WHILE 
A) Point-source pollution enters the environment and the place most affected is usually the area immediately around the source and are often neglected by the government. 
B) A great deal of water pollution happens not from one single source but from many different scattered sources which is called nonpoint-source pollution and are taken care of. 
C) We know that pollution is a human problem because it is a relatively recent development in the planet's history: before the 19th century Industrial Revolution, people lived more in harmony with their immediate environment. 
D) Many initiatives have been taken by local people to reduce pollution and take care of the point sources.