The natural pollutants are active only for a short duration. Due to natural reasons their activity is limited, and they are lost after a specific time. Their sources are not continuous and their spread too is not regular as in case of man-made pollutants which are emitted steadily.
Thus, we can avoid these substances. We also use them in limited quantity. Therefore, the natural substances, though may be polluting in nature, we are unable to perceive its toxicity. However, if we use them in abundance and create an imbalance, then its effect can be experienced as a great hazard.
