Which plume behavior has the most severe impact on human health

GPSC AE (Class 1 & 2) – 2019

⭕ A. Coning

⭕ B. Fanning

⭕ C. Trapping

⭕ D. Fumigation

📚 Explanation:

Fumigation is the most dangerous plume behavior for human health.

✔ Occurs when:
🔹 An **inversion layer exists above** the plume
🔹 Air **below is super-adiabatic**

This traps pollutants at ground level, causing severe human exposure.

Other plume behaviors:
🔸 Coning: Neutral conditions
🔸 Fanning: Stable conditions
🔸 Trapping: Pollutants trapped between two inversion layers

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👉 Therefore, the correct answer is: D. Fumigation

Key Points on Plume Behavior:

• Fumigation: Most severe plume type; pollutants forced downward.
• Cause: inversion above + super-adiabatic lapse rate below.
• Impact: High pollution at human breathing level.