Toxic Heavy metalscontaminants in the environment can be transported in to propagated to all the air, soil and water. By accumulating toxic substancesns in the soil, there will be more than any other resources, because the soil has accumulated minerals. Which soil contains high amount of metals. ion exchan
ge in soil. In effect, can with soil particles adhere better and substances that contaminated can also spread to the surface water and groundwater. Contamination of toxins in the water, Toxic contamination can be transported downstream and dilute that has affected less than in the soil. Cadmium contamination in the environment caused by 2 source including production and application of cadmium in various industries and disposal of waste contaminated with cadmium. In Thailand which has found that the cadmium contaminated in environment at Mae Sot, Tak Province in the years 2541-2544. The results showed the concentration of cadmium in soil samples from the field. The value is in the range 3.4 to 284 mg / kg. The samples for quality grain from the fields. Cadmium contamination was found 0.1 to 44 mg / kg., height above average cadmium in rice of Thailand. Such contamination by 95% higher than the maximum allow of CODEX Committee on Food Additives and Contaminants (CCFAC) which is defined at 0.2 mg/kg. (กลุ่มวิชาการและมาตรฐานสำนักบริหารและฟื้นฟูสิ่งแวดล้อมกรมอุตสาหกรรมพื้นฐานและการเหมืองแร่, 2547) Contaminated with high concentrations of contaminant levels are dangerous, causing Itai-Itai dDisease. (Petpailin Suwannachote, 2009)