The government is doing a few constructive things to try to cut down on pollution. One thing is requiring all vehicles to use unleaded gas and also most states require an emissions inspection, per the advice of the government. Another thing is that they set regulations on plants such as the electric plant in Nucla, Colorado that they are actually shutting down because it uses coal and coal is thought to harm the environment.
They have shut down other plants too and continue to rule things out for use as an aerosol can spray and the burning of certain things, like used tires. Companies are accountable to the government for their pollution index and levels so the government is monitoring them to make sure they are up to strict standards of air purity.
What government does to reduce pollution depends on which country you live in. countries like costa Rica lead the way in responsible management and care for their environment. Other countries have rules and processes to limit what damaging waste is conveyed to the atmosphere and water, and about how waste is managed.
For instance, the domestic division of waste into categories that are recyclable. Fines can be applied to those who dispose of waste in spaces that are not allocated for this. There are international meetings to decide on policies that will protect the environment.