Pedal medial arterial calcification in diabetic foot ulcers: A significant risk factor of amputation and mortality.

AIMS: Pedal medial arterial calcification (MAC) is frequently observed in individuals with diabetic foot ulcers (DFUs). However, the impact of pedal MAC on individuals with DFUs remains uncertain. The main aim of this study was to evaluate the association between pedal MAC with amputation and mortality outcomes. METHODS: A prospective, observational cohort study was conducted at West China Hospital from January 2012 to December 2021. Logistic regression analyses, Kaplan-Meier survival method, and Cox proportional hazards models were employed to evaluate the relationship between pedal MAC and amputation as well as mortality. RESULTS: A total of 979 patients were enrolled in the study. Peripheral artery disease (PAD) was observed in 53% of patients with DFUs, and pedal MAC was found in 8%. Over a median follow-up of 46 (23-72) months, foot amputation was performed on 190 patients, and mortality occurred in 246 patients. Pedal MAC showed a significant association with amputation both in unadjusted analysis (odds ratio [OR] = 2.98, 95% confidence interval [CI] = 1.86-4.76, p < .001) and after adjusting sex, age, albumin levels, hemoglobin levels, and diabetic retinopathy status (OR 2.29, 95% CI 1.33-3.93, p = .003). The risk of amputation was found to be twofold higher in individuals with PAD and pedal MAC compared to those with PAD alone (OR 2.05, 95% CI 1.10-3.82, p = .024). Furthermore, the presence of pedal MAC was significantly associated with an increased risk of mortality (p = .005), particularly among individuals with DFUs but without PAD (HR 4.26, 95% CI 1.90-9.52, p < .001), rather than in individuals presenting with both DFUs and PAD. CONCLUSION: The presence of pedal MAC is significantly associated with both amputation and mortality in individuals with DFUs. Moreover, pedal MAC could provide additional value to predict amputation other than PAD.

Lipid-lowering drugs and inflammatory bowel disease's risk: a drug-target Mendelian randomization study.

BACKGROUND: Inflammatory bowel disease (IBD) has been associated with lipid-lowering drugs in observational studies. Drug-target Mendelian randomization (MR) was utilized in this study to examine the causal relationship between lipid-lowering drugs and incidence of IBD, aiming to identify new preventive uses for the drugs. METHODS: We identified instrumental variables for three classes of lipid-lowering drugs: HMGCR inhibitors, PCSK9 inhibitors, and NPC1L1 inhibitors, using data from the Global Lipids Genetics Consortium. Summary statistics of IBD were obtained from UK Inflammatory Bowel Disease Genetics. The summary-data-based MR (SMR) and the inverse-variance weighted (IVW) MR were used for analysis. Sensitivity analyses were performed by conventional MR methods. RESULTS: The SMR analysis showed no significant genetic association between increased gene expression of HMGCR, PCSK9, and NPC1L1 and IBD, Crohn's disease (CD) and ulcerative colitis (UC). According to IVW-MR analysis, increased HMGCR expression is associated with a reduced risk of IBD (OR = 0.73, 95% confidence interval (CI) 0.59-0.90, P = 0.003) and CD (OR = 0.75, 95% CI 0.57-0.97, P = 0.03), but not with UC. Additionally, increased NPC1L1 gene expression was associated with elevated risk of IBD (OR = 1.60, 95% CI 1.07-2.40, P = 0.023), but not with CD and UC. However, no significant causal relationships were found between PCSK9 gene expression and IBD, CD, and UC. The sensitivity analysis demonstrated no evidence of heterogeneity or pleiotropy among the reported results. CONCLUSIONS: The heightened expression of genetic variations in HMGCR inhibitor targets could potentially reduce the risk of IBD and CD, while genetic variation in the expression of NPC1L1 targets was positively associated with IBD.

[Clinical Analysis of 17 Adult Patients With Fulminant Type 1 Diabetes Mellitus].

Objective: To explore the clinical characteristics of adult patients with fulminant type 1 diabetes mellitus (FT1DM), a specific subtype of type 1 diabetes mellitus (T1DM). Methods: We collected the clinical data of patients who were admitted to West China Hospital, Sichuan University in 2010-2019 for FT1DM and type 1 diabetes mellitus (T1DM) presenting with diabetic ketoacidosis (DKA) at the onset. In addition, all the FT1DM patients were followed up. Results: A total of 70 patients presenting with DKA at the onset of T1DM were admitted to and received treatment at West China Hospital in 2010-2019. Among them, 17 (24.3%) had FT1DM and 53 did not. The mean ages of the FT1DM patients and the non-FT1DM patients were (33.2±12.8) years and (27.5±11.2) years, and the mean body mass indices were (22.6±2.9) kg/m 2 and (19.2±2.9) kg/m 2, respectively. A total of 14 FT1DM cases had symptoms of upper respiratory tract infection or acute gastroenteritis before the onset of the disease and 4 cases were related to pregnancy. The median time from the onset of the disease to the first diagnosis of DKA of the FT1DM group (median [P 25-P 75]: 2 [1-4] days, P<0.001) was significantly shorter than that of the non-FT1DM group (median [P 25-P 75]: 30 [17-78] days). The mean maximum blood glucose levels at the time of the first visit to the doctor of the FT1DM patients ([39.9±11.4] mmol/L, P<0.001) were significantly higher than that of the non-FT1DM patients ([28.9±9.2] mmol/L), but the HbA1c (6.6%±0.6%, P<0.001) and glycosylated serum albumin (GA) (21.4%±3.0%, P=0.001) levels of the FT1DM patients were significantly lower than those of the non-FT1DM group (HbA1c: 12.8%±2.7%; GA: 44.8%±15.0%). The median serum amylase in the FT1DM group was significantly higher than that in the non-FT1DM group (101 [54-336] IU/L vs. 54 [42-166] IU/L, P=0.045) and the median serum lipase in the FT1DM group showed a trend of being higher than that in the T1DM group (81 [57-154] IU/L vs. 46 [28-195] IU/L, P=0.051). 8.7% of the non-FT1DM patients tested positive for anti-glutamic acid decarboxylase antibody (GAD-Ab), while the FT1DM patients all tested negative. At the time of discharge, the mean daily insulin dose of the FT1DM patients was (0.67±0.22) IU/kg, which was not significantly different from that of the non-FT1DM group ([0.74±0.29] IU/kg, P=0.349). After about 6.5 years of follow-up, the mean daily insulin dose of the FT1DM patients was (0.73±0.19) IU/kg, which was similar to the insulin dosage on discharge ( P=0.409). Conclusion: Compared with the non-FT1DM patients presenting with DKA at the onset, FT1DM patients have fewer typical diabetic symptoms, lower fasting C-peptide levels, higher serum amylase levels, and increased incidence of vomiting or other symptoms of gastrointestinal infections, and are more likely to be misdiagnosed. Therefore, it is very important for clinicians to correctly identify FT1DM as early as possible and administer early and long-term insulin replacement therapy.

Clinical characteristics and risk factors of lower extremity amputation in the diabetic inpatients with foot ulcers.

Objectives: To analyze clinical characteristics of the diabetic inpatients with foot ulcers and explore the risk factors of lower extremity amputation (LEA) in West China Hospital of Sichuan University. Methods: A retrospective analysis was performed based on the clinical data of the patients with diabetic foot ulcer (DFU) hospitalized in West China Hospital of Sichuan University from January 1, 2012 to December 31, 2020. The DFU patients were divided into three groups: non-amputation, minor amputation, and major amputation groups. The ordinal logistic regression analysis was used to identify the risk factors for LEA. Results: 992 diabetic patients (622 males and 370 females) with DFU were hospitalized in the Diabetic Foot Care Center of Sichuan University. Among them, 72 (7.3%) (55 minor amputations and 17 major amputations) cases experienced amputation, and 21(2.1%) refused amputation. Excluding the patients who refused amputation, the mean age and duration of diabetes of and HbA1c the 971 patients with DFU, were 65.1 ± 12.3 years old, 11.1 ± 7.6 years, and 8.6 ± 2.3% respectively. The patients in the major amputation group were older and had longer course of diabetes for a longer period of time than those in the non-amputation and minor amputation groups. Compared with the non-amputation patients (55.1%), more patients with amputation (minor amputation (63.5%) and major amputation (88.2%)) suffered from peripheral arterial disease (P=0.019). The amputated patients had statistically lower hemoglobin, serum albumin and ankle brachial index (ABI), but higher white blood cell, platelet counts, fibrinogen and C-reactive protein levels. The patients with amputation had a higher incidence of osteomyelitis (P = 0.006), foot gangrene (P < 0.001), and a history of prior amputations (P < 0.001) than those without amputation. Furthermore, a history of prior amputation (odds ratio 10.194; 95% CI, 2.646-39.279; P=0.001), foot gangrene (odds ratio 6.466; 95% CI, 1.576-26.539; P=0.010) and ABI (odds ratio 0.791; 95% CI, 0.639-0.980; P = 0.032) were significantly associated with LEAs. Conclusions: The DFU inpatients with amputation were older with long duration of diabetes, poorly glycemic control, malnutrition, PAD, severe foot ulcers with infection. A history of prior amputation, foot gangrene and a low ABI level were the independent predictors of LEA. Multidisciplinary intervention for DFU is essential to avoid amputation of the diabetic patients with foot ulcer.

Clinical and genetic diagnosis of autosomal dominant osteopetrosis type II in a Chinese family: A case report.

BACKGROUND: Osteopetrosis is a rare genetic disorder characterized by increased bone density due to defective bone resorption of osteoclasts. Approximately, 80% of autosomal dominant osteopetrosis type II (ADO-II) patients were usually affected by heterozygous dominant mutations in the chloride voltage-gated channel 7 (ClCN7) gene and present early-onset osteoarthritis or recurrent fractures. In this study, we report a case of persistent joint pain without bone injury or underlying history. CASE SUMMARY: We report a 53-year-old female with joint pain who was accidentally diagnosed with ADO-II. The clinical diagnosis was based on increased bone density and typical radiographic features. Two heterozygous mutations in the ClCN7 and T-cell immune regulator 1 (TCIRG1) genes by whole exome sequencing were identified in the patient and her daughter. The missense mutation (c.857G>A) occurred in the CLCN7 gene p. R286Q, which is highly conserved across species. The TCIRG1 gene point mutation (c.714-20G>A) in intron 7 (near the splicing site of exon 7) had no effect on subsequent transcription. CONCLUSION: This ADO-II case had a pathogenic CLCN7 mutation and late onset without the usual clinical symptoms. For the diagnosis and assessment of the prognosis for osteopetrosis, genetic analysis is advised.

[Clinical Characteristics and Prognosis of Diabetic Foot Ulcers Patients of Different Renal Function Statuses].

Objective: To explore the clinical characteristics and the prognosis of diabetic foot ulcers (DFU) inpatients of different renal function statuses. Methods: A retrospective analysis of 962 inpatients with DFU was conducted. The patients were divided into three groups according to their renal function statuses, and the clinical characteristics of the three groups were compared to identify differences. In addition, the patients were followed up in outpatient clinics or by telephone and their prognostic status and risk factors for death were analyzed. Results: Analysis of the clinical characteristics showed that, compared with diabetic patients with normal renal function or mild renal function impairment, diabetic patients with moderate and severe renal function impairment had a longer course of disease ( P<0.001). Patients with foot ulcers of Wagner grade 4 predominates the moderate and severe renal function impairment groups ( P<0.05). Patients in the moderate and severe renal function impairment groups had a relatively higher proportion of comorbidities, including hypertension, coronary heart disease, and peripheral arterial disease ( P<0.05). These patients had relatively lower levels of glycosylated hemoglobin and hemoglobin (all P<0.05) and relatively higher levels of neutrophil ratio and procalcitonin (all P<0.05). Of the two groups, patients in the moderate renal function impairment group were older ( P<0.001) and had lower ankle-brachial index ( P<0.001). The severe renal function impairment group had a higher proportion of patients with foot ulcers of Wagner grades 3 and 5 (all P<0.05). For the purpose of conducting prognostic analysis, 748 patients were followed up in outpatient clinics or by telephone for a median length of 41 months. Among them, 239 died. The all-cause mortality was 31.9%, and the mortality in the three groups was 25.8%, 46.2% ( P<0.001), and 59.4% ( P<0.001), respectively. The survival rate of patients in the moderate and severe renal function impairment groups was significantly lower than those in the normal renal function and mild renal function impairment groups ( P<0.001). Univariate Cox regression analysis showed that age, concomitant coronary heart disease and peripheral arterial disease, degree of renal function impairment, and foot ulcers of Wagner grade 4 and 5 were associated with all-cause deaths. Furthermore, multivariate Cox regression analysis showed that moderate and severe renal function impairment was an independent risk factor for all-cause deaths in DFU patients ( P<0.001). Conclusions: As renal function impairment worsens, patients with DFU present clinical characteristics of greater complexity, higher risks of cardiovascular events, and higher mortality. It is essential to prevent kidney damage and foot ulcers, to pay attention to the cardiovascular risks of DFU patients with moderate and severe renal function impairment, and to reduce mortality.

[Characteristics of Inflammatory Markers in Diabetic Foot Patients and Their Relationship With Prognosis of Diabetic Foot Ulcers]. / ç³–å°¿ç— è¶³æ‚£è€ ç‚Žç—‡æ ‡å¿—ç‰©ç‰¹å¾åŠå ¶ä¸Žè¶³æºƒç–¡é¢„åŽå ³ç³».

Objective: To explore the characteristics of baseline inflammatory markers in diabetic foot patients and their relationship with the prognosis of diabetic foot ulcers. Methods: The clinical data of diabetic foot patients (n=495) admitted to West China Hospital, Sichuan University since 2016 were retrospectively collected through the hospital electronic medical record system to analyze the characteristics of inflammatory markers and their relationship with the prognosis of diabetic foot ulcers. Results: White blood cell count (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) levels were significantly higher in patients defined as grade 4 on the Wagner Scale than those in patients defined as grade 0-3 on the Wagner Scale. Neutrophil percentage (NE%) was higher in Wagner grade-4 patients than those in Wagner grade-0 and grade-1 patients and higher in Wagner grade-3 patients than those in Wagner grade-0 patients. NE%, CRP, PCT, and IL-6 levels were positively correlated with the severity of diabetic foot, with the respective odds ratio (OR) at 95% confidence interval (CI) being 1.038 (1.019-1.056), 1.019 (1.012-1.026), 8.225 (2.015-33.576), and 1.017 (1.008-1.025). Using Wagner grade-0 patients as the reference, patients with higher WBC were more likely to progress to Wagner grade 2, 3, and 4, with the respective OR (95% CI) values being 1.260 (1.096-1.447), 1.188 (1.041-1.356), and 1.301 (1.137-1.490); patients with higher ESR were more likely to progress to Wagner grade 3 and 4, with the respective OR (95% CI) values being 1.030 (1.006-1.054) and 1.045 (1.019-1.071). Baseline ESR (P=0.008), CRP (P=0.039), and IL-6 (P=0.033) levels were lower in patients who had received antibiotics prior to their admission than those in patients who had not received antibiotics before admission. The levels of WBC, NE%, ESR, PCT, and IL-6 were lower in the full recovery group than those in the group of patients who did not respond to treatment. The higher the levels of NE% and IL-6, the worse the prognosis of diabetic foot ulcers became, with the respective OR (95% CI) values being 1.030 (1.010-1.051) and 1.008 (1.002-1.013). Conclusion: The severity of diabetic foot ulcers increased with the rise in baseline levels of inflammatory markers. Elevated baseline NE% and IL-6 levels suggest a poor prognosis. Our findings suggest that early assessment of diabetic foot infection and standardized antibiotic therapy should be implemented to improve the prognosis.

Physins in digestive system neoplasms.

The physin family of proteins, synaptophysin (SYP), synaptophysin like 1 (SYPL1), synaptophysin like 2 (SYPL2) and synaptoporin (SYNRP), are tetratransmembrane transport vesicle proteins distributed throughout the digestive system. Of these, SYP is a required marker for histopathologic identification of neuroendocrine neoplasms (NENs), especially in gastroenteropancreatic NENs (GEP-NENs). Recently, bloodstream SYP, i.e., on platelets and circulating tumor cells, has been correlated to clinicopathologic features of GEP-NENs and may have prognostic significance. Serum SYPL1 also represents a promising biomarker for colorectal cancer. This chapter provides an overview of physin structures and potential use as diagnostic, prognostic and therapeutic tools for digestive tract neoplasms.

[Clinical Characteristics of Diabetic Patients with Initial and Recurrent Foot Ulcers].

Objective: To explore the risk factors for the recurrence of foot ulcers by analyzing clinical characteristics of the patients with diabetic foot ulcers (DFU) in West China Hospital, Sichuan University. Methods: A retrospective analysis was carried out with the clinical data of 817 DFU patients hospitalized at West China Hospital, Sichuan University between January 1, 2012 and December 31, 2020. The patients were divided into an initial ulceration group (502 cases) and a recurrent ulceration group (315 cases) according to their history of foot ulcers. The differences in clinical characteristics between the two groups were compared, and multivariate logistic regression analysis was conducted to identify the risk factors associated with the recurrence of foot ulcers. Results: Initial and recurrent DFU patients both had predominantly neuro-ischemic foot ulcers, and the most common sites of ulceration were the first and fifth toes in both groups. Compared with the initial DFU group, more patients in the recurrent group had foot ulcers of Wagner grade 3 and ulcerous wounds located on calluses ( P<0.05), and fewer patients in the recurrent group suffered from foot gangrene ( P<0.05). Patients with recurrent DFU had lower glycated hemoglobin, platelet counts, and fibrinogen levels ( P<0.05), and higher serum uric acid and creatinine levels ( P<0.05). Hemoglobin, white blood cell count, estimated glomerular filtration rate, erythrocyte sedimentation rate and C-reactive protein levels were not significantly different between the two groups ( P>0.05). Multivariable logistic regression analysis showed that male sex ( OR=1.555, 95% CI: 1.097-2.204, P=0.013), duration of diabetes≥10 years ( OR=2.369, 95% CI: 1.473-3.810, P<0.001), history of amputation ( OR=4.518, 95% CI: 2.386-8.553, P<0.001), foot osteoporosis ( OR=1.711, 95% CI: 1.065 to 2.751, P=0.027), ulcerous wound located on foot callus ( OR=1.786, 95% CI: 1.058-3.012, P=0.030), and coronary heart disease ( OR=0.668, 95% CI:0.453-0.987, P=0.043) were significantly associated with the recurrence of foot ulcers. Conclusions: Male sex, duration of diabetes being over 10 years, history of previous amputation, foot osteoporosis, and ulcerous wounds located on foot callus are independent risk factors of recurrent foot ulcers in patients with DFU. Therefore, even after their foot ulcers have healed, special attention should be given to the care of foot for patients with DFU, which may reduce the recurrence of foot ulcers.

Microbial Infection and Antibiotic Susceptibility of Diabetic Foot Ulcer in China: Literature Review.

Objective: To investigate the microbial spectrum isolated from foot ulcers among diabetic patients in China, which was conducted to help clinicians choose optimal antibiotics empirically. Method: The PubMed, MEDLINE, Web of Science, China Biology Medicine (CBM), China National Knowledge Infrastructure (CNKI), WanFang, and VIP databases were searched for studies published between 2015 to 2019, that report primary data on diabetic foot infection (DFI) and antibiotic susceptibility in China. Result: A total of 63 articles about DFI and antibiotic susceptibility tests among diabetic patients in China were included. There were 11,483 patients with an average age of 60.2 ± 10.1 years and a mean course of 10.6 ± 5.0 years between 2010 and 2019, covering most geographical regions of China. The prevalence of Gram-positive (GP) bacteria (43.4%) was lower than that of Gram-negative (GN) (52.4%). The most prevalent pathogens isolated were Staphylococcus aureus (17.7%), Escherichia coli (10.9%), Pseudomonas aeruginosa (10.5%), Klebsiella pneumoniae (6.2%), Staphylococcus epidermidis (5.3%), Enterococcus faecalis (4.9%), and fungus (3.7%). The prevalence of polymicrobial infection was 22.8%. GP bacteria were sensitive to linezolid, vancomycin, and teicoplanin. More than 50% of GN bacteria were resistant to third-generation cephalosporins, while the resistance rates of piperacillin/tazobactam, amikacin, meropenem, and imipenem were relatively low. Among the 6017 strains of the isolated organisms, 20% had multi-drug resistance (MDR). Staphylococcus aureus (30.4%) was the most predominant MDR bacteria, followed by extended-spectrum ß-lactamase (ESBL) (19.1%). Conclusion: The microbial infection of foot ulcers among diabetic patients in China is diverse. The microbial spectrum is different in different geographic regions and Staphylococcus aureus is the predominant bacteria. Polymicrobial and MDR bacterial infections on the foot ulcers are common. This study could be valuable in guiding the empirical use of antibiotics for diabetic foot infections.

Evaluation of atmospheric sources of PCDD/Fs, PCBs and PBDEs around an MSWI plant using active and passive air samplers.

This study evaluated the spatial distributions and concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in ambient air around a municipal solid waste incineration (MSWI) plant located in eastern China in two sampling campaigns within one year. Twenty high-volume samples and 27 passive air samples were collected from May 2012 to May 2013. The mean sampling rate of the passive sampler was estimated to be 3.8 ± 1.8 m3 d-1 in summer and autumn, while the mean sampling rate was 2.8 ± 1.0 m3 d-1 in winter and spring. Hence, the annual mean sampling rate was approximately 3.2 ± 1.4 m3 d-1. The mean levels of PCDD/Fs, PCBs, PBDEs (excluding BDE-209) and BDE-209 in the passive air samples varied in the ranges of 0.086 ± 0.058-0.76 ± 0.51 pg TEQ m-3, 39 ± 26-170 ± 120 pg m-3, 3.3 ± 2.2-36 ± 24 pg m-3 and 58 ± 39-300 ± 150 pg m-3, respectively. The levels, congener profiles and spatial distributions of PCDD/Fs, PCBs and PBDEs were investigated. The results showed that the concentrations of PCDD/Fs and PCBs decreased with increasing distance from the emission source and that different sampling sites had slightly different effects. However, this trend was opposite to that observed for PBDEs. Moreover, principal component analysis (PCA) demonstrated that the MSWI emission source was the primary factor for PCDD/Fs in ambient air. Further monitoring should be conducted to evaluate the noticeable impact on the environment and human health due to exposure.

Multiple classes of chemical contaminants in soil from an e-waste disposal site in China: Occurrence and spatial distribution.

E-waste recycling is well known for releasing halogenated organic compounds (HOCs) and heavy metals. This study investigated the occurrence and distribution of traditional and novel classes of contaminants, including chlorinated, brominated, and mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and polyhalogenated carbazoles (PHCZs), in soil from an e-waste disposal site in Hangzhou. PBDEs were the most abundant, at 343-69306 ng kg-1, followed by PHCZs (896-41,362 ng kg-1), PCDD/Fs (349-19,396 ng kg-1), PCBs (51.3-1834 ng kg-1), PBDD/Fs (2.99-524 ng kg-1) and PXDD/Fs (0.104-21.2 ng kg-1). The detected target compound concentrations were generally lower than those reported in the literature for informal e-waste sites. Nevertheless, they can serve as a basis of information for evaluation and subsequent control. The toxic equivalent (TEQ) contributions from these contaminants (except PBDEs) decreased as follows: PCDD/Fs > PXDD/Fs > PHCZs > PCBs > PBDD/Fs. ΣDioxins (PCDD/Fs + PBDD/Fs + PXDD/Fs) accounted for 47.7%-97.2% of the total TEQs in the soil. OCDD, 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from combustion and transport because of their low saturated vapor pressure. PXDFs were more abundant than PXDDs, and homologue profiles suggested a similar formation mechanism for PXDFs and PBDFs involving successive Br-to-Cl exchange. PHCZs were reported in soil from an e-waste disposal area for the first time, and their concentrations were several orders of magnitude higher than those of the other contaminants. Although the risk of human exposure in this study was estimated to be lower than the values recommended by the WHO (1-4 pg TEQ/kg bw/day), health implications still exist, and further investigations are necessary.

Method development for analyzing ultratrace polyhalogenated carbazoles in soil and sediment.

In the past few years, polyhalogenated carbazoles (PHCZs) have been of increasing concern because their structure is similar to that of legacy POPs. In the present study, an analytical method, including intensive cleanup and fractionation procedures in combination with instrumental parameters, was developed to determine ultratrace polyhalogenated carbazoles (PHCZs) in soil and sediment. The eluting sorbents, volume and packing of the column were optimized. Our results showed that 5 g of florisil and 4 g of silica gel under 150 mL of hexane/DCM = 3:1 presented good performance in terms of recovery and repeatability. GC-HRMS, GC-MS/MS (EI-MRM) and GC-MS (EI-SIM) were applied to compare the performance of PHCZ analysis. For sensitivity, EI-MRM presents method detection limits comparable to those of GC-HRMS and much lower than those of EI-SIM. Regarding selectivity, GC-HRMS performed better than the other two techniques since GC-HRMS can reduce interference from perfluorokerosene (PFK) and DDX (DDT, DDE, and DDD) due to its high resolution. GC-HRMS was then further optimized by shortening the run time and modifying the SIM ion. The final method was successfully applied to determine PHCZs in soil and sediment, and the target compounds had almost 100% detection frequency in the samples. The ubiquitous presence of PHCZ in soil and sediment calls for a further investigation of its source, distribution and degradation in the environment.

Study on the pollution characteristics and emission factors of PCDD/Fs from disperse dye production in China.

According to an analysis of the input and output of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) of two disperse dye manufacturers, the average PCDD/F emission factor was 56.3 µg I-TEQ/T product, and dioxin was mainly emitted with products and solid waste. The PCDD/F concentrations of different series of disperse dyes varied from 2.87 to 323 pg I-TEQ/g, and the dominant congener was OCDD or 2,3,7,8-TCDF with the highest ratio of 83.4% or 79.3%, respectively. The distributions of PCDD/F congeners in raw materials and the products were different, indicating that the structure of PCDD/Fs greatly changed in the synthesis process. PCDD/Fs in the wastewater and sludge of the companies are mainly from the production process of a product with dominant emission factors. Our results confirm that disperse dyes may be a source of PCDD/Fs, resulting in human exposure and environmental contamination.

[Pollution characteristics of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in PM2.5 of Hangzhou City during winter].

In order to evaluate the distributions and concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in aerosol, PM2.5 samples were collected concurrently at five sites in January 2014 in Hangzhou. The analytes were analyzed with isotope dilution and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) based on US EPA 1613B method and US EPA 1668B method. The results showed that the mass concentrations of PM2.5 were in the range of 85-168 µg/m3, which were much higher than the national quality standard. The values suggested that the PM2.5 pollution was relatively serious in Hangzhou City, yet it has been improved when compared with the results of 2004. The toxic equivalent quantities (TEQs) of PCDD/Fs in PM2.5 were in the range of 0.277-0.488 pg I-TEQ/m3, which were much higher than the results in 2004. Octachlorodibenzo-p-dioxin (OCDD) accounted for a large proportion to the total concentrations in PCDD/Fs, while 2,3,4,7,8-pentachlorodibenzofurans (2,3,4,7,8-PeC- DF) contributed the highest to the TEQ. The values of PCBs and dioxin-like PCBs (DL-PCBs) varied from 2.9-8.1 pg/m3 and 2.6-6.1 fg WHO-TEQ/m3, respectively. PCB-28 was the most abundant contributor to the concentrations of PCBs, while PCB-126 contributed the highest to the TEQ of DL-PCBs. Gas-particle distributions of PCDD/Fs and PCBs shows that PCDD/Fs were mainly distributed in the particle phase, but PCBs were preferably adsorbed in the gas phase.

[Levels of PCDD/Fs and dioxin-like PCBs in soils near E-waste dismantling sites].

One hundred and fifty one soil samples from 125 sampling points were collected near E-waste dismantling sites and analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs). Total concentration of PCDD/Fs in topsoil samples ranged from 280 pg x g(-1) to 7 010 pg x g(-1) dry weight with the mean value of 1 380 pg x g(-1) dry weight. The mean value of the second layer and the deepest layer is 63% and 38% of that of top soils, respectively. The toxic equivalent quantity (TEQ) of PCDD/Fs in top soils ranged from 1.4 pg x g(-1) to 94.8 pg x g(-1) (I-TEQ). According to the guidelines for TEQ concentrations established in Germany, 19 of 125 topsoil samples (15% of the total topsoil samples analyzed) could not be expected to pose human health hazards. The rest of 85% of top soils needs investigations of source identification. If the contribution of PCB to TEQ was considered, 98% of top soils need investigations of source identification. Principle component analysis (PCA) is used to identify the PCDD/Fs sources. The homologue profiles of PCDD/Fs showed that dismantling activities are the main emission resources of the PCDD/Fs from thermal processes, also are the main emission resources of the PCDD/Fs in soils of this area.