Question

which role do ultrafine particles play in dirty air? they contribute to less than 13,000 premature deaths a year. they can worsen symptoms for people with breathing difficulties. they are easily removed from the air when people see them floating. they are constantly filtered by the nose, which prevents lung absorption.

Explanation:

Ultrafine particles in dirty air are very small and can penetrate deep into the respiratory system. They are known to exacerbate symptoms in people with pre - existing breathing difficulties like asthma or chronic obstructive pulmonary disease. The number of premature deaths attributed to them is often higher than 13,000 a year in many regions. They are too small to be seen floating and are not easily removed by the nose's filtering mechanism as they can bypass it and reach the lungs.

Answer:

They can worsen symptoms for people with breathing difficulties.