Prevalence of Japanese cedar pollinosis in Tokyo: a survey conducted by the Tokyo Metropolitan Government

Abstract

In 2006, a survey was conducted to estimate the prevalence of Japanese cedar pollinosis in three target areas in Tokyo, namely Akiruno-shi, Chofu-shi, and Ota-ku; this survey was similar to two surveys conducted previously, in 1983–1987 (first survey) and 1996 (second survey). In the most recent survey, the overall prevalence of Japanese cedar pollinosis in Tokyo, except the islands of Tokyo, was estimated as 28.2%. This prevalence rate exceeds that estimated by the first and second surveys by 18.2 and 8.8 percentage points, respectively. The prevalence of Japanese cedar pollinosis in the three survey target areas increased by 2.3–10.8 percentage points vs. the rates obtained in the second survey. Furthermore, differences among the prevalence rates in the three areas decreased. Compared with the results obtained in the second survey, increases in the prevalence rate were noted in all age groups other than in people aged 30–44 years. In particular, the prevalence rate in children aged 0–14 years increased markedly, showing a threefold increase. The prevalence rate exceeded 30% in all age groups between 15 and 59 years.