Pentachlorophenol Concentration Research Articles

Association of pentachlorophenol in urine and follicular fluid with ovarian reserve and reproductive outcomes among women undergoing in vitro fertilization based on a prospective cohort study.

Pentachlorophenol (PCP), a persistent organic pollutant, has endocrine disrupting properties and there may be a link between its exposure and reproductive outcomes. In this study, we assessed the relationship of PCP exposure levels with ovarian reserve markers and reproductive health outcomes in women (N = 656) undergoing in vitro fertilization (IVF). PCP concentrations were determined in urine (n = 1,968; repeated measures) and follicular fluid samples (n = 603). Generalized linear models or generalized estimating equations were used to analyze adjusted association between PCP exposure and selected outcomes (ovarian reserve and IVF outcomes among the women). The median concentration of PCP in the follicular fluid was (1.38 ng/mL) significantly higher compared with that in the urine (SG-adjusted: 0.79 ng/mL). We observed that the urinary PCP concentrations were significantly associated with increased estradiol levels (-12.4%; 95% CI: 0.76, 25.4%) but decreased total oocyte yield (-8.35%; 95% CI: -9.64, -7.04%), mature oocytes (-12.0%; 95% CI: -13.4, -10.6%), and fertilization proportion (-2.98%; 95% CI: -5.51, -0.39%). Moreover, there were significant associations of follicular fluid PCP concentrations with declines in total oocyte yield (-10.6%; 95% CI: -11.9, -9.26%), mature oocytes (-10.6%; 95% CI: -12.0, -9.09%), and proportions of fertilization (-3.75%; 95% CI: -6.39, -1.03%), blastocyst formation (-8.01%; 95% CI: -16.6, -0.37%), and usable blastocysts (-13.9%; 95% CI: -23.6, -3.03%). Our results revealed that exposure to PCP was related with impaired reproductive outcomes of IVF, while additional research is needed to confirm the findings and clarify the underlying mechanisms.

An ultra-low fouling electrochemical mocularly imprinted sensor based on size exclusion effect for highly selective pentachlorophenol detection

Pentachlorophenol (PCP) is considered as a highly toxic pollutant in water environment. However, detecting low concentrations of PCP precisely hindered by various interferences is still a tough challenge. In this study, an antifouling electrochemical molecularly imprinted (E-MIP) sensor harnessing the size exclusion effect was specifically designed for highly selective detection of PCP in water. The distinctive interaction between the size-selective poly-hydroxyproline helical peptide (PHHP) and poly(o-phenylenediamine) (p(o-PD)) molecularly imprinted films, strongly reduced non-specific adsorption. In the face of high concentrations of organic matters and ions, the reported sensor exhibited robust antifouling capabilities that it preserved 90 % of the initial signal. In addition, the limit of detection (LOD) reached an exceptionally low level of 1.13 nM (S/N = 3), spanning a wide linear range from 1 nM to 10 μM, and the sensor showed high selectivity with an impressive imprinted factor of 12.01 for PCP. Meanwhile, it owned great repeatability and reproducibility, long-term stability for PCP detection within 25 days, and decent reusability (retaining 92.33 % of its senor performance after 5 cycles), which ensured its excellent feasibility for determination of PCP in complex water samples with co-existing interferences due to acceptable recoveries. The development of this strategy provides an innovative platform for PCP quantification in real water samples, underscoring its potential as a key tool in managing PCP at relevant sites.

Removal mechanisms of pentachlorophenol in a horizontal-flow anaerobic immobilized biomass reactor (HAIB) inoculated with an indigenous estuarine sediment microbiota: adsorption and biodegradation processes.

Pentachlorophenol (PCP) is a highly toxic and carcinogenic compound with significant environmental impact, necessitating effective treatment technologies. This study evaluates PCP removal mechanisms, including adsorption and biodegradation, during the startup of a horizontal-flow anaerobic immobilized biomass reactor (HAIB), and examines the impact of PCP concentration on microbial diversity using denaturing gradient gel electrophoresis (DGGE). The primary mechanism for PCP removal in the HAIB was adsorption, effectively described by the Freundlich isotherm model. Adsorption efficiency ranged from 86 to 104% for PCP concentrations between 0.2 and 5.0mg/L, and 46% to 64% for concentrations between 0.098 and 0.05mg/L. Additionally, PCP degradation intermediates such as 2,3-DCP and 2,6-DCP were detected, indicating that biodegradation also occurred in the HAIB. Organic matter degradation averaged 81 ± 9%, and methane content in the biogas averaged 46 ± 9%, confirming the anaerobic process. No inhibition of microbial activity was observed due to PCP toxicity, even at a PCP load of 5mg PCP/g STV per day. While the archaeal community showed only slight changes, with similarity coefficients ranging from 88 to 95%, the bacterial community was significantly affected by PCP, with similarity coefficients ranging from 18 to 50%. Bacterial groups were responsible for the initial PCP degradation, while the archaeal community was involved in metabolizing the resulting byproducts. The use of indigenous inoculum from the Santos-São Vicente estuary demonstrated its potential for effective PCP removal. Polyurethane foam proved to be an effective support material, enhancing the adsorption process and reducing PCP toxicity to the microbial consortium. This study provides valuable insights into PCP adsorption and biodegradation mechanisms in HAIB, highlighting the effectiveness of indigenous inoculum and polyurethane foam for PCP removal.

Possible toxification mechanisms of acute and chronic pentachlorophenol to Montipora digitata: Limitation of energy supply and immunotoxicity

Pentachlorophenol (PCP) is widely found in coastal environments and has various adverse effects, and its potential impact on coral reef ecosystems concerning. The scleractinian coral Montipora digitata was used for PCP stress experiments in this study. Phenotypes, physiological indicators, microbial diversity analysis and RNA sequencing were used to investigate the mechanisms underlying the responses of corals to acute and chronic PCP exposure. After 96 h of acute exposure, coral bleaching occurred at 1000 μg/LPCP and there was a significant decrease in Symbiodiniaceae density, Fv/Fm, and chlorophyll a content. Exposure to different concentrations of PCP significantly increased the content of malondialdehyde (MDA), leading to oxidative stress in corals. Chronic PCP exposure resulted in bleaching at 60 days, with the Fv/Fm significantly reduced to 0.461. Microbial diversity analysis revealed an increase in the abundance of potential pathogens, such as Vibrio, during acute PCP exposure and the emergence of the degrading bacterium Delftia during chronic PCP exposure. Transcriptional analysis showed that PCP exposure caused abnormal carbohydrate and amino acid metabolism in zooxanthella, which affected energy supply, induced immune responses, and disrupted symbiotic relationships. Corals respond to injury by boosting the expression of genes associated with signal transduction and immune response. Additionally, the expression of genes associated with environmental adaptation increased with chronic PCP exposure, which is consistent with the results of the microbial diversity analysis. These results indicate that PCP exposure might affect the balance of coral- zooxanthellae symbiosis in the stony coral M. digitata, impairing coral health and leading to bleaching.

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 0.21μM. 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 0.002μM. 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.

Efficient photocatalytic remediation of persistent organic pollutants using magnetically recoverable spinel manganese ferrite nanoparticles supported on activated carbon

Magnetically recoverable spinel manganese ferrite (MFO) nanoparticles (NPs) supported on activated carbon (AC) (MFC), a promising photocatalyst, were prepared by simple and cost-effective gel combustion. AC supports prevented particle agglomeration and functioned as electron acceptors to promote charge separation on MFO. MFC samples demonstrated significant surface area, paramagnetic characteristics, and visible-light absorption bandgap of 2.02 eV. Pentachlorophenol (PCP) photodegradation using MFC showed degradation efficiency of at least 90 % after 150 min at pH 6.0 with the catalyst dose and PCP concentration of no more than 10 mg.L−1 and 9.0 ppm, respectively. MFC exhibited durability and recyclability with approximately 4 % decrease in degradation efficiency after five reuses while maintaining its material structure. The crucial roles of photo-generated electrons and hydroxyl radicals related to dechlorination and hydroxylation during PCP photodegradation were also highlighted in active species investigations with appropriate scavengers. Subsequently, a plausible PCP photodegradation mechanism with intermediates was proposed.

Associations of pentachlorophenol exposure during pregnancy with maternal and infant reproductive hormones based on a birth cohort

Pentachlorophenol (PCP), a typical environmental endocrine disruptor and a new persistent organic pollutant, has been extensively used as a pesticide worldwide. Although its use has been restricted for decades, PCP remains prevalent in both the environment and human bodies. Despite the known endocrine-disrupting and exogenous hormonal effects of PCP, few epidemiological studies examined such impact, especially among sensitive populations and during critical periods. Based on a prospective birth cohort in Wuhan, China, we collected maternal (first trimester; 13.0 ± 1.02 gestational weeks) and infant urine samples (1.16 ± 0.22 months postpartum) from 720 mother-infant pairs. We aimed to examine the association of PCP exposure during early pregnancy with maternal and infant urinary sex steroid hormones, including estrogens (estrone, E1; estradiol, E2; estriol, E3), progestogens (progesterone, P4; pregnenolone, P5; 17α-OH-Progesterone, 17OHP4; 17α-OH-Pregnenolone, 17OHP5), and androgens (testosterone, Testo; dihydrotestosterone, DHT; dehydroepiandrosterone, DHEA; androstenedione, A4). Additionally, gonadotropins [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] were measured in infant urine. Detection frequencies of all the sex steroid hormones in the maternal urine samples (>99 %) were higher than those in the infants' [most ≥80 %, except for E1 (3.36 %) and E2 (21.4 %)]. Maternal urinary PCP concentration was found to be significantly related with increased maternal sex steroid hormone concentrations; each interquartile increase in PCP concentration was positively related with percent change of the hormones (%Δ) ranging from 26.6 % to 48.5 %. On the other hand, maternal PCP exposure was associated with significantly increased P4 in male infants [%Δ (95 % confidence interval): 10.5 (0.56, 21.4)] but slightly decreased P4 in female infants [−11.9 (−21.8, 0.68)]. In addition, maternal PCP exposure was significantly associated with decreased FSH [%Δ (95 % CI): −9.90 (−17.0, −2.18)] and LH [−8.44 (−16.0, −0.19)] in the female infants, but not in the male infants. Sensitivity analyses, excluding infertility related treatment, pregnancy complications, preterm birth, or low birth weight, showed generally consistent results. Our findings implied that maternal/prenatal PCP exposure might disrupt the homeostasis of maternal and infant reproductive hormones. However, further studies are needed to confirm the findings.

Occurrence of pentachlorophenol in surface water from the upper to lower reaches of the Yangtze River and treated water in Wuhan, China.

Pentachlorophenol (PCP), a persistent organic pollutant, has been banned in many countries, but it is still used in China as a wood preservative, molluscicide, or reagent for fish-pond cleaning, which may pose risks to the ecosystem and humans. However, data on the occurrence of PCP in the environment are scarce in the recent decade. The Yangtze River was regarded as a priority area of PCP pollution according to previous documents. This study aimed to examine the spatial distribution of PCP in the Yangtze River water, the differences in dry and wet seasons, the ecological risk for aquatic organisms, and its removal efficiency in tap water treatment plants. The river water samples (n = 144) were collected from the upper, middle, and lower reaches across ten provinces (or municipalities) in December 2020 and June 2021, respectively. PCP was detected in 88.9% of all the samples, ranging from <MDL to 9.97 ng/L. Spatial distribution differences among the involved provinces were observed, with the highest PCP concentration in the Chongqing section (median: 1.61 ng/L), followed by Hubei (median: 0.23 ng/L), Jiangxi (median: 0.23 ng/L), Shanghai (median: 0.21 ng/L), and other provinces (<0.20 ng/L). Thesurface water from Qinghai had the lowest concentrations (median: <0.01 ng/L). PCP levels in the Yangtze River water were much lower than those reported in water samples worldwide a decade ago. PCP concentrations in the dry season were higher than in the wet season (p < 0.001). Ecological risk assessment suggested a low risk (RQMax: 0.02) to aquatic organisms posed by PCP in the river. In addition, 100% removal of PCP in tap water treatment plants was observed, while the transformation products of PCP need further studies. The risk of human exposure to PCP through water ingestion only was negligible. However, human exposure risks of PCP in highly contaminated areas still require attention, considering its bioaccumulation and biomagnification in the environment.

Effects of nano-TiO2 and pentachlorophenol on the bioenergetics of mussels under predatory stress

Organic and nanoparticle pollutants are the main environmental problems affecting marine species, which have received great attention. However, the combined effect of pollutants on marine life in the presence of predators needs to be clarified. In this study, the effects of pentachlorophenol (PCP) and titanium dioxide nanoparticles (nano-TiO2) on the energy metabolism of mussels (Mytilus coruscus) in the presence of predators were assessed through cellular energy allocation (CEA) approach. Mussels were exposed to PCP (0, 1, and 10 μg/L), nano-TiO2 (1 mg/L, 25 and 100 nm), and predators (Portunus trituberculatus presence/absence) for 14 days. Exposure to high concentrations of PCP (10 μg/L) with small particle size nano-TiO2 (25 nm) decreased cellular energy stores (carbohydrates, lipids, and proteins) and increased cellular energy demand (measured as the activity of the mitochondrial electron transport system, ETS). During the first 7 days, energy was supplied mainly through the consumption of carbohydrates, while lipids are mobilized to participate after 7 days. The presence of predators caused a further decrease in energy stores. These findings demonstrate that PCP, nano-TiO2 and predators have a negative impact on energy metabolism at the cellular level. Carbohydrates are not able to meet the metabolic demand, lipids need to be consumed, and energy metabolism was also mediated by the involvement of proteins. Overall, our results suggest that PCP, nano-TiO2 and predators disrupt the cellular energy metabolism of mussels through reduced cellular energy allocation, small particles and predators drive mussels to exert energetic metabolic adjustments for detoxification reactions when toxic contaminants are present.

Interpretable machine learning for predicting the fate and transport of pentachlorophenol in groundwater

Pentachlorophenol (PCP) is a commonly found recalcitrant and toxic groundwater contaminant that resists degradation, bioaccumulates, and has a potential for long-range environmental transport. Taking proper actions to deal with the pollutant accounting for the life cycle consequences requires a better understanding of its behavior in the subsurface. We recognize the huge potential for enhancing decision-making at contaminated groundwater sites with the arrival of machine learning (ML) techniques in environmental applications. We used ML to enhance the understanding of the dynamics of PCP transport properties in the subsurface, and to determine key hydrochemical and hydrogeological drivers affecting its transport and fate. We demonstrate how this complementary knowledge, provided by data-driven methods, may enable a more targeted planning of monitoring and remediation at two highly contaminated Swedish groundwater sites, where the method was validated. We evaluated 6 interpretable ML methods, 3 linear regressors and 3 non-linear (i.e., tree-based) regressors, to predict PCP concentration in the groundwater. The modeling results indicate that simple linear ML models were found to be useful in the prediction of observations for datasets without any missing values, while tree-based regressors were more suitable for datasets containing missing values. Considering that missing values are common in datasets collected during contaminated site investigations, this could be of significant importance for contaminated site planners and managers, ultimately reducing site investigation and monitoring costs. Furthermore, we interpreted the proposed models using the SHAP (SHapley Additive exPlanations) approach to decipher the importance of different drivers in the prediction and simulation of critical hydrogeochemical variables. Among these, sum of chlorophenols is of highest significance in the analyses. Setting that aside from the model, tetra chlorophenols, dissolved organic carbon, and conductivity found to be of highest importance. Accordingly, ML methods could potentially be used to improve the understanding of groundwater contamination transport dynamics, filling gaps in knowledge that remain when using more sophisticated deterministic modeling approaches.

Pentachlorophenol affects doxycycline and tetracycline resistance genes in soil by altering microbial structure

Tetracycline antibiotics play a vital role in animal husbandry, primarily employed to uphold the health of livestock and poultry. Consequently, when manure is reintegrated into farmland, tetracycline antibiotics can persist in the soil. Simultaneously, to ensure optimal crop production, organochlorine pesticides (OCPs) are frequently applied to farmland. The coexistence of tetracycline antibiotics and OCPs in soil may lead to an increased risk of transmission of tetracycline resistance genes (TRGs). Nevertheless, the precise mechanism underlying the effects of OCPs on tetracycline antibiotics and TRGs remains elusive. In this study, we aimed to investigate the effects of OCPs on soil tetracycline antibiotics and TRGs using different concentrations of doxycycline (DOX) and pentachlorophenol (PCP). The findings indicate that PCP and DOX mutually impede their degradation in soil. Furthermore, our investigation identifies Sphingomonas and Bacillus as potential pivotal microorganisms influencing the reciprocal inhibition of PCP and DOX. Additionally, it is observed that the concurrent presence of PCP and DOX could impede each other's degradation by elevating soil conductivity. Furthermore, we observed that a high concentration of PCP (10.7 mg/kg) reduced the content of efflux pump tetA, ribosome protective protein tetM, tetQ, and passivating enzyme tetX. In contrast, a low PCP concentration (6.4 mg/kg) only reduced the content of ribosome protective protein tetQ. This suggests that PCP may reduce the relative abundance of TRGs by altering the soil microbial community structure and inhibiting the potential host bacteria of TRGs. These findings have significant implications in understanding the combined pollution of veterinary antibiotics and OCPs. By shedding light on the interactions between these compounds and their impact on microbial communities, this study provides a theoretical basis for developing strategies to manage and mitigate their environmental impact, and may give some information regarding the sustainable use of antibiotics and pesticides to ensure the long-term health and productivity of agricultural systems.

Exposure to pentachlorophenol destructs the symbiotic relationship between zooxanthellae and host and induces pathema in coral Porites lutea

Stress from chemical pollutants is among the key issues that have adverse impacts on coral reefs. As a persistent organic pollutant, pentachlorophenol (PCP) has been detected in the seawater of Weizhou Island and was proved to have significant adverse effects on aquatic animals. However, little is known about its effects on scleractinian coral. Therefore, we investigated the response of the coral Porites lutea to PCP stress. Coral bleaching, photosynthesis parameters and antioxidant enzyme activities of P. lutea under PCP exposure were documented. After 96 h of exposure, significant tissue loss and bleaching occurred when the PCP concentration exceeded 100 μg/L. The density of symbiotic zooxanthellae decreased from 2.06 × 106 cells/cm2 to 0.93 × 106 cells/cm2 when the PCP concentration increased from 1 μg/L- 1000 μg/L. Long-term exposure of 120 days to PCP at 0.1 μg/L also led to coral bleaching, the maximum photochemical quantum yield of PSII in P. lutea nubbins significantly decreased to 0.482. The analysis of microbial community distribution indicated that the increase of the pathogenic bacterium Citrobacter may be one of the inducers of coral bleaching. Conjoint analysis of transcriptomics and proteomics showed that the metabolism of amino acids and carbohydrates in zooxanthellae was abnormal, leading to the destruction of its symbiotic relationship with the host. The immune system of the host was disrupted, which could be linked to the prevalence of coral pathema. The toxic responses of PCP on both zooxanthellae and its host were further confirmed by the upregulation of the differential metabolites including 1-naphthylamine and phosphatidylcholine, etc.

Pentachlorophenol degradation in the heterogeneous catalytic o zonation process using Al2O3as a catalyst agent

In this study, the catalytic ozonation of pentachlorophenol (PCP) in the presence of aluminum oxide (Al2O3) and the formation of byproducts during ozonationhas been studied. Results showed that catalytic ozonation in the presence of Al2O3 can substantially enhance PCP degradation efficiency compared with the using only ozonation process. The influences of severalenvironmental parameters including pH of the solution, initial PCP concentration, dosage of Al2O3 and dissolved ozone concentration were also investigated. The highest degradation efficiency of PCP was achieved at conditions: pH 8, 1.87 g/LAl2O3, and 0.49 g/L dissolved ozone concentration. The catalytic activity of Al2O3 was linked to highly hydroxylated surface. The surface hydroxyl groups on Al2O3 were the active places during catalytic ozonation. According to the drastic changes in the color of solution during ozonationin this study and results of some previous researches, formation of the intermediate reaction products during ozonationwas verified.Free chloride ion released, which was favored at slightly alkaline solution, was also followed in catalytic ozonation process.

Pentachlorophenol degradation in the heterogeneous catalytic o zonation process using Al2O3as a catalyst agent

In this study, the catalytic ozonation of pentachlorophenol (PCP) in the presence of aluminum oxide (Al2O3) and the formation of byproducts during ozonation has been studied. Results showed that catalytic ozonation in the presence of Al2O3 can substantially enhance PCP degradation efficiency compared with the using only ozonation process. The influences of several environmental parameters including pH of the solution, initial PCP concentration, dosage of Al2O3 and dissolved ozone concentration were also investigated. The highest degradation efficiency of PCP was achieved at conditions: pH 8, 1.87 g/LAl2O3, and 0.49 g/L dissolved ozone concentration. The catalytic activity of Al2O3 was linked to highly hydroxylase surface. The surface hydroxyl groups on Al2O3 were the active places during catalytic ozonation. According to the drastic changes in the color of solution during ozonation this study and results of some previous researches, formation of the intermediate reaction products during ozonation was verified. Free chloride ion released, which was favored at slightly alkaline solution, was also followed in catalytic ozonation process.

Compost-derived humic acid impacts on the biodechlorination of pentachlorophenol in high organic matter paddy soil

The long-term accumulation of pentachlorophenol (PCP) has adversely affected the paddy soil ecosystem. PCP reductive dechlorination under anaerobic conditions is an efficient pathway for PCP degradation. This process is affected by the content of organic matter and the iron mineral composition of the soil. Our previous study analyzed the effects of compost-derived Humic acids (HAs) on reductive dechlorination of PCP in a paddy soil system under Fe-reducing conditions. The effects and mechanisms of high organic matter and compost-derived HAs in promoting PCP dechlorination need further investigation. This study examined paddy soils with high organic matter content in Heilongjiang Province. PCP reductive dechlorination in this system was studied using HAs from three stages of municipal solid waste compost as soil supplements. The results showed that natural HA and microorganisms could promote the dechlorination and transformation of PCP in the paddy soil system. After removing humic acid, the detected concentrations of PCP in paddy soil and solid-liquid interface were 1.84 and 9.67 times of those in the original soil experiment, respectively. The concentration of low chlorine products decreased significantly in the sterilized group. Compost-derived HAs from different stage were also presented various effect on PCP reductive dichlorination. Furthermore, the synergistic effect between natural HA and compost-derived HAs would limit the electron donating capacity of compost-derived HAs in the paddy soil with high organic matter. Organic matter in soil has an important influence on pollutant fate. Late-stage HA were more effective in promoting PCP degradation than early-and middle-stage HAs. The research provided a comprehensive and meticulous analyses of the effects of compost-derived HAs on PCP bio-dechlorination in paddy soil with high organic matter.

Fish Oil Enhances Pentachlorobenzene Metabolism and Reduces its Accumulation in Rats

To investigate the influence of dietary fats on the metabolism and excretion of pentachlorobenzene (PECB), rats were fed semipurified diets containing soybean oil, lard or fish oil (10 g/100 g diet) for 2 wk. Rats then received a single dose of PECB by intragastric gavage. Blood concentration of pentachlorophenol (PCP), a major metabolite of PECB, was higher after 5 h through d 3 and that of PECB was lower after d 5 in the rats fed fish oil than in rats fed the other fats. After d 5, the highest ratio of PCP/PECB in the liver was seen in the fish oil—fed rats. Furthermore, fish oil intake resulted in a markedly lower concentration of PECB in fat tissues, where a large amount of PECB is typically distributed due to its lipophilic property. These findings indicate that fish oil feeding enhances PECB metabolism, thereby decreasing PECB residues in the body. Fish oil—fed rats had a smaller epididymal fat tissues mass compared with lard- or soybean oil—fed rats. The small mass of the fat tissues apparently limited the accumulation of PECB in those tissues and thus accelerated PECB metabolism in the liver.

Urinary pentachlorophenol in general population of central China: reproducibility, predictors, and associations with oxidative stress biomarkers.

Pentachlorophenol (PCP) is a ubiquitous environmental persistent organic pollutant and a Group 1 carcinogen. Human exposure level of PCP was reported to berelatively higher in China than in many other countries, because sodium pentachlorophenate was abused as molluscicide in China. PCP can induce oxidative stress; however, the relationship of PCP exposure with oxidative stress biomarkers (OSBs) in human beings has rarely been documented. In this study, 404 first-morning urine samples (including repeated samples in three days donated by 74 participants) were collected from 128 healthy adults (general population without occupational exposure to PCP) in autumn and winter of 2018, respectively, in Wuhan, central China. Urinary concentrations of PCP and three select OSBs [including 8-OHG (abbreviation of 8-hydroxy-guanosine), 8-OHdG (8-hydroxy-2'-deoxyguanosine), and 4-HNEMA (4-hydroxy-2-nonenal mercapturic acid), which reflect oxidative damage of RNA, DNA, and lipid, respectively] were determined. PCP was detectable in 100% of the urine samples (specific gravity-adjusted median concentration: 0.44ng/mL; range: 0.02-14.2ng/mL). Interday reproducibility of urinary PCP concentrations was excellent (intraclass correlation coefficient: 0.88) in three days. Significant differences in PCP concentrations were found among different age groups; the group of participants aged 20-45 y (median: 0.72ng/mL) had higher concentrations than those in theelders (aged 45-60 y and > 60 y). Spatial disparity was observed in autumn, and urban residents had higher PCP concentrations than rural residents (median: 0.60 vs. 0.31ng/mL), whereas such disparity was not found in winter. There were no season-, sex-, or BMI-related differences between the corresponding subgroups. The urinary PCP concentrations were found to be associated with increases in 8-OHdG and 8-OHG rather than 4-HNEMA. An interquartile range increase in urinary PCP concentration was associated with a 23.5% (95% CI: 9.18-39.6) increase in 8-OHdG and a 21.3% (95% CI: 9.18-32.4) increase in 8-OHG, implied that PCP exposure at environmental relevant dose might be associated with nucleic acid oxidative damage in the general population. This pilot study reported associations between PCP exposure and OSBs in human beings. Future studies are needed to elucidate the mediating roles of OSBs in theassociation between PCP exposure and certainadverse health outcomes.

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 0.43μg/L in surface water and 3.90 to 85.95μg/kg in aquatic products. Due to the carcinogenicity of PCP, the human health AWQC for PCP are 0.02μg/L for consumption of water and organisms and 0.03μg/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.

Variability, determinants, and associations with oxidative stress biomarkers of pentachlorophenol among Chinese pregnant women: A longitudinal study

Pentachlorophenol (PCP) is ubiquitous and moderately persistent in the environment, and it is an identified human carcinogen. Previous animal experiments indicate that toxic mechanisms of PCP include oxidative stress. However, no epidemiological study has reported the association between PCP exposure and oxidative stress; such association in pregnant women, a vulnerable population, is of particular interest. This study aimed to characterize PCP concentrations in 2304 urine samples from 768 pregnant women, explore its determinants, and evaluate the associations between PCP exposure and three oxidative stress biomarkers across three trimesters. The median concentrations of PCP (100% detected) in the first, second, and third trimester were 0.61, 0.59, and 0.48 ng/mL, respectively, with a significant decrease trend. The intraclass correlation coefficient of specific gravity (SG)-adjusted PCP was 0.26, indicating high variability for PCP across the three trimesters. PCP concentrations were significantly higher in older, pre-pregnancy overweight, multiparous, high-income, and employed women during pregnancy. Urinary PCP was markedly lower in samples collected during spring compared to other seasons. Linear mixed effect models for repeated measures revealed that ln-transformed SG-adjusted PCP was significantly associated with increased 8-hydroxy-2'-deoxyguanosine (8-OHdG; percent change [%Δ] caused by each interquartile range increase of PCP: 46.2, 95% confidence interval [CI]: 40.2, 52.5) and 8-hydroxyguanosine (8-OHG;%Δ [95% CI]: 44.8 [40.1, 49.8]), but the positive association with 4-hydroxy2-nonenal-mercapturic acid (HNE-MA) was not significant. PCP was also positively associated with increased 8-OHdG and 8-OHG in each trimester using general linear models, and its associations with HNE-MA were only significant at T1 (%Δ [95% CI]: 19.1 [1.05, 40.3]) and T2 (%Δ [95% CI]: 12.6 [0.32, 26.3]). Our findings provide valuable information about PCP exposure characteristics during pregnancy and the potential effects of PCP exposure on oxidative stress in pregnant women.

Toxicity of nZVI in the growth of bacteria present in contaminated soil.

The use of nano zero-valent iron (nZVI) for the remediation of degraded areas is a consolidated practice. However, the long-term reactions that occur in the environment remain unknown. This study aimed to evaluate the potential toxic effects on the growth of colony-forming units (CFUs) of Bacillus cereus and Pseudomona aeruginosa present in soil contaminated with hexavalent chromium (Cr6+) and pentachlorophenol (PCP) nanoremediated with nZVI. The treatments were natural soil (control), soil contaminated by Cr6+, soil contaminated by PCP, and soil contaminated by Cr6+ and PCP (Cr6+ and PCP), all in duplicate. The concentration of contaminants used was 100mg/kg of soil. One of the drums of the duplicate received an injection of nZVI solution with a concentration of 50g/kg. Analysis was performed 7, 15, 21, 30, 60, and 90 days after the nZVI injection. Temporary oscillations in the abundance of the microbiological community were observed, characterizing the adaptation of bacteria to the contaminants. The bacteria showed similar behavior. Ninety days after the injection of nZVI, the averages of the CFUs were statistically equal, with the lowest coefficient of variation and the highest concentration of CFUs occurring. The strains of B. cereus and P. aeruginosa were resistant to the concentrations of nZVI, Cr6+, and PCP. The nanoremediation of nZVI in soil contaminated by Cr6+ and PCP had no toxic effects on the population of the bacteria evaluated and did not present major disturbances in temperature, electrical conductivity, pH, and humidity over time.