Traffic policeman in Tokyo

Options

A. Wears gas mask
B. required daily oxygen treatment
C. Suffers from black lung disease
D. all the above

Answer

### Step-by-Step Solution:

1. **Understand the Context**: The question refers to the conditions faced by traffic policemen in Tokyo, a city known for its high levels of air pollution.

2. **Identify the Pollutants**: Recognize that Tokyo has significant air pollution, which includes pollutants like nitrogen oxides, sulfur oxides, and hydrocarbons. These pollutants can affect air quality and the health of individuals exposed to them.

3. **Impact on Health**: Acknowledge that prolonged exposure to these pollutants can lead to health issues, including respiratory problems. This is particularly relevant for traffic policemen who work outdoors and are exposed to these pollutants for extended periods.

4. **Consider the Options**:
- **Option A**: Wears gas mask - While this might be a precaution, it is not a standard requirement for all traffic policemen.
- **Option B**: Require daily oxygen treatment - This option suggests that due to the polluted environment, they may need supplemental oxygen to maintain healthy oxygen levels.
- **Option C**: Suffers from black lung disease - This is typically associated with coal dust exposure, not specifically with urban air pollution.
- **Option D**: All of the above - This would imply that all previous statements are correct.

5. **Evaluate the Best Answer**: Given the context of air pollution in Tokyo and its effects on health, the most accurate answer is that traffic policemen require daily oxygen treatment to counteract the effects of pollution on their respiratory health.

6. **Conclusion**: Therefore, the correct answer is **Option B: require daily oxygen treatment**.