Introduction: With increasing use of Indian made orthodontic materials, need was felt to know nickel and chromium release from these material.
Materials And Methods: This study was conducted on simulated appliances consisting of brackets (022″Roth, Modern orthodontics, Ludhiana, India), from second premolar to central incisor, buccal tube and 0.019×0.025- inch SS arch wires secured with SS ligatures. Immersion was done in artificial saliva. Samples were analysed to using Atomic Absorption Photospectrometer (GVC ScientificEquipment Pvt. Ltd Australia) at AES Laboratories (P) Ltd., Noida India on 1(st), 7(th), 14(th) and 28(th) day.
Results: SPSS (ver 17, Inc., Chicago, Illinois, USA) was used toperform the statistical analysis. Descriptive statistics i.e. median and 25 and75 percentiles were used. Peak nickel release was on 7(th) day and subsequently declined over 14(th) and 28(th) day. The peak level of chromium concentration was on 14(th) day, which declined thereafter.
Conclusion: Average daily release of nickel and chromium over a period of one month was 97.368 μg/day and 47.664 μg/day respectively. The estimated release rates were approximately 32% and 16% of the reported average daily dietary.
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http://dx.doi.org/10.7860/JCDR/2015/14404.6520 | DOI Listing |
Environ Monit Assess
December 2024
Central Department of Geology, Tribhuvan University, Kirtipur, Kathmandu, 44600, Nepal.
Freshwater ecosystems, including high-altitude lakes, can be affected by trace metal pollution derived from a mix of natural sources and anthropogenic activities. These pollutants often collect in surface sediments, with notable concentrations in the deeper areas of lakes. To evaluate the environmental risk associated with metal contaminated sediment in Rara Lake, southern Himalaya, surface sediment samples were systematically collected in November 2018, with a subsequent specific emphasis on determinations of trace element concentrations.
View Article and Find Full Text PDFHuan Jing Ke Xue
January 2025
Chongqing Key Laboratory of Land Quality Geological Survey, Southeast Sichuan Geological Group, Chongqing Bureau of Geology and Minerals Exploration, Chongqing 400038, China.
Heavy metals (HMs) pollution in agricultural soil-rice systems has attracted worldwide attention as it directly threatens regional ecological security and human health. To understand the heavy metal pollution of agriculture soil and rice in the high geological background areas, a total of 200 paddy soil and rice samples were collected in southeast Chongqing. The concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) in paddy soil and rice were analyzed.
View Article and Find Full Text PDFMar Environ Res
December 2024
Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, and College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, 266100, China. Electronic address:
The Bohai Sea (BS) is a semi-enclosed inland sea and China's most polluted coastal sea. With the rapid economic development of the circum-Bohai Sea region, large amounts of pollutants have been discharged into the BS, posing a significant threat to human health and the ecosystem. Great efforts have been made on investigating the levels of various pollutants in the BS; however, the priority pollutants which are required for the implementation of suitable environmental management and remediation measures in this system remain unclear.
View Article and Find Full Text PDFEnviron Geochem Health
December 2024
Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Cocoa-growing areas in Ghana have experienced a rise in mining activities affecting cocoa cultivation and increased concentrations of potentially toxic metals in the soil, which can accumulate in cocoa beans. This study evaluated potential toxic metal contamination in cocoa beans and soils from cocoa farms in mining and non-mining areas in Ghana. We used X-ray fluorescence and an ICP-MS to determine metal concentrations, and a Zeeman mercury analyzer to determine mercury.
View Article and Find Full Text PDFToxicol Rep
December 2024
Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States.
Unlabelled: Thermal spray, in general, is a process that involves forcing a melted substance, such as metal or ceramic in the form of wire or powder, onto the surface of a targeted object to enhance its desired surface properties. In this paper, the melted substance is metal wire generated by an electric arc and forcibly coated on a rotary iron substrate using compressed air. This thermal process is referred to as double-wire arc thermal spray.
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