Cadmium, copper, and zinc in rice produced in Java.
Cadmium (Cd), copper (Cu) and zinc (Zn) contents in 116 polished and unpolished rice samples produced in the Java Islands of Indonesia were assessed as a base-line study of trace metals. Arithmetic means and one standard deviation were 0.040 +/- 0.042 ppm Cd, 2.93 +/- 1.11 ppm Cu, and 18.17 +/- 3.13 ppm Zn. Concentration ratio of Cd to Zn was 0.00220 +/- 0.00222. The correlation coefficients between the metals were low. The two highest samples of rice contained 0.27 and 0.34 ppm Cd. Using the fact that Indonesians consume about 300 g of rice, the daily intake of Cd would exceed the tolerable limit proposed by FAO/WHO and could cause slight chronic renal damage to the rice eaters. Soil type by suborder and rice variety gave little difference of the three metals content in rice. Rice samples from West Java, where major soil type by order is Ultisol, contained higher cadmium and zinc, and lower copper than those from East Java (Vertisol).