- During winter, the concentration of PM2.5 is generally higher than in summer due to atmospheric conditions.
- PM2.5 primarily affects the lungs, whereas PM10 affects the upper respiratory tract.
Answer: Both 1 and 2
Notes: During winter, lower temperatures and atmospheric inversions tend to increase PM2.5 concentration. PM2.5, due to its tiny size, penetrates deeply into the lungs, while PM10 typically affects the upper respiratory tract. Both statements are thus correct based on established environmental and health studies.
