While photochemical oxidants (Ox = O3+ NO2) are known to increase asthma flare-ups, there is a paucity of studies of the Japanese population, especially for Tokyo residents. We used data on asthma cases (n = 7,455) from ambulance dispatches in Tokyo, 2015-2016. Variables included date and time of incidence, age, sex, occurrence location at the ward (ku) level, and the symptom/cause of dispatch as recorded by paramedics. Ox data were obtained from the nearest air quality monitoring station to the occurrence location, then linked them with the outcomes based on occurrence date. We directly incorporated a distributed lag model into a bi-directional case-crossover study design controlling for ambient temperature and day of week. A 10-ppb increase in Ox for lag days 0-3 was associated with a 5.51% (95% CI: 0.13 to 11.18) increase in ambulance dispatches related to asthma. The association was strongest on lag day 1 (4.67%, 95% CI: 0.51 to 9.00). Exposure to high levels of Ox was associated with increased ambulance dispatches related to asthma exacerbations in Tokyo, Japan.

中文翻译：

---

光化学氧化剂和救护车派遣用于东京的哮喘病症状。

虽然光化学氧化剂（Ox = O3 + NO2）会增加哮喘发作，但对日本人口的研究却很少，尤其是对东京居民而言。我们使用了2015-2016年东京急救人员派遣的哮喘病例（n = 7,455）数据。变量包括发病日期和时间，年龄，性别，病房（ku）级别的发生位置以及医护人员记录的派遣症状/病因。从最近的空气质量监测站获取到发生地点的氧气数据，然后根据发生日期将它们与结果关联起来。我们将分布式滞后模型直接合并到双向病例交叉研究设计中，以控制环境温度和星期几。滞后第0-3天的Ox升高10-ppb与5.51％（95％CI：0.13至11）相关。18）与哮喘有关的救护车派遣量增加。关联在滞后第1天最强（4.67％，95％CI：0.51至9.00）。在日本东京，暴露于高水平的氧气会导致与哮喘发作加剧相关的救护车调度增加。