Association of short-term exposure to ambient PM1 with total and cause-specific cardiovascular disease mortality

Abstract

BACKGROUND AND AIM: The acute effects of exposure to ambient particulate matter with an aerodynamic diameter ≤1 μm (PM1) on cardiovascular disease (CVD) mortality remain poorly understood. We aimed to investigate the association of short-term exposure to ambient PM1 with total and cause-specific CVD mortality, and estimate the corresponding excess mortality. METHODS: Using the Jiangsu provincial mortality surveillance system, we conducted a time-stratified case-crossover study among 988 446 CVD deaths in Jiangsu province, China during 2015-2019. Daily residential PM1 exposures for each subject was assessed using a validated grid data. Conditional logistic regression models integrated with distributed lag linear or nonlinear models were performed to conduct exposure-response analyses. RESULTS: Each 10 μg/m3 increase of PM1 exposure during the same day of CVD death and 1 day prior was significantly associated with a 1.46% (95% confidence interval [CI]: 1.27%, 1.66%), 1.46% (0.15%, 2.78%), 1.93% (1.24%, 2.64%), 1.25% (0.93%, 1.57%), 1.37% (1.07%, 1.66%), and 1.71% (1.22%, 2.21%) increase in odds of mortality from total CVDs, chronic rheumatic heart diseases (CRHD), hypertensive diseases, ischemic heart diseases (IHD), stroke, and sequelae of stroke, respectively. The excess fraction of total CVD mortality attributable to PM1 exposure was 5.72%, while the cause-specific excess fractions ranged from 5.34% for IHD to 8.25% for CRHD. Significantly higher associations and excess fractions were identified for mortality from total and/or certain cause-specific CVDs in adults 80 years or older. CONCLUSIONS: Short-term exposure to ambient PM1 was associated with increased risk of total and cause-specific CVD mortality, which may lead to a considerable excess mortality especially among older adults. Our findings highlight a potential approach to prevent premature deaths from CVDs by reducing ambient PM1 exposures and provide essential quantitative data for the formulation of future air quality standards for ambient PM1. KEYWORDS: Cardiovascular diseases; PM1; Mortality; DLM; DLNM; Case-crossover study.