Which statement about particulate matter (PM) is correct?

• A. PM comes from industrial/vehicle emissions, road dust, agriculture, construction, and wood burning
• B. PM forms only indoors
• C. PM has no health effects
• D. PM is produced only by volcanic activity

Answer: (A)

Particulate matter comes from a variety of sources, including combustion from industry and vehicles, road dust, agricultural activities, construction, and wood burning. This broad range reflects how PM is emitted and formed in the real world, making the statement capturing these sources the best choice. PM isn’t limited to indoors; it travels outdoors and can infiltrate indoor environments. It also has documented health effects, affecting respiratory and cardiovascular systems. It’s not produced only by volcanic activity—volcanoes are just one of many natural sources, with anthropogenic sources contributing a large share as well.