Risk assessment model for different foodstuff drying methods via AHP-FCE method: A case study of “coal-burning” fluorosis area of Yunan and Guizhou Province, China

Fluorosis is still a serious public health problem in China according to our field investigation. Current foodstuff drying methods were studied to evaluate the state of foodstuff contamination, including burning mixed coal (MC)/coal washing wastes (CWWs)/lump coal (LC)/fuelwood/fine coal + fixing materials (FCFM)/CWWs + fixing materials (CFM) in open stove (OS), honeycomb briquettes (HB) in improved stove (IS), sun-drying. The results demonstrate that elemental contents of F, As, Cd, Cr and Pb in roasted grain were 1.19-40.65 times higher than limting standard. The comprehensive risk of different drying methods based on AHP-FCE is ranked in the order of: CWWs(OS) > MC(OS) > HB(IS) > CFM(OS) > FCFM(OS) > LC(OS) > Fuelwood(OS) > sun-drying. It exhibits obviously higher risk due to burning CWWs/MC in OS than other methods. Burning CFM/FCFM/fuelwood in OS may be an economic and relatively safe foodstuff drying methods.