The duration of the contract to this project is between October 29th, 2012 and October 28th, 2013. The main job of this project is to investigate and verify the cause of the emerging problem of cadmium rice in an endless stream at Houli, Taichung and Huwei, Yunlin. The investigation works on farmland environment inspection, farmland soils, sediments in irrigation ditches, irrigation water quality, ambient air quality, emission channels and plant tissues, and the assessment on pollution sources via air pollution model and isotopic analysis on all kinds of transportation media have been accomplished. At Houli, Taichung , Feng Hsin Iron Co., LTD. is the top priority of investigated subject. According to all kinds of collected environmental samples and the analytical results, it appears that the fundamental reason for the contaminated farmlands with zinc and cadmium concentration above controlling standards is the diverged dust created from steel manufacturing. There are two transportation pathways. First, the over-loaded waste water and the water from the 12th supply ditch of Houli 1th branch irrigation tunnel, which pass through Feng Hsin Iron and Steel manufacturing factory, enter Houli 2nd branch irrigation tunnel and are used as irrigation purpose that results in accumulation of zinc and cadmium in farmlands. Second, the zinc and cadmium-contained dust diffused and precipitated through air and eventually accumulated in farmlands. As for the investigation at Huwei, Yunlin, Taiwan Colors & Chemicals CO., LTD. is the top priority of investigated subjects. The investigation result shows that dirt, dust, sewage sludge and No. 2-4 drainage have been measured with high concentration of cadmium. Hence, based on the assessment and judgement Huwei, Yunlin, Taiwan Colors & Chemicals CO., LTD is the source of cadmium accumulated in drainage ditch. The emerging problem of cadmium-contaminated farmlands at Huwei, Yunlin is attributed to two reasons. First, the dust was carried by surface runoff into drainage ditch and that results in pollution of farmlands downstream. Second, the sediments in are full of cadmium. Once the torrential rain comes the water flow out of drainage ditch and enter farmlands. Those cadmium in sediments is correlated with Taiwan Colors & Chemicals CO., LTD. In terms of the investigation results, the judgment has been made that the pollution source at agricultural area in Houli, Taichung is Feng Hsin Iron and Steel Co., LTD. And the pollution source at agricultural area in Huwei, Yunlin is Taiwan Colors & Chemicals CO., LTD. The further works in the future will be planning prevention strategy for pollution and prosecuting these two companies for environmental contamination. Also, compensation will be required in order to return a secured environment to local residents.

cadmium contamination of farmland;steel-making process with electric arc furnace;Manufacture of plastic pigment