Improper Waste Disposal: Not disposing of plastics properly is one of the biggest causes of plastic pollution. When plastic is not disposed of in the correct bins, it can easily end up in the environment and eventually in our waterways. Littering: Littering is a major cause of plastic pollution, leading to plastics ending up in our oceans and other waterways. Illegal Dumping: Illegal dumping of plastic waste is a massive problem and one of the major causes of plastic pollution. Ocean Debris Accumulation: Accumulation of marine debris, such as fishing nets and other plastic items, are a major contributor to ocean pollution.