Environmental geohydrochemistry and health of the high altitude population in Ladakh     

Norboo Tsering 《中国地球化学学报》2006,25(B08):69-69

Background： Radiographic signs of Pneumoconiosis found in farming Ladakhi despite absences of mines and industries were believed to be due to exposure to frequent dust storms and domestic fire pollutions. Seasonal Koilonychia （spoon nail） occurring predominantly in farming women in absences of iron deficiency anaemia was thought to arise from exposure to water made alkaline by weathering of hornblende minerals. The relation of these health conditions to environmental geohydrochemistry is postulated as the source of irrigation water in the affected population originates from glaciers in trans-Himalaya range of sedimentary geology and steep landscape favouring flushing of silica/silicate containing silts. Methods and results： Survey in two central Ladakh villages revealed radiographic evidence of silicosis in all middle aged women and half in middle aged men. In a large-scale study of 3105 subjects aged over 30 years from three villages; 101 （22.5%） of the 449 radiographed showed signs of pneumoconiosis （ILO 1980 criteria） including eggshell calcification of hilar gland and progressive massive fibrosis. Indoor dust analyzed using Philips 400T electron microscope with energy dispersive analysis system attached showed SiO2 levels upto 53.27% with particle size of 0.5 to 5.0 microns and the concentration during cooking period in the worst affected area was 7.495 mg/m^3. Microscopy and histopathology from the subject was characteristic of pneumoconiosis. Analysis of the inorganic dust in the lung showed 40.2% muscovite, 37.3% quartz with the extracted dust wt 147.9 mg/gm of dry tissue. Prevalence of chronic cough with chronic phlegm and percentage of villagers with FEV1/FVC ratio of less than 65% rose with age. Of 70 subjects studied 19 women and 2 men had Koilonychia with incidence being highest in summer. Absence of seasonal Koilonychia in villages fed by water derived from northern mountain range glaciers with mainly igneous geology supports our hypothesis.  相似文献   

Natural siliceous dust and human health： Pathways, toxicity, and impact     

Edward Derbyshire 《中国地球化学学报》2006,25(B08):219-219

Fine atmospheric dust includes mineral particles and aggregates, fibrous minerals and fibrous organic material. Generation, dislodgement and transport （deflation） of natural dust with the finer （〈4 microns） components suspended as silt-size aggregates, is widespread in and adjacent to the world＇s drylands, as well as deriving from volcanic vents. Silica is a highly fibrogenic agent in lung tissue. Long-term inhaling of siliceous dusts can lead to a number of fibrotic lung diseases, including natural （non-occupational） pneumoconioses （notably silicosis, but including asbestosis and others）. Different polymorphs of silica show different levels of toxicity in interaction with lung tissue. Particles with highly active surfaces may release radicals, causing cell damage. Some types of inhaled particulates are degraded by macrophages, but many are highly resistant and persist in the lungs, some stimulating fibroblastic cells to deposit collagen. Silicosis is an inflammation of the lung commonly caused by silicate mineral particles, leading to fibrosis. Three types are recognized： nodular pulmonary fibrosis （simple or chronic silicosis）, acute silicosis, and accelerated silicosis. Generally, finer particulates have greater oxidative capacity than the coarser fractions. They contain more reactive oxygen species, their greater bioreactivity making them more toxic to pulmonary tissue. Nevertheless, inhalation of large dust particles （〉 10μm） may constitute a health risk if the mineralogy is toxic, regardless of where the grains lodge in the respiratory system. Dust may absorb harmful gases, disease-generating bacteria and carcinogenic hydrocarbon compounds. Silica-related respiratory disease may also an exacerbate cardiac problem, and epidemiology suggests a link with tuberculosis. Quantification of dust loading and exposure requires study of spatial and temporal patterns, supported by meteorological analysis, airflow modeling and satellite-borne imagery. Some acute, short-term health impacts have been assessed using atmospheric and health records both before and after a dust storm or by comparison of populations within and outside such events. Analysis of the size, shape, mineralogy and geochemistry of ambient dust particulates provides information on natural dust sources, dust concentrations, and potential particulate toxicity, as well as providing a datum for assessment of human exposure levels.  相似文献   

Methylmercury and human biomarkers： Questioning the evidence     

《中国地球化学学报》2006,25(B08):239-239

Methylmercury （MeHg） is a powerful neurotoxicant in humans. In terms of biomarkers of MeHg exposure, hair and blood have long been used in epidemiological studies as the biomarkers of choice. In fact, total hair mercury （Hg） content as well as organic blood Hg concentrations reflects exposure to organic Hg from food consumption. Extensive studies, establishing a constant and linear relation between MeHg intake versus Hg levels in hair and blood, were conducted by governmental officials to establish guidelines on safe levels of MeHg exposure, which were translated into threshold daily fish consumption rates （usually expressed as μg MeHg per kg bodyweight）. Nowadays, in most epidemiologic studies blood or hair mercury （Hg） level is commonly used as a valid proxy to estimate human exposure to methylmercury （MeHg） through fish consumption without relating this signal to actual fish consumption patterns among populations. Human variability in mercury toxicokinetics was identified and measurement error has been pointed out to be a substantial contributor to observed variability, particularly where dietary information is retrospective and self-reported. However, experimental evidence indicates that significant variability among individuals may exist in the biokinetics of mercury. Also recent findings from previous population-based studies through COMERN initiative also revealed that MeHg metabolic processes might greatly vary across populations. In fact, it is unlikely that the magnitude of the difference measured between observed and expected levels of mercury, given the reported intake, can be entirely explained by laboratory measurement errors or reporting bias.  相似文献   

环境地球化学研究进展     

董国文 《煤田地质与勘探》2005,33(Z1):36-39

在全面综合国内外研究文献的基础上,分析了环境地球化学研究的主要内容以及不同介质的环境地球化学研究成果,并对环境地球化学的发展趋势进行了较为详细的论述和分析,指出在进一步深入研究环境地球化学的基础上,加强全球环境变化的历史记录、现代地球化学过程及元素环境地球化学方面的研究是今后环境地球化学研究的重要内容.  相似文献   

成都市生态环境地球化学特点   总被引：10，自引：0，他引：10  

赵琦  李萍  周平 《四川地质学报》2002,22(4):231-235

成都平原多目标地球化学调查表明，成都市区土壤Hg、Ag、Pb、Cu、Zn、Sb、P、S、Se、C、Sr、Mo、Na2O等13种元素和河流水系沉积物P、Hg、S、Zn、Pb、Cu、Mo等有机质、N、Cd、Cr等11种高含量元素，土壤中主要污染元素Hg、Pb、Zn、Cu的含量，在浅层样中较高，其污染状况市区内及工厂区比城郊严重，府河，南河的污染比沙河严重，但其污泥可以综合利用，研究表明，东部龙泉山区深层样丰富的农业有益元素为水果生长提供了有利条件。  相似文献   

矿产资源对人体健康的影响及其对策--以四川省为例     

尹建忠  何政伟  贺奋琴 《新疆地质》2003,21(4):504-505

随着社会的发展,人类对矿产资源的需求量日益增大.而某种程度上,一些国家或地区的环境污染状况,总是与这些国家和地区的矿产资源的富集程度、开发和利用水平相关联,以下就四川省矿产资源对人体健康影响及其对策加以分析.1 四川省矿产资源和人口密度分布特点四川境内分布的矿产资源中22种元素和矿种对人体健  相似文献   

兰州市人体舒适度预报系统开发研制   总被引：6，自引：0，他引：6  

许东蓓  王小勇  黄玉霞  杨民  何金梅 《干旱气象》2003,21(1):20-23

利用兰州市197l-2000年气象资料，统计分析各气象要素的变化规律，并探讨其对人体舒适度的影响。在国内外人体实验和有关研究方法基础上，结合本地特殊的气候状况，建立了与人体舒适度有关的8个指数的计算方法和相应的预报等级，并在预报实践中进行了效果检验和参数订正，可以满足兰州市气象指数预报业务的需要。  相似文献   

达尔文与风中的尘埃     

《发现．图形科普》2003,(4):18-21

  相似文献   

日照市人体舒适度指数预报   总被引：2，自引：1，他引：2  

王繁强  周阿舒  滕丽峰  于怀征 《山东气象》2003,23(2):18-20

通过选取老、中少人群各50名志愿者进行人体感觉试验，获取实感资料。根据对实感资料及气象资料的统计分析，在综合考虑温湿指数和风寒指数的基础上。确定了适合于日照地区的人体舒适度等级及其指数范围。依据T106数值模式输出结果建立了人体舒适度指数MOS预报方程。试用结果及近两年的业务使用证明该方法切实可行，并取得了较好的社会效益和经济效益。  相似文献   

农药污染对人体健康的危害及防治   总被引：1，自引：0，他引：1  

赵金辉  赵晓莉 《气象教育与科技》2003,25(2):21-25

我国是使用农药最早的国家之一，有着十分悠久的历史，农药用于防治农林牧业病、虫草害、鼠害和其他有害生物是调节植物生长的药物及加工制剂。大量的事实表明，农药在防治病虫害、保护庄稼生长方面的作用不容置疑。从不使用农药的自然农业发展到使用农药的现代农业，农药做出了一定的贡献。据统计，世界粮食因为农药的实用，产量相对增长，但如果不使用农药，因为病、虫、草害的影响，粮食将减少1／3[1]。由此可见，农药在人类农业史中起了十分重要的作用。但是由于农药是一种化学制剂，长期大量使用，会对环境生物安全和人体健康产生不利的影响。农药怎样污染环境和对人体健康产生危害，笔者就这一问题加以论述。  相似文献