Evaluation of acidity in late Permian outcrop coals and its association with endemic fluorosis in the border area of Yunnan,Guizhou, and Sichuan in China

The junction area of Yunnan, Guizhou, and Sichuan provinces is the heaviest coal-burning endemic fluorosis zones in China. To better understand the pathogenicity of endemic fluorosis in this area, 87 coal samples from the late Permian outcrop or semi-outcrop coal seams were collected in eight counties of the junction area of Yunnan, Guizhou, and Sichuan provinces. The total fluorine and sulfate content, etc. in the coal was determined using combustion-hydrolysis/fluoride-ion-selective electrode method and ion chromatography, respectively. The results show that the total fluorine concentrations in the samples ranged from 44 to 382 µg g^?1, with an average of 127 µg g^?1. The average pH of the coals is 5.03 (1.86–8.62), and the sulfate content varied from 249 to 64,706 µg g^?1 (average 7127 µg g^?1). In addition, the coals were medium- and high-sulfur coals, with sulfur mass fraction ranging from 0.08 to 13.41%. By heating the outcrop coals, HF release from the coal was verified quantitatively without exception, while simulated combustion directly confirmed the release of sulfuric acid (H₂SO₄). The acid in coal may be in the form of acidic sulfate (\({\text{HSO}}_{4}^{ - }\)/H₂SO₄) because of a positive relationship between pH and \(p\left( {{\text{SO}}_{4}^{2 - } } \right)\) in the acidic coal. The possible reaction mechanism would be that a chemical reaction between the acid (H₂SO₄ or \({\text{HSO}}_{4}^{ - }\)) and fluorine in the coal occurred, thereby producing hydrogen fluoride (HF), which would be the chemical form of fluorine released from coal under relatively mild conditions. The unique chemical and physical property of HF may bring new insight into the pathogenic mechanism of coal-burning endemic fluorosis. The phenomenon of coal-burning fluorosis is not limited to the study area, but is common in southwest China and elsewhere. Further investigation is needed to determine whether other endemic fluorosis areas are affected by this phenomenon.     

Coal utilization in China: environmental impacts and human health

Coal is one of the major energy resources in China, accounting for approximately 70 % of primary energy consumption. Many environmental problems and human health risks arise during coal exploitation, utilization, and waste disposal, especially in the remote mountainous areas of western China (e.g., eastern Yunnan, western Guizhou and Hubei, and southern Shaanxi). In this paper, we report a thorough review of the environmental and human health impacts related to coal utilization in China. The abundance of the toxic trace elements such as F, As, Se, and Hg in Chinese coals is summarized. The environmental problems (i.e., water, soil, and air pollution) that are related to coal utilization are outlined. The provenance, distributions, typical symptoms, sources, and possible pathways of endemic fluorosis, arsenism, and selenosis due to improper coal usage (briquettes mixed with high-F clay, mineralized As-rich coal, and Se-rich stone coal) are discussed in detail. In 2010, 14.8, 1.9 million, and 16,000 Chinese people suffered from dental fluorosis, skeletal fluorosis, and arsenism, respectively. Finally, several suggestions are proposed for the prevention and treatment for endemic problems caused by coal utilization.     

室内空气中多环芳烃污染的测量和特征性研究

本文就室内空气中多环芳烃典型污染源－室内燃煤和室内吸烟排放的多环芳烃组成和含量进行了测定，并同室外大气（对照）中多环芳烃组成含量进行了对比，研究了室内环境不同污染源排放多环烃组成和含量的特征性，结果表明，室内燃煤污染同燃煤型室外大气源排放多环芳烃具有相似组成含量特征，而室朵烟草烟雾污染源的多环芳烃组成含量特征，则与室外煤型和交通型均有显著区别。     

Fluorine in the UK environment

Relatively low concentrations of fluorine in drinking water ( 1 mg F/l) have been shown to significantly reduce the degree of dental caries in children and fluorine would also appear to have a beneficial effect on bone formation in both humans and farm animals. However, it is apparent that elevated levels of fluorine in the diet have sometimes resulted in problems of increased dental caries and of the development of bone deformities. Much of the fluorine in rocks and soils occurs in apatite and hydroxysilicate minerals, fluorite being the only relatively common rock forming mineral containing fluorine as an essential constituent.Little systematic data are available on fluorine concentrations in soils, plants and natural waters in the UK. General background soil concentrations lie in the range 200 – 400 mg F/kg. For waters the average fluorine content is low, <0.1 mg F/l.In the British Isles there are several areas where there are enhanced levels of fluorine. In the northern Pennines, Derbyshire, northeast Wales and Cornwall, fluorite occurs as a significant component of mineralisation and much fluorine has been added to the environment from mining waste dumps. Soils in northeast Wales contain up to 3,650 mg F/kg and in the northern Pennines up to 20,000 mg F/kg. Waters contain up to 2.3 mg F/l. In southwest England, the granites are generally fluorine-rich with the fluorite granites of the St Austell pluton containing as much as 1 percent fluorine. These rocks are frequently kaolinised and intensively worked as a source of china clay. Soils in the vicinity of the waste tips contain up to 3,300 mg F/kg and grasses up to 2,950 mg F/kg. Surface waters in the St Austell area contain up to 1.25 mg F/l.Atmospheric fluorine pollution around brickworks in the Peterborough and Bedford areas has resulted in fluorosis in farm animals. Other sources of atmospheric fluorine pollution are aluminium smelters, steelworks and fossil fuel burning.     

土氟静态吸附特性及其影响因素

采用室内试验方法,研究了4种土对氟的静态吸附特性及其影响因素.结果表明:四种土的吸附性能与氟质量浓度的关系用回归方程拟合达极显著的直线正相关水平,土吸附系数差异,表现为中沙<粉土<粉质粘土<粘土.此外,土吸附氟后的平衡溶液pH值随氟加入质量浓度增大而上升,主要是氟与OH-发生交换吸附作用;干扰因素试验中,HCO3对氟吸附有重要影响,随其质量浓度增加而减少,CR、S042-表现不明显;pH值因素试验中,氟的吸附性能随pH值先增加后下降,原因是酸碱条件影响了氟的存在形态,导致土氟吸附性能发生变化.     

The Contribution of Drinking Water towards Dental Fluorosis: A case study of Njoro Division, Nakuru District, Kenya

This study was carried out to measure the fluoride levels of water consumed in the Njoro division of Nakuru district, Kenya. The sources of drinking water, methods of water storage and utilisation, as well as the perceptions of the local community towards dental fluorosis and the percentage of children with moderate to severe dental fluorosis were also determined. Rainwater had mean fluoride levels of 0.5 mg L^-1, dams 2.4 mg L^-1, wells 4.1 mg L^-1, springs 5.5 mg L^-1, and boreholes 6.6 mg L^-1. Water stored in plastic and cement containers did not show appreciable reduction in fluoride content with storage time; water stored in metal containers reduced fluoride by up to 8.2%; water stored in clay pots had the highest reduction in fluoride content, ranging between 34.3 and 64.7%;. Forty eight point three percent of children observed in the area had moderate to severe dental fluorosis, even though most people in the area did not know the cause of the problem.There is need to educate the community on the causes of fluorosis, and to lay strategies for addressing the issue, such as encouraging more rainwater harvesting, treating drinking water with alum, or using clay pots for storage of drinking water.     

燃煤电厂氟对灰场复垦土壤和农作物的影响

以燃用高氟煤的安徽省淮北电厂为例,研究了电厂排放的氟对灰场土壤和小麦的影响。结果表明：部分灰场土壤和小麦受到氟污染,灰场土壤污染程度与灰场覆盖年限的长短、大气中氟浓度显著相关,灰场小麦氟污染主要来自大气中的氟     

氟与健康的环境流行病学研究

氟是与机体健康密切相关的微量生命元素,原生环境中氟过量或缺乏均会导致机体产生疾病。氟对人类健康的影响已成为全球性的环境健康问题。综合国内外近年来的相关资料,作者概述了环境生态系物质中氟的含量、分布及化学行为,阐述了氟对机体的健康效应,分析了我国地氟病的现状,并指出了今后在氟与健康研究领域中应关注的问题。     

A health risk assessment for fluoride in Central Europe

Like many elements, fluorine (which generally occurs in nature as fluoride) is beneficial to human health in trace amounts, but can be toxic in excess. The links between low intakes of fluoride and dental protection are well known; however, fluoride is a powerful calcium-seeking element and can interfere with the calcified structure of bones and teeth in the human body at higher concentrations causing dental or skeletal fluorosis. One of the main exposure routes is via drinking water and the World Health Organisation currently sets water quality guidelines for the element. In Central Europe, groundwater resources that exceed the guideline value of 1.5 mg l⁻¹ are widespread and effects on health of high fluoride in water have been reported. The aim of the current project was to develop a geographic information system (GIS) to aid the identification of areas where high-fluoride waters and fluorosis may be a problem; hence, where water treatment technologies should be targeted. The development of the GIS was based upon the collation and digitisation of existing information relevant to fluoride risk in Ukraine, Moldova, Hungary and Slovakia assembled for the first time in a readily accessible form. In addition, geochemistry and health studies to examine in more detail the relationships between high-fluoride drinking waters and health effects in the population were carried out in Moldova and Ukraine demonstrating dental fluorosis prevalence rates of 60–90% in adolescents consuming water containing 2–7 mg l⁻¹ fluoride.     

浙江省中部萤石产区氟环境与地方性氟病

通过对浙江省中部萤石产区氟地球化学环境的初步研究，探讨了该区地方性氟病的成因和分布规律，指出了地方性氟病与高氟环境的关系。     

型煤燃烧特性初探

本文使用热重分析仪对型煤的燃烧特性进行了初步探讨。煤灯样品在升温过程中，发生两次快速失重，对应的温度分别为Ｔ１和Ｔ２。由于制备型煤时，添加了无机粘结剂和无机固硫剂等无机物，导致制备型煤用的混合料的Ｔ１比原煤降低，而刷烈燃烧温度Ｔ２却比原煤升高。     

Influences of coal mining water irrigation on the maize losses in the Xingdong Mine area, China

In 2008, a maize underproduction disaster occurred in the Xianyu village after irrigation using the coal mining water from the Xingdong Mine, China. This disaster resulted in about 40 hectare maize underproduction and 20 hectare total loss of the maize yields. In order to study the reason, a total of 25 soil, water and plant samples were taken from the study area. These samples were analysed by inductively coupled plasma mass spectrometry and ion chromatography. The results indicate that the contents of both water-soluble fluorine and total fluorine are very high and resulting of maize underproduction and total loss of production. The possible pollution sources of fluorine in the study area could be from the coal mine water used for irrigation and glass chemical factory near the study area.     

燃煤电厂氟污染与治理对策

本文以一个包含干湿两种除尘系统的高氟煤源的电厂为例,研究了电厂的氟迁移转化规律和氟污染源对周围环境的影响。并提出了综合治理电厂氟污染的对策。研究表明：湿法除尘系统的氟污染物主要是渣氟、水氟,而干法除尘系统主要是渣氟和气氟;小麦氟含量与大气中氟显著相关;灰场附近的地表水受到灰水的氟污染,部分潜水井受到了灰场渗水的污染,部分灰场土壤受到大气氟污染。     

煤灰中部分重金属元素含量与燃料工况的关系模型

本文研究了燃烧温度、燃烧气氛、煤粉细度和灰粒细度等因素与煤燃烧产生的细微粒子中部分重金属元素含量的关系,建立了灰粒中元素含量与备因素关系的模型,发现燃烧工况和灰粒细度与灰粒中元素的含量具有一定的相关关系.用模型对不同灰粒中的元素含量进行了预报,可用控制燃烧条件来减少重金属元素向大气的释放.     

城市室内环境多环芳烃污染与源的相关性

本实验选择了天津市４类典型室内环境和２处室外对照点，共１９个采样点。现场采样测定了１０种ＰＡＨｓ组成含量。结果显示，室内燃煤和室内吸烟是室内环境中多环芳烃排放的主要污染源。同作为对照的室外大气中多环芳烃组成和含量进行了对比，研究了室内环境不同污染源排放多环芳烃组成和含量的特征性。提出了室内燃煤污染同燃煤型室外大气源排放多环芳烃具有相似组成含量特征，而室内烟草烟雾污染源的多环芳烃组成含量特征则与室外     

煤燃烧过程中5种微量元素的迁移和富集

通过一维炉燃烧模拟实验,研究了褐煤、肥煤、无烟煤及其燃烧产物中As,Cr,Pb,Cd,Hg的含量和分布;计算了在不同燃烧条件下的飞灰和底灰对煤的元素含量比和富集因子,以及飞灰对底灰的元素含量比和富集因子;详细探讨了3种煤在不同燃烧过程中5种元素的迁移和富集行为．结果表明,5种元素在各燃烧产物中都有一定含量的分布,只是各元素在不同燃烧过程中所呈现的集散规律不同,说明煤燃烧过程中微量元素的迁移和富集行为不仅与煤中微量元素的含量和赋存状态有直接关系,还受煤燃烧方式、炉温、气氛条件等人为因素的影响．     

Fluoride contamination in groundwater of central Rajasthan,India and its toxicity in rural habitants

This study was carried out to assess fluoride (Fl) concentration in groundwater in some villages of central Rajasthan, India, where groundwater is the main source of drinking water. Water samples collected from deep aquifer-based hand pumps were analyzed for Fl content. Fluoride in groundwater of 121 habitations of Bhilwara tehsil of Bhilwara district of Rajasthan was determined to examine the potential Fl-induced toxicity in rural locations. Fluoride concentrations in the tehsil ranged from 0.5 to 5.8 mg/l. In the tehsil, 69 villages (57%) were found to have Fl concentration beyond the maximum desirable limit recommended in Bureau of Indian Standards (BIS), 10500, 1991. Fifty-eight percent population of these villages was under the threat of fluorosis. One percent population of tehsil living in two villages ingested more than 5 mg/l Fl in each liter of drinking water and at maximal risk for dental and skeletal fluorosis. 142 individuals of these villages were examined for fluorosis. Data indicated that only four individuals (2.82%) did not exhibit dental fluorosis. Most individuals were found to suffer from mild (34.51% or 49 individuals) and moderate (31.69% or 45 individuals) fluorosis. Severe dental fluorosis was recorded in only 16 individuals (11.27%). In 104 individuals above 21 years of age examined for the prevalence of skeletal fluorosis, 66 were positive for skeletal fluorosis with a maximum 36.5% with grade I skeletal fluorosis. Grade II skeletal fluorosis was recorded in 28 individuals (26.9%). Data in this study demonstrate that there is a need to take ameliorative steps in this region to prevent fluorosis.     

北京大气气溶胶单个颗粒的化学表征

用安德逊分级采样器采集京都三个点（北辛安，冷泉村和生态环境研究中心）的大气气溶胶颗粒，用扫描电镜／Ｘ射线能谱观察和分析单个颗粒的形貌和元素成分，对粗细颗粒分别进行了Ｘ射线物相分析，通过对颗粒的形貌，组分和化合物形态等的综合分析结果表明，细粒样品中常含有较多的铁或铵的硫酸盐及氯化铵，粗粒样品中则主要为矿物物质如石英，方解石，石膏，白云石和一些粘土矿物，圆形颗粒可能是煤的燃烧产物，许多不规则形的颗粒大