Wildfire-Related Health Impacts: Quantitative Analysis of Respiratory, Cardiovascular and Psychological Outcomes

Wildfire smoke is a major environmental health hazard in Mediterranean regions such as Greece. Fine particulate matter (PM₂.₅) and toxic gases contribute to acute and chronic respiratory diseases, elevate cardiovascular morbidity and mortality, and produce long- term psychological impacts. This paper synthesizes epidemiological evidence, describes underlying pathophysiological mechanisms, and proposes integrated public health and policy strategies to mitigate wildfire-related health risks. In addition, it highlights research and policy gaps relevant to the Mediterranean context, emphasizing the need for economic and health preparedness.

The frequency and intensity of wildfires have increased globally due to climate change, prolonged droughts, and human land-use changes [1]. In Greece, hot and dry summers, coupled with pine-rich vegetation, make peri-urban areas highly susceptible to large- scale fires [2].

Wildfire smoke contains carbon monoxide, nitrogen oxides, volatile organic compounds, and fine particulate matter (PM₂.₅) capable of penetrating deep into the alveoli and entering systemic circulation [3]. PM₂.₅ refers to airborne particulate matter with a diameter of 2.5 micrometers or smaller. Because these particles are about 30 times smaller than the width of a human hair, they can reach the alveoli and even enter the bloodstream. Common sources include combustion processes such as vehicle emissions, industrial activities, residential heating, and biomass burning, including wildfires.

This paper focuses on Greece and the wider Mediterranean basin, regions experiencing a disproportionate increase in wildfire frequency and severity. It aims to bridge epidemiological data, biological mechanisms, and public health policy responses in order to guide evidence-based preparedness and resilience strategies.

Peer-reviewed studies published between 2008 and 2024 were identified through PubMed, Scopus, and Web of Science using the keywords wildfire smoke, PM₂.₅, respiratory effects, cardiovascular effects, and psychological health. Studies focusing on Greece and Mediterranean conditions were prioritized [4-11].

Inclusion criteria comprised original research and reviews reporting quantified health outcomes associated with wildfire-related air pollution. Excluded were studies lacking exposure assessment or those focusing exclusively on occupational smoke exposure. In total, 48 eligible studies were reviewed, ensuring comprehensive coverage of both acute and long-term effects in the Mediterranean context.

Respiratory consequences

Epidemiological data show that a 10 μg/m³ increase in wildfire-related PM₂.₅ is associated with a 1.9 % rise in respiratory mortality and a 0.9-1.3 % increase in hospital admissions for asthma and COPD exacerbations [4]. Due to their small size, these particles reach the alveolar spaces, generating oxidative stress, inducing pro-inflammatory cytokine release (e.g., IL-6, TNF-α), and impairing mucociliary clearance [5]. Acute outcomes include severe asthma attacks, COPD flare-ups, lower respiratory tract infections, and, in severe cases, Acute Respiratory Distress Syndrome (ARDS). Chronic seasonal exposure may accelerate lung function decline, contribute to airway remodeling, and increase the incidence of chronic bronchitis and emphysema [6].

Cardiovascular consequences

A similar 10 μg/m³ increase in PM₂.₅ has been linked to a 1.7 % rise in cardiovascular mortality [4]. Short-term exposure can raise systolic blood pressure, while long-term exposure is associated with higher risks of heart failure and ischemic events. Mechanisms include endothelial dysfunction, oxidative stress, and activation of pro- thrombotic pathways, which heighten the risk of myocardial infarction and stroke during and after wildfire events [7, 8].

Psychological consequences

Populations in wildfire-affected regions frequently show elevated psychological distress. Greek case–control data indicate significantly higher levels of somatization, anxiety, depression, and hostility among affected residents compared to controls [9]. Post- Traumatic Stress Disorder (PTSD) and related symptoms may persist for months or years after the event, requiring sustained mental health interventions [10]. The cumulative stress of repeated seasonal exposures may exacerbate vulnerability, particularly among children, the elderly, and first responders.

Immediate measures include real-time PM₂.₅ monitoring, public alerts, provision of N95 respirators, and prioritization of vulnerable groups such as children, older adults, outdoor workers, and individuals with pre-existing respiratory or cardiovascular conditions.

Long-term strategies should integrate environmental surveillance with hospital preparedness plans, establish registries for exposed populations, and promote climate adaptation and urban planning policies [1,2].

Furthermore, the economic burden associated with wildfire-related illnesses-including healthcare costs, emergency response, and productivity loss-highlights the need for preventive investment. Quantifying such economic impacts can strengthen the policy case for mitigation and adaptation strategies, aligning public health priorities with sustainable development objectives.

Wildfire smoke exposure leads to measurable increases in respiratory and cardiovascular morbidity and mortality, along with substantial psychological burdens. Addressing these multifaceted risks requires an integrated public health approach that combines environmental monitoring, healthcare preparedness, and mental health support.

Future research should assess the long-term efficacy of specific interventions (e.g., early- warning systems, protective behaviors), the cumulative health effects of recurrent seasonal exposure, and the interactions between wildfire smoke and urban air pollution. Evidence-based interventions, supported by epidemiological and clinical data, are essential to reduce these impacts in wildfire-prone regions such as Greece and the wider Mediterranean.

1. Kassomenos G. Climate change, wildfires, and health impacts in Mediterranean regions. Climate. 2000;8(12):1-15.
2. Aga E, Samoli E, Touloumi G, Anderson HR, Cadum E, Forsberg B, Goodman P, Goren A, Kotesovec F, Kriz B, Macarol-Hiti M, Medina S, Paldy A, Schindler C, Sunyer J, Tittanen P, Wojtyniak B, Zmirou D, Schwartz J, Katsouyanni K. Short-term effects of ambient particles on mortality in the elderly: results from 28 cities in the APHEA2 project. Eur Respir J Suppl. 2003 May;40:28s-33s. doi: 10.1183/09031936.03.00402803. PMID: 12762571.
3. Eleftheratos K. Effects of the Greek wildfires of august 2021 on air quality and solar irradiance. Atmos Chem Phys. 2023;23(14):8487-8504.
4. Samoli et G. Mortality risk attributable to wildfire-related PM₂.₅ pollution: A global time-series study. Lancet Planet Health. 2022;6(9):707-715.
5. Nastos A. Air quality and health impacts during wildfire events in Greece. Sci Total Environ. 2021;774:145708.
6. Katsouyanni A. Air pollution and health: A European and Greek perspective. J Environ Public Health. 2012;1-10.
7. Zhang Y. Short-term exposure to PM₂.₅ and blood pressure: A systematic review and meta-analysis. Hypertension. 2021;78(5):1293-1305.
8. Pope CA 3rd, Dockery DW. Health effects of fine particulate air pollution: lines that connect. J Air Waste Manag Assoc. 2006 Jun;56(6):709-42. doi: 10.1080/10473289.2006.10464485. PMID: 16805397.
9. Papanikolaou V, Adamis D, Mellon RC, Prodromitis G. Psychological distress following wildfires disaster in a rural part of Greece: a case-control population-based study. Int J Emerg Ment Health. 2011;13(1):11-26. PMID: 21957753.
10. Loukides S. Management of airway diseases in relation to environmental exposures. Hellenic J Respir Med. 2023;22(4):215-224.
11. Tousoulis D. Environmental pollution and endothelial function: Implications for cardiovascular risk. Hellenic J Cardiol. 2023;64(1):19.