Forthcoming global environmental changes threaten to endanger human survival through direct and indirect influences. In this paper, the contemporary world food supply situation and resultant nutritional status was first reviewed on by country and region. When compared with the nutritional energy requirement, countries with an inadequate food supply were concentrated in the developing world, in particular in some parts of Africa. The life expectancy at birth is clearly shorter in such countries, and peoples of African countries with an inadequate food supply have shorter life expectancies than other countries with a similar inadequacy.
Global warming is likely to decrease food production in some parts of the world. According to the present estimation using various methods, a future crisis of food production may occur in African countries which are at present most vulnerable to food shortages, as well as in countries which are presently food exporters. Thus, a future crisis of human health conditions caused by the imbalance of food production and trade may be least avoidable in the region of present predicament.

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We carried out this investigation to elucidate the effect of calcium (Ca) deficiency (Ca(-)) on aluminum (Al) accumulation in tissues of rats treated by oral Al administration.
Thirty-two four-week-old rats (65g) were divided into two groups; a normal (N) diet group and a Ca(-) diet group. The N diet group was fed the N diet for 45 consecutive days, and then divided into four groups. Group (G)-1 rats were fed normal diet (N) for 9 days, G-2, G-3 and G-4 rats were fed an Al-overloaded N diet (1mg Al/g diet) for 3, 6 or 9 days, respectively. The Ca(-) diet group was fed Ca(-) diet for 45 consecutive days, and then divided into four groups. G-5 rats were fed the Ca(-) diet for 9 consecutive days, G-6, G-7 and G8 rats were fed an Al-overloaded Ca(-) diet for 3, 6 or 9 days.
We studied the accumulation of Al in Ca- deficient rats fed Al (Ca(-)+Al) for 3, 6, and 9 days, comparing that of the normal- diet rats fed Al (N+Al) for the same period.
The Al concentration in the small intestine increased on the third day after Al, and then decreased to the normal level on the 6th day in both N+Al and Ca(-)+Al rats. However, that of the Ca(-)+Al rats increased significantly compared to N+Al rats on the 9th day.
Al secretion of Ca(-)+Al rats per day was significantly higher than that of N+Al rats on the 9th day.
We observed a significant increment in parathyroid hormone (PTH) in all of the Ca(-) diet rats, approximately 5-7 times higher than the N-diet rats used in this experiment.
These data suggested that a nonpermeable barrier existed in the intestine of N+Al rats, and the significant increment of gastrointestinal absorption in the Ca(-)+Al rats was affected by PTH due to Ca deficiency.
On the other hand, it was observed that the Al concentration in the brain of Ca(-)+Al rats did not increase even on the 9th day. However, changes of Al concentration had the same tendency seen in Al concentration in the intestine, showing a single peak at the third day. It was indicated that it is necessary to investigate the relationship between gastrointestinal absorption of Al and accumulation in the brain when rats are fed Al for longer periods.

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The mercury concentration in red blood cells (RBCs) is one of the most useful indicators for people exposed to methylmercury. Sex- and age-related differences in mercury concentrations in red blood cells were studied by considering fish consumption in 1, 253 adults (511 males and 742 females) participating in a mass health examination conducted in a town of Kumamoto Prefecture in 1989.
The results were as follows:
1. The mercury concentrations in RBCs showed lognormal distributions for both sexes with a higher mode in males than in females. The geometric mean of the mercury concentrations in the RBCs was 28.5ng/g (ranging from 5.6 to 71.0ng/g) for males and 20.4ng/g (ranging from 3.7 to 70.4ng/g) for females and was significantly higher in males than in females. The mercury concentrations in RBCs decreased with aging for both sexes.
2. The mercury concentrations in RBCs significantly increased with the amount of fish consumption for both sexes. The mercury concentrations in RBCs were significantly higher in drinkers than in non-drinkers for males and the concentrations increased significantly with body weight for females.
3. The mercury concentrations in RBCs were higher in males than in females and decreased with aging for both sexes under conditions of a constant level of fish consumption.
4. In couples who consumed same amount of fish, the mercury concentrations in RBCs were significantly higher in husbands than in wives.
These results suggest that the mercury concentrations in RBCs are higher in males than in females and decrease with aging under a constant level of fish consumption.

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To investigate the effect of Cu deficiency on the distribution of metals in organs when Cd was administered, 8-week-old female rats of the SD strain were fed a Cu-deficient diet (0.5ppm Cu)or a basal diet (3.5ppm Cu) and given 50 oral doses of 200μg/rat of Cd. Then, the concentrations of Cd, Zn, Cu, Fe, Ca, Mn and Mg in each tissue were determined.
In the Cu-deficient state, the serum Cu concentration was decreased and it was further decreased by Cd administration to about 1/4 of the normal value. The accumulation of Cd in the liver and kidney was increased by Cu deficiency. Cu deficiency caused decreases in the Cu concentration of the liver, kidney, brain, lung and pancreas. The administration of Cd caused additional remarkable decreases in the Cu concentration in the blood as well as in the hematopoietic organs, such as liver and spleen. Fe was increased by the Cu deficiency in the brain, heart, pancreas and muscle, though this increase was inhibited by Cd administration. The changes in tissue Fe were more greatly affected by Cd administration than by Cu deficiency. The Zn concentration was increased in the liver and kidney by Cd administration but was not affected by Cu deficiency. Mn, Ca and Mg concentrations showed no changes caused by Cu deficiency or Cd administration.

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The effects of traffic noise on sleep were evaluated in an experimental room using recorded truck-passing sounds. Peak sound levels were 45, 50, 55dB (A) at a frequency of one per hour. The background noise of the exposure night was Leq 32.4dB (A). The subjects were five male students 22 to 23 years old. The sleep stage of each epoch with a 20-second duration was judged visually based on the criteria of a standardized sleep EEG atlas. Data for 10 noise-exposed nights and the same number of control nights were analyzed excluding the first-night data. The sleep parameters used were total sleep time (TST), each sleep stage in minutes, % of sleep stage against TST, sleep efficiency, sleep latency, REM latency, REM cycle, REM duration, waking from sleep, number of stage shifts and subjective sleep as judged by the OSA sleep inventory. The Mann-Whitney test was used for statistical analysis.
TST, each sleep stage in minutes, % of sleep stage against TST, sleep efficiency, sleep latency, REM latency, REM cycle, REM duration, waking from sleep and the number of stage shifts of the exposure night did not significantly change compared to those of the control night. However, the sleep latency of the noise-exposed night increased significantly. Subjective sleep measured by five-factor scores and 8 items out of 29 constructing the five-factor scores of the OSA sleep inventory were decreased significantly by noise exposure, indicating deterioration of sleep quality.
Exposure to intermittent truck-passing sounds 20 to 30 times per night with peak levels of 45, 50 and 55dB (A), and a background noise of Leq 32.4dB (A), caused the sensitivity to sleep disturbance in subjective sleep to be higher than those in objective sleep parameters.

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Appropriate dietary instruction on fat intake is required for Japanese to prevent coronary heart disease because there has been a consistent increase in fat intake during the past two decades. To gain fundamental information for dietary instruction, we examined the relation between dietary habits related to fat and serum fatty acid compositions in women aged 40-69 of four Japanese populations (fishing, coastal farming, inland farming and urban populations) and a Caucasian population in which different dietary habits have been reported.
Among Japanese, dietary intake of monounsaturated and polyunsaturated fatty acids (in particular ω6-polyunsaturated fatty acid) were higher in the urban population than in the other populations. Intake of ω3-polyunsaturated fatty acids did not vary among the Japanese populations, but intakes of eicosapentaenoic acid and docosahexaenoic acid were higher in fishing and coastal farming populations than in the other two populations.
Serum concentrations and compositions of ω6-polyunsaturated fatty acids (mostly linoleic acid) were higher in the urban and inland farming populations than in the other two populations whereas those of ω3-polyunsaturated fatty acids (in particular eicosapentaenoic acid) showed the opposite trend. The proportion of ω6-polyunsaturated fatty acids was higher and that of ω3-polyunsaturated fatty acids was lower in Caucasian women than in the Japanese populations.
The ratio of ω3 (polyunsaturated fatty acids) to ω6 was highest in the fishing population (ratio=0.38), intermediate in coastal farming (0.35), urban (0.27) and inland farming (0.24) populations, and lowest in Caucasians (0.07).
Within populations, the percentage of serum ω6-polyunsaturated fatty acids increased with the increase of frequency of meat intake and oil intake. The percentage of serum ω3-polyunsaturated fatty acids increased with the increase in frequency of fish intake.
Because there are evident associations between the frequency of fish, meat and oil intake and serum fatty acid compositions, a frequency questionnaire on these foods would be useful for dietary instruction in the prevention of coronary heart disease.

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Various organophosphorus compounds with low acute toxicity levels are widely used as insecticides. Human acute poisoning by organophosphates has often occured accidentally. We determined the activity and isoenzyme patterns of serum cholinesterase (ChE) obtained from 13 human patients who attempted suicide with various organophosphates, i. e. Fenitrothion, Malathion, Isoxathion, Pyridaphenthion and Trichlorfon, and studied on the changes in the activity and isoenzyme patterns of serum ChE after ingestion. The following results were obtained.
1) Twenty ChE isoenzyme bands from normal human serum were detected by electrophoretic separation on polyacrylamide gradient gel. The main bands in the ChE isoenzyme pattern in normal serum were bands 4 and 5 which had the highest activity of acetylcholinesterase (AChE) with a molecular weight of 600, 000-800, 000, and bands 7, 12, 14, 17 and 18.
2) Inhibition of serum ChE activity was more severe as the amount ingested increased in patients who took Fenitrothion and Malathion. Reactivation of serum ChE activity was very slow in patients treated with PAM (2-pyridine aldoxime methiodide) in the late stage of ingestion or whose symptoms reappeared.
3) There were no differences in the patterns of serum ChE isoenzyme by organophosphorus compound. Band 7 disappeared in the serum ChE isoenzyme of almost every patient, and bands 12, 18, 14 and 17 of the serum ChE isoenzyme disappeared successively with the decline of serum ChE activity. Only band 5 of the isoenzyme remained in cases who had serum ChE activity lower than 5% of normal.
4) All 13 patients were treated with PAM and atropine immediately after being admitted to hospitals. We could not clearly determine the efficacy of PAM on reactivation of serum ChE activity and isoenzyme, because it was impossible in human poisoning to compare PAM efficacy with no treatment and with pre- and post- PAM treatment.
5) The activity and isoenzyme patterns of serum ChE recovered rapidly after combined hemoperfusion and hemodialysis treatment (HP-HD treatment) of the patients poisoned with Malathion. But HP-HD treatment had no effect on poisoning by Fenitrothion and Isoxathion.
These findings demonstrated the changes in the activity and isoenzyme pattern of serum ChE in patients poisoned with several organophosphates after PAM and HP-HD treatment.

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Carotid sonography were conducted in people of one community (122 males and 243 females) in 1990 and 1991, The intima-media thickness (IMT) in the main trunk and bifurcation-bulb areas of bilateral carotid arteries were measured in 122 males. IMTs of four areas increased with aging. In all cases, the average IMT of the right main trunk was 0.8±0.1mm (mean±SD) and those of the remaining three areas were 0.9±0.2mm. The IMT of the right bifurcation area in males aged 75 years or older was the thickest; i. e., 1.1±0.3mm. Therefore, atherosclerotic lesions (AL) were defined as an IMT of 1.5mm or more.
The incidence of AL increased along with aging both in males and females. In those who were less than 65 years old, the incidence in males was 12.8% (10/78) and that in females was 9.0% (12/134). In those who were 65 years old or older, the incidence in males was 31.8% (14/44) and that in females was 26.9% (29/109). The incidence of AL tended to increase rapidly from 65 years of age in both males and females. Moreover, the incidence of AL in bilateral carotid arteries increased along with aging as well.
Since IMT, the incidence of AL and that of AL in bilateral carotid arteries increased with aging, we considered that these parameters could be used as indices of the degree of general atherosclerosis.

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Paraquat removal by chitosan with different substituents was investigated in vitro for evaluation of chitosan as a paraquat adsorbent in emergency treatment for acute paraquat poisoning.
Chitosan CM and SU, in which the hydroxyl group at the C₆ position is replaced by a carboxymethyl and sulfonic group, respectively, removed paraquat abundantly in purified water. However an inhibitory effect of sodium chloride on paraquat removal by CM and SU was recognized.
On the other hand, paraquat removal by cross-linked chitosan (BCW) was accelerated in saline solutions. It was recognized that more paraquat was removed by BCW chitosan when the sodium chloride concentration was less than 1.8%.
It was confirmed that some chitosan beads (CM and SU) could function as effective paraquat adsorbents through in vitro experiments.

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To clarify lead exposure and factors relevant to it, an occupational health survey and air lead-concentration survey were conducted among 425 workers in the ceramics industry in the Seto region in Aichi Prefecture. As for biological monitoring, blood lead level was measured according to sex, job, product, factory size and duration of lead exposure. The following major findings were obtained in the present analysis. Workers making dolomite novelties showed higher blood lead levels than those making porcelain novelties, semi-porcelain novelties and tableware. The difference in blood lead level by job was statistically significant, but not that by factory size. In males, the highest blood lead level was found for spray painting work (28.7μg/dl), followed by glazing work (28.0μg/dl), kiln work (23.3μg/dl) and painting work (22.3μg/dl). In females, the blood lead level for painting work (13.5μg/dl) was lower than those for glazing work (26.1μg/dl) and kiln work (31.4μg/dl). The blood lead level was significantly increased with the number of years of lead exposure in females (painting work). It was coincidentally clarified that the environmental lead concentration varied according to the job in which workers were engaged. As protective measures against lead exposure for workers in the ceramics industry, the development of nonlead paint and glaze and the introduction of more effective dust collectors at the workplace should be established.

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To clarify the alteration of serum immunoglobulin levels with age, serum immunoglobulin and other parameters (age, symptoms, blood biochemical parameters, etc.) of inhabitants (213 persons; 63 men, 150 women) of a remote island in Shimane Prefecture were studied. Their subjective symptoms were collected by means of a questionnaire and various blood parameters were measured. These data were analyzed by t-test and multivariate analysis. The IgM level was decreased with age and each immunoglobulin level correlated with the total-protein level in serum. The IgG level of the subjects feeling fatigue was higher than that of the subjects not feeling fatigue.

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The interaction of trichloroethylene (TCEL) and isopropyl alcohol (IPA) was studied in the perfused rat liver. Experiments consisted of four parts; TCEL administration with or without IPA, chloral hydrate (CH) administration with or without IPA, IPA administration with or without CH, IPA administration with or without trichloroethanol (TCE). The chemicals were administered into the perfusate of Krebs-Henseleit buffer saturated with 95%O₂/5%CO₂ in a non-recirculating circuit. Concentrations of the following three metabolites in the effluent were continuously measured by gas chromatograph and chemical methods: TCE and trichloroacetate (TCA) (metabolites of TCEL and CH), and acetone (a metabolite of IPA). Fluorescence from intracellular reduced pyridine nucleotides (NADH, NADPH) was monitored by surface fluorometry. The results showed that IPA changed the TCA/TCE ratio in the TCEL metabolism because of an increase in NADH production, and IPA oxidation was suppressed by CH because of an inhibitory effect of TCE on alcohol dehydrogenase. It was concluded that IPA and TCEL, both ubiquitous agents, interacted with each other in their metabolic pathways in the perfused rat liver, suggesting a new feature of a combined effect of these chemicals when they coexist.

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