Identify the waterborne diseases caused by viral pathogens:
Step 1: Recall the causative agents of each disease.
- Acute anterior poliomyelitis (Polio): Caused by the poliovirus (a viral pathogen), and can be transmitted through contaminated water.
- Cholera: Caused by the bacterium Vibrio cholerae, not a virus.
- Infectious hepatitis (Hepatitis A \& E): Caused by Hepatitis viruses (A and E), which spread through contaminated water.
- Typhoid fever: Caused by the bacterium Salmonella typhi, not a virus.
Step 2: Identify viral waterborne diseases.
Thus, among the given options, the viral diseases are:
- (A) Acute anterior poliomyelitis
- (C) Infectious hepatitis
\[
\boxed{\text{Correct options: (A) and (C)}}
\]
Henry's law constant for transferring \( O_2 \) from air into water, at room temperature, is 1.3 \( \frac{\text{mmol}}{\text{liter-atm}} \) . Given that the partial pressure of \( O_2 \) in the atmosphere is 0.21 atm, the concentration of dissolved oxygen (mg/liter) in water in equilibrium with the atmosphere at room temperature is \[ \text{(Consider the molecular weight of O}_2 \text{ as 32 g/mol)} \]