Ingestion, absorption, metabolism and excretion of nitrate and nitrite in humans and experimental animals are described on the viewpoint that carcinogenic N-nitroso compounds are formed by the reaction of nitrite with amines or ureides. Although nitrate is an inactive substance on animals and most of that administered is excreted in the urine, nitrite which is derived from nitrate in vivo by microorganisms in the digestive tracts has highly pharmacological and biochemical activities. The latest problems on the possibility of the nitrification in the body and the nitrate balance are also reviewed. It seems that nitrate highly affects the human health because the substance is easily reduced to nitrite in the body.

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Carbon monoxide and pesticides are the most serious substances in poisoning from drugs and toxic substances in Japan. Organic phosphorous compounds such as sumithion, malathion, DDVP and EPN, and paraquart have been used for murder and suicide. Recently, abuse of methamphetamine and sniffing thinner have increased year by year in Japan. Radio-, enzyme and spin immunoassays were applied to microanalysis of dependence causing drugs in body fluids. Hemagglutination-inhibition test was developed as a screening test for methamphetamine in the human urine. In order to identify drugs and their metabolites in biological materials such as brain, liver, blood and urine, systematic extraction using organic solvent was carried out after β-glucuronidase treatment of the materials, fractionated extracts were purified by preparative thin-layer chromatography, and mass spectrometry was performed. Drugs and metabolites in extract were rapidly detectable by chemical ionization mass spectrometry and coloration on thin-layer chromatograms.

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The amphetamines, especially methamphetamine, have again become a source of widespread public concern due to the increasing number of abusers. In this context, this review is mainly concerned with biochemical toxicology of amphetamines in experimental animals in relation to behavioral changes. Recent progress in analytical methodology of amphetamines is briefly described. The metabolic fate of amphetamines is one of the major concerns of this review, thus described extensively with respect to enzymatic systems, distribution, excretion and the role of metabolites in the action of the amines. Acute toxicity of amphetamines and some factors which modify the toxicity are discussed. Teratogenic effect of amphetamines is also presented. In addition to the acute effect of amphetamines, chronic effects of the amines on brain biogenic amines, tyrosine hydroxylase, tryptophan hydroxylase and receptor have been emphasized, especially in relation to discussions on tolerance and reverse tolerance. Finally, sex difference in the amphetamineinduced stereotypy, the amine-mediated damage of dopaminergic nerve terminal and amphetamine binding protein found in hypothalamus membrane are discussed.

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Formaldehyde (HCHO) released from plywoods and furnitures has caused odor problems. In 1980, Japanese Government revised Japanese Agricultural Standard (JAS) to give a standard of HCHO-release from plywoods, in which desiccator method is used as the test method. However, there is not such an official standard for furnitures. For the test of HCHO-release from furnitures, so called "Petri dish method" is usually used. In order to understand the underlying principles of these methods, some experimental and theoretical investigations were carried out. Consequently, the following conclusions were obtained : 1) Because HCHO-release from plywood increases exponentially as temperature rises, it is necessary to keep temperature constant during the test. 2) Capacity of the space doesn't affect the values by these methods. 3) Under such conditions that surface area of plywood (S_p) is sufficiently larger than that of water (S_w), the following equation is found to hold : C_wW≒(m/a_p)a_wS_wt where C_wW, amount of HCHO absorbed in water ; m, amount of HCHO-release from unit area of plywood ; a_p and a_w, coefficients of HCHO-absorption by plywood and water, respectively ; and t, standing time. It is necessary to change the diameter of Petri dish from 12 cm to not more than 5.2 cm for satisfying the condition of S_p»S_w in both of these methods. 4) Therefore, when a Petri dish with diameter of 5.2 cm is used, and temperature, volume of water and standing time are kept constant, the values by these methods are independent of S_p values and depend only on m/a_p values, which are characteristic of HCHO-releases from plywoods or furnitures. It is possible to set up a standard for furnitures by using "Petri dish method."

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The analytical method for multi-residues of chlorinated phenoxy agricultural chemicals (2, 4-D, 2, 4, 5-T and 2, 4, 5-TP) in several kinds of fruits and vegetables was investigated. These compounds could be analyzed by gas chromatography with ECD (ECD-GC) after methylation of the sample extract with diazomethane followed by clean-up on silica gel column. The minimum detectable residues of 2, 4-D, 2, 4, 5-T and 2, 4, 5-TP in fruits and vegetables (e.g. apple, egg apple, lemon and tomato) by ECD-GC were 0.005 ppm, 0.001 ppm and 0.0005 ppm, respectively. 2, 4-D separated from a lemon sample was methylated with diazomethane and confirmed by comparing the mass spectrnm and mass chromatograms obtained by GC-MS with those of the methyl ester of the authentic sample. Furthermore, in the surveillance of 2, 4-D residues in the citrus fruits imported from U.S.A. in 1979 to 1981, 2, 4-D was never detected in all of grapefruit and navel orange samples, but it was detected at the levels of 0.010 to 0.21 ppm in all of lemon samples.

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Pretreatment of liquid scintillation wastes containing hydrophilic radioactive compounds before combustion was studied. In various kinds of scintillation solutions, high removal percentages of the radioactivity were observed with calcium hydroxide (Ca (OH)₂), molecular sieves, and synthetic zeolite compared with anhydrous calcium chloride (CaCl₂), aluminum oxide, and silicic acid. The retention capacities of CaCl₂ and Ca (OH)₂ for ¹⁴C-methanol were approximately twice those of molecular sieves and synthetic zeolite. One gram of Ca (OH)₂ was effective in the removal of radioactivity from 10 ml of toluene-triton scintillator waste if it contained less than 10% (v/v) of water. In case of waste which contains only a trace amount of hydrophilic labeled compounds, it is possible to remove the radioactivity by the treatment with CaCl₂ or Ca (OH)₂. Treatments with molecular sieves with suitable micropore size or synthetic zeolite were effective to remove the radioactivity from the waste containing hydrophilic substances. These data indicate that, by the combination of these pretreatments, it is possible to remove the radioactivity from the various wastes.

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