資料 IV-1
国際疫学会西太平洋地域学術大会 2007（オーストラリア・ホバート）2007.8.24～31(Australasian Epidemiologist 2007; 14: 57-58.)

Descriptive Study of Volunteer Disaster Response for the Chuetsu Earthquakein JapanToshiyuki Ojima1, Shinya Hayasaka2, Chiyoe Murata3, Tatsuya Noda4, Yosuke Shibata5,
Machiko Miwa6, Takeshi Hashitani7, Ichiro Fukunaga8
1 Department of Community Health and Preventive Medicine, Hamamatsu University School of Medicine; 1-20-1 Handayama,Higashi-ku, Hamamatsu, 431-3192, Japan; Email: ojima@hama-med.ac.jp
2 Same as above, Email: hayasaka@hama-med.ac.jp
3 Same as above, Email: cmurata@hama-med.ac.jp
4 Same as above, Email: t-n@umin.ac.jp
5 Same as above, Email: shibata@hama-med.ac.jp
6 Faculty of Community Health Nursing, Hamamatsu University School of Medicine; 1-20-1 Handayama, Higashi-ku, Hamamatsu,
431-3192, Japan; Email: miwama@hama-med.ac.jp
7 Japanese Red Cross Toyota College of Nursing; 12-33 Nanamagari, Hakusann-cho, Toyota-shi, Aichi, 471-8565, Japan; Email:hashitani@rctoyota.ac.jp
8 Institute of Health Planning; 1-6-20 Motomachi, Sakaide City, Kagawa, 762-0045, Japan; Email: jinnta2@nifty.com

Objective: Studies on disaster response and preparation is one of the frontiers in epidemiology.
The Chuetsu Earthquake occurred in Oct 23, 2004. The epicentre was about 200 km northwest ofTokyo; the magnitude was 6.8. Number of death from the earthquake was 40; that of injured was4510. The aim of the study was to describe the characteristics of volunteers in disaster response.
Methods: Most of the volunteers were registered at Volunteer Disaster Response Centres before
they participate in response activities. Data collected by the Niigata Social Welfare Council wereanalysed for the study.
Results: The cumulative number of volunteers was 94,548 from the onset of the earthquake until
March 31, 2007. Maximum number of volunteers in a day was 3,096 registered at the 11th day
after the earthquake. Such number in weekends and holidays was 1.74 times higher than that inweekdays. By weekly analysis, the number of volunteers decreased exponentially; the half-lifetime was about 38 days. Proportion of volunteers from outside of the prefecture was under 20%
during the first 3 days; increased to about 80% from the 3rd to the 30th week; after, it suddenly
dropped to about 20%. Such proportion was 63% in weekends and holidays; while it was 71% inweekdays. The reasons of these specific trends will be discussed to make use for future volunteer
management.
Conclusion: The descriptive data of volunteer disaster response may be useful to prepare
volunteer acceptance or to recruit volunteers.

Key Words
Descriptive study, Volunteer, Disaster response, Earthquake, Japan

Table 1 Number of non-professional volunteers
for response to major disasters in Japan
Name of the disasters

Number ofvolunteersJan 1995

Hanshin-Awaji great earthquake

13,770,000

100000

Sep 2000

Tokai flood

20,00010Jul 2004

Niigata & Fukushima flood

45,0001Jul 2004

Fukui flood

58,000Source: Fire and Disaster Management Agency and Cabinet Office of JapanFig 2 Transition of number of volunteers
and media reports about volunteers

0100000

SunMonTueWedThuFri
Sat10000
Oct 21, 2004

100

Weekday
Holiday1
1-0.0136x

100

200

300

400

500
450

260
318
320
300
306
485

Jan 13, 2005

June 30, 2005

10y = 1E+229e

Fig 3 Average number of volunteers
by the day of the week

Number of volunteers per week1000

Media reports per week

-0.0181x

05/5/21100

05/4/219,000

05/3/21

Eruption of Mt Usu

05/2/21

Mar 2000

05/1/211000

04/12/21

280,000

04/11/21

Petroleum pollution by shipwreckof the Tanker Nakhodka

04/10/21

Jan 1997

y = 2E+304e

Volunteers per week

10000

05/6/21Year

Fig 1 Number of volunteers
and media reports about volunteers

10100

1000

Total285
480348Media reports per week
From Oct 24, 2005 to Jun 30, 2007

Fig 4 Proportion of volunteers
from outside of Niigata prefecture
100%
80%
60%
40%
20%
2005/6/21

2005/5/21

2005/4/21

2005/3/21

2005/2/21

2005/1/21

2004/12/21

2004/11/21

2004/10/21

0%