Oil, gasoline, and trash.
They can cause pollution.
Rainwater pollution is caused by lake and river pollution (the polluted water evaporates and then becomes rain). If people stopped dumping garbage in lakes, then there would be less rainwater pollution.
Geography
the wastes of industry are directly thrown to the river and cause a huge amount of water pollution.
human waste is causing pollution by the drains being emptied in to the river causing water contamination.
cause of you
Geography
Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds
Because of the sea creatures that live in the river(they could die), and it can make the water toxic
River pollution could be toxic waste discharged from a factory (or untreated sewerage) - which can cause ulcers, gills and scale damage, and kill fish and other aquatic life. Or, the pollution could be from fertilizer run-off from farmland - which can cause excessive weed and algae growth chocking the river - even leading to lack of oxygen in the water.
Liquid substances can be poured into lakes and river which the horses may drink and rubbish, well, they can get stuck or caught in it, or, they can eat it!
pollution can get into the river and kill the fish, among other creatures in the rive