Utilizing Carbon Dots Derived from Waste Face Masks for Pentachlorophenol Detection.

Pentachlorophenol is a very toxic chemical that is used as a pesticide, fungicide, herbicide, wood preservative, etc., and it should be monitored in terms of human health and environmental production. Another environmental problem is the increase in the use of facemasks, especially during the COVID-19 pandemic. This study provides a value added chemicals to sustainability of recycling process. Fluorescent carbon dots (CDs) were synthesized from waste facemasks and investigated their fluorescence sensor performances. UV-Vis and fluorescence spectra of the synthesized carbon dots were recorded in different organic solvents. The sensor properties of these carbon dots against pesticides were investigated, and a 'turn-off' response was observed toward pentachlorophenol. The limit of detection was found 8.5 µM in the linear range from 43.3 µM to 375 µM. This study showed that waste plastics such as facemasks can be recycled to obtain carbon dots, which are used in different technological areas such as photocatalysis, bioimaging, etc., as well as in sensors.

A cell-free fluorescence biosensor based on allosteric transcription factor NalC for detection of pentachlorophenol.

Pentachlorophenol (PCP) was once used as a pesticide, germicide, and preservative due to its stable properties and resistance to degradation. This study aimed to design a biosensor for the quantitative and prompt detection of capable of PCP. A cell-free fluorescence biosensor was developed while employing NalC, an allosteric Transcription Factor responsive to PCP and In Vitro Transcription. By adding a DNA template and PCP and employing Electrophoretic Mobility Shift Assay while monitoring the dynamic fluorescence changes in RNA, this study offers evidence of NalC's potential applicability in sensor systems developed for the specific detection of PCP. The biosensor showed the capability for the quantitative detection of PCP, with a Limit of Detection (LOD) of 0.21 µM. Following the addition of Nucleic Acid Sequence-Based Amplification, the fluorescence intensity of RNA revealed an excellent linear relationship with the concentration of PCP, showing a correlation coefficient (R2) of 0.9595. The final LOD was determined to be 0.002 µM. This study has successfully translated the determination of PCP into a fluorescent RNA output, thereby presenting a novel approach for detecting PCP within environmental settings.

Bisphenol-A and pentachlorophenol sodium levels in patients with rosacea.

BACKGROUND/ OBJECTIVES: Rosacea is a common chronic inflammatory skin disorder. Endocrinedisrupting chemicals (EDC) are toxic substances, that may gain entry through the skin and subsequently interfere with hormonal and immune functions. Bisphenol A (BPA) and pentachlorophenol sodium (PCS) are two of these EDCs, incriminated in the pathogenesis of certain inflammatory skin disorders. We aimed to test the hypothesis that exposure to BPA and PCS might be involved in the pathogenesis of rosacea. METHODS: This prospective cross-sectional study involved 34 patients with rosacea (18F/16 M; mean age 48.5 ± 11 years) and 34 age and sex-matched healthy controls (20 F/14 M; mean age 48.2 ± 10.2 years). Main anthropometric measures, fasting plasma glucose (FPG), insulin, HOMA-IR, lipids, C-reactive protein (CRP), BPA, and PCS levels were quantified and recorded. RESULTS: Serum CRP (9.6 ± 3.4 vs. 3.7 ± 1.6 mg/L, respectively, p0.05 for all). Serum BPA levels were 55.8 ± 14.4 and 51.9 ± 19.2 ng/mL, and PCS levels were 63.3 ± 45.9 ng/mL and 68.6 ± 40.8 ng/mL for patients and healthy controls, respectively. There was no significant difference in BPA and PCS levels between the two groups (p > 0.05 for both). No significant association was found among HOMAIR, CRP, BPA, and PCS levels (p > 0.05 for all). CONCLUSIONS: Although the present study fails to provide presumptive evidence for the role of BPA and PCS in rosacea, the question as to other EDCs might be involved in its etiopathogenesis remains. This hypothesis requires confirmation in large-scale future prospective trials.

Pentachlorophenol exposure induced neurotoxicity by disrupting citrulline metabolism in larvae and adult zebrafish.

Pentachlorophenol (PCP) is a ubiquitous environmental toxicant with various adverse effects. Although its neurotoxicity has been reported, the underlying mechanism and subsequent detoxification remain unclear. In this study, embryos and adult zebrafish were exposed to PCP to determine its potential neurotoxic mechanism and protective indicators. The survival rate, heart rate, mobility time, active status and moving distance were significantly decreased in larvae after 30 µg/L PCP exposure. Likewise, the mobile time, latency to the first movement, velocity and moving distance of adult zebrafish were significantly reduced by PCP exposure. Untargeted metabolomics analysis of larvae revealed that arginine and proline metabolism was the primary pathway affected by PCP exposure, reflected by increased proline and decreased citrulline (CIT) contents, which were confirmed by quantitative data. PCP exposure suppressed the conversion from arginine to CIT in larvae by downregulating the expression of nos1 and nos2a. Ornithine content was increased in the brains and intestines of adult zebrafish after PCP exposure, which inhibited ornithine catabolism to CIT by downregulating otc, resulting in reduced CIT. Intriguingly, CIT supplementation significantly restored the neurobehavioral defects induced by PCP in larvae and adult zebrafish. CIT supplementation upregulated the expression of ef1α and tuba1 in larvae and inhibited the downregulation of ef1α in the brains of adult zebrafish. Taken together, these results indicated that CIT supplementation could protect against PCP-induced neurotoxicity by upregulating the expression of genes involved in neuronal development and function.

Synthesis of magnetically recyclable porous cross-linked aggregates of Tramates versicolor MTCC 138 laccase for the efficient removal of pentachlorophenol from aqueous solution.

The primary objective of this study is to synthesize the magnetically separable highly active porous immobilized laccase for the removal of pentachlorophenol (PCP) in an aqueous solution. Magnetic porous cross-linked enzyme aggregates (Mp-CLEAs) of laccase were synthesized using 1% starch solution with 5 mM glutaraldehyde followed by 10 h of cross-linking time with an activity recovery of 90.85 ± 0.2%. The biocatalytic efficiency of magnetic porous CLEAs (Mp-CLEAs) was 2-fold higher than that of magnetic CLEAs. The synthesized Mp-CLEAs were mechanically stable with enhanced catalytic efficiency, and reusability thus overcoming the mass transfer limitations and enzyme loss. At 40 °C, the thermal stability of the magnetic porous immobilized laccase was improved, with a 602 min half-life compared to 207 min half-life for the free enzyme. Using 40 U/mL of laccase for the removal of 100 ppm of PCP, M-CLEAs, and Mp-CLEAs removed 60.44% and 65.53% of PCP, respectively. Furthermore, to enhance PCP removal, a laccase-aided system was harnessed by optimizing various surfactants and mediators. Of these, 0.1 mM of rhamnolipid and 2,3 dimethoxy phenol had the highest PCP removal rates of 95.12% and 99.41%, respectively, for Mp-CLEAs. This study demonstrates the efficacy of the laccase-surfactant-mediator system for the removal of PCP from the aqueous solution, which can also be proposed for real-time application.

Designing a novel poly (methyl vinyl ether maleic anhydride) based polymeric membrane with enhanced antifouling performance for removal of pentachlorophenol from aqueous solution.

In this current study, poly (methyl vinyl ether maleic anhydride) (PMVEAMA), a sustainable additive, was incorporated into poly (ether-ether sulfone) (PEES) polymer to design a novel polymeric hybrid membrane for the efficient filtration of toxic pentachlorophenol (PCP) from an aqueous medium. Hydrophilic additives significantly altered the membrane's morphology, structure, porosity, water content, and flux performance compared to the bare PEES membrane. The influence of PMVEAMA on the structural modification of the synthesized polymer membrane was confirmed by SEM, ATR-FTIR, XRD, AFM, zeta potential and contact angle. Findings revealed that the addition of PMVEAMA to the PEES polymer enhances the porosity (17.7%-28.9%), water content (29.8%-39.8%), and pure water flux (186 Lm-2h-1 to 349 Lm-2h-1). The effect of PMVEAMA concentration on the PEES membrane exhibited more finger like pores, better porosity and hydrophilicity, reduced surface roughness, fouling and increased permeability. The fouling studies exhibit an improved 57% PCP rejection and permeation flux of 22.3 Lm-2h-1 due to the addition of the hydrophilic additive. Surprisingly, the incorporation of PMVEAMA into the bare PEES membrane resulted in a high flux recovery ratio of 73.7%. The antifouling properties and enhanced permeability of the PEES/PMVEAMA membrane indicates its potential application in water purification sectors for the efficient separation of contaminants.

Organotin and organochlorine toxicants activate key translational regulatory proteins in human immune cells.

Environmental contaminant exposures occur due to the widespread use of synthetic chemicals. Tributyltin (TBT), dibutyltin (DBT), and pentachlorophenol (PCP) are each used in a variety of applications, including antifouling paints and stabilizers in certain plastics. Each of these compounds has been found in human blood, as well as other tissues, and they have been shown to stimulate pro-inflammatory cytokine production in human immune cells, Inflammatory cytokines mediate response to injury or infection. However, if their levels are increased in the absence of an appropriate stimulus, chronic inflammation can occur. Chronic inflammation is associated with a number of pathologies including cancer. Stimulation of pro-inflammatory cytokine production by these toxicants is dependent on activation of ERK 1/2 and/or p38 MAPK pathways. MAPK pathways have the capacity to regulate translation by increasing phosphorylation of key translation regulatory proteins. There have been no previous studies examining the effects of TBT, DBT, or PCP on translation. The current study shows that ribosomal protein S6 (S6), eukaryotic initiation factor 4B (eIF4B), and eIF4E are phosphorylated (activated) and/or their total levels are elevated in response to each of these compounds at concentrations found in human blood. Activation/increased levels of translational proteins occurred at concentrations of the compounds that have been shown to elevate pro-inflammatory cytokine production, but where there is no increase in mRNA for those proteins was seen. Compound-stimulated increases in translation appear to be part of the mechanism by which they elevate protein production in immune cells.

Pentachlorophenol causes redox imbalance, inhibition of brush border membrane and metabolic enzymes, DNA damage and histological alterations in rat kidney.

Pentachlorophenol (PCP) is a synthetic organochlorine compound that is widely used in biocide and pesticide industries, and in preservation of wood, fence posts, cross arms and power line poles. Humans are usually exposed to PCP through air, contaminated water and food. PCP enters the body and adversely affects liver, gastrointestinal tract, kidney and lungs. PCP is a highly toxic class 2B or probable human carcinogen that produces large amount of reactive oxygen species (ROS) within cells. This work aimed to determine PCP-induced oxidative damage in rat kidney. Adult rats were given PCP (25, 50, 100, 150 mg/kg body weight), in corn oil, once a day for 5 days while control rats were given similar amount of corn oil by oral gavage. PCP increased hydrogen peroxide level and oxidation of thiols, proteins and lipids. The antioxidant status of kidney cells was compromised in PCP treated rats while enzymes of brush border membrane (BBM) and carbohydrate metabolism were inhibited. Plasma level of creatinine and urea was also increased. Administration of PCP increased DNA fragmentation, cross-linking of DNA to proteins and DNA strand scission in kidney. Histological studies supported biochemical findings and showed significant damage in the kidneys of PCP-treated rats. These changes could be due to redox imbalance or direct chemical modification by PCP or its metabolites. These results signify that PCP-induced oxidative stress causes nephrotoxicity, dysfunction of BBM enzymes and DNA damage.

Effectiveness of combined tools: adsorption, bioaugmentation and phytoremediation for pesticides removal from wastewater.

The aim of this study was the comparison of two process in pentachlorophenol (PCP: 100 mg L-1) removal by combined process bioaugmentation-adsorption and bioaugmentation-phytoremediation in secondary treated wastewater (STWW). The phytoremediation procedure was conducted by using two plants such as Typha angustifolia and Schoenoplectus acutus, and the bioaugmentation procedure was operated by Pseudomonas putida HM 627618 as a plant growth promoting bacteria (PGPR). The adsorption process was performed by palm date activated carbon. The PCP monitoring was assessed by high performance liquid chromatography (HPLC) and the optical density determination at 600 nm (OD600). The performance of the two processes was observed by the determination of total bacteria, chlorophylls and physical and chemical analysis (COD, pH, conductivity, chloride, and organic carbon). The alfalfa seed germination test was conducted to assess the two operational performance procedures. According to the results obtained from the physical and chemical analysis of the treated STWW, there was no significant differences in the pH and in the EC content of the bioaugmentation-phytoremediation treatment, while a significant increase of the EC content was observed in the bioaugmentation-adsorption to 5.08 mS cm-1. The COD value significantly decreased up to 1320 mg L-1 in bioaugmentation-adsorption treatment (control value 2400 mg L-1) and 98 mg L-1 in bioaugmentation-phytoremediation treatment (control value 98 mg L-1). Microbial biomass monitoring of P. putida shows significant greater in both processes in the order of 9.18 and 7.01 Log CFU mL-1 for bioaugmentation-adsorption and bioaugmentation-phytoremediation, respectively. The chlorophyll content in Typha angustifolia and Schoenoplectus acutus significantly decreased after 144 h with the exception of the chlorophyll a content of Schoenoplectus acutus in which the content increased up to 3.31 mg mL-1. Comparing the performance of these two treatments, it was found according to HPLC analysis that the bioaugmentation-adsorption process was more efficient in removing about 97% of PCP after 48 h, against around 90% of PCP after 72 h for the phytoremediation-bioaugmentation. The alfalfa seeds showed a germination rate after the 5th day of incubation of 100% and 95%, respectively for the PCP-non-contaminated and treated STWW, while for wastewater containing PCP the germination was totally inhibited.

This paper describing sensitive methods of combined bioaugmentation-phytoremediation and bioaugmentation-adsorption for pentachlorophenol (PCP) depletion in wastewater. The novelty is the choice of a macrophyte Typha angustifolia and Schoenoplectus acutus in constructed wetland fixed in clay matrix. The two-selected plants are still used for the elimination of heavy metals but not for pesticide in wastewater. Also, the combined process bioaugmentation-adsorption was not tested in other researches. On the other side, in this study, the phytoremediation technique combined with bacteria positively affected the plants activity in order to promote pollutant remediation. Hence, the Pseudomonas putida HM 627618 in wastewater with the macrophyte presence or date stone adsorbent have a great capacity to reduce this pollutant (PCP) by improving the bioremediation process.

Determination of Pentachlorophenol in Seafood Samples from Zhejiang Province Using Pass-Through SPE-UPLC-MS/MS: Occurrence and Human Dietary Exposure Risk.

Pentachlorophenol (PCP) has attracted wide attention due to its high toxicity, persistence, and bioaccumulation. In this study, a sensitive UPLC-MS/MS method for the determination of PCP in seafood samples was developed and validated. The samples were ultrasonic extracted with acetonitrile containing 1% acetic acid-acetonitrile and followed by using a pass-through solid-phase extraction (SPE) cleanup on Captiva EMR-Lipid cartridges. The linearity of this method ranged from 1 to 1000 µg/L, with regression coefficients of >0.99. The detection limit and quantitation limit were 0.5 µg/kg and 1.0 µg/kg, respectively. The recoveries in different types of seafood samples ranged from 86.4% to 102.5%, and the intra-day and inter-day relative standard deviations (RSDs) were 3.7% to 11.2% and 2.9% to 12.1%, respectively (n = 6). Finally, the method has been successfully utilized for the screening of PCP in 760 seafood samples from Zhejiang Province. PCP was detected in 5.8% of all seafood samples, with the largest portion of detections found in shellfish, accounting for approximately 60% of the total. The average concentrations detected ranged from 1.08 to 21.49 µg/kg. The non-carcinogenic risk indices for adults and children who consume PCP ranged from 10-4 to 10-3 magnitudes. All of these indices stayed significantly below 1, implying that the health risk from PCP in marine organisms to humans is minimal.

Human health ambient water quality criteria and risk assessment of pentachlorophenol in Poyang Lake Basin, China.

Pentachlorophenol (PCP) has been widely used as an insecticide for killing oncomelania (the intermediate host of schistosome) in China and leads to severe environmental contamination. Poyang Lake, as the largest freshwater lake and bird habitat in China, was once a schistosomiasis epidemic area. In this study, the concentrations of PCP in water and aquatic products from Poyang Lake were determined and analyzed, and then the human health ambient water quality criteria (AWQC) was derived based on native parameters of Poyang Lake basin. Finally, a comprehensive analysis of the health risks of drinking water and different types of aquatic products consumption was carried out. The results showed that PCP concentrations were ranged from 0.01 to 0.43 µg/L in surface water and 3.90 to 85.95 µg/kg in aquatic products. Due to the carcinogenicity of PCP, the human health AWQC for PCP are 0.02 µg/L for consumption of water and organisms and 0.03 µg/L for consumption of organisms only. Deterministic and probabilistic risk analysis indicated that the non-carcinogenic risk of PCP were acceptable in Poyang Lake, while the carcinogenic risk cannot be ignored. The health risks of PCP caused by aquatic products consumption were higher than that by drinking water. The percentages of acceptable risk for the population in Poyang Lake Basin were 99.95% at acceptable level of 10-4. Based on the sensitivity analysis, the impact of PCP concentrations on health risk values ranged from 53 to 82%. The study provided valuable information for regional water quality criteria development and water quality assessment.

Synergistic Effect of Soil Organic Matter and Nanoscale Zero-Valent Iron on Biodechlorination.

Nanoscale zero-valent iron (nZVI) provides a promising solution for organochlorine (OC)-contaminated soil remediation. However, the interactions among nZVI, soil organic matter (SOM), and indigenous dechlorinating bacteria are intricate, which may result in unascertained effects on the reductive degradation of OCs and merits specific investigation. Herein, we isolated an indigenous dehalogenation bacterium (Burkholderia ambifaria strain L3) from a paddy soil and further investigated the biodechlorination of pentachlorophenol (PCP) with individual and a combination of SOM and nZVI. In comparison with individual-strain L3 treatment, the cotreatment with nZVI or SOM increased the removal efficiency of PCP from 34.4 to 44.3-54.2% after 15 day cultivation. More importantly, a synergistic effect of SOM and nZVI was observed on the PCP removal by strain L3, and the PCP removal efficiency reached up to 75.3-84.5%. Other than the biodegradation through ortho- and meta-substitution under the individual application of SOM or nZVI, PCP was further biodegraded to 2,4,6-trichlorophenol (TCP) through para-substitution by the isolated bacteria with the cotreatment of SOM and nZVI. The main roles of the nZVI-SOM cotreatment in the biodegradation included the SOM-facilitated microbial proliferation, the nZVI-promoted microbial transformation of SOM, and the induced higher electron transport capacity of redox Fe-PCP biocycling. These findings provide a novel insight into the action of nZVI in environmental remediations.

3,4-Dihydroxybenzaldehyde attenuates pentachlorophenol-induced cytotoxicity, DNA damage and collapse of mitochondrial membrane potential in isolated human blood cells.

Pentachlorophenol (PCP) is a chlorophenolic compound that is widely used as pesticide, biocide and as a wood preservative to treat utility poles and wharf pilings. PCP is rapidly absorbed through the gastrointestinal tract and enters the blood where it generates active oxygen species in target cells. We have, therefore, examined the protective effect of plant antioxidant 3,4-dihydroxybenzaldehyde (DHB) against PCP-induced cyto-and geno-toxicity in human red blood cells (RBC) and lymphocytes, respectively. Human RBC were incubated at 37°C with 0.75 mM PCP, either alone or in presence of different concentrations of DHB (0.05-2.0 mM). Several biochemical parameters were determined in whole cells and hemolysates. Incubation of RBC with PCP alone increased the formation of reactive oxygen and nitrogen species (ROS and RNS) that resulted in oxidation of proteins, lipids, cellular thiols and plasma membrane damage. The antioxidant defense system was impaired and glucose metabolism was inhibited. However, prior treatment of RBC with DHB lowered ROS and RNS generation and attenuated PCP-induced oxidative damage of cell components. DHB alone enhanced electron transport by the plasma membrane redox system and also prevented its inhibition by PCP. DHB significantly prevented PCP-induced transformation of RBC morphology from normal biconcave shape to spherocytes, spiculated acanthocytes and echinocytes. DHB protected human lymphocytes from PCP-induced DNA damage and strand breaks, lysosomal membrane damage and collapse of the mitochondrial membrane potential. These results show that DHB mitigates PCP-induced cytotoxicity and can potentially function as a chemoprotective agent against the harmful effects of PCP and possibly other chlorophenols.

Macrophyte and indigenous bacterial co-remediation process for pentachlorophenol removal from wastewater.

This study has contributed in the description of bioaugmentation-phytoremediation efficiency process using Typha angustifolia concerning PCP tolerance and removal from wastewater. Samples of wastewater were collected from industrial wastewater plants, namely row wastewater effluent "E.WW", primary wastewater "P.WW", secondary wastewater "S.WW", clarified wastewater "AC.WW". These effluents were spiked with PCP at different rate (100, 500, and 1000 mg.L-1), physical, chemical and biological properties were monitored. A second experiment was set up in order to check the efficiency of phytoremediation treatments of the different effluents artificially contaminated with 200 mg.L-1 PCP after 20 days lab scale experiment. An important PCP removal by indigenous bacteria was showed in S. WW with values from 1000 to 72.2 mg.L-1 from T0 (start of the experiment) to TF (end of the experiment), respectively. Phytoremediation process allowed a decrease of PCP rate from 200 to 6.4 mg.L-1, a decrease of chloride content from 14.0 to 4.0 mg.L-1 in S.WW samples was observed. Furthermore, a significant increase of bacterial number in S.WW and AC.WW to 1.700 × 106 and 1.450 × 106 CFU.mL-1, respectively was observed. In addition, the DGGE analysis showed that after bioaugmentation-phytoremediation treatments, the highest species richness and relative abundance in wastewater effluent was observed. Novelty statement Pentachlorophenol (PCP) is one of highly toxic of polychlorophenols and required to continuously monitor in environment. This paper presenting a sensitive method phytoremediation and bioaugmentation for PCP biotransformation in wastewater. The novelty is the choice of a macrophyte Typha angustifolia, which is still used for the elimination of heavy metals but it not used for pesticide and pollutant removal in wastewater. Also, there are different analysis that was performed in order to check phyto-technique process (DGGE and HPLC). On the other side, in this study, the phyto-techniques with Typha angustifolia positively affected intrinsic microorganisms in order to promote pollutant remediation. So, the intrinsic microorganisms in wastewater with the macrophyte presence have a great capacity to reduce this pollutant and improve the bioremediation process.

Surfactant efficiency on pentachlorophenol-contaminated wastewater enhanced by Pseudomonas putida AJ 785569.

This study aims to evaluate the effect of three surfactants on the removal of PCP (800 mg L-1) from Secondary Treated Wastewater (STWW) by Pseudomonas putida AJ 785569. The effect of surfactants [sodium lauryl sulfate (SDS) as anionic, Tween 80 (TW80) as non-anionic and cetyltrimethylammonium bromide (CTAB) as cationic] is tested about the three following aspects: (1) bacterial growth, (2) bacterial biofilm formation or development and (3) PCP rate removal. The results showed that strain P. putida AJ 785569 could adsorb around 30 mg L-1 and remove 600 mg L-1 of PCP within 168 h of incubation. The SDS developed the growth of bacteria and the removal of PCP. This PCP removal in mineral salt medium (MSM) is around 760 mg L-1 (95% degradation) higher than the ones registered with CTAB and TW80 with a value 506.75 (63% degradation) and 364.1 mg L-1 (45% degradation), respectively. The obtained results of chloride concentration showed an important relation with PCP removal during incubation with an important value. Monitoring the development of bacterial biofilm, in MSM medium added with PCP (100 mg L-1) by strain P. putida AJ 785569, showed a significant increase in the optical density value from 0.9 to 4 at λ = 595 nm, a modification of strain P. putida AJ 785569's morphotype, density and color colonies.

Exhaustion of pentachlorophenol in soil microcosms with three Pseudomonas species as detoxification agents.

Pentachlorophenol (PCP) is a toxic compound, which is widely used as a wood preservative product and general biocide. It is persistent in the environment and has been classified as a persistent organic pollutant to be reclaimed in many countries. Bioremediation is an emerging approach to rehabilitating areas polluted by recalcitrant xenobiotics. In the present study, we evaluated the potential of three strains of Pseudomonas (P. putida S121, P. rhizophila S211, and P. fuscovagiceae S115) as bioremediation agents in depletion and detoxification of PCP in soil microcosms. PCP removal was effectively optimized using a central-composite experimental design and response surface methodology (RSM). The optimum conditions for maximum PCP removal yield (85 ± 5%) were: 500 mg/kg PCP concentration, 108 UFC/g soil inoculum size of each strain and 55 days incubation period. The bacterial strains, P. putida, P. rhizophila, and P. fuscovagiceae, showed good capability to tolerate and degrade PCP so that they could be successfully used in synergistic effect to treat PCP polluted soils.

Applicability of Enchytraeus bulbosus as a model species in ecotoxicology and risk assessment.

Enchytraeus bulbosus is listed in the ISO and OECD standard guidelines as a possible test species of enchytraeid. However, in contrast to other listed species, its applicability in ecotoxicological studies as well as its sensitivity is widely unknown. Therefore, copper, pentachlorophenol(PCP), carbendazim, and chloroacetamide have been investigated by performing two-generation studies with multiple endpoints. Comparable toxicity trends to the existing studies were shown for copper and PCP in the two-generation studies of E. bulbosus. Dose-related abnormal swelling of clitella were found for the first time with PCP and chloroacetamide treatments. Sensitivity comparisons of E. bulbosus to other terrestrial test species were also conducted. E. bulbosus showed high sensitivity, it has comparable sensitivity as other sensitive species of genus Enchytraeus ( E. albidus or E. luxuriosus)to different chemicals, and was more sensitive than E. crypticus and earthworm species ( Eisenia fetida or Eisenia andrei). Combined with the phylogenetic and biological characterization, the results lead to the conclusion that E.bulbosus is a suitable model species in ecotoxicology and the chemical risk assessment (especially in multi-generation) because it has a short generation time, comparatively moderate fecundity, ideal and reasonable sensitivity.

Effects of compost-derived humic acid on the bio-dechlorination of pentachlorophenol in high iron content paddy soil.

Pentachlorophenol (PCP) is a common residual organic pollutant in paddy soil, and its harmful effects on soil ecosystems have been confirmed. Humic acid (HA) could act as an electron shuttle to promote the reductive dechlorination of PCP under anaerobic conditions. Humic-like substances produced by composting of kitchen waste were able to facilitate the reductive dechlorination of PCP during Fe(III) oxide reduction by iron-reducing bacteria. However, the effects of compost-derived HAs on reductive dechlorination of PCP in a paddy soil system with a high iron content have not been fully confirmed. The characteristics of HAs from different stages of composting during bio-dechlorination of PCP were still unclear. The functional components of compost-derived HAs, which are responsible for reductive dechlorination of PCP in different stages of composting, also need further investigation. In this study, we conducted a series of experiments on the Guangdong paddy soil system with high iron content (17.5 mg kg-1) to investigate the reductive dechlorination of PCP by HA in the early, middle, and later stages of food waste composting. The results showed that the middle- and late-stages of compost-derived HAs all promoted reductive dechlorination of PCP in the paddy system, but it was opposite in the early-stage. Significant differences were also presented in the components of HAs from different stages of composting. The early-stage compost-derived HAs contain numerous easy degradable components, it would inhibit the dechlorination of PCP by the changes of microbial metabolism in paddy soil. Compost-derived HAs in the middle composting stage showed the best reductive dechlorination effects on PCP. The reason might be that the compost-derived HAs in the middle composting stage could act both as electron donors and transfers. The electron transfer capacities (ETC) of middle-stage compost-derived HAs were significantly higher than those in the early and later composting stages. Compared with the natural HAs in the soil system, compost-derived HAs contained more chlorinated products with lower toxicities after the PCP degradation. This result mainly contributed to the detoxification and mineralization of PCP in the soil. These findings clarified the effects of compost-derived HAs on PCP bio-dechlorination in paddy soil with high iron content, identifying the optimal phase of compost-derived HA and providing a theoretical basis for the utilization of kitchen waste composting as a resource of HA.

Effects of carboxylated multi-walled carbon nanotubes on bioconcentration of pentachlorophenol and hepatic damages in goldfish.

Carboxylated multi-walled carbon nanotubes (MWCNT-COOH) exerts strong adsorption capacity for pentachlorophenol (PCP) and they inevitably co-occur in the environment, but few studies have characterized the effects of MWCNT-COOH on the bioavailability of PCP and its oxidative and tissue damages to fish. In this work, we assessed the PCP accumulation in different organs and the induced oxidative and tissue damages of goldfish following 50-d in vivo exposure to PCP alone or co-exposure with MWCNT-COOH. Our results indicated that PCP bioaccumulation in goldfish liver, gill, muscle, intestine and gut contents was inhibited after co-exposure with MWCNT-COOH in uptake phase. PCP exposure alone and co-exposure with MWCNT-COOH evoked severe oxidative and tissue damages in goldfish bodies, as indicated by significant inhibition of activities of antioxidant enzymes, remarkable decrease in glutathione level, simultaneous elevation of malondialdehyde content, and obvious histological damages to liver and gill. The decreased accumulation of PCP in the presence of MWCNT-COOH led to the reduction of PCP-induced toxicity to liver tissues, as confirmed by the alleviation of hepatic oxidative damages. However, co-exposure groups had higher concentrations of PCP in the tissues than PCP treatment alone (p < 0.05 each) in the depuration phase, revealing that MWCNT-COOH-bound pollutants might pose higher risk once desorbed from the nanoparticles. These results provided substantial information regarding the combined effects of PCP and MWCNT-COOH on aquatic species, which helps to deeply understand the potential ecological risks of the emerging pollutants.

[Vigilance against a highly lethal insecticide chlorfenapyr poisoning (report of 4 cases and literature review)].

In order to improve the clinical attention to the poisoning of chlorfenapyr, the diagnosis and treatment strategy of chlorfenapyr poisoning were discussed. This paper collected 4 cases of chlorfenapyr in the emergency department of the Second Hospital of Hebei Medical University and 4 cases of literature review, summarized the clinical characteristics of pesticide poisoning cases containing chlorfenapyr in China, and summarized and analyzed the clinical data of the cases. Seven of the 8 patients died from poisoning by chlorfenapyr. Exposure to chlorfenapyr through respiratory tract and digestive tract showed high mortality. Fever, hyperhidrosis, elevated muscle enzymes and progressive central nerve damage were its prominent clinical characteristics. Most of the initial symptoms of exposure were not serious. Some patients, especially those with low exposure dose, had a relatively stable stage with or without clinical diagnosis and treatment. In case of sweating, obvious fever and disturbance of consciousness, the condition would deteriorate rapidly, respiratory and circulatory failure and eventually die. With the increase of production capacity and market launch, people have more opportunities to be exposed to chlorfenapyr. It is urgent to strengthen the basic and clinical research of chlorfenapyr poisoning; Attention should be paid to the observation and treatment in the initial stable stage of poisoning, which can be used as a reference for the treatment of oxidative phosphoric acid dissolving coupling agent (sodium pentachlorophenol) poisoning.