Diseases like typhoid, cholera etc may be caused due to

Options

A. burning of fossil fuel
B. industrial effluents
C. domestic sewage
D. radio active sub- stances

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the causes of diseases like typhoid and cholera. These diseases are known to be waterborne and can be linked to environmental factors.

2. **Identifying the Sources of Contamination**: The primary sources of contamination that can lead to diseases like typhoid and cholera include domestic sewage, industrial effluents, and other forms of waste.

3. **Role of Domestic Sewage**: Domestic sewage is wastewater from homes and hospitals. This type of sewage often contains pathogenic microorganisms, which are harmful bacteria and viruses that can cause diseases.

4. **Pathogenic Microorganisms**: These microorganisms are responsible for causing diseases. For instance, the causative agent of typhoid is the bacterium Salmonella typhi, while cholera is caused by Vibrio cholerae. Both of these pathogens can be found in contaminated water sources.

5. **Consequences of Improper Sewage Disposal**: If domestic sewage is not treated properly before being released into water bodies, it can lead to the spread of these pathogenic microorganisms, resulting in outbreaks of diseases like typhoid and cholera.

6. **Industrial Effluents**: While industrial effluents can contain toxic substances (like heavy metals), the diseases mentioned (typhoid and cholera) are primarily associated with pathogens found in domestic sewage.

7. **Conclusion**: Therefore, the main causes of diseases like typhoid and cholera are primarily linked to the presence of pathogenic microorganisms in domestic sewage.

**Final Answer**: Diseases like typhoid and cholera may be caused due to the presence of pathogenic microorganisms in domestic sewage.

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