Cadmium contamination of soils and rice plants caused by zinc mining

Cadmium

“…The residents had been ingesting Cd over a 30-yr period in both their drinking water and in their rice, in which Cd had accumulated through the river water used for irrigation. Similarly, in areas in Fukui Prefecture in Japan, unpolished rice harvested along the Kuzuryu River had Cd concentrations ranging from 0.02 to 1.82 ppm, with some rice containing > 1 ppm found near a Zn mining station (Takijima and Katsumi, 1973). Cadmium in soils ranged from 0.20 to 10.4 ppm.…”

Cadmium contamination of soils and rice plants caused by zinc mining IV. Use of soil amendment materials for the control of Cd uptake by plants

“…The summer of 1970 was so hot that irrigation water appeared to be insufficient. Hence, it would be reasonable to ascribe high Cd burdens in rice to climatic conditions and thereby to the enhanced metal uptake from the soil ( 4,(7)(8)(9). The marked decrease in 1971 was obviously accounted for by the use of materials associated with the rather rainy summer weather.…”

“…In 1971. the effects of the amendment materials were investigated on problem fields throughout the country on schedules of the Ministry of Agriculture and Forestry of Japan. In Fukui Prefecture the field experiment was conducted by the authors at Izumi Village, where waste ores· from zinc mining had been polluting paddy fields with heavy metals ( 7,8).This paper will describe the good results of this experiment together with those obtained from the soil-incubation test. …”

Cadmium contamination of soils and rice plants caused by zinc mining

“…using the same procedures of decomposition and extraction described in the previous paper ( 8 ). Since contamination by Cu was extremely slight in the concerned paddy field areas, data on the content of this metal have been partly omitted in the interest of brevity.…”

“…In a previous paper ( 8) waste ores from zinc mining were proven to cause the -production of high cadmium rice along the Kuzuryu River. Environmental conditions -of paddy fields, other than the Cd content of soil, were also suggested to influence Cd uptake by the rice plant.…”