"So ubiquitous and inexpensive are plastics that we've become a single-use, throwaway society. Synthetic plastics do not biodegrade. At best, they break and break again into smaller and smaller pieces. The fact remains that, save those incinerated, every single molecule of synthetic plastic ever created is still on this planet and probably will be for centuries". from Breaking the cycle of plastics in the ocean by Andrew Myers Ocean Conservancy Magazine Autumn 2007
Even though waste in Singapore is incinerated, lots of single-use plastics end up as litter when they are not disposed of properly, or they fall onto the ground due to wind or other reasons, subsequently go into the drain, flush into the canal, then into the sea. Singapore is not a clean city, but a cleaned city. There is plenty of litter here that potentially pollutes the environment.