Tracking biochemical indicators of air pollution exposure in acute cardiorespiratory emergencies: a scoping review.

BACKGROUND: Short-term ambient air pollution is a known trigger for acute cardiovascular and respiratory events. Biochemical markers help reveal pollution-induced physiological changes during emergency presentations, though evidence remains fragmented. OBJECTIVES: This scoping review mapped existing literature on short-term biochemical responses to air pollution in patients presenting acutely with cardiorespiratory conditions. ELIGIBILITY CRITERIA: Eligible studies were human studies assessing at least one biochemical marker in people presenting to emergency departments after short-term exposure to outdoor air pollution. SOURCES OF EVIDENCE: Five databases (PubMed, Scopus, Web of Science, Embase, CINAHL) were searched from 2000 to 2025. CHARTING METHODS: Data were extracted using the PCC framework and summarized in structured tables. RESULTS: Twelve studies met criteria. PM2.5, PM10, and NO2 were most frequently linked to inflammatory and coagulative markers such as CRP, IL-6, D-dimer, and troponins, often with effects seen within hours to days. CONCLUSIONS: The mapped evidence suggests that short-term air pollution exposure is associated with acute biochemical alterations. Standardized exposure windows, harmonized biomarker panels, and more detailed subgroup analyses are needed before these markers can support emergency-care pathways and environmental health policy.