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Objectives: The Tokyo subway sarin attack in 1995 was an unprecedented act of terrorism that killed 13 people and sickened more than 6,000. The long-term somatic and psychological effects on its victims remain unknown., Methods: We conducted analyses on the self-rating questionnaire collected annually by the Recovery Support Center (RSC) during the period from 2000 to 2009. The RSC is the only organization that has large-scale follow-up data about sarin attack victims. The prevalence of self-reported symptoms was calculated over 10 years. We also evaluated the prevalence of posttraumatic stress response (PTSR), defined as a score ≥ 25 on the Japanese-language version of the Impact of Event Scale-Revised. The multivariate Poisson regression model was applied to estimate the risk ratios of age, gender, and year factor on the prevalence of PTSR., Results: Subjects were 747 survivors (12% of the total) who responded to the annual questionnaire once or more during the study period. The prevalence of somatic symptoms, especially eye symptoms, was 60-80% and has not decreased. PTSR prevalence was 35.1%, and again there was no change with time. The multivariate Poisson regression model results revealed "old age" and "female" as independent risk factors, but the passage of time did not decrease the risk of PTSR., Conclusions: Although symptoms in most victims of the Tokyo subway sarin were transient, this large-scale follow-up data analysis revealed that survivors have been suffering from somatic and psychological long-term effects., Competing Interests: The authors have declared that no competing interests exist.

The behavior of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) pollens in an urban area was examined through the measurements of the dispersion characteristics at the various sampling locations in both outdoor and indoor environments. Airborne pollens were counted continuously for three months during the Japanese cedar pollen and Japanese cypress seasons in 2005 and 2006 by the use of Durham's pollen trap method in and around Tokyo, Japan. The dispersion of pollens at the rooftop of Kyoritsu Women's University was observed to be at extremely high levels in 2005 compared with previously reported results during the past two decades. As for Japanese cedar pollen, the maximum level was observed as 440 counts cm(-2) day(-1) on 18 March 2005. Japanese cypress pollen dispersed in that area in the latter period was compared with the Japanese cedar pollen dispersions. The maximum dispersion level was observed to be 351 counts cm(-2) day(-1) on 7 April 2005. Total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 5,552 and 1,552 counts cm(-2) for the three months (Feb., Mar. and Apr.) in 2005, respectively. However, the dispersion of both pollens in 2006 was very low. The total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 421 and 98 counts cm(-2) for three months (Feb., Mar. and Apr.) in 2006, respectively. Moreover, the pollen deposition on a walking person in an urban area showed that the pollen counts on feet were observed to be extremely high compared with the ones on the shoulder, back and legs. These findings suggested that pollen fell on the surface of the paved road at first, rebounded to the ambient air and was deposited on the residents again. Furthermore, the regional distribution of the total pollen dispersion in the South Kanto area was characterized on 15-16 March 2005 and on 14-15 March 2006. Although the pollen levels in 2005 were much higher than in 2006, it was commonly observed that higher pollen counts existed in the outlying areas. That is, the pollen counts in an urban area were confirmed to be at a lower level. As for the indoor dispersion of pollens, two cases were evaluated. At the lobby of the main building of Kyoritsu Women's University, the averaged ratio of the indoor to the outdoor pollen count is 4.1%. Another case was at the hospital building of a medical school. The pollen dispersion in the indoor environment was also observed to be low. It was concluded that the indoor pollen would be mainly carried from the outer environment by the movement of air.