生活衛生
Online ISSN : 1883-6631
Print ISSN : 0582-4176
ISSN-L : 0582-4176
36 巻, 6 号
選択された号の論文の6件中1~6を表示しています
  • 清水 充
    1992 年 36 巻 6 号 p. 315-326
    発行日: 1992/11/10
    公開日: 2010/03/11
    ジャーナル フリー
  • 3. 下痢原性大腸菌
    石井 営次
    1992 年 36 巻 6 号 p. 327-337
    発行日: 1992/11/10
    公開日: 2010/03/11
    ジャーナル フリー
  • 圓藤 吟史, Yoshitsugu KONISHI, Yoko Endo ICHIKAWA, Ikuko KITOTA, Shunichi ...
    1992 年 36 巻 6 号 p. 339-344
    発行日: 1992/11/10
    公開日: 2010/03/11
    ジャーナル フリー
    Urinary excertion of N-acetyl-β-D-glucosaminidase (NAG) is regarded as the most sensitive indicator of renal damage caused by occupational exposure to lead. In order to clarify the increase of NAG excretion caused by damage to the proximal renal tubule, we compared NAG isoenzyme patterns between a group of 17 male office workers and a group of 15 male lead-exposed workers using the electrofocusing-MCP-NAG method.
    Blood levels of lead (PbB) in the office workers and the lead exposed workers were 9.7±3.1 and 64.9±9.8μg/100g blood (mean±S. D.), respectively. All the means of the total NAG, NAG-A and NAG-B activity of the lead-exposed workers (5.7±4.9, 4.6±4.1, 1.1±0.8U/g creatinine, respectively) were significantly higher than those of the office workers (2.8±1.4, 2.2±1.0, 0.6±0.4U/g creatinine, respectively). But no difference was observed in the mean percentages of the isoenzymes (NAG-A and NAG-B) between the two groups.
    Since we found a significant increase in NAG excretion, but failed to find that the excess excretion was mainly due to NAG-B, there remained the possibilities that the lead exposure damaged the proximal renal tubular cell only very slightly, or stimulated the exocytosis of NAG, or stimulated renal activity of NAG.
  • 中村 武夫, Seiki TANADA, Shojiro KYOTANI, Tukasa HARA, Tamotsu MIYOSHI, Hi ...
    1992 年 36 巻 6 号 p. 345-350
    発行日: 1992/11/10
    公開日: 2010/03/11
    ジャーナル フリー
    The efficacy of five kinds of clay minerals as paraquat adsorbent was discussed in vitro from standpoints of equilibrium amount adsorbed and adsorption rate.
    The equilibrium amount of paraquat adsorbed onto natural aluminium silicate (ADSORBIN) was the largest. The amount of paraquat adsorbed onto clay mineral was large in purified water and normal saline solution, and was small in artificial gastric juice. It was found that the paraquat adsorption onto clay mineral was influenced by the pH of solution rather than the coexistence of sodium cation.
    It is assumed that the difference in the adsorption rate of paraquat onto clay mineral is based on the interaction between the surface charge of clay mineral and the paraquat cation.
  • 森 義明
    1992 年 36 巻 6 号 p. 351-366
    発行日: 1992/11/10
    公開日: 2010/03/11
    ジャーナル フリー
    Sprayed-on material samples from 270 rooms were examined for asbestos and, if found, were analyzed quantitatively by X-ray diffraction. In spite of the fact that 58 samples were from buildings where the specifications stated sprayed-on rockwool, asbestos was detected from 26, suggesting that sprayed-on materials should be analyzed for asbestos.
    Air samples on membrane filters from 130 rooms with sprayed-on asbestos were analyzed using both phase contrast microscopy (PCM) and transmission electron microscopy (TEM) with selected area electron diffraction. The indoor airborne asbestos concentrations measured by PCM and TEM were 0.47-7.44 and 8-380 fibers per liter (f/L), respectively. These concentrations were higher when fans were operating to move the air. There was no relationship between the asbestos contents of sprayed-on materials and the indoor airborne asbestos concentrations by PCM or TEM. Of the 47 rooms in which there was only slight damage to the sprayed-on asbestos, 10 showed asbestos concentrations in excess of 2f/L determined by PCM, suggesting the need to determine the indoor airborne asbestos concentration. The relationship was good between the concentrations of indoor airborne asbestos measured by PCM and by TEM at higher concentrations, suggesting that PCM is useful for screening rooms with sprayed-on asbestos. Chrysotile fibers were observed in rooms with sprayed-on chrysotile asbestos and in the atmospheric environment, while both chrysotile and amosite were observed in rooms with sprayed-on amosite asbestos. When the indoor airborne asbestos concentration was below 100f/L as determined by TEM, the proportion of amosite was 13%, while at above 100f/L, it was 56%. The common frequency distribution of asbestos fibers was 1-2μm long. Longer fibers were detected in rooms with sprayed-on asbestos rather than in the atmospheric environment.
    When risks of asbestos exposure (for 40 years) were assessed in a room with sprayed-on asbestos in which the maximum concentration (7.44f/L) was determined by PCM, the excess risk for lung cancer was 0.002 and the risk for mesothelioma was 2 deaths/1, 000, 000 population, respectively.
  • 清田 郁子
    1992 年 36 巻 6 号 p. 367-381
    発行日: 1992/11/10
    公開日: 2010/03/11
    ジャーナル フリー
    Erythrocyte δ-aminolevulinic acid dehydratase (ALAD) activity has not been used as a parameter of occupational lead exposure at high concentrations because it is too sensitive to lead. However, as high concentrations of occupational lead exposure are less frequently found due to envionmental improvement and other measures, the importance of measuring ALAD activity should be reevaluated. This study was thus performed to clarify the relationship between exposure to lead and lead content in the blood, the ALAD activity and the activity ratio, by comparing these parameters between lead workers and non-lead workers (controls). Animal experiments were also carried out to check blood lead content, ALAD activity and activity ratio at the beginning, during, and after lead administration. The following results were obtained. For the human subjects, the mean blood lead content of the controls was 4.13μg/100ml, the mean ALAD activity was 38.4μmolALA/min⋅1RBC, and the mean activity ratio was 1. The correlation coefficient r between blood lead content and ALAD activity was -0.13, that bet ween blood lead, content and activity ratio -0.27. The mean blood lead content, ALAD activity and activity ratio of lead workers were 58.1μg/100ml, 11.9μmolALA/min⋅1RBC and 4, respectively. Between blood lead content and ALAD activity or activity ratio, r was -0.83 or 0.86, respectively.
    The validity (sensitivity+specificity) of ALAD for each cut-off level of blood lead of 20, 50 and 60μg/100ml was calculated to be 1.60 (0.94+0.66), 1.78 (0.91+0.87) and 1.72 (0.89+0.83) at each cut off level of ALAD of 95% upper limit of non exposed group, 75% decreasing value of non exposed group and 80% decreasing value of non exposed group. The validity of ALAD activity ratio was calculated to be 1.89 (0.89+1), 1.63 (0.76+0.87) and 1.50 (0.89+0.61) in the same way as ALAD activity.
    In rats, ALAD activity, activity ratio and blood lead content (in descending order of magnitude) changed even on day 1 of lead administration. During the administration period, ALAD activity remained low; the activity ratio rose on days 1 and 2 but remained unchanged thereafter; the blood lead content increased dose-dependently. In rats receiving 1% lead, ALAD activity began to rise on day 1 of observation following administration and recovered to the control level on day 2 of observation; in 5%-lead-treated rats, ALAD activity was still low on day 1 of observation but sharply jumped to higher levels than controls on days 2 and 4, reaching the control value 2 weeks later.
    The activity ratio and blood lead content promptly decreased after the end of administration and did not return to the control level during the observation period.
    These data suggest that ALAD activity and activity ratio can serve as reliable parameters of lead exposure because both accurately reflect the blood lead content.
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