地球科学と気候変動ジャーナル

抽象的な

A Mineralogy Study from Settleable Dust Samples in Mpumalanga Province, South Africa

Maphuti G Kwata, Shadung J Moja, Khuthadzo Masindi, Tlou Mashalane, Ongeziwe Mtyelwa and Mafeto R Malatji

Exposure to asbestos fibers pose serious health problems which are exacerbated by wind currents and by rain water that transports fibers from asbestos mine dumps to nearby residential areas. Most of asbestos mine dumps in Mpumalanga Province are old, ownerless and not rehabilitated. The aim of this pilot study is to characterize the captured settleable dust samples. The two Sites, A and B which were selected for monitoring purpose are located about 20 km away from Mbombela, the capital city of the province. The South African National Dust Control Regulations (SANDCR) 827 of 2003 method was used to collect settleable dust around residential areas that are within 2 km of the asbestos mine dump sources in July 2015 and July 2016. The samples were chemically treated and characterized to identify the type of minerals present and to determine the morphological composition with an XRD and the SEM-EDS analytical techniques respectively. The XRD and SEM/EDS results at Site A confirms the presence of serpentine (26% m/m), organic (4% m/m) and quartz (31% m/m) minerals. Site B contain 35% m/m of serpentine, 10% m/m of amphibole, 37% m/m quartz, 21% m/m organic and 10% m/m fiber glass.

Other minerals detected at both sites were the calcite, k-feldspar, plagioclase, mica and smectite. The SEM/EDS analyses confirm that fiber glass, organic and amphibole are the longest particles/fibers with length of 485 μm, 100 μm and 64 μm respectively. The presence of asbestos dust around the residential areas highlights the possible environmental risk to those who are exposed.