The mechanism of cadmium absorption was studied in vitro using sacs of the small intestine of the rat. The relation between the concentration of cadmium in the mucosal fluid and the rate of transport of ¹⁰⁹Cd to the serosal fluid showed that the higher the concentration of cadmium, the greater was the transfer of ¹⁰⁹Cd. Wall uptake of ¹⁰⁹Cd was limited and could be saturated at relatively low concentrations.
It was suggested that a special mechanism is concerned in the absorption of cadmium, because there was no linear relation between the initial concentration of cadmium and the rate of transport across the intestinal wall.

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The absorption rate of cadmium orally administered in a single dose to rats, and the sites in the digestive canal primarily concerned in absorbing cadmium were studied. The following results were obtained:
(1) When ¹⁰⁹CdCl₂ was orally administered in a single dose to rats, the average absorption rate of cadmium 24hrs after administration was 1.92% (range, 0.99 to 3.33%).
(2) The transported amounts of cadmium from the mucosal to the serosal fluid in the simple everted sac method were highest in the small intestine and lowest in the stomach.
(3) Cadmium absorption was characteristically uniform throughout the small intestine.

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The absorption rate of ¹⁰⁹Cd administered to mice previously treated continuously with cadmium for 3, 8, 16, and 32 days.
The results were
(1) The 32-day group was the only one that showed a significant decrease in the absorption rate as compared to the control group.
(2) The uptake of ¹⁰⁹Cd in the mucosal epithelium of the small intestine of the 32-day group was significantly lower than that of the control group.
(3) Animals exposed for 16 and 32 days showed significant decrease in the average count of ¹⁰⁹Cd per gram of kidney when compared to the control animals.
(4) The 32-day group was the only group with a significant increase in its excretion rate when compared to the control group.

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Many reports have revealed that the prevalent rate of bronchial asthma among schoolchildren, as well as among aged residents, is closely related to the degree of regional air pollution in Japan. Recent findings of epidemiological, clinical, and immuno-pathological studies have demonstrated the close relationship between bronchial asthma and recurrent respiratory infection, which is regarded as a precursor of childhood asthma. To prevent these diseases in childhood and to improve health conditions, it is necessary to investigate precisely the association of these health hazards in airpolluted districts.
We obtained 5, 283 schoolchildren's respiratory symptoms in three air-polluted districts by means of questionnaires. Five hundred and fifty three of these children were tested clinically for bronchial asthma. We also investigated the influence of the housing environments on asthmatics in a highly polluted district.
The results are as follow:
1. Subjective symptoms of a higher specificity rate in those diagnosed as asthmatics are wheezing with orthopnea in the past 2 years, diagnosed as asthmatic by a doctor in the past, and wheezing with orthopnea in the past 2 years, In contrast, those of a higher sensitivity rate are wheezing only in the past 2 years, and wheezing with slight dyspnea in the past 2 years.
2. Asthmatic children have various complaints of the upper-and lower-respiratory tract, such as cough, phlegm, breathlessness, recurrent respiratory infection, and nasal trouble. In a comparison of sex-and school year-matched groups, a close relationship was found between bronchial asthma and recurrent respiratory infection or the so-called “frequent colds”.
3. Case-control studies reveale the influence of dwellings and environment on asthmatic children. A retrospective study showed that their influence was not remarkable in the years of high-grade air pollution, but a follow-up study from 1976 to 1977 showed a major influence with lower-grade air pollution. Dwellings and their environment has been shown to be an indicator of the socio-economical situation of each house hold by many other authors. As air pollution these days is becoming less concentrated but widespread in Japan, it must be noticed that the health of the children in industrial districts is influenced by many socio-economical factors as well as by air pollution, itself.

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To estimate environmental assimilation to the tropical climate for Okinawan residents, a comparative study was made on the hunting reactions of native Okinawans and immigrants from the mainland of Japan. Twenty-eight healthy immigrating subjects and 26 Okinawan controls were used for this study. The hunting reactions were performed twice in different periods under extreme climatic conditions, and measurements were made for pairs of an Okinawan and an immigrating subject. For ordinary procedures, the thermister was applied to the dorsal surface of the right middle finger, and continuous recording of local skin temperatures was followed for five minutes until they stabilized, then the finger was immersed in 0°C water, and the temperature fluctuation was recorded for 30 minutes on an EH-300 continuous temperature recorder. Through the data obtained, each component of the hunting reaction was calculated by Nakamura's method as the mean skin temperature (M.S.T.), the temperature at the first rise (T.F.R.), the time by the rise in temperature (T.T.R.), the amplitude of the temperature reaction (A.T.) and the resistance index (R.I.).
For the M.S.T., differences were greater for the immigrants than for the Okinawans throughout these two experiments: the mean values of the summer experiment particularly were higher than those of the winter experiment for each group. High T.F.R. levels existed for Okinawans in both experiments. Higher levels were maintained in the summer experiment than in the winter experiment for both groups. Retardation of T.T.R. existed for Okinawans, but the time was shorter in the summer experiment for both groups. For the A. T., the immigrants had high levels in both experiments, but they were more prominent in the winter experiment. The reverse effect was found for Okinawans with higher values in the summer experiment. The resistance index was dominant for the immigrants in both experiments. Cummulative results also showed the same tendency with the significant difference between them. Although the results of the hunting reactions altered with environmental temperatures according to seasonal changes, almost all the data were more dominant for the immigrants than for the Okinawans.
Evaluation of the correlations between the years of residence of the immigrants and the change in each component of the hunting reaction showed significant correlation for the M.S.T., T.F.R. and R.I. in the summer experiment, but no correlation was found between in the winter experiment. Observations of immigrants with up to four years of residence did not confirm that the mainland group showed improved assimilation to the tropical climate of Okinawa.

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The study coverd 45 Itai-itai disease patients, 71 suspected patients and 81 inhabitants in three cadmium-polluted areas.
These people were considered to be heavily damaged by cadmium.
The reference group was comprised of 82 inhabitants in nonpolluted areas.
Spot urine samples were collected and analysed for specific gravity, creatinine, amino-N, proline, total protein, glucose, calcium, phosphorous, cadmium, β₂-microglobulin, retinol binding, protein and lysozyme.
Itai-itai disease patients had high excretions of total protein, glucose, amino-N, proline, calcium, cadmium and low-molecular weight protein (β₂-m., R.B.P. and lysozyme). The Ca/P ratio in urine was highest in patients with Itai-itai disease.
There were no significant differences in the urinary findings between Itai-itai disease patients and suspected patients.
The inhabitants in the three cadmium-polluted areas showed the same abnormal tendency for urinary findings as did the patients with Itai-itai disease.
We concluded that the abnormal urinary findings of Itai-itai disease patients are common among the inhabitants of cadmium-polluted areas and give an advanced picture of chronic cadmium poisoning.

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The study covered 40 Itai-itai disease patients, 61 suspected patients and 9 inhabitants of Tsushima Island. These people were considered to be heavily damaged by cadmium. The reference group was comprised of 27 inhabitants in a nonpoulluted area.
Blood specimens were collected from the people and examined biochemically.
Itai-itai disease patients showed low levels of plasma inorganic phosphorous, potassium, total protein and uric acid. They also showed high levels of sodium, chloride, GOT, alkaline phosphatase, LDH, BUN and creatinine.
No significant differences in the blood findings, except for alkaline phosphatase and total protein, were observed between the patients with Itai-itai disease and suspected patients.
The inhabitants of Tsushima Island showed the same abnormal tendency for blood findings as did the Itai-itai disease patients.
We concluded that the abnormal blood findings of Itai-itai disease patients were common among inhabitants of cadmium-polluted areas and that they give an advanced picture of chronic cadmium poisoning.

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This paper presents data on 27 anthropometric measurements of 310 single, matured newborn infants (160 males, 150 females) and their placental weight. They were obtained from July 1975 to June 1976 at a maternity hospital in Tokyo.
Variables of the measurements are given in table 1.
The mean, standard deviation and coefficient of variation for each variable were caluculated and the correlation coeficient matrix was composed. These data were applied to a principal components analysis.
Results:
1) The mean, S. D. and C. V. on 28 variables are given in table 2.
2) Correlation coefficients between birth weight and placental weight are 0.369 in males and 0.497 in females.
3) Cephalic indices are 82.99±4.58 in males and 83.34±4.34 in females.
4) The correlation coefficient matrix among the 28 variables of newborn infants are given in table 3 (males lower left, females upper right). The highest correlation coefficients are 0.728 in males and 0.670 in females, and both are between girth of the upper arm and girth of the forearm.
5) The eigenvalues more than 1.0 are up to the ninth principal component in both sexes. Their cumulative contributions are 68.2% in males and 66.0% in females.
6) The first principal component accounts for the size factor.
7) The second principal component explains the shape factor.

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Dibutyl phthalate (DBP) and Diethyl hexyl phthalate (DEHP) are widely used as plasticizers of poly vinyl chloride, but then health effects have been worried recently through the environmental pollution by phthalate esters (PAE) has caused about their effects on health.
Quick, simple and convenient methods for measuring quantitatively the concentration of DBP and DEHP in various materials were established with Gas chromatography-mass spectrometry. In this report, experimental results on the absorption, decrease, accumulation and metabolism of DBP and DEHP in mice are summarized, and the accumulation rate in gold-fish and decomposition rate in bacteria of these compounds are also reported.
Both DBP and DEHP were widely detected in environmental materials (human blood, mother's milk, fish, processed foods, fruit, leaves, river water and sediments), but the levels of concentration were very low. However, the concentration of DBP and DEHP was high in the leaves of a tree on the mountain. It was suggested that PAE is produced naturally by plants.
In mice, the gastrointestinal absorption rates of DBP and DEHP were very low. In mice administered DBP intraperitoneally the amounts decreased to less than 2% within 24 hours. The speed of decreased for DEHP was slower than for DBP, nor was DEHP accumulated within 49 days when administered orally to mice.
Phthalic acid was detected in the urine of mice intravenously administered DBP and was identified as the metabolite. DBP and DEHP were easily metabolized by dispersed liver tissues of mice. Mono butyl phthalate, mono ethyl phthalate and phthalic acid were detected in dipersed liver tissues and identified as the metabolites of DBP. Gold-fish kept in water containing DBP and DEHP for 2 weeks did not accumulate these compounds. Both DBP and DEHP were easily decomposed by the bacteria.
No accumulation of PAE was found like that of methylmercury and PCB in the environment. This compound thus dose not appear to affect human health through environmental pollution.

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The residualibility of following five chemical products in mammals: 2, 6-di-tert-butyl hydroxy toluene (BHT), para-Dichlorobenzene (DCB), 1, 3, 5-Trichlorobenzene (TCB), Hexachlorobenzene (HCB) and 2, 2', 3, 3'-Tetrachloro diamino diphenyl methane (TCDAM) is reported. These substances are easily accumulated in fish, and are difficult for bacteria to decompose. The experimental results of the absorption, decrease and accumulation rates in mice are reported.
Quick, simple and convenient methods of measuring samples from living bodies were established with Gas chromatography and Gas chromatography-mass spectrometry.
The gastrointestinal absorption rate of BHT was very low (2.0±0.2%). BHT decreased to 27±3.0% of the dose within 24 hours, and its accumulation rate was about 0.02% of the total dose. There was no difference in the accumulation rate of BHT between mice administered a fish-meal diet of BHT accumulated in gold-fish and others given a diet with BHT added directly.
The absorption rates of DCB and TCB were, respectively 11±2.9% and 50±7.8%. But both decrease rates were very fast. Neither DCB nor TCB accumulated within 35 days when orally administered to mice.
The gastrointestinal absorption rate of HCB was 38±3.3% and decrease rate was slower than the rates for DCB and TCB. The amounts accumulated agreed with the theoretical values.
The absorption rate of TCDAM was 8.0±1.7% and its decrease rate was rapid. No TCDAM was accumulated when orally administered to mice.
These five chemical products were difficult for bacteria to decompose, and they were easily accumulated in fish. However, some products were easily metabolized and were not accumulated in mammals. When discussing the effects of these chemical products on health, it is necessary to understand the accumulation factor in mammals.

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