Governments try to protect people from that can be harmful to the environment and to people.
positive externalities
negative externalities

The answer is “negative externalities.” Externalities are additional positive or negative consequences (costs or benefits) that happen to a third party, who did not have any decision in the matter at hand. Some examples of negative externalities which affect society or the environment include increased air pollution in a residential neighborhood due to the construction of a highway nearby or the destruction of wetlands due to the construction of a dam upriver. It is the government’s job to study and regulate the possible negative externalities before projects are undertaken in order to limit their impact.