Iodine, bromine and chlorine contents in soils and plants of Japan

Open Access
Publisher Website
Google Scholar
Abstract
As a part of the studies on the determination of the average contents of iodine, bromine and chlorine in the soils and plants of Japan, the contents of the three elements, mainly in the forests of the Andosol region of Central Honshu were evaluated, and the results were as follows. 1. The average contents of iodine and bromine in the soils of grasslands, orchards and upland crop fields were about 10 times higher than those recorded in data from overseas, but the content of chlorine was similar to the average level reported (for horizon A of the forest soil, 46 ppm of iodine, 123 ppm of bromine and 126 ppm of chlorine). The average contents of the three elements in these soils were slightly higher than those recorded in the forest soil of the basins of the Miomote and Nagara Rivers. 2. The average contents of the three elements in the leaves of all plants were similar tc the average values reported previously outside of Japan, and to the values reported in the basins of the Miomote and Nagara Rivers (wild plants: 0.60 ppm of iodine, 12 ppm of bromine, 4,270 ppm of chlorine). 3. The contents of iodine and bromine in the forest soil, plants and rainwater were generally higher in coastal areas than in the inland areas. 4. In the Andosols of the forests, grasslands, orchards and upland fields of Central Honshu, iodine and bromine from soil became dissolved in association with the conversion of these lands to paddy fields. This condition may be damaging to the rice plants due to the excessive absorption of iodine and the increase in the content of bromine residues in crops that exceed the permissible limits.