An invalid character in descriptions - sql query to remove?

I've come across a zen cart (1.3.9h) that is having a problem getting the rss feed to display. The problem is due to invalid characters in many of the descriptions showing up as this �. When viewing the descriptions in admin you can not see anything but a space where the invalid character occupies in the description on the front end. The site owner is not sure how they got there but it is possible the descriptions were typed in microsoft word, copied and pasted into zen cart.

There are sooo many descriptions to be fixed. My question. Is there an sql query that can be run in the database to remove the invalid characters from the description table?

I am getting the same character � when i copy and paste product description from my vendor, i did not have that problem with zen 1.3.7 .

problem on zen 1.3.9h.

Could it be a collation problem?