Components of particulate matter as potential risk factors for acute myocardial infarction

Particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5) is a heterogeneous mixture, and specific substances that affect cardiovascular events remain unknown. We aimed to examine the association of short-term exposure to PM2.5 and its components with hospital admissions for acute myocardial infarction (AMI). The concentrations of total PM2.5 and its individual components were continuously measured using Aerosol Chemical Speciation Analysers. From a national-scale administrative database collected from 828 facilities in 47 prefectures across Japan from April 2017 to December 2019, we extracted AMI data for seven prefectures where these aerosol analysers were installed. The primary outcome was the relationship of PM2.5 and its components with AMI hospitalisation. A time-stratified case-crossover analysis was conducted, and the approximate risk of AMI by pollutant concentrations was estimated using a conditional logistic regression model. In total, 44,232 patients with AMI aged 40–104 years (74.9% male) were examined. The estimated effect of an increase in the total PM2.5 concentration is significantly associated with AMI-related hospitalisation. Upon further examination of the components of PM2.5, black carbon has a more substantial influence on AMI development than water-soluble organic compounds, nitrate, and sulphate ions. Short-term exposure to PM2.5 is associated with an increased incidence of AMI. Future research prioritises the components of PM2.5, with particular focus on whether a decrease in black carbon concentrations can mitigate the risk of future air quality-related AMI. This study examined whether short-term exposure to fine air particles, known as PM2.5, increases the risk of heart attacks. PM2.5 consists of tiny substances that can enter the lungs and bloodstream. Researchers analysed over 44,000 heart attack cases in seven regions of Japan between 2017 and 2019. They found that higher PM2.5 levels shortly before each case were linked to more hospital visits for heart problems. Among the components of PM2.5, black carbon—produced by car exhaust, factories, and smoke—showed the strongest link to heart attacks. The findings suggest that reducing black carbon in the air may help lower the risk of heart attacks. Cleaner air could lead to better heart health and benefit public well-being. Kojima et al. examine the association of particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5) and its components with hospital admissions for acute myocardial infarction (AMI). Short-term exposure to PM2.5 is linked to increased incidence of AMI, with black carbon identified as a key harmful component.