluent, the estrogenic activity was reduced to 0.87 ng EEQ/L with a total removal efficiency of more than 99%, suggesting that the estrogenic activity was almost completely removed in the coking wastewater. For the fractions of raw extracts, bioassay results showed that the estrogenic activities were mostly present in the polar fractions. Correlation analysis between estrogenic activities and responses of identified chemicals indicated that potential xenoestrogens were the derivatives of indenol, naphthalenol, indol, acridinone, fluorenone, and carbazole. The estrogenic activity in the final effluent was higher than the predicted no effect concentration (PNEC) for E2, implying that the discharged effluent would probably exert estrogenic activity risk to the aquatic ecosystem in "the worst-case scenario."

Multispecies acute toxicity evaluation of wastewaters from different treatment stages in a coking wastewater-treatment plant

Coking wastewater contributes approximately 5% of the total discharge volume of industrial wastewaters every year in China. The toxicity of coking wastewater to aquatic organisms is still unknown. The authors evaluated the toxicity of wastewater from different treatment stages in a coking wastewater treatment plant, South China, using 5 test species belonging to different trophic levels: luminous bacteria, green alga, a crustacean, duckweed, and zebrafish embryos. The raw influent displayed the highest toxicity to the test species, with toxic units ranging from 16.2 to 1176. The toxicity in the wastewater was then gradually removed by sequential primary treatment, biological fluidized-bed treatment, and secondary clarifier treatment. The toxic unit of the final effluent was reduced to 2.26 for the green alga (Pseudokirchneriella subcapitata) and to 0 for the other 4 organisms. Quantitative analysis of metals and polycyclic aromatic hydrocarbons (PAHs) and qualitative scanning by gas chromatography-mass spectrometry showed the presence of a variety of pollutants in the coking wastewaters. Multivariate statistical analysis revealed that the toxicity in the coking wastewater was correlated to the chemical oxygen demand, total nitrogen, ammonia nitrogen, volatile phenols, sulfide, metals (Cr, As, Sb, Hg, Pb, and Ni), and ΣPAHs. Based on the results, it is required to set a safety emission limit value for the discharge of coking wastewater to protect aquatic organisms in the receiving water bodies.

Toxicity evaluation of pig slurry using luminescent bacteria and zebrafish

Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri), larvae and embryos of zebrafish (Danio rerio) were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC₅₀ for luminescent bacteria and the LC₅₀ for larvae were only 6.81% (v/v) and 1.95% (v/v) respectively, and embryonic development was inhibited at just 1% (v/v). Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR), while the LC₅₀ of larvae was 75.23% (v/v) and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent.

Identification of specific organic contaminants in different units of a chemical production site

Due to the very limited number of studies dealing with the chemical composition of industrial wastewaters, many industrial organic contaminants still escape our view and consequently also our control. We present here the chemical characterization of wastewaters from different units of a chemical complex, thereby contributing to the characterization of industrial pollution sources. The chemicals produced in the investigated complex are widely and intensively used and the synthesis processes are common and applied worldwide. The chemical composition of untreated and treated wastewaters from the chemical complex was investigated by applying a non-target screening which allowed for the identification of 39 organic contaminants. According to their application most of them belonged to four groups: (i) unspecific educts or intermediates of industrial syntheses, (ii) chemicals for the manufacturing of pharmaceuticals, (iii) educts for the synthesis of polymers and resins, and (iv) compounds known as typical constituents of municipal sewage. A number of halogenated compounds with unknown toxicity and with very high molecular diversity belonged to the second group. Although these compounds were completely removed or degraded during wastewater treatment, they could be useful as "alarm indicators" for industrial accidents in pharmaceutical manufacturing units or for malfunctions of wastewater treatment plants. Three potential branch-specific indicators for polymer manufacturing were found in the outflow of the complex. Among all compounds, bisphenol A, which was present in the leachate water of the on-site waste deposit, occurred in the highest concentrations of up to 20 000 μg L(-1). The comparison of contaminant loads in the inflow and outflow of the on-site wastewater treatment facility showed that most contaminants were completely or at least significantly removed or degraded during the treatment, except two alkylthiols, which were enriched during the treatment process. The chemical composition of the inflow samples showed a very heterogenic composition and strongly varied, reflecting that large scale industrial synthesis is carried out in batches. The outflow contained mainly unspecific chlorinated educts or intermediates of industrial syntheses as well as compounds which are known as typical constituents of municipal wastewaters.

Thyroid hormone disrupting activities of sediment from the Guanting Reservoir, Beijing, China

In the present study, yeast bioassays were used to evaluate and characterize the thyroid receptor (TR) disrupting activities of the organic extracts and elutriates of the sediments from the Guanting Reservoir, Beijing, China. An accelerated solvent extraction was used to separate the organic extracts, which were subjected to a yeast bioassay. The organic extracts could affect thyroid hormone signaling by decreasing the binding of the thyroid hormone. The TR antagonistic activity equivalents (TEQbio) referring to amiodarone hydrochloride were calculated and the observed TEQbio-organic extracts ranged from 25.4 ± 3.7 to 176.9 ± 18.0 μg/g. Elutriate toxicity tests using the modified yeast bioassay revealed that the elutriates also significantly antagonized the TR, with the TEQbio-elutriates ranging from N.D. to 7.8 ± 0.8 μg/L. To characterize the toxic compounds, elutriates were extracted by using a C18 cartridge or treated with ethylenediaminetetraacetic acid (EDTA, 30 mg/L). The results suggested that the addition of EDTA eliminated over 74.3% of the total effects, and the chemical analysis revealed that heavy metals, some of which exhibited TR disrupting potency, for example Zn and Cd, were detectable with higher concentrations in the elutriates. Thus, the cause(s) of toxicity in the elutriate appear to be partly related to the heavy metals.

Identification and mRNA expression of two 17β-hydroxysteroid dehydrogenase genes in the marine mussel Mytilus galloprovincialis following exposure to endocrine disrupting chemicals

17β-Hydroxysteroid dehydrogenases (17β-HSDs) are multifunctional enzymes involved in the metabolism of steroids, fatty acids, retinoids and bile acid. In this study, two novel types of 17β-HSDs (named as MgHsd17b10 and MgHsd17b12) were cloned from Mytilus galloprovincialis by using rapid amplification of cDNA ends (RACE) approaches. Sequence analysis showed that MgHsd17b10 and MgHsd17b12 encoded a polypeptide of 259 and 325 amino acids, respectively. Phylogenetic analysis revealed that MgHsd17b10 and MgHsd17b12 were evolutionarily clustered with other invertebrate 17β-HSD type 10 and 17β-HSD type 12 homologues. The MgHsd17b10 and MgHsd17b12 transcripts could be detected in all examined tissues with higher expression levels in digestive glands and gonad. After exposed to endocrine disrupting chemicals (Bisphenol A or 2,2',4,4'-tetrabromodiphenyl ether), the expression of MgHsd17b10 and MgHsd17b12 transcripts was both down-regulated in digestive glands. These findings suggest that MgHsd17b10 and MgHsd17b12 perhaps play an important role in the endocrine regulation of M. galloprovincialis.

Identification of toxicity variations in a stream affected by industrial effluents using Daphnia magna and Ulva pertusa

A comprehensive toxicity monitoring study from August to October 2011 using Daphnia magna and Ulva pertusa was conducted to identify the cause of toxicity in a stream receiving industrial effluents (IEs) from a textile and leather products manufacturing complex. Acute toxicity toward both species was observed consistently in IE, which influenced toxicity of downstream (DS) water. A toxicity identification evaluation (TIE) confirmed that both Cu and Zn were key toxicants in the IE, and that the calculated toxicity based on Cu and Zn concentrations well simulated the variation in the observed toxicity (r(2)=0.9216 and 0.7256 for D. magna and U. pertusa, respectively). In particular, U. pertusa was sensitive enough to detect acute toxicity in DS and was useful to identify Zn as a key toxicant. Activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and malondialdehyde were induced significantly in D. magna, although acute toxicity was not observed. In addition, higher levels of antioxidant enzymes were expressed in DS than upstream waters, likely due to the Cu and Zn from IE. Overall, TIE procedures with a battery of bioassays were effective for identifying the cause of lethal and sub-lethal toxicity in effluent and stream water.

Toxicity identification evaluation of cosmetics industry wastewater

The cosmetics industry has shown steady growth in many developing countries over the past several years, yet little research exists on toxicity of wastewaters it generates. This study describes a toxicity identification evaluation conducted on wastewater from a small Brazilian hair care products manufacturing plant. Physicochemical and ecotoxicological analyses of three wastewater treatment plant inlet and outlet samples collected over a six month period revealed inefficient operation of the treatment system and thus treated wastewater organic matter, suspended solids and surfactants contents consistently exceeded discharge limits. Treated wastewater also presented high acute toxicity to Daphnia similis and chronic toxicity to Ceriodaphnia dubia and Pseudokirchneriella subcapitata. This toxicity was associated with suspended solids, volatile or sublatable and non-polar to moderately polar organic compounds that could be recovered in filtration and aeration residues. Seven surfactants used in the largest quantities in the production process were highly toxic to P. subcapitata and D. similis. These results indicated that surfactants, important production raw materials, are a probable source of toxicity, although other possible sources, such as fragrances, should not be discarded. Improved treatment plant operational control may reduce toxicity and lower impact of wastewater discharge to receiving waters.