The Potential of Lipid Droplet-associated Genes as Diagnostic and Prognostic Biomarkers in Head and Neck Squamous Cell Carcinoma.

OBJECTIVE: The role of lipid droplets (LDs) and lipid droplet-associated genes (LD-AGs) remains unclear in head and neck squamous cell carcinoma (HNSCC). This study aimed to investigate LDs in HNSCC and identify LD-AGs essential for the diagnosis and prognosis of HNSCC patients. METHODS: The LDs in the HNSCC and normal cell lines were stained with oil red O. Bioinformatic analysis was used to find LD-AGs in HNSCC that had diagnostic and prognostic significance. RESULTS: LDs accumulation was increased in HNSCC cell lines compared with normal cell lines (P<0.05). Fifty-three differentially expressed genes, including 34 upregulated and 19 downregulated, were found in HNSCC based on the TCGA platform (P<0.05). Then, 53 genes were proved to be functionally enriched in lipid metabolism and LDs. Among them, with an AUC value > 0.7, 34 genes demonstrated a high predictive power. Six genes (AUP1, CAV1, CAV2, CAVIN1, HILPDA, and SQLE) out of 34 diagnostic genes were linked to overall survival in patients with HNSCC (P<0.05). The significant prognostic factors AUP1, CAV1, CAV2, and SQLE were further identified using the univariate and multivariate cox proportional hazard models (P<0.05). The protein expression of CAV2 and SQLE was significantly increased in the HNSCC tissue compared to normal tissues (P<0.05). Finally, the knockdown of the four LD-AGs decreased LDs accumulation, respectively. CONCLUSIONS: Increased LDs accumulation was a hallmark of HNSCC, and AUP1, CAV1, CAV2, and SQLE were discovered as differentially expressed LD-AGs with diagnostic and prognostic potential in HNSCC.

Continuous artificial intelligence-assisted DNA aneuploidy cytology for surveilling dysplastic oral leukoplakia treated by photodynamic therapy.

Oral leukoplakia (OLK) is one of the most common potentially malignant disorders. High-risk lesions require early intervention before developing into oral cancer. Photodynamic therapy (PDT) is a noninvasive technique for premalignant lesions. Scalpel biopsy remains a reliable method for monitoring the prognosis of OLK, but it is an invasive procedure with poor reproducibility to suspicious lesions. DNA aneuploidy cytology by oral cytobrush has been proposed as a promising objective and noninvasive tool in screening and diagnosing premalignant and malignant lesions. Here, we discussed the significance of artificial intelligence (AI)-assisted DNA aneuploidy cytology by image cytometry (DNA-ICM) for surveilling non-homogeneous OLK with moderate-to-severe dysplasia that was treated by 5-aminolevulinic acid-mediated PDT (ALA-PDT). The present study provides a scheme of the sequential management and surveillance strategy for OLK.

Dynamic variation and inhalation exposure of organophosphates esters and phthalic acid esters in face masks.

The coronavirus pandemic (COVID-19) has posed a huge global health threat since December 2019. Wearing face masks is known as an effective measure for controlling the wide spread of COVID-19 and its variants. But on the other hand, face masks could be a potential source of organophosphate esters (OPEs) and phthalic acid esters (PAEs) as they are extensively added in masks. However, knowledge associated with the occurrence as well as inhalation risks of OPEs and PAEs in masks is limited. In this study, OPEs and PAEs were determined in different types of mask samples collected from the local market. OPEs and PAEs were detected in mask samples ranging from 36.7 to 855 ng/g, and from 251 to 3830 ng/g, respectively. Relatively lower OPEs and PAEs concentrations were observed in disposable mask for toddlers. Simulated inhalation experiment indicated that the mass loss of OPEs and PAEs was 136 and 3910 ng/mask in disposable masks, 71.9 and 763 ng/mask in disposable mask for toddlers, 924 and 1020 ng/mask in N95 mask after 12 h, respectively. Significantly negative correlations were exhibited between the decrement of OPEs in masks and the increment of OPEs in corresponding polyurethane foams (PUFs) during the course, elucidating OPEs released from masks could be well captured by PUFs. With regard to the variation over time, predominant OPE and PAE analogues showed semblable release and absorption tendency in mask and corresponding PUF. Inhalation exposure risk of OPEs and PAEs was estimated based on the increment of pollutants in PUF. The estimated daily intakes (EDIs), hazard index (HI) and carcinogenic risk (CR) were also calculated and they were within the threshold levels. This study provides the evidence of OPEs and PAEs releasing from the face masks during wearing and unveiled a potential source of OPEs and PAEs exposure to humans.

Occurrence, correlation, and partitioning of organophosphate esters in soil and tree bark from a megacity, Western China.

Concern over the influences of constant addition of emerging anthropogenic chemicals to the environment has become a public issue during the rapid urbanization. Here, we investigated the occurrence of organophosphate esters (OPEs) in soil and corresponding tree bark in a megacity, Western China. Our results showed levels of OPEs in tree bark (1250 ± 573 ng/g dry weight (dw)) were 1-2 orders of magnitude higher than those in soil (40.4 ± 30.8 ng/g dw). Rooster Mountain is a background mountain area, exhibiting significantly lower concentrations of OPEs in soil and tree bark than those in other sites with relatively high population density. This result highlights the effect of human activities on the distribution of OPEs in environmental matrices. Alkyl-OPEs were predominant compounds in soil, whereas halogenated- (Cl-) OPEs were characterized in tree bark. Furthermore, tris(2-chloroethyl) phosphate (TCEP) positively correlated with tris(2-chloroisopropyl) phosphate (TCIPP) in soil (r2 = 0.43, P < 0.05) while negatively correlated with TCIPP in tree bark (r2 = 0.31, P < 0.05). The ratios of logarithm concentrations of OPEs in tree bark to those in soil correlated well with logKOA values of OPEs from 6 to 10, indicating the equilibrium status was achieved between OPE partitioning in soil and in tree bark. Nevertheless, tris (2-butoxyethyl) phosphate (TBEP) and tris(2-ethylhexyl) phosphate (TEHP) with high values of logKOA deviated from this linear tendency, which was possibly due to the fact that they were subjected to the particle-bound deposition process, leading to partition into the soil.

Glaucocalyxin A impairs tumor growth via amplification of the ATF4/CHOP/CHAC1 cascade in human oral squamous cell carcinoma.

ETHNOPHARMACOLOGICAL RELEVANCE: The natural extract glaucocalyxin A (GLA), purified from the aboveground sections of the Chinese traditional medicinal herb Rabdosia japonica (Burm. f.) Hara var. glaucocalyx (Maxim.) Hara, has various pharmacological benefits, such as anti-bacterial, anti-coagulative, anti-neoplastic, and anti-inflammatory activities. Although GLA has shown anti-tumor activity against various cancers, the therapeutic potential and biological mechanisms of GLA remain to be further explored in oral squamous cell carcinoma (OSCC). AIM OF THE STUDY: This study aimed to elucidate the therapeutic potential and regulatory mechanisms of GLA in OSCC. MATERIALS AND METHODS: The cell proliferation and apoptosis effects of GLA were analyzed by CCK-8, clone formation, Annexin V/PI staining, and apoptotic protein expression in vitro. An OSCC xenograft model was applied to confirm the anti-neoplastic effect in vivo. Furthermore, the changes of reactive oxygen species (ROS) were determined by DCFH-DA probe and GSH/GSSG assay, and inhibited by the pan-caspase inhibitor Z-VAD(OMe)-FMK and the ROS scavenger N-acetylcysteine (NAC). The modulation of GLA on mitochondria and ER-dependent apoptosis pathways was analyzed by JC-1 probe, quantitative real-time PCR, and Western blot. Finally, public databases, clinical samples, and transfection cells were analyzed to explore the importance of GLA's indirect targeting molecule CHAC1 in OSCC. RESULTS: GLA significantly inhibited cell proliferation and induced apoptosis in vitro and in vivo. GLA perturbed the redox homeostasis, and cell apoptosis was totally rescued by Z-VAD(OMe)-FMK and NAC. Furthermore, GLA activated the mitochondrial apoptosis pathway. Simultaneously, the overexpression and knockdown of CHAC1 dramatically affected GLA-mediated apoptosis. The endoplasmic reticulum stress-associated ATF4/CHOP signal was identified to participate in GLA-upregulated CHAC1 expression. Finally, we found that CHAC1 expression was lower in OSCC compared with normal tissues and positively correlated with 4-Hydroxynonenal (4-HNE) level. High CHAC1 expression also indicated better overall survival. Moreover, CHAC1 selectively regulated the viability of oral cancer cells. CONCLUSION: GLA is a promising therapeutic agent that activates the ROS-mediated ATF4/CHOP/CHAC1 axis in OSCC patients.

[Influence of Different Soil Conditioner on the Transfer and Transformation of Cadmium and Phthalate Esters in Soil].

This study examines the existing common form of soil pollution, combined organic and inorganic pollution. Cadmium (Cd) is the most important inorganic element in soil pollution. Due to the widespread use of plastic film, phthalates have become the main organic pollutants in soil. Pot experiments were conducted with purple soil from southwest China, and Chinese cabbage was used as a biological indicator. Different concentration gradients of Cd and diethylhexyl phthalate (DEHP) was used as foreign pollutants. The soil was treated with one of the six common soil conditioners, namely potassium feldspar powder, oyster shell powder, biological carbon powder (biochar), calcium, potassium carbonate, and calcium phosphate, to examine the effect of conditioners on cadmium morphology, DEHP content in contaminated soil, and cadmium and DEHP absorption in Chinese cabbage. The results showed that biochar is the optimal soil conditioner for the remediation of cadmium-phthalate composite pollution in purple soil. Subsequently, the effects of soil biochar content on cadmium pollution and phthalate ester migration were studied. Uncontaminated control soil, Cd-contaminated soil, and DEHP-contaminated soil were examined by pot experiments, and biochar treatments with mass fraction of 0%, 0.5%, 1%, 3%, and 5% added to cadmium contaminated soil were used to determine its influence on Cd morphology and DEHP content of contaminated soil.

Heterogeneity of Outcome Measures Used in Randomized Controlled Trials for the Treatment of Oral Lichen Planus: A Methodological Study.

OBJECTIVE: Oral lichen planus (OLP) is a chronic inflammatory immune disease, recognized as an oral potentially malignant disorder by the World Health Organization. There is considerable controversy over the standardized treatment of OLP, with great diversities in the outcome measures in clinical trials. This methodological study aimed to estimate the degree of consensus on outcome measures in randomized controlled trials (RCTs) for OLP treatment. METHODS: PubMed, Embase, and Cochrane databases were searched to identify RCTs published from 2004 to 2018 about OLP treatment. All the outcome measures and measurement methods mentioned in the trials were extracted and analyzed. RESULTS: After identification of 1087 articles, 88 RCTs were included. A total of 193 single-outcome measures and 119 composite outcome measures were classified into 11 different domains, the chief of which consisted of clinical symptom (78 trials; 88.6%) and clinical score (58 trials; 65.9%). Visual analog scale (65 trials; 73.9%) and Thongprasom scoring system (38 trials; 43.2%) were the predominant measurement methods. Oral health-related quality of life (except for clinical symptoms) accounted for 4.8% of all the outcome measures. CONCLUSIONS: There was high heterogeneity in outcome measures of RCTs for OLP treatment, making it difficult to make valid comparisons between different clinical trials. A core outcome set should be developed and adopted in future trials for OLP treatment.

Phthalate esters in biota, air and water in an agricultural area of western China, with emphasis on bioaccumulation and human exposure.

Phthalate esters (PAEs) have been shown to be ubiquitous in abiotic and biotic environmental compartments; however, information about bioaccumulation behavior and human exposure, both via environmental exposure and the diet, are limited. Herein, we report the concentrations and composition profiles of phthalate esters (PAEs) in biological samples, river water, indoor air, and outdoor air samples collected from an agricultural site in western China. Dibutyl phthalate (DNBP) occupied a relatively high abundance in biological samples, discrepant with the environmental samples in which di-(2-ethylhexyl) phthalate (DEHP) was the dominant congener. Significant correlations (P < 0.05) were observed between the biota and river water samples, indicating that river water heavily influenced PAE accumulation in biological samples. The mean log Bioaccumulation Factors (BAFs) varied from 0.91 to 2.96, which implies that most PAE congeners are not likely to accumulate in organisms. No obvious trends were observed between log octanol-water partition coefficient (KOW) and log BAF values, nor between log octanol-air partition coefficient (KOW) and biota-air accumulation factors (BAAFs). Nevertheless, the calculated log air-water partitioning factors (AWPFs) of diethyl phthalate (DEP), dimethyl phthalate (DMP), and butyl benzyl phthalate (BBP) were similar to predicted values whereas those for diisobutyl phthalate (DIBP), DNBP and DEHP were significantly higher. The estimated daily intakes of PAEs via food ingestion and environmental exposure were 15, 9.4 and 1.2 ng/kg-bw/day in toddlers, children and adults, respectively, laying at the low end of the reported data and well below the reference dose.

[Absorption Characterization and the Identification of Factors Influencing Five Organophosphate Esters in Water-Soil System].

In this study, the absorption behavior of five organophosphate esters (OPEs) congeners was monitored in a water-soil system, and three absorption isotherm equations were modeled. Furthermore, the factors influencing the absorption process including temperature and dissolved organic carbon (DOC) were also investigated. The results showed that an equilibrium state was reached after 12 hours of absorption for these five OPEs congeners, which could be appropriately modeled by the Freundlich isotherm equations with R2 values ranging from 0.963 to 0.995. Significant correlations were observed among the Kd (partitioning coefficient) values and similar chemical structures of OPEs. The Kd values decreased with increasing temperature, indicating the significant role played by temperature. TBEP and TDCP were highly impacted by the DOC content, and for the other OPEs congeners, no clear tendency in Kd values was found with increasing of DOC content.

All-trans retinoic acid induces anti-tumor effects via STAT3 signaling inhibition in oral squamous cell carcinoma and oral dysplasia.

BACKGROUND: Oral squamous cell carcinoma (OSCC), which may arise from oral dysplasia, is one of the most prevalent cancers around the world. In recent years, all-trans retinoic acid (ATRA) has shown great potential in cancer treatment. However, the molecular mechanism for the anti-tumor effects of ATRA remains unclear. MATERIALS AND METHODS: After treated with ATRA, inhibition of cell proliferation of OSCC and oral dysplasia cell lines, CAL27 and DOK, respectively, was analyzed by a Cell Counting Kit-8 (CCK8) assay. The cell cycle arrest, cell apoptosis induction, and PD-L1 expression level were measured by flow cytometry. A small molecular inhibitor was utilized to block STAT3 pathway, and the related proteins expression was measured by Western Blot. RESULTS: The present study demonstrated that ATRA inhibited cell proliferation at 5-75 µmol/L, arrested cell cycle at S and G2-phase, induced apoptosis effect in OSCC, and oral dysplasia cell line, CAL27 and DOK, respectively. ATRA led to inhibition of p-STAT3, p-JAK2, increased the level of p-ERK, and significantly decreased the PD-L1 expression. Moreover, targeting STAT3 signaling increased (P < .001) the level of cleaved caspase-3 and effectively (P < .001) decreased the expression of cyclin A2 and PD-L1. The effect of ATRA on cell growth inhibition, apoptosis induction, and PD-L1 expression decrease was significantly (P < .05) enhanced after the STAT3 signaling blockade. CONCLUSION: These findings suggested that ATRA-induced anti-tumor effects and downregulated PD-L1 expression via STAT3 signaling inhibition in both OSCC and oral dysplasia.

Expression of programmed cell death-ligand 1 in oral squamous cell carcinoma and oral leukoplakia is associated with disease progress and CD8+ tumor-infiltrating lymphocytes.

OBJECTIVE: In recent years, monoclonal antibodies targeting programmed cell death-ligand 1 (PD-L1) have become a promising cancer immunotherapy. However, the role of PD-L1 in oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs), including oral leukoplakia (OLK), remains controversial. The aim of the present study was to investigate the expression level of PD-L1 in OSCC and OPMDs, and examine its relationship with CD8 expression and different clinicopathological features. METHOD: Expression of PD-L1 and CD8 were conducted in 41 OSCC, 21 OLK, and 25 normal mucosa samples by immunohistochemistry. Then, the density of PD-L1 expression was measured, and its correlation with CD8 expression and different clinicopathological features was analyzed. RESULTS: PD-L1 protein was detected in 97.6% of OSCC, 61.9% of OLK, and 0% of normal tissues. PD-L1 was highly expressed in human OSCC tissue (P < 0.0001), when compared to both OLK and control tissues. PD-L1 positivity was significantly associated with CD8 density (P < 0.0001, r = 0.8491). The PD-L1 high expression OSCC group displayed a trend for improved overall survival (OS) and disease-free survival (DFS) compared to the low expression group, although the differences were not significant. Moreover, the expression level of PD-L1 in OSCC was positively correlated with the pathological grade (P < 0.0001), but it was independent of age, gender, smoking, drinking, tumor size, lymph node status, or recurrence (P > 0.05). Also, there was a significant upregulation of PD-L1 expression observed in the OLK group compared to the control group (P < 0.0001). PD-L1 positivity in OLK patients was associated with gender and smoking habits (P < 0.05), but it did not correlate with age, drinking, or dysplasia (P > 0.05). CONCLUSION: The upregulation of PD-L1 may be associated with disease progress and CD8+ tumor-infiltrating lymphocytes in oral premalignant and malignant lesions.

Organophosphate Esters in Road Dust from a Suburban Area of Chongqing, China: Characterization of Particle Size Distribution and Human Exposure.

Four types of road dust, including main road, industrial road, campus road, and campus walking street dust, were analyzed in a suburban area of Chongqing, western China. The organophosphate esters (OPEs) concentrations varied from 3.69 to 1600 ng/g dry weight, with a median of 292, 476, 203, and 48.8 ng/g dw in main road, industrial road, campus road, and campus walking street dust, respectively. The industrial sources should be responsible for the elevated OPEs concentrations in industrial road dust, while the vehicle emissions may play a role in the OPEs distribution in main road dust. Semblable OPEs composition patterns were observed among different types of road dust; tributyl phosphate predominated followed by tris(methylphenyl) phosphate. Significantly positive correlations were obtained between industrial road dust and campus road dust and main road dust, respectively, and statistical correlations also were found between main road dust and other road dust. An increasing trend of OPEs was displayed with the descending particle size in industrial road dust, whereas highest values were at F3 (90-150 µm) (340 ng/g dw) and F5 (< 75 µm) (305 ng/g dw), with a peak value at F3 in main road dust. This result may suggest that OPEs are prone to accumulate in finer particles. The estimated daily intake values for toddlers were approximately two times greater than those for adults in each region, implying that toddlers may be more vulnerable to OPEs intake via road dust.

Artemisinin and its derivatives: a potential therapeutic approach for oral lichen planus.

BACKGROUND: Oral lichen planus (OLP) is a common T-cell-mediated oral mucosal disease, whose pathogenesis mainly includes antigen-specific and non-specific mechanisms. As a refractory chronic inflammatory disease, there is still no curable management for OLP till now. FINDINGS: Artemisinins are a family of compounds that are widely used as frontline treatment for malaria worldwide. In addition to its well-established antimalarial properties, emerging evidence hints that artemisinin family drugs also possess preferential immunoregulatory and anti-inflammation properties, such as modifying T lymphocytes' activation and cytokines release, modulating Th1/Th2 balance, activating regulatory T cells (Tregs), modulating inflammatory signaling pathways, as well as acting on non-specific mechanisms of OLP. However, there is still no report focused on the influence of artemisinins on OLP. CONCLUSION: This review outlined the data-based immunomodulatory effects of artemisinins on different immune cells in conjunction with their therapeutic prospective with regard to the pathogenesis of OLP, suggesting that artemisinin and its derivatives might be possible candidates for treatment of OLP.

Organophosphate esters in biota, water, and air from an agricultural area of Chongqing, western China: Concentrations, composition profiles, partition and human exposure.

We measured the concentrations of organophosphate esters (OPEs) in some biotic samples which can serve as human foodstuffs and ambient environments including air and river water from an agricultural area of Chongqing, western China. Fish samples exhibited highest OPEs levels (960 ng/g lipid weight) among the biota, followed by chicken (676 ng/g lw), cattle (545 ng/g lw) and pigs (535 ng/g lw). Tributyl phosphate (TNBP), tris (2-methylpropyl) (TIBP) and chlorinated OPEs were the major analogs in biotic samples, which appeared similar with the patterns from river water and outdoor air, but apparently different from indoor air. To further investigate the influence of ambient environment on the distribution of OPEs in biota, we analyzed the correlation between OPEs concentrations in ambient environment and biological samples, and the results revealed that most of the samples (except for pig samples) heavily correlated with outdoor air, whereas only fish and cattle samples were strongly correlated with river water. The partitioning behaviors of OPEs among biota, air and river water were also studied through calculating the biota-water accumulation factors (BWAFs), biota-air accumulation factors (BAAFs) and air-water partitioning factor (AWPFs). Significantly linear correlations (P < 0.05) were observed between log (BWAFs) and log (KOW) values, and between log (AWPFs) and log H (Henry's law constants), nevertheless log (BAAFs) was increasing along with the log (KOA) values. The daily intake (DI) values were estimated via foodstuffs ingestion and environmental exposure. The estimated DI values of OPEs from food and ambient environments were 1.78 ng/kg-bw/day, 1.23 ng/kg-bw/day and 1.42 ng/kg-bw/day in toddlers, children and adults, respectively, which lay at the low end of the reported data and well below the reference dose (RfD).

[Occurrence and Distribution of Phthalate Esters in Urban Soils of Chongqing City].

In total, 66 soil samples were collected from five different urban functional areas in Chongqing, and the concentration levels of phthalate esters (PAEs) were analyzed using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Meanwhile, the composition and characteristics of PAEs were discussed, along with their possible sources, through correlation analysis and principal component analysis. The results showed that the concentrations of ∑PAEs ranged from 93.1-312 ng·g-1 dry weight, which is at the low end of the worldwide figure. DEHP, DBP, and DIBP were the dominant compounds, contributing 87.4%-92.9% of the total ∑PAEs. DEHP was the most abundant PAE congener, responsible for 52.4% of the total ∑PAEs. Through correlation analysis, it was noted that PAEs with similar molecular weight were more likely to show a significant relationship with each other, which suggested that these PAEs may share a similar source. According to the principal component analysis, DBP, DIBP, and DEHP had a similar source, while BBP and DnOP strongly correlated with each other. Compared to other studies, relatively low PAE concentrations were apparently observed in this study, but the potential human risk via exposure to these compounds should also been considered.

Occurrence of tetrabromobisphenol a (TBBPA) and hexabromocyclododecane (HBCD) in soil and road dust in Chongqing, western China, with emphasis on diastereoisomer profiles, particle size distribution, and human exposure.

Currently, the HBCDs were listed in Annex A by the Stockholm Convention, and the knowledge on the contamination of TBBPA and HBCDs in soil and road dust in China is still limited, and it is unclear what role is played by dust particle size distribution. In this study, a total of 81 soil and 43 road dust samples were analyzed with TBBPA and ΣHBCDs concentrations ranging from < LOQ to 33.8 ng/g dw (dry weight) and 0.43-15.2 ng/g dw in soil, and from < LOQ to 74.1 ng/g dw and 7.25-14.0 ng/g dw in road dust, respectively. TBBPA and HBCDs exhibited different spatial distribution patterns in soil, where relatively high levels of HBCDs were found in industrial area and commercial area, while high levels of TBBPA were detceted in residential area. However, no distinct variation in spatial distribution of these two compounds was observed in road dust. Different diastereoisomer profiles of HBCDs were also found with γ-HBCD predominating in soil and α-HBCD occupying a large proportion in road dust. The α-/γ-HBCD values in road dust were significantly greater (T-test, P < 0.05) than those in soil, which suggested that γ-HBCD in road dust were likely to transform into α-HBCD compared with soil. The distribution of dust particle size showed that HBCDs levels were increasing with the decreasing in particle sizes, while the TBBPA showed some "accidental" peak values in specific diameter ranges. The estimated daily intakes (EDIs) of TBBPA and HBCDs were assessed through dust ingestion, dermal absorption and inhalation via road dust, and all the exposure estimates were well below the reference dose (RfD), but the toddlers were more vulnerable to TBBPA and HBCDs intakes, which should be paid more attention.

Organophosphate esters and phthalate esters in human hair from rural and urban areas, Chongqing, China: Concentrations, composition profiles and sources in comparison to street dust.

Human hair and street dust from rural and urban areas in Chongqing were collected to analyze Organophosphate esters (OPEs) and phthalate esters (PAEs). Concentrations of OPEs in urban hair were significantly higher than those in rural hair, whereas PAEs concentrations in rural hair were significantly higher than those in urban hair. Different composition patterns of OPEs were observed in rural and urban hair, where tris (2-chloroisopropyl) phosphate (TCIPP), tris (butyl) phosphate (TNBP) and triphenyl phosphate (TPHP) were the dominating analogues in rural hair, accounting for 62.1% of the OPEs burden, and tris (methylphenyl) phosphate (TMPP) exhibited a high contribution in urban hair, responsible for 51.3% of total OPEs, which differed from the composition profiles in corresponding street dust. Analogous composition patterns of PAEs were found in hair of both areas. Di-(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DNBP), diisobutyl phthalate (DIBP) and diethyl phthalate (DEP) were the most abundant analogues in hair samples, while DEHP was the predominant analogue in dust samples. No clear tendency was obtained between the increasing ages and the concentrations of both compounds. Most OPEs and PAEs congeners showed significantly positive correlation with one another in rural hair. On the contrary, different correlation patterns were observed in urban hair for OPEs and PAEs, indicating multiple or additional sources existed in urban areas. Significant correlations of OPEs and PAEs were found between hair and corresponding street dust samples, but poor correlations of OPEs and PAEs were observed between rural hair and rural indoor dust, suggesting that street dust may be a predominant exogenous source for human exposure to OPEs and PAEs in this area.

[Occurrence and Distribution of the Organophosphate Esters in Soils of Mixed-land Use Area in Chongqing City].

Organophosphate esters (OPEs) in surface soil of four different functional areas in Chongqing were identified and quantified using ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS). The composition and characteristics of OPEs were discussed along with the relationships between soil organic matter (SOM) and OPEs through correlation analysis, and possible sources of OPEs were simultaneously investigated through principal component analysis (PCA). The results showed that the concentrations of ∑OPEs ranged from 10.7 to 108 ng·g-1 dry weight, with a mean concentration of 46.4 ng·g-1, which was at the low-level end of the global figure. The average concentration was 55.6 ng·g-1 in the industrial area, 55.5 ng·g-1 in the residential area, 41.8 ng·g-1 in the commercial area, and 34.1 ng·g-1 in the city park. Tris (1-chloro-2-propyl) phosphate (TCPP) and 2-ethylhexyl diphenyl phosphate (EHDPP) were dominant compounds, contributing up to 31.5% in the industrial area for TCPP and 23.4% and 24.7% in the commercial area and city park, respectively, for EHDPP. Significant relationships between concentrations of SOM and ∑OPEs (P<0.05) and tricresyl phosphate (TCP) (P<0.01), respectively, indicated that SOM was a factor affecting the concentration and distribution of the OPEs. The PCA suggested that there were multiple sources of OPEs in urban soil. Sewage irrigation, road runoff, indoor source pollution, and sludge reuse could be potential sources of soil OPEs.

[Simulation of the Migration and Release Characteristics of Organophosphate Esters in Fluctuation Zone Soil of the Three Gorges Reservoir During Flooding].

In this study, we investigated the effects of organophosphate ester (OPE) concentrations, temperature, soil organic matter, and microorganisms on the migration and release of several common OPEs from fluctuation zone soil in the Three Gorges Reservoir (TGR) to the overlying water by simulation experiments in the lab. The results indicate that the release of OPEs is determined based on their concentrations in the soil. The release of OPEs from soil to the overlying water decreases with increasing organic matter content, which indicates that the presence of organic matter could inhibit the migration of OPEs. However, the inhibition of the release of OPEs of organic matter is not significantly enhanced when the organic content (dry weight) is greater than 30 g·kg-1. The average migration amount of OPEs is 1077.3 ng·mL-1 at 27℃, which was higher than that at 7℃, indicating that high temperature promotes the release of OPEs. The effect of microorganisms is not notable. Chlorine-based OPEs including Tris(2-chloroethyl) phosphate (TCEP), Tris(1-chloro-2-propyl) phosphate (TCPP), and Tris(1,3-Dichloro-2-Propyl) phosphate (TDCP) are the main monomers in the overlying water, mainly because both the Octanol-Water Partition Coefficient (Kow) and Organic Carbon Partition Coefficient (Koc) of chlorine-based OPEs are lower than that of alkane-based OPEs and aromatic-based OPEs. Thus, chlorine-based OPEs are more easily dissolved in water and are not easily adsorbed by organic matter in the soil. Therefore, chlorine-based OPEs are more likely to migrate from the soil and to be released into the overlying water than other OPEs and become the main OPE monomers in the overlying water of the TGR.

Current State, Distribution, and Sources of Phthalate Esters and Organophosphate Esters in Soils of the Three Gorges Reservoir Region, China.

Phthalate esters (PAEs) and organophosphate esters (OPEs) were identified and quantified in surface soils from farmland and riparian areas of the Three Gorges Reservoir (TGR), western China. Generally, the mean values of PAEs and OPEs were 618 and 266 ng/g dry weight (dw) in farmland soil and 560 and 499 ng/g dw in riparian soil, respectively. The occurrence of OPEs should be regarded as a risk factor in the TGR region. Analogous spatial distribution patterns for PAEs were observed with higher concentrations observed at site WZ in both types of soil, which might relate to the anthropogenic activities. The hydrodynamic conditions might be important factors contributing to the slightly different spatial distribution of OPEs. The concentrations of OPEs in riparian soil exceed those in farmland soil at all sampling sites, which could partly be ascribed to the complete operation of the TGR. Dibutyl phthalate (DnBP) was the most dominated PAEs congener in both types of soil. Of particular note is the elevated contribution of tris(methylphenyl) phosphate (TMPP), followed by 2-ethylhexyl diphenyl phosphate (EHDPP), accounting for more than 90% of the total OPEs, and the shipping or/and the local human activity might be considered as the major contributor. The slight differences in PAEs composition of principal components might largely attribute to the variety of emission sources in two types of soil. The different cluster patterns between two types of soil indicated that the anthropogenic activities as well as the full operation of TGR, may play a role.