Refers to the point or place where something originates, such as a fire, pollution, sound, or problem.
It is difficult to identify the source of the fire.
この川の汚染の発生源は上流の工場だ。
The source of pollution in this river is a factory upstream.
It turned out that this factory was the source of the air pollution.
The investigators tracked down the source of the strange smell.
It is difficult to identify the source of an infectious disease.
The old pipes turned out to be the source of the water leak.
message origin authentication