In the context of WHO Air Quality Guidelines, consider the following statements

2022

Environment, PollutionXImpact & remediation

In the context of WHO Air Quality Guidelines, consider the following statements :
1. The 24-hour mean of PM 2.5 should not exceed 15 μg/m3 and annual mean of PM 2.5 should not exceed 5 μg/m3.
2. In a year, the highest levels of ozone pollution occur during the periods of inclement weather.
3. PM 10 can penetrate the long barrier and enter the bloodstream.
4. Excessive ozone in the air can trigger asthma.

Which of the statements given above are correct?

(a)

1,3 and 4

(b)

1 and 4 only

(c)

2,3 and 4

(d)

1 and 2 only

Answer:

(b)

Factual

Explanation

Statement 1 is correct: According to the guidelines, The annual average for PM2.5 should not exceed 5 micrograms per cubic metre of air, while the 24-hour average should not exceed 15 micrograms per cubic metre. Statement 2 is not correct: Highest levels of ozone pollution occur during periods of sunny weather. Statement 3 is not correct: While particles with a diameter of 10 microns or less, (≤ PM10) can penetrate and lodge deep inside the lungs, they can’t penetrate the lung barrier and enter the blood system. Statement 4 is correct: Excessive ozone in the air can have a marked effect on human health. It can cause breathing problems, trigger asthma, reduce lung function and cause lung diseases.