Question

which is a source of land pollution?
heavy traffic producing large amounts of exhaust
mold growing on an indoor windowsill
people smoking tobacco outside a building
fertilizer running off from a large agricultural farm

Explanation:

• Heavy traffic producing exhaust is air pollution.
• Mold on a windowsill is an indoor issue, not land pollution.
• Smoking outside is mainly an air - related and health issue (second - hand smoke), not land pollution.
• Fertilizer runoff from a farm can contaminate soil (land) as well as water (if it gets into water bodies). But when considering land pollution directly, the fertilizer that remains on the land or infiltrates the soil (before runoff) is a source of land pollution.

Answer:

fertilizer running off from a large agricultural farm