Characterisation and modelling of mercury speciation in urban air affected by gold mining - assessment of bioavailabilityE. M. Cukrowska, J. Lusilao-Makiese, B. Yalala, H. Tutu and L. ChimukaE3S Web of Conferences, 1 (2013) 20004DOI: https://doi.org/10.1051/e3sconf/20130120004