As soon as people realized that their health was related to the environment they began to think out principles for improving it.
The Romans constructed aqueducts to prevent drought and to create a clean, healthful water supply for the metropolis of Rome.
In the mid-19 th century in London Joseph Bazalgette designed the first major sewerage system.
The field emerged as a separate environmental discipline during the middle third of the 20 th century.
In many cases, as societies grew, action that were intended to achieve benefits for those societies had longer-term impacts which reduced other environmental qualities. One example is the widespread application of DDT (dichlorodiphenyltrichloroethane) to control agricultural pests in the years following World War 2.
F or thousands of years, people have come up with laws that restrict public actions that could harm the environment. for example the construction of sewer culverts in London and Paris in the 19th century and the creation of the US national Park system in the early 20th century