A systematic review of low-level ambient fine particulate matter (PM2.5) exposures and adverse cardiovascular health outcomes

Clinical Snapshot

Key Findings

• P Value: Not reported

• Effect Size: 67% of included studies (64/95) showed significant associations

• Primary Outcome: Adverse cardiovascular health outcomes associated with low-level PM2.5 exposure

• Nnt Or Sensitivity: Variable by outcome type: direct measurements 69%, cardiovascular endpoints 44%, events/mortality 76%, biomarkers 67%

• Confidence Interval: Not reported

Clinical Application

Findings suggest current air quality standards may be insufficient for cardiovascular protection Relevant to Australian urban populations; current Australian PM2.5 standards (25 μg/m³ annual average) may need review given evidence of harm below regulatory thresholds General population in areas with PM2.5 levels below current regulatory standards

Abstract

Associations between exposure to fine particulate matter and impacts in the cardiorespiratory system are well-established, but associations are expected to vary based on exposure duration and concentration. Domestic and international agencies set standards and guidelines for PM2.5 in part to protect public health. This systematic review explores if associations exist between adverse cardiovascular endpoints and PM2.5 exposure when the concentrations are below regulatory standards. In total, 1349 documents were screened, with 95 articles meeting criteria (i.e. peer-reviewed, PM2.5 concentrations reported, cardiovascular endpoints measured). Of the included articles, 67% (64 articles) observed significant associations with adverse cardiovascular endpoints with variable findings based on specific cardiovascular endpoints (e.g. direct measurements - 69% of articles, cardiovascular endpoints - 44% of articles, events and mortality - 76% of articles, and biomarkers - 67% of articles). While not universally consistent, significant associations were observed between PM2.5 exposure and adverse cardiovascular effects, even at levels deemed compliant with current regulations. This review highlights the necessity for further research across diverse geographical settings and populations to clarify the implications of low-level PM2.5 exposure on cardiovascular health. The findings advocate for a review of regulatory standards for PM2.5 exposure in the context of cardiovascular health.

References

1. 1.Roper, C., Aminone, V. T., Abedin, M., Fletcher, L. M., Harden, L., Stewart, J. A., & Faruque, F. S. (2026). A systematic review of low-level ambient fine particulate matter (PM2.5) exposures and adverse cardiovascular health outcomes. Environmental Pollution, 127978. https://doi.org/10.1016/j.envpol.2026.127978