The Taihang Mountain area of the Henan, Hebei, and Shanxi Provinces in North China has one of world’s highest esophageal cancer mortality rates, affecting a total of 90 million people. The predominant histological type in this area is esophageal squamous cell carcinoma (ESCC). Despite decades of research and intervention programs, however, the epidemic of ESCC in this region has not seen convincing explanation by any risk factor yet and the incidence has not seen a substantial decrease. There might be some unknown risk factors not under control and the lingering high incidence of ESCC in North China calls for new etiological hypotheses. We have lately raised this hypothesis that silica fiber from wheat husks is an important risk factor for the ESCC epidemic in North China. Now we present our latest progress in: 1) The detection of numerous silica fragments (phytolith) in waste water from the wheat washing operation in a mill of the epidemic area of esophageal squamous cell carcinoma (ESCC), and 2) The detection of fractured phytolith particles in a wheat flour sample collected from a household in the ESCC epidemic area. We collected wheat flour and washing water from one farm mill in Linzhou, where the incidence of ESCC is highest in China. The standard method of phytolith extraction as described previously. Residual solid particles from washing water are obtained by high-speed centrifugation; wheat flour is directly used. The samples are then digested with nitric acid for 12 hours, and centrifuged and washed until the upper liquid was colorless. Scanning Electron Microscopy (SEM) observation combined with energy-dispersive X-ray spectroscopy (EDS) analysis was applied afterward. Numerous phytoliths in the acid digested samples from the wheat washing waste water and tentatively in wheat flour were identified by the typical topological characteristics of phytoliths and silicon/oxygen mapping in the literature. It needs to be noted that the wheat flour preparation one and two decades ago usually did not follow strenuous wheat washing procedures before milling because of water scarcity in the arid and semi-arid areas in this ESCC epidemic region. We will further simulate the historical procedures of wheat flour preparation in the study area and perform further analysis.