Eisei Shikenjo hokoku. Bulletin of National Institute of Hygienic Sciences最新文献

To investigate compensative effects in leaves of Papaver somniferum L., the relation between photosynthetic rate and light density and leaf temperature, and the influences on photosynthetic and transpiration rates of removal of the three upper leaves were examined under field conditions. The light saturation point in leaves of P. somniferum was about 900 micro molm-2sec-1 and the photosynthetic rate at the light saturation point was about 13.5 micro molm-2sec-1 between 23 and 28 degrees C in leaf temperature. The light compensation point in leaves was nearly 50 micro molm-2sec-1. The influence of leaf temperature on photosynthetic rate was significant, so that the latter showed a remarkable decrease when the leaf temperature was above 30 degrees C. When the three upper leaves were removed, the photosynthetic and transpiration rates in the 4th leaf tended to increase as compared with control level, although the increases were not significant.

A simple and efficient cleanup method was established for capillary gas chromatographic determination of 12 organochlorine and 11 organophosphorus pesticides in beef. Extracted fat was subjected to silica gel dry column chromatography and further cleaned up by Florisil minicolumn chromatography for organochlorine pesticide analysis, while partitioning between n-hexane and acetonitrile of the extract and silica gel minicolumn chromatography were employed for the analysis of organophosphorus pesticides. Several samples (imported Australian beef) were analyzed by the proposed method. DDT was detected in 14 (0.01-0.10 ppm). BHC was found in 11 (0.003-0.031 ppm) and dieldrin was demonstrated in 2 (0.004 and 0.008 ppm). Heptachlors and the 11 organophosphorus pesticides investigated were not detected in any of the meat samples.

The raw material of elcatonin was examined for preparation of the "Elcatonin Reference Standard". The candidate material was evaluated by a domestic collaborative study in which five laboratories participated. The biological activity was determined to be 11.3 Unit/Amp. against the International Elcatonin Reference Standard (Code 84/614), based on one hour hypocalcaemia rat bioassay. In spite of the differences in rat strain, sex, administration method, dosage and assay method for serum calcium etc., the separately obtained biological activities for the candidate agreed closely with each other (95% confidence limits 11.08-11.53 Unit/Amp.). The physico-chemical evaluation of the candidate material was also performed, by using HPLC and amino acid chromatography. Based on the above results, this raw material was authorized to be the Elcatonin Reference Standard of the National Institute of Health Sciences.

The preparation of MSDS (material safety data sheets) began in Japan in April 1993 with the notice of three Ministries, the Ministry of Health and Welfare, the Ministry of International Trade and Industry and the Ministry of Labor. MSDS are designed to provide chemical information to protect human health and the environment from chemical hazards. Important points in describing hazard information in MSDS are explained as well as references which are useful for preparation of MSDS. Problems for further discussion are also pointed out.

Information on ethylenethiourea (ETU) was collected to estimate the amount of actual intake into the body. Useful information such as physical properties, toxicological data and environmental data was selected and described for the preparation of material safety data sheets (MSDS).

Raw human insulin material was examined for preparation of the "Human Insulin Reference Standard". The candidate material was evaluated by a domestic collaborative study in which four laboratories participated. The biological activity was determined to be 26.0 Unit/mg against the International Human Insulin Reference Standard (Code 83/500), based on the rabbit blood-glucose method specified in the JP XII (1991). Because of the possibility of application as a chemical reference standard for assay by the HPLC method, a physico-chemical evaluation of the candidate material was also performed. The total desamide form, dimer and oligomer impurities were estimated to be about 1% by HPLC. Based on the above findings, this raw material was authorized as the Human Insulin Reference Standard of the National Institute of Health Sciences.

The raw material for estradiol was examined for preparation of the "National Institute of Health Sciences (NIHS) Estradiol Reference Standard (Control 931)". Analytical data obtained were as follows: melting point, 179.0 degrees C; infrared spectrum, the same as that of the present NIHS Estradiol Reference Standard; optical rotation, -alpha-20D = +80.4 degrees; thin-layer chromatography, no impurity was detected; high-performance liquid chromatography (HPLC), a trace amount of two impurities were detected; loss on drying, 0.24%; assay, 100.4% by UV spectrophotometry and 101.2% by HPLC. Based on the above results, the raw material was authorized as the NIHS Estradiol Reference Standard (Control 931).

Raw cyclandelate material was tested for preparation of the "Cyclandelate Reference Standard (Control 931)". Analytical data obtained were as follows: melting point, 57.4 degrees C; ultraviolet spectrum, lambdamax = 252.0, 258.1 and 264.1 nm and E 1cm 1% = 5.85 (252.0 nm), 6.95 (258.1 nm), 5.30 (264.1 nm), respectively; infrared spectrum, the same as that of the JP Cyclandelate Reference Standard; thin-layer chromatography, no impurities were detected up to 1000 micro g; high-performance liquid chromatography (HPLC), no impurities were detected; loss on drying, 0.03%; assay result, 101.4% by HPLC. Based on the above findings, the raw material was authorized as the JP Cyclandelate Reference Standard (Control 931).

Recently, social concerns regarding tap water quality have increased, mainly because of the possible reduction in safety due to contamination of tap water by various chemicals and more frequent occurrence of the strange odors and tastes in as a result of resource water eutrophication. Consequently, the Ministry of Health and Welfare conducted a detailed two-year investigation of the Water Quality Standards of the Water Works Law by summoning an expert committee, and as a result, totally revised the Standards in December 1992. This was the first overall revision since 1958 when the Water Quality Standards were established, and an additional 21 items, including mainly hazardous chemicals including pesticides and chlorinated by-products, were newly added. Values and testing methods are now listed for 46 items, and the Law obliges every water supply to conduct periodical water testing for the necessary items almost every month with ad-hoc testing, as required of hydrants. Simultaneously, 26 monitoring items are listed in hazardous contaminants guidelines which should be checked, when necessary. The new Water Quality Standards and the guidelines were brought into force in December 1993, and the quality of all parts of the water supply is now tested in accordance. Risk assessment is a scientific process that includes some form of measurement as one of its central elements. In many cases, the measured parameter is the level of exposure to a hazard. Also, measurements are essential in establishing the quantitative relationship between exposure and response, and in determining natural baseline conditions in the environment. Exposure assessment is the process of measuring or estimating the intensity, frequency, and duration of human or other population exposures to risk agents. Exposures may occur in a variety of ways, such as through ingestion, dermal contact, or inhalation. For many risk assessments, exposure assessment is the most difficult task. The reason for this is that exposure assessment often depends on factors that are hard to estimate and for which there are few data. Critical information on the conditions of exposure is often lacking. To be comprehensive, an exposure assessment must describe the levels of exposure and all conditions that might be needed to assess the effects of such exposures, including their magnitude, duration, schedule, and route. This report presents the various problems covered in exposure assessment relevant to monitoring, testing, and methodology.

A 13-week subchronic oral toxicity study of isopropyl p-hydroxybenzoate was performed in both sexes of F344 rats. CRF-1 diet containing 0, 0.25, 1.25, 2.5 or 5% isopropyl p-hydroxybenzoate was fed to 5 randomly constituted groups of animals, each consisting of 10 males and 10 females, to determine appropriate dose levels for a subsequent 2-year carcinogenicity study. No animals died during the administration period. Significant suppression of body weight gain was observed in males of the 2.5% and 5% isopropyl p-hydroxybenzoate groups, and in females of the groups treated with 1.25% or above as compared with the control group. Serum biochemistry evaluations revealed increases in gamma-GTP and total cholesterol in male groups treated with 2.5% or more and increases in gamma-GTP, ALP and BUN in female groups treated with 1.25% or more, as compared to the controls. Histopathologically, centrilobular hepatocellular swelling was observed in males treated with 2.5% or more and in females of the 5% group. In the affected populations, hepatocytes filled with small vacuoles, possibly of lipid native, were sometimes found. An increased severity of intracytoplasmic eosinophilic globule formation in the renal proximal tubular epithelia of males of the 5% group was noted. Based on these results, a dietary concentration of 1% in males or 0.5% in females was concluded to be a suitable maximum tolerable dose (MTD) of this chemical for a 2-year carcinogenicity study in rats.