Mercury is still used in developing countries to extract gold from the ore in small-scale gold mining areas. This is a major health hazard for people living in mining areas. The concentration of mercury in urine was analysed in different mining areas in Zimbabwe, Indonesia and Tanzania. First the urine samples were analysed by CV-AAS (cold vapour atomic absorption spectrometry) during the field projects with a mobile mercury analyser (Lumex(®) or Seefelder(®)) and secondly, in a laboratory with a stationary CV-AAS mercury analyser (PerkinElmer(®)). Caused by the different systems (reduction agent either SnCl(2) (Lumex(®) or Seefelder(®))) or NaBH(4) (PerkinElmer(®)), with the mobile analysers only the inorganic mercury was obtained and with the stationary system the total mercury concentration was measured. The aims of the study were whether the results obtained in field with the mobile equipments can be compared with the stationary reference method in the laboratory and allow the application of these mobile analysers in screening studies on concerned populations to select those, who are exposed to critical mercury levels. Overall, the concentrations obtained with the two mobile systems were approximately 25% lower than determined with the stationary system. Nevertheless, both mobile systems seem to be very useful for screening of volunteers in field. Moreover, regional staff may be trained on such analysers to perform screening tests by themselves.
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http://dx.doi.org/10.1016/j.ijheh.2011.06.005 | DOI Listing |
Sci Rep
December 2024
School of Minging and Geomatics Engineering, Hebei University of Engineering, Handan, 10076, China.
The height of the water-conducting fracture zones (WCFZ) is crucial for ensuring safe coal mining beneath aquifers, particularly considering the secondary development of the WCFZ in upper seams due to repeated mining in close distance coal seams. Accurately predicting this height is essential for mine safety, groundwater protection, and optimal coal resource use. This study compiles extensive measured data from various mining areas in China to analyze the coupling relationship between the WCFZ development height and six influencing factors: mining thickness, mining depth, coal seam spacing, hard rock lithology ratio, and the slope length of working face.
View Article and Find Full Text PDFData Brief
December 2024
Centre of Marine Sciences (CCMAR), Campus de Gambelas, University of Algarve, Faro 8005-139, Portugal.
The dataset gathers available regulations of human activities and protection levels of Marine Protected Areas (MPAs) of the European Union (EU). The MPA list and polygons were extracted from the MPA database of the European Environment Agency (EEA) and completed with available zoning systems (all were filtered for their marine area reported under the Marine Strategy Framework Directive). Fully-overlapping MPAs were merged.
View Article and Find Full Text PDFSci Total Environ
December 2024
Technical Centre for Soil, Agricultural and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing 100012, China.
An accurate understanding of the spatial distribution of soil heavy metals (HMs) is crucial for the effective prevention of soil pollution and remediation strategies. Traditional machine learning models often overlook the spatially stratified heterogeneity inherent to environmental data, which can impair predictive accuracy. Therefore, we combined the Geodetector model (GDM) with machine learning models.
View Article and Find Full Text PDFSci Rep
December 2024
College of Energy Engineering, Xi'an University of Science and Technology, Xi'an, 710054, China.
Affected by weakening effect of water in the goaf, the bearing capacity of coal pillar reduced, and coal pillar rock burst is prone to occur, which is a serious threat to mine safety in production. In order to study the equivalent width and stability of coal pillar in water-rich coal seam, taking the section coal pillar of a working face as the research object, combined with laboratory test, theoretical analysis, simulation and engineering practice, the stress, elastic core area width, damage degree and energy accumulation of 36 m water-immersed coal pillar and 26 m, 28 m, 30 m, 32 m, 36 m unimmersed coal pillars are analyzed. The research results show that: (1) The reasonable width of coal pillar under flooded and unflooded conditions is 36.
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