Aerosol Pollutants and Health: Role of Size and Chemical Composition.

Air, an essential environmental component that surrounds us everywhere and is easily inhaled, is no longer the same as it was hundreds or thousands of years ago. Today, it carries a wide range of suspended particles and pollutants originating from both natural phenomena-such as dust storms and volcanic activity-and anthropogenic sources like vehicle emissions and various human activities. Particulate matter in the air is often classified by size, including PM10, PM2.5, and ultrafine particles, but particle size alone does not determine their behavior or impact. Other important characteristics, including surface area, chemical and biological composition, aspect ratio, and electric charge, also play a critical role in how these particles interact with living systems and the environment. These pollutants, especially with long-term exposure, pose serious threats to human health, ecosystems, and the environment. Recent advances in microfluidic technologies have enabled more precise assessment of air pollutant toxicity and exposure effects on human tissues. Among these, organ-on-a-chip (OoC) devices are particularly valuable for measuring the toxicity of pollutants on various human tissues and for quantifying the pollutant. In this article, in addition to extensively reviewing the fundamentals and recent developments in the field of aerosol pollutants, we present a simple mathematical explanation demonstrating how surface area plays a significant role in the interaction of biological molecules or chemicals with surfaces. A promising approach involves collecting data from ground-based and satellite monitoring and integrating it into predictive models, which may help in understanding and identifying potential air pollution sources and mitigating exposure.