Urinary concentrations of phenols, oxidative stress biomarkers and thyroid cancer: Exploring associations and mediation effects

Phenols have been shown to influence the cellular proliferation and function of thyroid in experimental models. However, few human studies have investigated the association between phenol exposure and thyroid cancer, and the underlying mechanisms are also poorly understood. We conducted a case-control study by age- and sex-matching 143 thyroid cancer and 224 controls to investigate the associations between phenol exposures and the risk of thyroid cancer, and further to explore the mediating role of oxidative stress. We found that elevated urinary triclosan (TCS), bisphenol A (BPA) and bisphenol S (BPS) levels were associated with increased risk of thyroid cancer (all P for trends < 0.05), and the adjusted odds ratios (ORs) comparing the extreme exposure groups were 3.52 (95% confidence interval (CI): 2.08, 5.95), 2.06 (95% CI: 1.06, 3.97) and 7.15 (95% CI: 3.12, 16.40), respectively. Positive associations were also observed between urinary TCS, BPA and BPS and three oxidative stress biomarkers measured by 8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F_2α (8-isoPGF_2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), as well as between urinary 8-isoPGF_2α and HNE-MA and the risk of thyroid cancer. Mediation analysis showed that urinary 8-isoPGF_2α mediated 28.95%, 47.06% and 31.08% of the associations between TCS, BPA and BPS exposures and the risk of thyroid cancer, respectively (all P < 0.05). Our results suggest that exposure to TCS, BPA and BPS may be associated with increased risk of thyroid cancer and lipid peroxidation may be an intermediate mechanism. Further studies are warranted to confirm the findings.     

Fine particulate matter (PM2.5/PM1.0) in Beijing, China: Variations and chemical compositions as well as sources

Particulate matter (i.e., PM_1.0 and PM_2.5), considered as the key atmospheric pollutants, exerts negative effects on visibility, global climate, and human health by associated chemical compositions. However, our understanding of PM and its chemical compositions in Beijing under the current atmospheric environment is still not complete after witnessing marked alleviation during 2013–2017. Continuous measurements can be crucial for further air quality improvement by better characterizing PM pollution and chemical compositions in Beijing. Here, we conducted simultaneous measurements on PM in Beijing during 2018–2019. Results indicate that annual mean PM_1.0 and PM_2.5 concentrations were 35.49 ± 18.61 µg/m³ and 66.58 ± 60.17 µg/m³, showing a positive response to emission controls. The contribution of sulfate, nitrate, and ammonium (SNA) played an enhanced role with elevated PM loading and acted as the main contributors to pollution episodes. Discrepancies observed among chemical species between PM_1.0 and PM_2.5 in spring suggest that sand particles trend to accumulate in the range of 1–2.5 µm. Pollution episodes occurred accompanied with southerly clusters and high formation of SNA by heterogeneous reactions in summer and winter, respectively. Results from positive matrix factorization (PMF) combined with potential source contribution function (PSCF) models showed that potential areas were seasonal dependent, secondary and vehicular sources became much more important compared with previous studies in Beijing. Our study presented a continuous investigation on PM and sources origins in Beijing, which provides a better understanding for further emission control as well as a reference for other cities in developing countries.     

Highly Oriented Thermoplastic Poly (vinyl alcohol) Films by Uniaxial Drawing: Effect of Stretching Temperature and Draw Ratio

Journal of Polymers and the Environment - With the advantages of excellent processability and biodegradability, polyvinyl alcohol (PVA) becomes an environmentally friendly and biocompatible...     

Response of activity and community composition of nitrite-oxidizing bacteria to partial substitution of chemical fertilizer by organic fertilizer

Environmental Science and Pollution Research - Nitrite oxidation as the second step of nitrification can become the determining step in disturbed soil systems. As a beneficial fertilization...     

省级环境管理部门基础信息网络建设实践与思考

阐述省级环境管理部门基础信息网络建设的重要性及建设应遵循的基本要求,结合实践,讨论设计和实际施工中出现的问题及解决办法,为环境管理部门基础信息网络建设提供有益参考。     

Dispersion of carbon dioxide released from buried high-pressure pipeline over complex terrain

Environmental Science and Pollution Research - To quantitatively assess the risks associated with Carbon Capture and Storage (CCS) technology, a better understanding of the dispersion...     

基于储层非均质的水淹水窜风险评价

水淹和水窜是油田在水驱开发时常见的安全问题,储层非均质性是引起水淹和水窜的主要原因之一。为研究储层非均质性对于水淹水窜的作用,通过层次聚类分析法建立储层非均质综合指数关系式,并将其转化为水淹水窜风险概率,把水淹水窜风险概率进行分级,以此判断非均质性对于水淹水窜的作用。以BD油田阜二段第三砂层组为例进行水淹水窜风险评估,结果表明:研究区非均质性严重,水淹水窜风险概率均大于80%,储层非均性极容易导致油田在注水开发时发生水淹水窜。该区在注水开发时需要重视工艺设计与防护措施,以降低水淹水窜风险。     

Bioremediation of oily sludge-contaminated soil by stimulating indigenous microbes

In situ bioremediation of oily sludge-contaminated soil by biostimulation of indigenous microbes through adding manure was conducted at the Shengli oilfield in northern China. After bioremediation for 360 days, total petroleum hydrocarbon (TPH) content was reduced by 58.2% in the treated plots compared with only 15.6% in the control plot. Moreover, bioremediation significantly improved the physicochemical properties of the soil in the treated plot. Soil microbial counts and community-level physiological profiling were also examined. Manure addition increased TPH degraders and polycyclic aromatic hydrocarbon (PAH) degraders in the contaminated soil by one to two orders of magnitude. The activity and biodiversity of soil microbial communities also increased markedly in the treated plot compared with that of the control. Finally, biotoxicity was used to evaluate the soils and a sharp increase in the EC50 of the soil after bioremediation was observed, indicating that bioremediation had reduced the toxicity of the soil.     

生活垃圾焚烧发电厂的环境风险评价

垃圾焚烧技术兼具环境效益和经济效益,环境风险评价的结论是该类项目选址的关键问题之一。在分析中国城市生活垃圾排放现状和生活垃圾焚烧项目环境风险的基础上,分析了二恶英风险事故的环境影响及环境防护距离的计算方法与传统卫生防护距离的差异,并以秦皇岛生活垃圾焚烧发电厂为实例进行了计算。结果表明:在不同工况下人体经呼吸每日最大摄入二恶英的量均远小于允许摄入量参考标准值,环境防护距离确定方法更为科学和人性化,有利于消除公众对此类建设项目的误解。     

液柱塔喷浆管道设计与优化

为了研究喷淋液柱吸收塔喷浆管道的喷嘴喷射流量以及液柱高度,对喷浆管道的流场进行了研究。采用基于计算流体力学的Fluent软件平台,对某电厂2×360MW机组液柱脱硫塔喷浆管建立数学物理模型。采用基于有限体积法的SIMPLE算法进行计算,计算对比了不同结构喷浆管各喷嘴对应的液柱高度分布以及流量分布,得到了最优化的液柱塔喷浆管道结构,并根据计算结果指导设计。