Question

Read the following statements carefully.
1. Photochemical smog always contains ozone.
2. The toxic effect of carbon monoxide is due to its greater affinity for haemoglobin as compared to oxygen.
3. Lead is the most hazardous metal pollutant of automobile exhaust.
Which of the above statements is not true?

• A. $1$
• B. $2$
• C. $3$
• D. None of these

Answer 1

Answer: (D)

All of the above statements are true.

• Photochemical smog is composed of two types of pollutants. Primary pollutants include nitrogen oxides and volatile organic compounds. Secondary pollutants, like ozone, are the result of the reaction of primary pollutants with Uv light.
• Hemoglobin is the oxygen-carrying protein contained in the RBC's. It has three types. One of which is carboxyhemoglobin(COHb) which comprises less than 2% of total hemoglobin, it is the product of carbon monoxide and hemoglobin. This increased level of carbon monoxide results in carbon monoxide poisoning and its concentration more than 1,900 ppm is fatal.
• Lead is the most hazardous metal pollutant of the automobile and has caused extensive environmental contamination and health problems in many parts of the world.