Hisao Nishizaki

The critical levels and the maximum metal uptake for wheat and rice plants when applying metal oxides to soil

Wheat is more sensitive to CdO and ZnO compared with rice plant. The yield of wheat decreased by 30% in the presence of 30 ppm Cd, but that of rice plants by only 8%. The critical levels of meal uptake by wheat and rice plants for applying metal oxides to soil (CdO, ZnO, PbO) were determined. The highest concentration obtained for wheat grain was 141 micrograms/g Cd at the Cd 10,000 ppm in soil. This value is higher than the value of 4.97 micrograms/g for unpolished rice and higher than any other we have seen in the reports for treatment with CdO. Also, concentration of more than 1.0 micrograms/g Cd in wheat was observed at 5 pm Cd, while similar concentrations for rice plants were observed at 30 ppm Cd in soil.

Variation in some element contents of water hyacinth due to cadmium or nickel treatment with or without anionic surface active agents

Abstract The changes in some metal components of water hyacinth by exposure to cadmium, nickel with or without surface‐active agents are determined. Metal contents of Cd, Ni, Al, Ca, Si, Mn in tops and roots were changed in relatively short time by treatment with Cd or Ni. The values of concentration factors are reduced in both tops and roots under the presence of the anionic surface‐active agents.

Effects of fluorine emission on agricultural products surrounding an aluminum factory

The F concentrations of precipitate dust, agricultural products, and fingernail and hair at the surrounding Al factory were investigated. The F content of dust ranged from 15400 to 42500 micrograms/g dry weight, 190,000 to 380,000 micrograms/g Al. Rice grain contained about 3.4 times more F than that in the control area, but some kinds of agricultural products, egg plants (S. melongena L.), mulberry plants (M. japonica Bailey non Sieb.), and soy beans (G. max (L.) Merrill) were almost equal to that of controls. Also, the high F concentration in the hair and nails of some workers was affected by available F contents in the emission from the factory as well as food and water surrounding the aluminum factory compared with those of control area.

Fluoride content of children's teeth in one district in Japan with high fluoride content in water.

We investigated the relationship between the degree of mottling and the fluoride content in mottled childrens teeth in Takarazuka city where the down stream of Muko river is situated. That river originates in Rokko mountain which is composed of high fluoride content granite rocks