London smog of 1952 that killed about 4000 lives persons, was

Options

A. photochemical and rich in `NO_(2)`
B. coal induced and rich in `SO_(2)`
C. effect of nuclear accident
D. due to atomic explosion

Answer

**Step-by-Step Solution:**

1. **Understanding the Event**: The London smog of 1952, also known as the Great Smog of London, was a severe air pollution event that occurred in December 1952. It is important to recognize the historical context and the impact it had on public health.

2. **Identifying the Cause**: The primary cause of the London smog was the burning of coal, which released large amounts of pollutants into the atmosphere. The smoke was rich in sulfur dioxide, a major component of the pollution.

3. **Recognizing the Effects**: The smog led to severe health issues, including respiratory problems, and is estimated to have caused around 4,000 deaths during the event. The high concentration of sulfur dioxide and particulate matter in the air contributed to these health crises.

4. **Differentiating Types of Smog**: It is crucial to differentiate between types of smog. The London smog is classified as "classical smog," which occurs in winter and is associated with high humidity and low temperatures. In contrast, photochemical smog, which occurs in urban areas with high sunlight and temperatures, is rich in nitrogen oxides and is exemplified by the smog in Los Angeles.

5. **Conclusion**: Based on the information gathered, the London smog of 1952 was primarily coal-induced and rich in sulfur dioxide, making it a classical smog event. This event serves as a significant example of the impacts of air pollution on human health.

**Final Answer**: The London smog of 1952 that killed about 4,000 people was coal-induced and rich in sulfur dioxide.

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