Development of the global measurement system and its ongoing importance for accurate and effective air quality measurements.

This article emphasizes the crucial role of metrology, the science of measurement, in modern life. It explores the history and importance of the global measurement system in ensuring reliable and comparable data; how this system has evolved over the years into what we now recognise as the International System of Units; and the recent changes that have future proofed our system of measurement against the challenges of technological developments yet to come. The text highlights the particular significance of accurate measurements for air quality studies as having direct impact on policy decisions and assessment of the health effects of air pollution. To enhance the credibility and efficiency of air quality research, the article advocates for widespread adoption the principles of accreditation - the independent assessment and recognition of one's measurement capabilities - to strengthen the confidence in the conclusions made by air quality studies and thereby improve the discipline's effectiveness in supporting and assessing evidence-based policies to reduce air pollution.