HRMS analysis of pesticides in vegetables from Shanghai and risk assessment.

A rapid analytical method for the simultaneous determination of 550 pesticide residues in vegetable samples was developed based on ultra-high performance liquid chromatography-tandem Q/Orbitrap high-resolution mass spectrometry (UPLC-Q/Orbitrap-HRMS). To investigate the risk of exposure to pesticide residues through vegetable consumption, 704 leafy vegetable samples from Shanghai were analysed for multiple residues using this method. A total of 54 pesticide residues were identified in these vegetable samples and 302 samples contained one or more pesticide residue. The levels of the detected pesticides did not pose a health risk in the long term and were acceptable according to the results of the chronic dietary risk assessment. Risk rankings displayed that most of the pesticides were low to medium risk. The findings of this study provide a reference for future pesticide monitoring programmes.

Bayesian-based calibration for water quality model parameters.

To improve the efficiency and accuracy of water quality model parameter calibration and avoid local optima and the phenomenon in which different parameters have the same effect, this paper proposed a novel Bayesian-based water quality model parameter calibration method. Using Bayesian inference, the parameter calibration problem was converted into a posterior probability function sampling problem, which was sampled using the Markov Chain Monte Carlo algorithm. The convergence speed of the calibration was further improved by setting the optimized initial sampling value. The influences of the initial sampling value, Markov chain length, and proposal distribution form on the calibration effect were evaluated using four specific cases. The results indicate that (1) the mean relative error (MRE) of the parameter calibration results of this method is less than 10%, with the calibration MRE of Dx and Dy being 5.3% and 8.3%, respectively; (2) when the parameter sensitivity is low, the calibration effect of this method is relatively poor, with a calibration MRE of 46% for k; (3) the parameter calibration can be completed more efficiently by setting an optimized initial value for the MCMC, choosing a reasonable Markov chain length and a suitable proposal distribution form. PRACTITIONER POINTS: Bayesian-based water quality model parameter calibration method is proposed and posterior probability distribution was sampled using the MCMC algorithm. Parameter calibration can be completed more efficiently by setting an optimized initial value for the MCMC. As a result, efficient and accurate parameter calibration of water quality models was achieved. This method is widely applicable to various models, and the calibration speed depends on the calculation speed of the model.

Role of the Emphysema Index Combined with the Chronic Obstructive Pulmonary Disease Assessment Test Score in the Evaluation of Chronic Obstructive Pulmonary Disease.

Background: This study aimed to evaluate the efficacy of the emphysema index (EI) in distinguishing chronic bronchitis (CB) from chronic obstructive pulmonary disease (COPD) and its role, combined with the COPD Assessment Test (CAT) score, in the evaluation of COPD. Methods: A total of 92 patients with CB and 277 patients with COPD were enrolled in this study. Receiver operating characteristic (ROC) curves were analyzed to evaluate whether the EI can preliminarily distinguish chronic bronchitis from COPD. Considering the heterogeneity of COPD, there might be missed diagnosis of some patients with bronchitis type when differentiating COPD patients only by EI. Therefore, patients with COPD were classified according to the CAT score and EI into four groups: Group 1 (EI < 16%, CAT < 10), Group 2 (EI < 16%, CAT ≥ 10), Group 3 (EI ≥ 16%, CAT < 10), and Group 4 (EI ≥ 16%, CAT ≥ 10). The records of pulmonary function and quantitative computed tomography findings were retrospectively analyzed. Results: ROC curve analysis showed that EI = 16.2% was the cutoff value for distinguishing COPD from CB. Groups 1 and 2 exhibited significantly higher maximal voluntary ventilation (MVV) percent predicted (pred), forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC), maximal midexpiratory flow of 25-75% pred, carbon monoxide-diffusing capacity (DLCO)/alveolar ventilation (VA), FEV1 % pred (p ≤ 0.013), and maximal expiratory flow 50% pred (all p < 0.05) than Group 4. FEV1/FVC and DLCO/VA were significantly lower in Group 3 than in Group 2 (p=0.002 and p < 0.001, respectively). The residual volume/total lung capacity was higher in Group 3 than in Groups 1 and 2 (p < 0.05). Conclusions: The combination of EI and CAT was effective in the evaluation of COPD.

Pesticides and risk assessment in Shanghai fruit and raw eaten vegetables.

A database of 392 pesticides established by an Ultrahigh performance liquid chromatography-tandem Q/Orbitrap high-resolution mass spectrometer (UPLC-Q/Orbitrap-HRMS) was used to screen multiple residues of pesticides in fruit and raw eaten vegetables from planting farms in Shanghai. Risk assessment was conducted with the screened results of the determined pesticides as to evaluate food safety. In 95% of the samples, one or more pesticides had a content below the maximum residue limits (MRLs) as set in the national Chinese standard. The co-occurrence of multi-residues of pesticides was more severe in peach and muskmelon, when compared with other food. All hazard index values of different groups were in the range of 0.19% to 12.3%, demonstrating that chronic dietary risk of studied fruits and raw eaten vegetables is low and the studied food samples were safe for human consumption in terms of these detected pesticides.

Determination and dietary risk assessment of 284 pesticide residues in local fruit cultivars in Shanghai, China.

The presence of pesticide residues has become one of the main risk factors affecting the safety and quality of agro-food. In this study, a multi-residue method for the analysis of 284 pesticides in five local fruit cultivars in Shanghai was developed based on ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS). The limits of determination and the limits of quantitation of pesticides were 0.6-10 and 2-30 µg/kg, respectively. A total of 44, 10, 10, 18, and 7 pesticides were detected in strawberries, watermelons, melons, peaches, and grapes, respectively. The pesticide levels in 95.0% of the samples were below the maximum residual limits (MRLs) prescribed by China, and in 66.2% of the samples below the EU MRLs. The dietary risk assessment study showed big differences in the chronic and acute exposure risk values among different Chinese consumer groups. Through fruit consumption, children/females showed higher exposure risks than adults/males. But both the risk values were less than 100%, indicating that potential dietary risk induced by the pesticides was not significant for Chinese consumers. Nevertheless, certain measures are needed for both growers and the government in order to decrease the MRL-exceeding rate of pesticide residues and ensure the quality and safety of fruits for consumers.

Ambient air pollution and adverse birth outcomes: a systematic review and meta-analysis.

Several reviews have assessed the relationship between exposure to ambient air pollution and adverse birth outcomes during pregnancy, but the results remain controversial. The objective of this study was to assess this correlation quantitatively and to explore sources of heterogeneity. We included all published case-control or cohort studies that evaluated the correlation between ambient air pollution and low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA). Analytical methods and inclusion criteria were provided on the PROSPERO website (CRD42018085816). We evaluated pooled effects and heterogeneity. Subgroup analyses (grouped by exposure period, study settings, study design, exposure types, data source, Newcastle-Ottawa quality score (NOS), and adjustment for smoking or meteorological factors) were also conducted and publication bias was examined. The risk of bias in systematic reviews (ROBIS) tool was used to evaluate the overall risk of bias in this review. Forty studies met the inclusion criteria. We observed pooled odds ratios (ORs) of 1.03-1.21 for LBW and 0.97-1.06 for PTB when mothers were exposed to CO, NO2, NOx, O3, PM2.5, PM10, or SO2 throughout their pregnancy. For SGA, the pooled estimate was 1.02 in relation to NO2 concentrations. Subgroup analysis and sensitivity analysis decreased the heterogeneity to some extent, such as the subgroups of continuous measures (OR=0.98 (0.97-0.99), I2=0.0%) and NOS>7 (OR=0.98 (0.97-0.99), I2=0.0%) in evaluating the association between PTB and NO2. This review was completed with a low risk of bias. High concentrations of air pollution were significantly related to the higher risk of adverse birth outcomes. However, the sources of heterogeneity among studies should be further explored.

Liquid chromatography-mass spectrometry method for evaluating the dissipation dynamics of cyromazine and its metabolite in Agaricus bisporus and dietary risk assessment.

Providing guidance on the reasonable use of pesticide in agricultural production is of particular importance for ensuring food safety. In the present study, a field trial was performed to study the dissipation and accumulative pattern of cyromazine (CA) and its metabolite in Agaricus bisporus (A. bisporus) cultivation. An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was first developed and validated for the determination of CA and melamine (MEL) in the casing soil and fruiting body. During the cultivation period, the dissipation rates of CA in the casing soil were between 51.57 and 63.48% at three dose groups. The fruiting body presented higher accumulation ability for MEL compared with CA. The terminal residues of MEL never exceeded the maximum residue limits (MRLs) in food. In addition, the intake health risk from the CA and MEL residues in the fruiting body were negligible to humans. This study will help to provide valuable guidance on the application strategies of CA in A. bisporus cultivation.

The Role of Family Environment in Depressive Symptoms among University Students: A Large Sample Survey in China.

OBJECTIVE: To explore the relationship between family environment and depressive symptoms and to evaluate the influence of hard and soft family environmental factors on depression levels in a large sample of university students in China. METHODS: A multi-stage stratified sampling procedure was used to select 6,000 participants. The response rate was 88.8%, with 5,329 students completing the Beck Depression Inventory (BDI) and the Family Environment Scale Chinese Version (FES-CV), which was adapted for the Chinese population. Differences between the groups were tested for significance by the Student's t-test; ANOVA was used to test continuous variables. The relationship between soft family environmental factors and BDI were tested by Pearson correlation analysis. Hierarchical linear regression analysis was conducted to model the effects of hard environmental factors and soft environmental factors on depression in university students. RESULTS: A total of 11.8% of students scored above the threshold of moderate depression (BDI≧14). Hard family environmental factors such as parent relationship, family economic status, level of parental literacy and non-intact family structure were associated with depressive symptoms. The soft family environmental factors--conflict and control--were positively associated with depression, while cohesion was negatively related to depressive symptom after controlling for other important associates of depression. Hierarchical regression analysis indicated that the soft family environment correlates more strongly with depression than the hard family environment. CONCLUSIONS: Soft family environmental factors--especially cohesion, conflict and control--appeared to play an important role in the occurrence of depressive symptoms. These findings underline the significance of the family environment as a source of risk factors for depression among university students in China and suggest that family-based interventions and improvement are very important to reduce depression among university students.

[Assessment model for heavy metal pollution in sediment based on trapezoidal fuzzy numbers and case study].

Due to the practical shortcomings of the classical deterministic pollution assessment model, the theory of trapezoidal fuzzy numbers was introduced to the environmental assessment system. A fuzzy risk assessment model was built based on the geoaccumulation index and biotoxicity coefficients of heavy metals. Using the fuzzy pollution risk assessment model, the risk of heavy metal pollution was evaluated for the surface sediment of Dongting Lake. The results showed that the pollution risk in a descending order was Hg > Cd > Pb > Cu > Cr > Zn > As, with Hg,Cd and Pb being the priority pollutants in Dongting Lake. Both the intervals of possible values for the geoaccumulation indexes of heavy metals and their credible levels were calculated using this model. Compared with the results of the deterministic assessment model, the fuzzy pollution risk assessment model gave a better characetriztaion of the actual pollution status and spatial distribution difference of the heavy metals in the sediment of the studied region which is more objective and comprehensive.