Answer:
B
Explanation:
Pollutants themselves may not be harmful but the negative impact they constitute to the environment over time dictates the extent of their danger.
These pollutants that are released into the estuaries tends to be broken down over time. While breaking down, they tend to release toxins which are far more dangerous to the environment than their initial composition. This calls for the reasons why these pollutants needs to be checked the more before being released into the receiveing water body.