What problems occurs by overuse of plastics?

Some of the problems are:

1) reduction of non-renewable resources (in the most common case, plastics are a petrochemical product...made from hydrocarbons, which are made from refined crude oil, which is a non-renewable resource);

2) (polution) - when not recycled, plastics create a lot of waste (see large masses of plastic floating around our oceans);

3) (pollution) - some plastics also form toxic substances when they are broken down