Touru Abe

Fallout 3H ingestion in Akita, Japan.

To study fallout 3H ingestion in Japan, 16 separate food group samples were collected from Akita during 1985. The 3H concentration in free water and that in a tissue-bound form were determined separately. The average 3H concentration in the tissue-bound form was 2.2 Bq L-1, 1.7 times higher than in the free water of the food. The ingestions of 3H in the tissue-bound form and as free water in the diet were 0.60 Bq d-1 and 1.0 Bq d-1, respectively. Cereals represented the food group that contributed the most to the ingestion of tissue-bound 3H. Total 3H ingestion was estimated to be 4.1 Bq d-1. The contribution of the tissue-bound form to the total ingestion was 15%, considerably lower than reported for Italian diets. The ratio of 3H ingestion in the tissue-bound form to the free water form in the diet was similar to the ratio reported for New York City.

Simultaneous multielemental analysis of daily food samples by inductively coupled plasma mass spectrometry

Several toxic elements in total composite food samples of hospital diets were determined simultaneously by inductively coupled plasma mass spectrometry (ICP-MS). Trace element concentrations of Be, Cr, As, Cd, Sn, Sb, Ce, Hg and Pb changed widely ranging from a few ng.g-1 to less than 3 micrograms.g-1 in all 24 samples collected through a year. Be, Sn, and Hg were not detected in rice sample alone, and other trace elements, with the exception of Cr and As, were less than approximately 50% levels, as compared with mixed diet samples. The daily intakes of these toxic elements were in the ranges of a few to several hundreds of micrograms.

Fallout Pu in the Japanese diet

The ingestion of fallout Pu from seven or six separate food groups collected in Japan during 1962 and 1983-84 are reported. The contribution of ingested Pu from algae was the highest among the food groups studied: approximately 60% of the total ingested Pu during 1962, and 74% in 1983-84. The contribution from whole marine products, i.e. algae and fish/shellfish, was approximately 70% of the total Pu ingested in 1962, and more than 90% in 1983-84. The higher Japanese ingestion rate than that of the United States is attributable to the higher consumption rate of marine food products in Japan. Also reported in this paper are the ingestion rate for 137Cs from fallout through the same food groups, and the concentration of Pu and other radioactive nuclides in specific individual foodstuffs and algae samples.

Atmospheric mercury concentrations in the basin of the amazon, Brazil.

A wide regional mercury pollution in Amazon, Brazil is closely associated with goldmining that has been carried out in the basin of tributaries of the Amazon since the eighteenth century. Possible involvement has been discussed on atmospheric circulation in distributing the volatile pollutant. We developed a portable air sampler for the collection of mercury compounds and determined atmospheric mercury concentrations at several sites in Brazil including the basin of the Amazon tributaries. The mean concentration of total mercury was between 9.1 and 14.0 ng/m3 in the basin of the Uatumã River located in the tropical rain forest far from goldmining sites and from urbanized area. These mercury levels exceeded the background level previously reported in rural area and, furthermore, were higher than concentrations observed in Rio de Janeiro and in Manaus that were compatible with the reference values for urban area. Mercury concentrations were also determined in gold refineries in the basin of the Tapajos River, and detected at a significant but not a health deteriorating level. Although only preliminary data were available, the present observations were in favor of the hypothesis that mercury is distributed widely by long distant transport by the atmospheric circulation after released at gold mining sites.

Concentration of fallout plutonium in tissues of Japanese who died during 1980-1984

The concentrations of fallout 239 + 240Pu in various body tissues of subjects who were born before 1941 and who died in Akita and Niigata Prefectures in Japan during 1980-1984 are reported. The median concentrations in vertebrae, sternum, liver, lung, spleen, and kidney were 0.21, 0.08, 0.62, 0.11, 0.08, 0.03 pCi/kg wet weight, respectively. The concentration levels in vertebrae were approximately three times higher than in the sternum. No significant correlation between the concentration in the various tissues and age at the time of death was observed. No differences in the concentration levels in liver and lung were observed between the sexes. Correlation between the concentration in liver and that in lung was not significant. The concentration in liver was similar to that estimated from the ICRP 30 model. However, the concentration in lung was considerably higher than the estimated value. This difference may be caused by the pulmonary lymph nodes contained in the present lung samples. To obtain the average concentration of plutonium in the entire skeleton, further information regarding the macrodistribution of plutonium is required.

The tissue distribution of 2,3,7,8-chlorine substituted dibenzo-p-dioxins in humans who died of cancer

The tissue distribution of 2,3,7,8-chlorine substituted dibenzo-p-dioxins was conducted in 11 patients who died of cancer. The concentration of octachlorodibenzo-p-dioxin (octa-CDD) was the highest in each organ and tissue and hepta-CDD was also found at relatively high levels, second only to OCDD. The levels of 1,2,3, 7,8-penta-CDD and 1,2,3,6,7,8-hexa-CDD in the spleen were the highest, respectively. 2,3,7,8-Tetra-CDD was also detected and its concentration was the highest in the gonad (0.8-3.2 pg/g-range). From the 2,3,7,8-TCDD toxic equivalent calculations, the highest equivalent value was obtained from a 54-year-old female who died of cancerous goiter. This individual had the highest concentrations of 2,3,7,8-substituted penta- and hexa-CDDs among the 11 patients.