Subscripts and superscripts ignored by screen readers (accessibility issue)

Hello,

At my job we are required to make accessible documents.  That means they can be read out loud by a screen reader like NVDA.   I am having trouble getting subscripts and superscripts to read properly by the screen reader.  I did a simple test by making a file with Word with a few subscripts and superscripts.   The screenreader reads them properly in Word but when I make a PDF, it just reads right through them like they are on the base line.

Does anyone have any idea how to get subscripts and superscripts to read properly in a PDF?????

here are the Word and PDF file (attached to this post)

thank you

gary in Vermont