Mineralogical and geochemical variations from coal to deposited dust and toxicity of size-segregated respirable dust in a blasting mining underground coal mine in Hunan Province, South China

This study systematically investigates the mineralogical and geochemical variations in parent coal, coal gangue (roof, parting, and floor), deposited coal mine dust (DD), and respirable fractions of DD (RD) in an underground coal mine using the blasting mining method in China to evaluate the major sources of DD. The emission of dust in this study is affected by coal gangue sources during the mining process, which causes different geochemical patterns in the DD samples. Moreover, weathering of the cement gunite walls plays an important role in the enrichment of specific elements in the DD from air uptake and air out galleries. Furthermore, the spatial variation in RD characteristics, including mineralogy, geochemistry, and oxidative potential (OP), is discussed, with emphasis on the major health-relevant species and elements. Organic species from coal dust seem to be the essential components contributing to OP rather than metals, although some metals (e.g., Cr, Co, Ge, Se, Zn, Ba, Rb, Cs, Sn, and Pb) influence OP to some degree.This research was supported by the National Science Foundation of China (No. 41972180), the Overseas Top Scholars Program, part of the “Recruitment Program of Global Experts” (No. G20190017067), China and the Open Research Fund Project for Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences), Ministry of Education, China (No. TPR-2019-14).Peer reviewe