Using medications to prevent or reduce the impact of poor air quality on health: a systematic review
Authors: Hassan N , March C , Mohammadkhan A , Zarandi I , Wilson S , Slight S 
Published: November 2024

Abstract

Introduction
Particulate matter (PM) is a mixture of tiny solid materials and liquid particles in the air that can trigger inflammatory reactions in multiple body systems, including the respiratory, cardiovascular and endocrine systems. Currently, there are no licensed pharmacological interventions to prevent or modify the effects of PM on different organs. However, several existing medications have shown promising results towards modifying or preventing the negative impact of PM.

Aim
To conduct a systematic review to explore pharmacological interventions that could potentially prevent, delay or treat the effects of PM on human health.

Methods
This systematic review complied with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework and was registered with PROSPERO database (CRD42023476448). Four databases were searched including; MEDLINE, Embase, PsycINFO and Scopus. Keywords were arranged into different relevant sets such as ‘air pollution’, ‘medication’ and ‘prevention’/’treatment’. All the resulting titles, abstracts and full-texts were screened independently by two researchers. Only peer reviewed articles published in English were included. A tailored data extraction sheet was used to collate all relevant data, including the study description (i.e. country, year), study design (i.e. prospective), medication information (i.e. type of medication, dose, indication), population (i.e. demographics and disease), effect on air pollution (i.e. treatment or prevention). Quality assessment was conducted using Newcastle Ottawa tool. Ethical approval was not required to undertake this systematic review.

Results
The search produced 689 articles, 676 of which were removed at the title (n=463), and abstract (n=184) and full-text (n=29) stages. Thirteen articles were included, 10 of which were rated ‘good’ quality, two ‘fair’ quality, and one ‘poor’ quality. There was a range of pharmacological interventions evaluated, including beta blockers, oral anti-diabetic agents, statins, non-steroidal anti-inflammatory drugs (NSAIDs), systematic glucocorticoids, inhalers (adrenergic, glucocorticoid and anticholinergic inhalers) and theophylline. All studies focused only on PM, with six providing information on the particle diameter (e.g., PM10, PM2.5 and PM0.1). Statins, NSAIDs and bronchodilators demonstrated the most significant impact on reducing the damage caused by PM on both the cardiovascular and respiratory systems through anti-inflammatory, vascular re-modelling, and broncho-dilating effect. These medications had already been prescribed in these study patients for other indications (e.g., diabetes or asthma). None of the included studies used a medication for the prevention or treatment of air pollution effects as an indication.

Conclusion
Some medications significantly prevented/treated the effects of poor air quality; however, this was inconsistent across studies. However, all studies were conducted in high to middle-high income countries; findings may have been different in low-income countries. More research is required on the effective medication dose, duration of administration, if being prescribed solely for air pollution protection, and benefits and risks for more vulnerable populations (i.e. multimorbid).

References
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2. Arias-Pérez RD, Taborda NA, Gómez DM, Narvaez JF, Porras J, Hernandez JC. Inflammatory effects of particulate matter air pollution. Environmental Science and Pollution Research. 2020 Dec;27(34):42390-404.