Re: Are we polluting the environment when we drink from plastic cups

At one point many plastics were contaminated with PCB's(poly chlorinated 

biphenyls). Since these compounds are now banned, plastics tend not to 

contain them. However, the chain like polymer molecules in conventional 

plastics are not biodegradable, that is if they are left lying around 

bacteria and fungi will not be able to break them down into more basic 

elements.
Some newly developed plastics used in packaging do break down, at least 

partially, in the environment. 
Although it is unlikely that the plastic in the cup you're using has 

degradable plastics, it is possible that if you place it in a recycling bin 

when it is time to throw it away, it will be recycled into another plastic 

product. That will depend on how sophisticated your neighbourhood recycling 

program is.