Answer:

If chemicals are harmful, well, that’s it—they cause harm. But what is interesting is that earthworms are uniquely sensitive to all substances in their environment. The reason is that their skin is a big diffusion membrane. It is more like the inside of our lungs than like our skin. This allows molecules of all kinds to pass through it rapidly. Good molecules like oxygen diffuse in, not so good molecules like carbon dioxide diffuse out. Harmful chemicals in the soil would