Impacts of disinfection byproduct exposures on male reproductive health: Current evidence, possible mechanisms and future needs.

Disinfection byproducts (DBPs) are a class of ubiquitous chemicals in drinking water and inevitably result in widespread human exposures. Potentially adverse health effects of DBP exposures, including reproductive and developmental outcomes, have been increasing public concerns. Several reviews have focused on the adverse pregnancy outcomes of DBPs. This review summarized current evidence on male reproduction health upon exposure to DBPs from toxicological and epidemiological literature. Based on existing experimental studies, there are sufficient evidence showing that haloacetic acids (HAAs) are male reproductive toxicants, including reduced epididymal weight, decreased semen parameters and sperm protein 22, and declined testosterone levels. However, epidemiological evidence remains insufficient to support a link of DBP exposures with adverse male reproductive outcomes, despite that blood and urinary DBP biomarkers are associated with decreased semen quality. Eight potential mechanisms, including germ/somatic cell dysfunction, oxidative stress, genotoxicity, inflammation, endocrine hormones, folate metabolism, epigenetic alterations, and gut microbiota, are likely involved in male reproductive toxicity of DBPs. We also identified knowledge gaps in toxicological and epidemiological studies to enhance future needs.

Comparison of ARIMA model, DNN model and LSTM model in predicting disease burden of occupational pneumoconiosis in Tianjin, China.

BACKGROUND: This study aims to explore appropriate model for predicting the disease burden of pneumoconiosis in Tianjin by comparing the prediction effects of Autoregressive Integrated Moving Average (ARIMA) model, Deep Neural Networks (DNN) model and multivariate Long Short-Term Memory Neural Network (LSTM) models. METHODS: Disability adjusted life year (DALY) was used to evaluate the disease burden of occupational pneumoconiosis. ARIMA model, DNN model and multivariate LSTM model were used to establish prediction model. Three performance evaluation metrics including Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) were used to compare the prediction effects of the three models. RESULTS: From 1990 to 2021, there were 10,694 cases of pneumoconiosis patients in Tianjin, resulting in a total of 112,725.52 person-years of DALY. During this period, the annual DALY showed a fluctuating trend, but it had a strong correlation with the number of pneumoconiosis patients, the average age of onset, the average age of receiving dust and the gross industrial product, and had a significant nonlinear relationship with them. The comparison of prediction results showed that the performance of multivariate LSTM model and DNN model is much better than that of traditional ARIMA model. Compared with the DNN model, the multivariate LSTM model performed better in the training set, showing lower RMES (42.30 vs. 380.96), MAE (29.53 vs. 231.20) and MAPE (1.63% vs. 2.93%), but performed less stable than the DNN on the test set, showing slightly higher RMSE (1309.14 vs. 656.44), MAE (886.98 vs. 594.47) and MAPE (36.86% vs. 22.43%). CONCLUSION: The machine learning techniques of DNN and LSTM are an innovative method to accurately and efficiently predict the burden of pneumoconiosis with the simplest data. It has great application prospects in the monitoring and early warning system of occupational disease burden.

Online evaluation method of coal mine comprehensive level based on FCE.

An online evaluation method of coal mine comprehensive level based on Fuzzy Comprehensive Evaluation method (FCE) is proposed. Firstly, following the principles of fairness, systematicness and hierarchy, taking research and development, production, sales, finance, safety and management as the first level indicators, a set of multi-level evaluation indicator system of coal mine comprehensive level combining objective and subjective evaluation indicators is established. Secondly, according to the characteristics of the indicator system, the specific process of FCE of coal mine comprehensive level is given. Then, taking SQL Server as the database management system and C#.NET as the development language, a set of B/S structure online evaluation system of coal mine comprehensive level based on FCE is designed and developed. Finally, the proposed method is applied to Coal group PM for test. The application shows that the method proposed can provide an efficient and convenient online evaluation platform to evaluate the comprehensive level of coal mines for the Coal group, and the horizontal and longitudinal comparison of the evaluation results can urge the coal mines to maintain their advantages and avoid their disadvantages, which is of some significance for improving the overall competitiveness of the Coal group.

Clinical management and treatment of obesity in China.

China has one of the largest populations with obesity in the world, and obesity has become a major challenge for the country's health-care system. Current guidelines for obesity management are not adequately supported by evidence from clinical studies in Chinese populations. Effective lifestyle interventions suitable for Chinese populations are scarce, insufficient weight-loss medications have been approved by regulatory bodies, and there is low acceptance of non-lifestyle interventions (ie, medications and surgery) among both health-care providers and the general public. Large, well designed, and well implemented clinical trials are needed to strengthen the evidence base for the clinical management of obesity in China. Obesity management can be improved through use of a tiered system involving health management centres, integrated lifestyle interventions and medical treatments, strengthened obesity education and training, and use of advanced electronic health technologies. Resource mobilisation, support from major stakeholders for people with overweight or obesity, and education and changes to social norms among the wider public are also needed. National health policies should prioritise both obesity prevention and improvement of the treatment and management of obesity.

Urinary bisphenol A and its alternatives among pregnant women: Predictors and risk assessment.

BACKGROUND: Exposure to bisphenol A (BPA) has been associated with various adverse health outcomes. Recently, an increasing concern on its alternatives such as bisphenol S (BPS) and bisphenol F (BPF) has been aroused due to the restriction use of BPA. Few studies have identified predictors of exposure to BPA alternatives and assessed their health risks. OBJECTIVE: The aim of this study was to identify predictors of BPA and its alternatives and to assess their health risks among pregnant women. METHODS: We detected first morning urinary concentrations of BPA and its alternatives (BPS and BPF) among 1097 pregnant women from an established Chinese cohort. A questionnaire was conducted to obtain demographic characteristics, dietary habits, and lifestyles. We examined the predictors of creatinine-adjusted urinary BPA and its alternatives concentrations using multivariable linear regression. Risk assessment of exposure to BPA and its alternatives was calculated based on the estimated of daily intake (EDI). RESULTS: Geometric means of creatinine-adjusted urinary BPA, BPF, and BPS were 0.92, 0.12, and 0.08 µg/g creatinine, respectively. Pregnant women from Wuhan had lower concentrations of BPA, BPF, and ∑BPs (sum of BPA, BPF, and BPS) than those from Xiaogan. Intake of fried food was related to higher concentrations of BPA, and intake of pickled food was associated with higher concentrations of BPF and ∑BPs. The maximum EDI values for exposure to BPA, BPF, BPS, and ∑BPs ranged from 5.6428 to 13.3356 nmol/kg body weight/day, which were below the tolerable daily intake (TDI) for BPA defined by the European Food Safety Authority (EFSA) (18 nmol/kg body weight/day). The maximum hazard index (HI) value was 0.7409. CONCLUSION: Several predictors identified in this study may inform public recommendations to reduce exposure to BPA and its alternatives.

Spatial, temporal variability and carcinogenic health risk assessment of nitrosamines in a drinking water system in China.

Nitrosamines, as a class of emerging frequently detected nitrogenous disinfection byproducts (N-DBPs) in drinking water, have gained increasing attention due to their potentially high health risk. Few studies focus on the occurrence variation and carcinogenic health risk of nitrosamines in drinking water systems. Our study aimed to investigate the spatial and temporal variability of nitrosamines in a drinking water system and to conduct a carcinogenic health risk assessment. Three types of water samples, including influent water, treated water and tap water, were collected monthly during an entire year in a drinking water system utilizing a combination of chlorine dioxide and chlorine in central China, and 9 nitrosamines were measured. The nitrosamine formation potentials (FPs) in influent water were also determined. N-nitrosodimethylamine (NDMA) was the most prevalent compound and was dominant in the water samples with average concentrations ranging from 2.5 to 67.4 ng/L, followed by N-nitrosodiethylamine (NDEA) and N-nitrosopiperidine (NPIP). Nitrosamine occurrence varied monthly, and significant seasonal differences were observed in tap water (p < .05). There were decreasing mean NDMA, NDEA and NPIP concentrations from influent water to treated water to tap water, but no significant spatial variability was observed within the water distribution system (p > .05). The average and 95th percentile total lifetime cancer risks for the three main nitrosamines were 4.83 × 10-5 and 4.48 × 10-4, respectively, exceeding the negligible risk level (10-6) proposed by the USEPA. Exposure to nitrosamines in drinking water posed a higher cancer risk for children than for adults, and children aged 0.75 to 1 years suffered the highest cancer risk. These results suggest that nitrosamine occurrence in tap water varied temporally but not spatially. Exposure to drinking water nitrosamines may pose a carcinogenic risk to human health, especially to children.

Predictors of phthalate metabolites in urine and follicular fluid and correlations between urine and follicular fluid phthalate metabolite concentrations among women undergoing in vitro fertilization.

BACKGROUND: Phthalate metabolites in follicular fluid (FF) may negatively affect normal folliculogenesis; however, the predictors of phthalate metabolite concentrations in urine and FF and relationships between urine and FF phthalate metabolite concentrations among women undergoing in vitro fertilization (IVF) are poorly understood. OBJECTIVE: To investigate predictors of phthalate metabolites in urine and FF and correlations between urine and FF phthalate metabolite concentrations among women undergoing IVF. METHOD: We recruited 305 women seeking infertility treatment at a reproductive center in Wuhan, China, from October to November 2016. Information regarding demographic characteristics, personal care product use and plastic material contact was obtained through direct interviews. Concentrations of 8 phthalate metabolites in urine and FF samples were measured using high-performance liquid chromatography and tandem mass spectrometry. Associations regarding metabolite concentrations in urine and FF samples were analysed by Spearman's correlation and linear regression. Generalized linear regression was used to examine potential predictors of phthalate metabolite concentrations in urine and FF. RESULTS: Weak to moderate associations between urine and FF samples were found for monoethyl phthalate (MEP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) (correlation coefficient: MEP, 0.350; MEOHP, 0.377); no associations were observed for other metabolites. The predictive powers of urinary metabolite concentrations in determining FF metabolite concentrations were uniformly low, with R2 ≤ 0.113. Body mass index (BMI) and educational level were inversely associated with the urinary concentrations of certain metabolites. Higher household income, intake of bottled drinks within 48 h, and use of shower gel and soap were frequently associated with higher urinary metabolite concentrations. BMI, higher household income and use of disposable plastic cups within 48 h were associated with higher metabolite concentrations in FF. CONCLUSION: Phthalate metabolite concentrations in urine and FF vary according to sociodemographic characteristics and lifestyle factors. Phthalate metabolite concentrations in urine may not be appropriate for estimating ovary phthalate exposure.

Controlled attenuation parameter by vibration-controlled transient elastography for steatosis assessment in members of the public undergoing regular health checkups with reference to magnetic resonance imaging-based proton density fat fraction.

AIM: Controlled attenuation parameter (CAP) measured by vibration-controlled transient elastography (FibroScan) allows repeatable and reliable assessment of liver steatosis for screening of patients at risk of non-alcoholic steatohepatitis development among asymptomatic individuals at a community level. However, this has never been compared with another quantitative method, such as magnetic resonance imaging-based proton density fat fraction, among the Chinese health checkup population. METHODS: A multicenter prospective study was conducted with Chinese individuals undergoing regular health checkups. Steatosis grading by magnetic resonance imaging-based proton density fat fraction was used as the reference to evaluate the diagnostic performance of CAP. RESULTS: A total of 173 individuals were included with mean age of 45 ± 11 years and body mass index of 25.8 ± 4.0 kg/m2 . A linear correlation was found between CAP and log10 -transformed magnetic resonance imaging-based proton density fat fraction results (Pearson's coefficient 0.772, P < 0.001). The areas under the receiver operating characteristic curve for distinguishing ≥S1 and ≥S2 steatosis were 0.88 (95% confidence interval 0.83-0.93) and 0.89 (95% confidence interval 0.83-0.95), respectively. When optimized for ≥90% sensitivity, the CAP cut-off for staging ≥S1 steatosis was 244 dB/m. CAP could classify patients with ≥S1 steatosis with similar performance as an ultrasound examination. CONCLUSIONS: As a non-invasive and quantitative method, CAP is highly adapted for population screening at a community level. With the integration of liver stiffness and CAP results in risk stratification scores for non-alcoholic steatohepatitis, vibration-controlled transient elastography can be useful in regular health checkups.

Spatial distribution of fluoride in drinking water and health risk assessment of children in typical fluorosis areas in north China.

China has been suffering from endemic fluorosis for the past 30 years. This study investigated fluoride concentrations in 10 districts of Tianjin, China, to illustrate their spatial distribution characteristics and potential human health risks. The results showed fluoride concentration of 0.01-6.30 mg L-1 with a mean value of 0.99 mg L-1, and 78.82% of water fluoride reaches the standard for drinking water (1.5 mg L-1). Higher fluoride levels were recorded in deep well pumps supply zones, and more potential changes in fluoride occurred was positively correlated with pH in groundwater. Mean value of fluoride in drinking water in 10 districts followed the order of WQ > BC > JZ > NH > BD > BH > JN > JH > DL > XQ. Estimations of non-carcinogenic risk for drinking water indicated that mean hazard quotient values of fluoride for combined pathways (i.e., oral ingestion and dermal absorption) were >1.0 for all age groups of WQ and BC. The results also showed that the estimated risk primarily came from the ingestion pathway. Risk levels for children varied obviously, generally in the order of 1-4y > 4-7y > 7-9y (years old). In the central tendency center and reasonable maximum exposure conditions, estimated risks were 1.25, 1.12, 0.771 and 3.66, 3.29, 2.27, respectively. The results supply material information for health authorities in fluorosis areas to put forward more efficient policies to control the endemic diseases. Attention should be paid to the formulation of health promotion strategies and measures to reduce fluoride intake in order to protect the health of residents.

Projections of the effects of global warming on the disease burden of ischemic heart disease in the elderly in Tianjin, China.

BACKGROUND: Ischemic heart disease (IHD) is one of the leading causes of deaths worldwide and causes a tremendous disease burden. Temperature is an important environmental determinant among the many risk factors for IHD. However, the emerging temperature-related health risks of IHD in the elderly is limited because of the lack of estimates that integrate global warming and demographic change. METHODS: Data on daily IHD deaths in the elderly aged ≥65 years and meteorological conditions were collected in Tianjin, a megacity of China, from 2006 to 2011. First, the baseline relationship between the temperature and years of life lost (YLL) from IHD was established. Then, future assessments were performed in combination with temperature projections for 19 global-scale climate models (GCMs) under 3 representative concentration pathways (RCPs) for the 2050s and 2070s. RESULTS: Increased YLL from IHD in the elderly was found to be associated with future ambient temperatures. The annual temperature-related YLL from IHD in the 2050s and 2070s were higher than the baseline. For instance, increases of 4.5, 14.9 and 38.3% were found under the RCP2.6, RCP4.5 and RCP8.5 scenarios, respectively, in the 2070s. The most significant increases occurred in warm season months. The increase in heat-related YLL will not be completely offset, even with the 25% adaptation assumed. When considering demographic change, the temperature-related disease burden of IHD in the elderly will be exacerbated by 158.4 to 196.6% under 3 RCPs in the 2050s and 2070s relative to the baseline. CONCLUSIONS: These findings have significant meaning for environmental and public health policy making and interventions towards the important issue of the health impacts of global warming on the elderly.

Pore Structure Damages in Cement-Based Materials by Mercury Intrusion: A Non-Destructive Assessment by X-Ray Computed Tomography.

Mercury intrusion porosimetry (MIP) is questioned for possibly damaging the micro structure of cement-based materials (CBMs), but this theme still has a lack of quantitative evidence. By using X-ray computed tomography (XCT), this study reported an experimental investigation on probing the pore structure damages in paste and mortar samples after a standard MIP test. XCT scans were performed on the samples before and after mercury intrusion. Because of its very high mass attenuation coefficient, mercury can greatly enhance the contrast of XCT images, paving a path to probe the same pores with and without mercury fillings. The paste and mortar showed the different MIP pore size distributions but similar intrusion processes. A grey value inverse for the pores and material skeletons before and after MIP was found. With the features of excellent data reliability and robustness verified by a threshold analysis, the XCT results characterized the surface structure of voids, and diagnosed the pore structure damages in terms of pore volume and size of the paste and mortar samples. The findings of this study deepen the understandings in pore structure damages in CBMs by mercury intrusion, and provide methodological insights in the microstructure characterization of CBMs by XCT.

The quantitative assessment of the public excess disease burden advanced by inhalable particulate matter under different air quality standard targets in Tianjin, China.

Currently, the quantitative assessment of the public excess risk for the update of the air quality guidelines only considered the mortality and morbidity without disease burden indicators. To provide evidences for the update of air quality guidelines and the policy analysis of air control, a simple framework to identify the excess disease burden of PM10 was used in this study. Daily data on PM10, meteorological factors, and deaths were collected in this 10-year (2001-2010) time series study in Tianjin, China. The excess disease burden advanced by PM10 was assessed when the PM10 levels exceeded the expected levels. Generalized additive model was used to estimate the associations of PM10 with mortality and years of life lost (YLL). Our study found that the exposure of PM10 was associated with the increasing of mortality and YLL in different diseases. The excess deaths and YLL of different diseases advanced by PM10 when the PM10 levels exceeded the expected levels were high and showed a decreasing trend from 2001 to 2010. The annual deaths and YLL standardized per million population advanced by PM10 when the annual PM10 levels exceeded the China national ambient air quality secondary standard targets (70 µg/m3) and WHO guideline (20 µg/m3) were 126 persons, 2670 person years and 260 persons, 5449 person years, respectively. This study may provide a simple framework to identify the excess disease burden of PM and provide basic and intuitive evidences to update the air quality guidelines. Furthermore, these findings may also provide decisionmakers with intuitive quantitative information for policymaking and emphasize health considerations in air quality policy discussions.

Acute Stroke: Prognostic Value of Quantitative Collateral Assessment at Perfusion CT.

Purpose To develop a quantitative assessment of collateral perfusion at CT and to investigate its value in the prediction of outcome in patients with acute ischemic stroke (AIS). Materials and Methods This retrospective study reviewed data from consecutive patients with AIS and an occluded M1 segment of the middle cerebral artery who underwent pretreatment perfusion CT between May 2009 and August 2017. The maximum cerebral blood flow (CBF) of collateral vessels (cCBFmax) within the Sylvian fissure was calculated for each patient. Good outcome was defined as a 90-day modified Rankin scale score of 0-2. Multivariable logistic regression analysis was used to determine the relationship between cCBFmax and (a) hemorrhagic transformation and (b) clinical outcome. Results The final analysis included 204 patients (median age, 73 years; interquartile range, 62-80 years; 82 [40.2%] women). Multivariable logistic regression analysis showed that higher cCBFmax was an independent predictor for (a) a lower risk of hemorrhagic transformation (odds ratio [OR], 0.99; 95% confidence interval [CI]: 0.98, 1.00; P = .009) after adjusting for baseline National Institutes of Health Stroke Scale (NIHSS), endovascular thrombectomy, baseline infarct core volume, and recanalization and (b) better outcome (OR, 1.02; 95% CI: 1.01, 1.03; P = .001) after adjusting for age, baseline NIHSS score, endovascular thrombectomy, hypertension, baseline infarct core volume, and recanalization, respectively. Conclusion The measurement of maximum cerebral blood flow of collateral vessels within the Sylvian fissure is a feasible quantitative collateral assessment at perfusion CT. Maximum cerebral blood flow of collateral vessels was associated with clinical outcome in patients with acute ischemic stroke. © RSNA, 2019 Online supplemental material is available for this article.

Differentiation between pilocytic astrocytoma and glioblastoma: a decision tree model using contrast-enhanced magnetic resonance imaging-derived quantitative radiomic features.

OBJECTIVE: To differentiate brain pilocytic astrocytoma (PA) from glioblastoma (GBM) using contrast-enhanced magnetic resonance imaging (MRI) quantitative radiomic features by a decision tree model. METHODS: Sixty-six patients from two centres (PA, n = 31; GBM, n = 35) were randomly divided into training and validation data sets (about 2:1). Quantitative radiomic features of the tumours were extracted from contrast-enhanced MR images. A subset of features was selected by feature stability and Boruta algorithm. The selected features were used to build a decision tree model. Predictive accuracy, sensitivity and specificity were used to assess model performance. The classification outcome of the model was combined with tumour location, age and gender features, and multivariable logistic regression analysis and permutation test using the entire data set were performed to further evaluate the decision tree model. RESULTS: A total of 271 radiomic features were successfully extracted for each tumour. Twelve features were selected as input variables to build the decision tree model. Two features S(1, -1) Entropy and S(2, -2) SumAverg were finally included in the model. The model showed an accuracy, sensitivity and specificity of 0.87, 0.90 and 0.83 for the training data set and 0.86, 0.80 and 0.91 for the validation data set. The classification outcome of the model related to the actual tumour types and did not rely on the other three features (p < 0.001). CONCLUSIONS: A decision tree model with two features derived from the contrast-enhanced MR images performed well in differentiating PA from GBM. KEY POINTS: • MRI findings of PA and GBM are sometimes very similar. • Radiomics provides much more quantitative information about tumours. • Radiomic features can help to distinguish PA from GBM.

Predictors and correlations of phthalate metabolite concentrations in urine and seminal plasma among reproductive-aged men.

BACKGROUND: Certain phthalates are suspected to be endocrine disruptors that are adversely associated with male reproductive health. However, the predictors and correlations of phthalate metabolite concentrations in urine and seminal plasma among reproductive-aged men have not been thoroughly studied. OBJECTIVE: To investigate the predictors and correlations of phthalate metabolite concentrations in urine and seminal plasma among adult Chinese males. METHOD: We measured mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-n-octyl phthalate (MOP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) concentrations in seminal plasma and repeated spot-urine samples from 687 men who visited a reproductive center. Mixed-effect models were used to examine the associations of sociodemographic, lifestyle and medical factors with urinary metabolite concentrations. Linear regression models were used to identify predictors of metabolite concentrations in seminal plasma and correlations between metabolite concentrations in spot urine samples and seminal plasma. RESULTS: Measurements taken from spot urine samples poorly predicted same-day seminal plasma concentrations (all R2<0.10). Inverse associations were observed between education level and urinary MBP and MEOHP and between household income and urinary MMP; receiving intravenous infusion therapy was associated with increased urinary MBP, MEHHP and MEOHP, use of facial cleanser/cream was associated with increased MEP, and smoking was associated with increased MEHP. The predictors of metabolite concentrations in seminal plasma differed from those in urine, except for the association of intravenous infusion therapy with MBP. BMI was associated with increased seminal plasma MBP, MEHP and MEOHP, smoking was associated with increased MEP, and contact with plastics was associated with increased MEOHP. CONCLUSIONS: Phthalate metabolite concentrations in adult men varied in accordance with sociodemographic variables, lifestyle factors and intravenous therapy. Measures of metabolite levels in urine may not directly reflect the exposure status of the male reproductive system.

[Application Potential and Assessment of Metallurgical Contaminated Soil After Remediation in Tongguan of Shaanxi].

There has been a growing interest in soil replacement and in-situ stabilization techniques in recent years. Many techniques in the remediation of contaminated soils have been proven to be effective methods. In this study, lime and calcium phosphate were added to immobilize the heavy metals in contaminated soils. The long-term application potential of these techniques were evaluated by taking the demonstration project of the soil remediation in Tongguan of Shaanxi as the case study.The status of heavy metal contamination in the study area resulted from artisanal gold mining was discussed. The strategies of remediation and the evaluation of the remediation results including the safety of agricultural practices were also studied. The results showed that soil was seriously contaminated in the study area with Cd, Pb, and Hg, and the residue mining waste was the main source. The potential ecological risk index ranged from 668 to 10969, suggesting that all the samples posed a very strong ecological hazard. Based on the pollution status, the soil replacement method and stabilization method were applied. Acceptable remediation results were obtained with lower total metal content (except Cd) and decreased heavy metal availability. However, the metal content of agricultural products was higher than the permissible value according to GB 2762-2012, which means that agricultural practices pose risks on remediated soils. Soil replacement and stabilization would be practical techniques for heavy metal polluted soil remediation. However, a consecutive investigation should be conducted for the assurance of food safety.

[Health Risk Assessment of Drinking Water Quality in Tianjin Based on GIS].

This study intends to assess the potential health hazards of drinking water quality and explore the application of geographic information system( GIS) in drinking water safety in Tianjin. Eight hundred and fifty water samples from 401 sampling points in Tianjin were measured according to the national drinking water standards. The risk assessment was conducted using the environmental health risk assessment model recommended by US EAP, and GIS was combined to explore the information visualization and risk factors simultaneously. The results showed that the health risks of carcinogens, non-carcinogens were 3.83 x 10⁻5, 5.62 x 10⁻9 and 3.83 x 10⁻5 for total health risk respectively. The rank of health risk was carcinogen > non-carcinogen. The rank of carcinogens health risk was urban > new area > rural area, chromium (VI) > cadmium > arsenic > trichlormethane > carbon tetrachloride. The rank of non-carcinogens health risk was rural area > new area > urban, fluoride > cyanide > lead > nitrate. The total health risk level of drinking water in Tianjin was lower than that of ICRP recommended level (5.0 x 10⁻5), while was between US EPA recommended level (1.0 x 10⁻4-1.0 x 10⁻6). It was at an acceptable level and would not cause obvious health hazards. The main health risks of drinking water came from carcinogens. More attentions should be paid to chromium (VI) for carcinogens and fluoride for non-carcinogens. GIS can accomplish information visualization of drinking water risk assessment and further explore of risk factors.

Assessment of the prophylactic activity and pharmacokinetic profile of oral tafenoquine compared to primaquine for inhibition of liver stage malaria infections.

BACKGROUND: As anti-malarial drug resistance escalates, new safe and effective medications are necessary to prevent and treat malaria infections. The US Army is developing tafenoquine (TQ), an analogue of primaquine (PQ), which is expected to be more effective in preventing malaria in deployed military personnel. METHODS: To compare the prophylactic efficacy of TQ and PQ, a transgenic Plasmodium berghei parasite expressing the bioluminescent reporter protein luciferase was utilized to visualize and quantify parasite development in C57BL/6 albino mice treated with PQ and TQ in single or multiple regimens using a real-time in vivo imaging system (IVIS). As an additional endpoint, blood stage parasitaemia was monitored by flow cytometry. Comparative pharmacokinetic (PK) and liver distribution studies of oral and intravenous PQ and TQ were also performed. RESULTS: Mice treated orally with three doses of TQ at 5 mg/kg three doses of PQ at 25 mg/kg demonstrated no bioluminescence liver signal and no blood stage parasitaemia was observed suggesting both drugs showed 100% causal activity at the doses tested. Single dose oral treatment with 5 mg TQ or 25 mg of PQ, however, yielded different results as only TQ treatment resulted in causal prophylaxis in P. berghei sporozoite-infected mice. TQ is highly effective for causal prophylaxis in mice at a minimal curative single oral dose of 5 mg/kg, which is a five-fold improvement in potency versus PQ. PK studies of the two drugs administered orally to mice showed that the absolute bioavailability of oral TQ was 3.5-fold higher than PQ, and the AUC of oral TQ was 94-fold higher than oral PQ. The elimination half-life of oral TQ in mice was 28 times longer than PQ, and the liver tissue distribution of TQ revealed an AUC that was 188-fold higher than PQ. CONCLUSIONS: The increased drug exposure levels and longer exposure time of oral TQ in the plasma and livers of mice highlight the lead quality attributes that explain the much improved efficacy of TQ when compared to PQ.

Evaluation of exposure to trihalomethanes in tap water and semen quality: a prospective study in Wuhan, China.

Trihalomethanes (THMs) have been demonstrated to adversely affect male reproductive health in animals, but the evidence in humans is limited. The study aimed to examine the association between THM exposure and semen quality in a Chinese population. We recruited 324 men from the same water supply district in Wuhan, China between April 2011 and May 2012. Exposure to THMs was evaluated based on their concentrations in tap water measured within 90 days preceding semen collection, the uptake factors of THMs and personal information on ingestion and showering/bathing. We found that TTHM [sum of chloroform (TCM) and brominated THMs (Br-THMs)], TCM and Br-THM uptakes via ingestion were associated with significant or suggestive decreasing trends in sperm concentration (P for trend=0.01, 0.03 and 0.05, respectively) and sperm count (P for trend=0.02, 0.05 and 0.09, respectively). Our results suggest that THM exposure via ingestion may adversely affect semen quality.

[Health-based risk assessment in the excavating process of VOCs contaminated site].

The dissipative concentration test of VOCs in the remediation process of a typical contaminated site was operated, and three routes of exposure were set up for health risk assessment in the repair process. Analysis showed that carbon tetrachloride was the single pollutant with highest multi-route cumulative non-carcinogenic index, which was as high as 8.86E + 01, and its contribution rate to the integrated non-carcinogenic effects was 74.45%. Respiratory exposure was the exposure route with highest multi-pollutant hazard index, which was 1.01E + 02, accounting for 84. 87% of the comprehensive risk index, and the index of integrated non-carcinogenic damage was 1.19E + 02. 1,2-dichloroethane was the single pollutant with highest multi-route cumulative carcinogenic index, which was as high as 3.08E-02, and its contribution rate to the integrated carcinogenic effects was 69.53%. Respiratory exposure was the exposure route with highest multi-pollutant hazard index, which was 3.96E -02, accounting for 89.39% of the comprehensive risk index, and the index of integrated carcinogenic damage was 4.43E-02.