Background and purpose:
Acute myocardial infarction (AMI) is a manifestation of coronary artery disease. Fine particulate matter (PM2.5) has been regarded as a risk factor for AMI-related mortality and hospitalizations. Agricultural activities contribute greatly to PM2.5 formation, indicating potential health risks of PM2.5 in agricultural areas. Health effect studies on agricultural source remain scarce, and currently available evidence is controversial. This study investigated the health effects of short-term exposure to PM2.5 from agricultural sources on AMI onset using a nationwide analysis in China.
Methods:
We reviewed case records from the China Cardiovascular Association Database and extracted the data of 355,815 patients with AMI onset from 1,653 hospitals for the period 2015 to 2018. We obtained daily concentrations of PM2.5 from agricultural sources using the source-oriented Community Multiscale Air Quality model. Moreover, we proposed a time-stratified case-crossover study to examine associations between exposure to PM2.5 from agricultural sources and AMI onset and determined lag effects with a maximum of 3 days. Additionally, we conducted multiple subgroup and sensitivity analyses.
Results:
Exposure to PM2.5 from agricultural sources caused a significantly increased risk of the onset of AMI and its subtypes. Short-term exposure to PM2.5 from agricultural sources on the current day (lag 0) was positively associated with a 4.4% (95% confidence interval [95% CI]: 3.3%–5.5%), 4.9% (95% CI: 3.5%–6.3%), and 3.4% (95% CI: 1.5%–5.4%) increase in the odds of AMI, ST-elevation myocardial infarction (STEMI), and non-STEMI (NSTEMI), for each 10 μg/m3 increase. Meanwhile, higher risk estimations were pronounced in individuals who were aged above 65 years, who lived in southern China, and who resided in the rural area setting, and significant differences were mostly found in NSTEMI onsets.
Conclusions:
Short-term exposure to PM2.5 from agricultural sources may trigger the onset of AMI and its two subtypes. Improving agriculture management through ammonia emission abatement can help in achieving PM2.5 reduction and protecting public health.