Rusty Base Board heating cover

I am having issues in all the bathrooms in my home. My base board heat covers are rusting. They are rusting at the end where the toilet is located. I assume this is due to moisture from the toilet, am I correct? Is there a type of base board for a forced hot water system I can get that will not rust? Why isn't this a standard? Maybe it is and I had a lousy builder. Thanks in advance for any info.

don,t blame the con,t

stand a little closer to the throne!
happens all the time. sand and repaint