Why is improper disposal of waste a curse to environment?

Disposing of waste materials can harm the environment by leading to many problems. Collection of waste at nearby places to residential area can cause many communicable diseases and epidemics. Moreover, if it is not covered, it will create stench issues in the surrounding area for persons living there. Moreover, if the waste is not properly segregated at some place, then it might not be biodegrade and thus can pollute the environment. So, improper disposal of waste can prove a curse to the environment.