The gastrointestinal absorption of cadmium (Cd) in humans and animals was reviewed from the following viewpoints. 1) Various experimental techniques of gastrointestinal absorption. 2) The extent of gastrointestinal absorption of Cd after single and continuous oral doses of Cd. 3) The sites and mechanism of gastrointestinal absorption of Cd. 4) The effects of nutritional factors such as proteins, fibers, amino acids, organic acids, chelating agents, essential trace elements, vitamins and milk, on the intestinal absorption of Cd. 5) The effects of physiological factors such as age, sex, gestation and lactation, and the other factors on the intestinal absorption of Cd. 6) Morphological changes of gastrointestinal mucosa.

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^<14>C (U)-carbazole was orally administrated to female rats, and the distribution of ¹⁴C in organs and tissues and the excretion were examined. The mutagenicity of carbazole was tested by spore rec-assay with B. subtilis and by Ames test with S. typhimurium TA 100 and TA 98. In 24h, 70% of ¹⁴C-carbazole was excreted in the urine and the rest (33%) in the feces. Most of the metabolite of carbazole was conjugated and existed as hydroxy-carbazole. Intaked ¹⁴C was mainly distributed into blood, kidney and liver in the early stage. The same trend was shown until 24 h after the administration, although the concentration gradually decreased. From these results of distribution, Biological Half Life (BHL) was calculated as follows, liver (13.7 h), adrenal (12.4 h), thyroid (12 h) and brain (11.5 h). The ¹⁴C concentration in gastrointestinal tract decreased to less than 1% in 24 h and small discharge to bile was observed. The mutagenicity was not detected by rec-assay nor by Ames test.

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A simple and rapid analysis of polynuclear aromatic hydrocarbons (PAHs) in soil and sediment by high performance liquid chromatography (HPLC) was investigated. The following method was used for the analysis ; soil and dried sediment samples were sieved through a screen (32 mesh) for removing large particles. PAHs in the soil and sediment samples were extracted with 4 ml of acetonitrile for 15 minutes by using a ultrasonic apparatus, and then PAHs in the supernatant was separated and determined by HPLC [guard column : (35 mm×4.0 mm, i. d.) and analytical column (250 mm×4.0 mm, i. d.) packed with LiChrosorb RP 18 (5 μm), mobile phase : acetonitrile-water (9 : 1, v/v), flow rate : 1.5 ml/min] with UV and fluorescence detectors. This method was applied to the analysis of PAHs in soil and sediment and eleven PAHs were identified. Recovery rates of PAHs from soil and sediment were 101.0% and 99.1% for benzo (a) pyrene (BaP), 98.8% and 99.4% for perylene, and 102.5% and 98.2% for benzo (k) fluoranthene (BkF), respectively. An apparent correlation was found between particle size of soil and distribution rate of BaP and perylene. The BaP contents in soil decreased with increasing the depth from the surface. PAH contents in soils sampled at the road sides of Kitakyushu high way in March 1983 were ranged from 13.9 to 175 ppb for BaP, 11.7-171 ppb for BkF, 3.5-76.4 ppb for perylene and 20.8-273 ppb for benzo (ghi)-perylene. BaP contents in soils sampled from the road side in Orio area were 656-1630 ppb. PAH contents in sediment which were sampled in Onga river in October 1983 were ranged from 6.4 to 82.9 ppb for BaP, 2.8-38.3 ppb for BkF and 2.7-27.2 ppb for perylene. BaP contents in sediments obtained from the polluted area of Wakamatsu harber were 1150 ppb and 12400 ppb. In this method several kinds of PAHs in soil and sediment including carcinogenic BaP can be analysed easily.

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A new and simple method is presented for simultaneously determining the preservatives in foodstuffs, such as benzoic acid, sorbic acid, and ethyl, isopropyl, propyl, isobutyl, and butyl esters of p-hydroxybenzoic acid. This method is characterized by the achievement of ethanol extraction and clean-up of the extract at a single step. The target compounds were determined by high-performance liquid chromatography. The sample was homogenized with ethanol, and the extract was injected onto a reverse-phase colume (ODS packing) with a mixture of methanol-0.4 M acetate buffer, pH 4.6 (45 : 55) as the mobile phase. The effluent was monitored with a UV detector at a wavelength of 240 nm. The preservatives in complicated matrices such as fermented foods have been determined with recoveries of more than 95%.

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Wet digestion in a microwave oven for rapid determination of total arsenic was examined. Organic matter in samples was digested very rapidly in comparison with other heating methods. We then investigated Hirayama's method, in which nickel is added to samples to prevent loss of arsenic due to volatilization, and confirmed the effectiveness of nickel ion. Thus loss, of arsenic during wet digestion can be prevented by addition of nickel and by shortening the digestion time by the use of a microwave oven. By this method, arsenic contents in various foods could be determined with a recovery of 85.9-104% and a coefficient of variation of 1.8-5.7%. This microwave oven-digestion (MOD) method might also be applicable to the determination of other metals in foods.

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The presumptive test of water-borne coliform bacteria by use of desoxycholate agar and violet red bile agar were reviewed experimentally by the procedures indicated in the Standard Methods of Analysis, authorized by the Pharmaceutical Society of Japan. According to the results obtained on 5 kinds of known strains of coliform bacteria and many samples of sewage and sea water, the authors proposed the criteria for detecting coliform bacteria as shown below ; After incubation at 34-36°C for 18-22h on desoxycholate agar, typical colonies appear as round, rice grain like or oval, more than 1 mm in diameter, presenting the color of 1 R 4/14, vivid purplish red ; 1 R 3/10, deep purplish red ; 4 R 3.5/10, deep red or 6 RP 4/13.5, vivid red purple, comparing with the color-standards specified in Japanese Industrial Standard. After incubation at 34-36°C for 18-22h on violet red bile agar, typical colonies appear as round or oval, more than 1 mm in diameter, presenting the color of 1 RP 4/13, vivid red purple or 7.5 P 2.4/8, deep purple

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Photometric ion chromatography is a novel method by using the photometer as a detector. A feature of this method is the use of light absorbing ion in the mobil phase, and the appearance of transparent sample ion in the effluent is detected by "trough"in the base line absorbance. We applied this technique by using a conventional HPLC system equipped with a commercially available ion exchange separation column to the determination of bromate in such foodstuffs as bread and kamaboko. Sample solution was prepared by aqueous extraction and mixed with acetone for removal of proteins. After evaporation of the organic solvent, the aqueous solution was dechlorinated by a DOWEX column (Ag-form), and then was subjected to chromatography. Samples of bread and kamaboko were spiked with 5.4 ppm and 8.4 ppm of bromate, respectively, and examined by the above method. The average recoveries were 88.3% in bread and 82.9% in kamaboko, and the coefficients of variation were 7.7% and 7.9%, respectively. The detection limit was 1 ppm. The above findings indicate that bromate can be detected by HPLC using conventional instrumentation, and the sensitivity of this system is comparable to conductimetric detection.

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Valuable data for extraneous material in food, additives (e. g. plasticizer) in marketed plastic products and characterization of marketed plastic products were simply offered by direct inlet mass spectrometry (DI-MS) without any pretreatments. DI-MS conditions : (a typical example) EI 20 eV, scan duration 4 sec., scan range m/z 10-500, DI-temp. ; 100°C/0-75 scan, 100-400°C/75-105 scan, 400°C/105-200 scan Sample size was appropriate weight less than 0.5 mg. Data acquiring range : Data of extraneous material in food were given from all range of scan. Data for the additive in marketed plastic product were offered from 0-105 scan range, whereas an information on characterization of marketed plastic product was shown in 105-200 scan range.

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The persistent organochlorines such as PCBs, DDT compounds and HCH (BHC) isomers were detectable all over the environmental media and biota, in which much higher levels were found in agricultural soil, coastal sediment and biological samples due to their hydrophobic, lipophilic and less biodegradable properties. These pollutants extend the boundaries of distribution over the global environment, being evidenced by their occurrence in Antarctic atmosphere, hydrosphere and biosphere. In open ocean environment, organochlorine contamination is much more prominent in northern hemisphere than in southern hemisphere. The open ocean water serves as a vast reservoir and final sink of these persistent organochlorines. The clearance rate of these chemicals from surface to deeper layer in open ocean water columns is relatively slower in tropical waters than in high latitude ones. This implies the possible prolonged contamination of persistent organochlorines in the tropical marine environment, even if their uses would be stopped in the future. The bioaccumulation processes in marine organisms depend primarily on the physicochemical and biochemical properties of organochlorines and the metabolic capacity and life-span of organisms. The species-specific drug metabolizing enzymes might be related to the differencial ecotoxicity of xenobiotics in wild animals. Of these organochlorines, PCBs are most noticeable chemicals in view of the future trend of environmental contamination. About two thirds of cummulative production of PCBs are still in use mainly for electrical equipments. The pertinent measures to prevent the further discharge of PCBs are required to reduce the present status of contamination in abiotic and biotic environment.

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In this study, it was clarified that transition and correlation of organochlorinated compounds, which were used until the early part of 1970 in our country, in food stuffs and human milk. In addition, a difference between "Kanemi Yusho"and other PCB exposures was explained by use of analytical and toxicological data. (1) Through hygienic institutes in our whole country, residual levels of HCH and DDT in vegetables, fruites and dairy foods were recognized to decrease rapidly year by year. The contamination routes of human bodies by them, as well as PCBs, through food chains was clarified to change from rice and dairy foods at those days of their usage to mainly fish and sellfish today, through total diet studies of these few years. (2) In analytical data of human milk in Osaka for 10 years since 1972, on the decrease of residual levels in foods, the levels of β-HCH and dieldrin in human milk decreased sharply, whereas those of p, p'-DDE and PCB were constant or decreased slightly. On the other hand, chlordane is used today and the contamination residue of them except heptachlor epoxide have been increasing. (3) From analytical data of the blood from mothers and their children or mouse experiments, organochlorinated compounds were revealed to be mainly transferred from mother to children through milk rather than placenta. (4) Analytical data of "Yusho"patients'organs and animal experiments (mouse, rat and monkey) revealed a primary causal agent of Yusho to be PCDFs, which at a dose of 60 μg/kg, gave deleyed toxicological effects accompanying with death. This fact indicates biological effects on man between and other PCB exposures to be different. A follow-up study of another Yusho-like disease found in Taiwan in 1979 was also explained.

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The biochemical effects of organochlorine compounds are classified and reviewed. Enzyme induction, sub-cellular particle proliferation, protein binding, membrane interaction, enzyme inhibition and other biochemical effects were evaluated qualitatively and quantitatively as predictive parameters of the health effect of various organochlorines.

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As motivated by the epidemiological evidence suggesting that the majority of human cancers result from exposures to environmental carcinogens, an international cooperative project aiming at the primary prevention of cancers has been proceeded to test a number of chemicals for potential carcinogenicity in animals. With accumulation of test data, it becomes aware that for carcinogenic risk assessment in human, one needs, at times, 2 kinds of additional informations concerning 1) by which mechanism and 2) how intensely the test compounds can induce cancers in experimental animals. Regarding the mechanistic issues, the WHO expert committee members have discussed a scientific basis for classifying chemical carcinogens into 3 categories, genotoxic (primary) carcinogens, epigenetic (secondary) carcinogens and promoters. As an approach to quantitative risk assessment of carcinogens, it is attempted to estimate "Virtually Safe Dose (VSD)"or carcinogenic doses at extremely low risk levels by downward extrapolation of animal dose-response data. Various mathematical models such as one-hit model, probit model, logit model, multi-hit model or Weibull model are proposed for the purpose. Finally, it must be emphasized that most human cancers might be etiologically attributable to a complex interaction of multiple factors. Therefore, the development of methodology for evaluating the effect of combined or sequential exposures of 2 or more carcinogens is now regarded as an important project in cancer research.

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