| Project/Area Number |
61480168
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
公衆衛生学
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| Research Institution | Kanazawa University |
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Principal Investigator |
OKADA Akira Dept. of Public Health, School of Medicine, Kanazawa Univ. Professor, 医学部公衆衛生学, 教授 (10019573)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Hideki Dept. of Public Health, School of Medicine, Kanazawa Univ. Assistant, 医学部公衆衛生学, 助手 (70172426)
INABA Ryoichi Dept. of Public Health, School of Medicine, Kanazawa Univ. Assistant, 医学部公衆衛生学, 助手 (10168411)
NOHARA Seiichi Dept. of Public Health, School of Medicine, Kanazawa Univ. Lecturer, 医学部公衆衛生学, 講師 (70115260)
ARIIZUMI Makoto Dept. of Public Health, School of Medicine, Kanazawa Univ. Assistant Professor, 医学部公衆衛生学, 助教授 (90143883)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1986: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | Infra- and low frequency sound / Sleep disturbance / Electroencephalogram / 住民反応 |
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| Research Abstract |
1. Experimental study: (1) Subjects were exposed to four kinds of sounds with frequencies of 10, 20, 40 and 63 Hz at various sound pressure levels, and electroencephalogram was recorded throughout their sleep. In non-REM sleep, the reaction rate was the highest in sleep stage 1(S1) and the lowest in sleep stage 3+4(S3+4). When the sound pressure level which couses the reactions over 50 % for the first time was used as the threshold level signifying the occurrence of sleep disturbance, the threshold levels of 40 and 63 Hz were 95 and 90 dB respectively. The pattern of sleep was little affected by the exposure to infra- and low frequency sound. (2) Subjects were exposed to sounds which consisted of 10-20 Hz, 10-40 Hz and 10-80 Hz at sound pressure levels of 50, 60 and 70 dB. The effects of infra- and low frequency sound with band frequency were evaluated to be remarkable in the frequency range of 10 to 20 Hz in case of levels under 70 dB. When the subjects were exposed to the synthesized traffic noise( 40, 50, 60 dB; L50 ), the sleep was the most affected at a sound pressure level of 60 dB and the least at 40 dB at each sleep stage. The effects of exposure to synthesized traffic noise was not transient and the pattern of sleep was considerably affected.
2. Response of inhagitants to infrasound: 444 inhabitants living nearby a rapid transit highway where not only audible noise but also infrasound with considerable high sound pressure levels occurred, were interviewed on questionnaires relating to their health status. Symptoms based on noise appearec notably from sound pressure level of 60 dB, and those based on infrasound appeared notably from sound pressure level of 80 dB. The percentage of inhagitants complaining of sleep disturbance was considerably higher in relation to noise than in relation to infrasound.
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