What is a major health impact associated with PM2.5 exposure?

• A. Allergic symptoms only
• B. Penetrates deep into lungs and bloodstream
• C. Only irritates the eyes
• D. Improves oxygen transport.

Answer: (B)

PM2.5 are fine particles small enough to bypass many natural defenses and reach the deepest parts of the lungs, and some can even enter the bloodstream. This enables widespread inflammation and oxidative stress, which can disrupt normal lung function and contribute to cardiovascular problems like high blood pressure, heart attacks, and strokes. Because of this deep lung entry and systemic effect, the major health impact is not just irritation or allergy symptoms but the potential for serious respiratory and cardiovascular health issues.

Allergic symptoms can occur with some exposures, but PM2.5’s real significance lies in its ability to affect the entire body beyond the eyes or upper airways. It does not improve oxygen transport; in fact, it can impair it by causing inflammation and reduced gas exchange.