Exposure to polycyclic aromatic hydrocarbons and risk for premature ovarian failure and reproductive hormones imbalance

Polycyclic aromatic hydrocarbons (PAHs) are a typical class of persistent organic pollutants that is ubiquitous worldwide. Previous animal studies suggested that PAHs had adverse effects on female reproduction. However, the human data regarding relationship of PAHs exposure with women reproductive health, such as ovarian dysfunction, are scarce. In this case-control study, the associations of serum levels of PAHs with the risk of premature ovarian failure (POF) and reproductive hormones in Chinese women were investigated, with recruiting 157 POF patients and 217 healthy women. The serum levels of 12 types of PAHs, as well as reproductive hormones, including follicle-stimulating hormone, luteinizing hormone and anti-mullerian hormone, were determined. In the logistic regression models, most individual PAH congeners showed significantly positive correlations with the risk of POF (p < 0.05), except for fluorine and pyrene. Benzo(a)pyrene (BaP), as the most carcinogenic PAH congener, was observed to be significantly positively associated with the risk of POF. After adjustment for age, body mass index, educational levels and household income, per one-unit increase in the log-transformed BaP concentration was significantly correlated with 2.191-fold increased risk of POF (OR = 2.191, 95%CI: 1.634–2.938, p < 0.05). To the best of our knowledge, this is the first study to report an association between internal exposure levels of PAHs and the increased risk of POF in women.     

2017—2018年秋冬季唐山市PM2.5中元素组成特征及来源解析

为研究唐山市大气PM_2.5中元素组成特征及其来源,于2017年10月19日—2018年1月31日（秋冬季）在唐山市的超级站（典型城市站点）、开平站（工业站点）和古冶站（工业站点）开展了PM_2.5的手工连续采样,定量分析测定了PM_2.5中23种无机元素.结果表明:Si、Al、Ca和Na等地壳元素的质量浓度均在10月最高,在1月最低.10月,ρ（Cr）在开平站最高（0.020 0 μg/m3）,随后逐月略微降低,其主要受钢铁冶炼工业的减产和限产影响.多数重金属元素质量浓度在11月或12月最高,包括Zn、Pb、Mn、Cu、Ni、Se、V、Cd和Co,其可能受燃煤取暖影响.Cd、Zn、Pb和Cu四种元素的富集因子值分别为2 677、616、422和77,均达到极强富集,且均受人为排放源影响最大.基于因子分析法得出,唐山市大气PM_2.5中元素的主要来源有燃煤源、钢铁工业源与扬尘源的混合源、交通源以及土壤扬尘源,其方差贡献率分别为56.3%、21.6%、7.1%、5.4%.研究显示,秋冬季唐山市大气颗粒物PM_2.5中元素最主要的污染来源为工业源、燃煤源和扬尘源.      

Spatiotemporal characterization and regional contributions of O3 and NO2: An investigation of two years of monitoring data in Henan, China

To investigate the characteristics of ground level ozone(O_3) for Henan Province,the ambient air quality monitoring data of 2015 and 2016 were analyzed.The result showed that the 8 h-max-O_3 concentrations displayed a distinct seasonality,where the maximum and minimum values,averaging 140.41,54.19 μg/m~3,occurred in summer and winter,respectively.There is a significant correlation between meteorological factors and O_3 concentration.The Voronoi neighborhood averaging analysis indic ated that O_3,temperature,and ultraviolet radiation in Henan province were decreased from northwest to southeast,while relative humidity and precipitation displayed the opposite trend.Besides meteorological factors,the chemical processes play an essential role in ozone formation.Reactions of NO,NO_2 and O_3 form a closed system,and the partitioning point of the OX-component(O_3+NO_2) was at 40 and 80 μg/m~3 for nitrogen oxide(NO_x) in winter and summer,respectively,with NO_2 dominating at higher NO_x pollution and O_3 being the m ajor component at lower levels.The relationship between oxidant(OX=O_3+NO_2)and NOx concentrations were evaluated to understand the regional and local contribution of OX.It showed that high regional contribution occurred in the spring,whereas the highest local contribution lead to the summer peak of O_3 observed in Zhengzhou.This present study reveals important environment impacts from the photochemical process and the meteorological conditions in the region with better understanding on the O_3 characterization.     

Impact of environmental factors on gastric cancer: A review of the scientific evidence, human prevention and adaptation

Globally, gastric cancer (GC) ranks fifth in prevalence and third in fatalities, and shows a distinct geographical distribution in morbidity and mortality. Such a spatial pattern indicates that environmental factors could be an important contributor to GC. We reviewed a total of 135 relevant peer-reviewed articles and other literature published 1936–2019 to investigate the scientific evidence concerning the effects of environmental factors on GC worldwide. Environmental factors affect GC from the aspects of water, soil, air, radiation, and geology. Risk factors identified include water type, water pollution, water hardness, soil type, soil pollution, soil element content, climate change, air pollution, radiation, altitude, latitude, topography, and lithology; and most of them have an adverse impact on GC. Furthermore, we found that their effects followed five common rules: (1) the leading environmental factors that affect GC incidence and mortality vary by region, (2) the same environmental factors may have different effects on GC in different regions, (3) some different environmental factors have similar effects on GC in essence, (4) different environmental factors often interact to have combined or synergistic effects on GC, and (5) environmental factors can affect human factors to have an impact on GC. Environmental factors have a great impact on GC. Human beings may prevent GC by controlling carcinogenic factors, screening high-risk populations and providing symptomatic and rehabilitative treatments. Furthermore, adaptation measures are recommended to reduce GC risk on private and public levels. Future studies should transcend existing empirical studies to develop causal relationship models and focus on vulnerable population analysis.     

嗪草酮降解菌Rhodococcus sp.MA的降解特性及固定化应用

从农田土壤中分离得到1株嗪草酮高效降解菌株,命名为MA,该菌5 d对50 mg·L^-1嗪草酮的降解率达到74.8%,最适反应温度和pH分别为30℃和7.0.根据表型与生理生化特征及16S rRNA序列分析,将其鉴定为Rhodococcus sp.MA.利用气相色谱-质谱联用（GC-MS）鉴定菌株MA降解嗪草酮的中间产物为脱氨基嗪草酮.以海藻酸钠为包埋剂,经正交试验表明,3%海藻酸钠、2% CaCl₂、包埋比8：1和固定时间6 h条件下,菌株对嗪草酮的降解效率最高,为71.2%.将固定化菌体细胞用于修复实验,结果表明,未固定化处理的菌液对湖水及池塘水中嗪草酮（15 mg·L^-1）的去除率分别为72.1%和69.9%;固定化处理后可提高对嗪草酮的去除率,分别达到87.3%和82.6%,具有良好的应用前景.     

基于D-S证据理论的“丝绸之路旅游带”5A景区区位优势度测评

景区发展与其区位条件密切相关,处于优势区位的景区更容易获得优先快速发展。以“丝绸之路旅游带”为例,综合考虑资源、市场、交通及服务四大区位因子,将其视为证据,引入D-S证据理论对景区区位优势进行测度,以I~V级表征区位由优到劣的状态,最后对景区区位与旅游发展核心区进行对比。结果显示：（1）区位优势等级区域差异化显著,总体呈现由东南至西北逐级递减的空间分布规律,自I至V级,重心逐步向西北方向偏移。（2）各区位因子分布存在差异性,东南地区景区资源区位优于西北地区;市场区位地带间差异最为明显,存在“长尾”特征及陕西“一省独大”现象;交通区位内在差异性与区位优势相仿;服务区位已不再是制约景区区位的主要因子,但就单个省份来看,“核心—边缘”结构较为明显。（3）与景区旅游发展对比来看,二者具有明显的空间关联性,但仍存在一定程度的空间错位现象。     

嘉兴市2015年人为源VOCs排放清单

根据收集的嘉兴市人为源活动水平数据,采用科学合理的估算方法和排放因子,建立了该地区2015年人为源挥发性有机物（VOCs）排放清单.结果表明,嘉兴市2015年VOCs排放总量为10.21×10⁴ t,其中工业源、移动源、生活源、储运源、废弃物处理源、农业源的排放量分别占排放总量的78.15%、12.08%、5.83%、3.24%、0.26%和0.44%.工业源中包装印刷、表面喷涂、纺织印染、化学原料制造、石化是重点排放行业.海宁市、桐乡市和平湖市VOCs排放量位居前三,约占嘉兴市总排放量的50%,经开区、海宁市、南湖区VOCs平均排放强度均超过30 t·km^-2.     

旱雨季岩溶地表河不同河段正构烷烃相态组成变化和来源解析

岩溶作用产生的无机碳可以在水生植物、微生物等作用下形成有机质,转化为较稳定的内源有机碳,这为寻找全球遗漏碳汇提供了新的突破口,而加强对岩溶区有机质的溯源研究是重要手段.为探究金佛山岩溶地表河溶解态、颗粒态和沉积物正构烷烃的含量、组分及来源,于2017年3月20日、9月26日分别在石钟溪上、中、下游进行采样,并利用气相色谱-质谱联用仪(GC-MS)对三相态正构烷烃的组分进行定量分析.结果显示,旱季溶解态、颗粒态和沉积物正构烷烃的平均含量分别为737 ng·L~(-1)、6108 ng·L~(-1)和7149 ng·g~(-1),雨季三者的平均含量分别为7129 ng·L~(-1)、8146 ng·L~(-1)和6213 ng·g~(-1).正构烷烃的含量整体表现为雨季高于旱季,以溶解态正构烷烃表现得最为显著,这主要由外源高等植物输入增多所致.旱季上、下游正构烷烃含量差异明显,以沉积物正构烷烃表现得最为显著,自上而下整体保持微升态势;雨季外源输入量较大,差异性减弱,整体变幅较小.不同季节降雨和气温的变化导致水动力条件、浊度及水温的不同,深刻地影响着不同相态和不同河段正构烷烃的来源和迁移.整体上,随着海拔降低,高等植物贡献度降低,水生植物和低等生物贡献度增高.当水动力条件较弱和浊度较低时,造成内源溶解有机质增多,同时会出现溶解态至颗粒态乃至沉积物的缓慢沉降迁移.     

Cl-/PMS体系降解甲氧苄啶的效能与机理

采用氯离子（Cl^－）作为阴离子活化剂,活化单过硫酸氢钾（PMS）氧化降解甲氧苄啶（TMP）.研究了Cl^－/PMS体系降解TMP中起主要作用的活性物种,同时考察了Cl^－浓度、PMS投加量、初始pH值对降解效果的影响,并研根据中间产物推断了TMP降解路径.实验结果表明,Cl^－/PMS体系中的主要活性物种是Cl^－和PMS直接反应生成的活性氯.降解过程符合拟一级反应动力学模型（R²>0.99）;随着Cl^－浓度和PMS投加量增加,反应速率常数k_obs增大;初始pH范围在5.0~9.0范围内,随着pH值的增大,TMP的去除率先减小后增大;TMP主要经历了氯取代和羟基取代过程,其核心结构上没有实质性的分解.     

南京市秋季大气颗粒物中金属元素的粒径分布

在南京市仙林地区,采用ANDERSON八级撞击采样器,于2016年秋季采集了63个大气颗粒物有效样本,并利用ICP-MS分析了金属元素的含量.结合气象等资料,研究了大气颗粒物金属元素的粒径分布与富集特征,并对其来源进行了探讨.结果表明：南京秋季大气颗粒物质量浓度的粒径分布呈双峰型,峰值分别位于0.4~1.1和3.3~9μm;金属元素的粒径分布呈3种类型,一是粗粒子单峰型,峰值位于3.3~5.8μm,主要元素包括Na、Al、Ca、Mg、Co、Ce、Sr和Ba;二是细粒子单峰型,峰值位于0.4~1.1μm,主要元素包括Zn、As、Cd、Ag、Tl和Pb;三是粗细粒子双峰或多峰型,峰值位于1.1和5μm粒径段,主要元素包括K、Se、Li、Be、Mn、V、Cu、Cr、Ni和Fe.按富集因子的大小,可将元素分为3类,低富集元素包括Ba、Ca、Ce、Sr、Mg、Fe、Co、Mn、Be和V,中富集元素包括Li、Na、Ni、K和Cr,高富集元素包括Cu、Tl、Zn、As、Pb、Ag、Cd和Se.不同的粒径分布和富集水平反映了大气颗粒物的来源特征.研究结果可以为深入认识大气颗粒物金属元素的来源及其环境与健康效应提供科学依据.