Civil Services Examination · प्रश्न 44
In the context of WHO Air Quality Guidelines, consider the following statements: 1. The 24-hour mean of PM2.5 should not exceed 15 µg/m³ and annual mean of PM2.5 should not exceed 5 µg/m³. 2. In a year, the highest levels of ozone pollution occur during the periods of inclement weather. 3. PM10 can penetrate the lung barrier and enter the bloodstream. 4. Excessive ozone in the air can trigger asthma. Which of the statements given above are correct?
उत्तर देखें और व्याख्या
उत्तर: (B) 1 and 4 only
व्याख्या
The 2021 WHO limits for PM2.5 are 15 (24-h) and 5 (annual) µg/m³, and ozone triggers asthma. Ozone peaks in sunny, not inclement, weather, and it is PM2.5 (not PM10) that enters the bloodstream.