As far as plastic bowls go:

http://www.snopes.com/medical/toxins/petbottles.asp

I have to call BS on the bowls. Should they be washed? Yep. Any water bowl should be washed.

As far as the ceramics go, any ceramic bowl that's okay for human food should be okay for dog food/water.

There have been issues with lead paint in some ceramics imported into the US, but I haven't heard anything about it for a long time.