Railway suicide attempts are associated with amount of sunlight in recent days.
BACKGROUND
To assess the relationship between hours of sunlight and railway suicide attempts, 3-7 days before these attempts.


METHODS
All railway suicide attempts causing railway suspensions or delays of 30 min or more between 2002 and 2006. We used a linear probability model to assess this relationship. This study was conducted at Tokyo, Kanagawa, and Osaka prefectures in Japan. Data were collected from the railway delay incident database of the Japanese Railway Technical Research Institute and public weather database of the Japan Meteorological Agency.


RESULTS
About 971 railway suicides attempts occurred between 2002 and 2006 in Tokyo, Kanagawa, and Osaka. Less sunlight in the 7 days leading up to the railway suicide attempts was associated with a higher proportion of attempts (p=0.0243). Sunlight over the 3 days before an attempt had a similar trend (p=0.0888). No difference was found in sunlight hours between the days with (median: 5.6 [IQR: 1.1-8.8]) and without (median: 5.7 [IQR: 1.0-8.9]) railway suicide attempts in the evening. Finally, there was no apparent correlation between the railway suicide attempts and the monthly average sunlight hours of the attempted month or those of a month before.


CONCLUSIONS
Railway suicides were not the main suicidal methods in Japan,


CONCLUSIONS
We observed an increased proportion of railway suicide attempts after several days without sunlight. Light exposure (blue light or bright white light) in trains may be useful in reducing railway suicides, especially when consecutive days without sunshine are forecasted.
Center for Genomic Medicine, Graduate School of Medicine, Kyoto University, Yoshida-Konoe, Sakyo, Kyoto 606-8501, Japan. Electronic address: kadotani@belle.shiga-med.ac.jp.
Hiroshi
H
Kadotani
Yumiko
Y
Nagai
Takashi
T
Sozu
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011890:Railroads; D013406:Suicide, Attempted / Q000523:psychology / Q000706:statistics & numerical data*; D013472:Sunlight; D013997:Time Factors; D055815:Young Adult
Exposure; Japan; Railway suicide; Sunlight