Asian Dust and Risk of Emergency Transport among Elderly People in Japan: a Case-Crossover StudyAbstract Number:1979 Saori Kashima*, Takashi Yorifuji, Etsuji Suzuki, and Akira Eboshida Saori Kashima* Department of Public Health and Health Policy, Institute of Biomedical & Health Sciences, Hiroshima University, Japan, E-mail Address: [email protected] Search for more papers by this author , Takashi Yorifuji Department of Human Ecology, Graduate School of Environmental and Life Science, Okayama University, Japan, E-mail Address: [email protected] Search for more papers by this author , Etsuji Suzuki Department of Epidemiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Japan, E-mail Address: [email protected] Search for more papers by this author , and Akira Eboshida Department of Public Health and Health Policy, Institute of Biomedical & Health Sciences, Hiroshima University, Japan, E-mail Address: [email protected] Search for more papers by this author AbstractBackground: While Asian dust spreads to wide areas of Asian countries, the evidence of its independent effects remains sparse. We aimed to evaluate the impact of Asian dust on disease onset independent of particulate matter. Furthermore, we examined potential effect modifications according to a past history of disease.Methods: We used a time-stratified case-crossover design and obtained data of 17,874 elderly residents (=65 years) who were transported to hospital emergency rooms from 2006–2010 in Okayama, Japan. We assessed daily concentrations of Asian dust and suspended particulate matter (SPM). We calculated odds ratios for emergency transport per an interquartile increase of Asian dust, while adjusting for SPM concentrations. Then, we conducted stratified analyses by patients with or without each history of hypertension, diabetes, arrhythmia, coronary heart disease, and cerebrovascular disease.Results: Asian dust was associated with higher risk of emergency transport, while adjusting for SPM concentrations. The excess risk per an interquartile (20.7 µg/m3) increase in Asian dust exposure was 2% (95% confidence interval (CI): 0–4) for cardiovascular disease (lag 3), 4% (95% CI: 1–7) for cerebrovascular disease (lag 0), and 2% (95% CI: 0–5) for respiratory disease (lag 3). We also found a significantly higher excess risk among patients with history of diabetes (14% (95% CI: 2–27) for cerebrovascular disease (lag 2): p for interaction: 0.02), whereas there was no clear association among patients without the disease history. While a significant interaction was also observed with cardiovascular disease (lag2: p for interaction: 0.05), no clear association was found among either patients with or without the history of respiratory disease.Conclusions: Asian dust had adverse effects on circulatory, and respiratory morbidity independent of exposure to SPM. Its effects on cardiovascular disease were stronger among those who had diabetes.