Associations between short-term PM(2.5) exposure and daily hospital admissions for circulatory system diseases in Ganzhou, China: A time series study

OBJECTIVE: Previous epidemiological studies have shown that both long-term and short-term exposure to fine particulate matters (PM(2.5)) were associated with the morbidity and mortality of circulatory system diseases (CSD). However, the impact of PM(2.5) on CSD remains inconclusive. This study aimed to investigate the associations between PM(2.5) and circulatory system diseases in Ganzhou. METHODS: We conducted this time series study to explore the association between ambient PM(2.5) exposure and daily hospital admissions for CSD from 2016 to 2020 in Ganzhou by using generalized additive models (GAMs). Stratified analyses were also performed by gender, age, and season. RESULTS: Based on 201,799 hospitalized cases, significant and positive associations were found between short-term PM2.5 exposure and hospital admissions for CSD, including total CSD, hypertension, coronary heart disease (CHD), cerebrovascular disease (CEVD), heart failure (HF), and arrhythmia. Each 10 μg/m(3) increase in PM(2.5) concentrations was associated with a 2.588% (95% confidence interval [CI], 1.161%–4.035%), 2.773% (95% CI, 1.246%–4.324%), 2.865% (95% CI, 0.786%–4.893%), 1.691% (95% CI, 0.239%–3.165%), 4.173% (95% CI, 1.988%–6.404%) and 1.496% (95% CI, 0.030%–2.983%) increment in hospitalizations for total CSD, hypertension, CHD, CEVD, HF, and arrhythmia, respectively. As PM(2.5) concentrations rise, the hospitalizations for arrhythmia showed a slow upward trend, while other CSD increased sharply at high PM(2.5) levels. In subgroup analyses, the impacts of PM(2.5) on hospitalizations for CSD were not materially changed, although the females had higher risks of hypertension, HF, and arrhythmia. The relationships between PM(2.5) exposure and hospitalizations for CSD were more significant among individuals aged ≤65 years, except for arrhythmia. PM(2.5) had stronger effects on total CSD, hypertension, CEVD, HF, and arrhythmia during cold seasons. CONCLUSION: PM(2.5) exposure was positively associated with daily hospital admissions for CSD, which might provide informative insight on adverse effects of PM(2.5).