What term refers to tiny particles and droplets less than 10 micrometers in size suspended in the air?

• A. Particulate Matter (PM)
• B. Volatile Organic Compound
• C. Sulfur Dioxide
• D. Nitrogen Dioxide

Answer: (A)

Tiny particles and droplets suspended in the air are called Particulate Matter. This term covers a mix of solid particles and liquid droplets, and when we talk about those smaller than 10 micrometers, we’re referring to PM10 (with finer PM2.5 being the especially health-relevant subset). These small particles are important because they can be inhaled deep into the lungs and even enter the bloodstream, affecting respiratory and cardiovascular health. The other options describe gases or vapor-phase pollutants rather than particles: Volatile Organic Compounds are organic chemicals that exist as gases, while sulfur dioxide and nitrogen dioxide are gaseous pollutants produced from burning fuels and industrial processes.