There are different kinds of pollution like land pollution, water pollution, air pollution etc.
Pollution affects the health of living beings. Humans, plants, animals all affected this.

Sewage water, water from factories, and use of chemical fertilizers are important sources of water pollution.
Polluted water is the cause of many diseases, the water cannot be used for cooking food, washing cloths, drinking purpose etc.
Many important cities are battling with air pollution. It leads to many respiratory diseases.

Due to air pollution, some time trains run late, flights are delayed etc.
Plastics are the main reason for many types of pollution. Many countries had banned the use of plastic.
Noise pollution is another major pollution in many cities. The use of horn, loud music systems etc led to noise pollution.