You would need to still get a graduate degree with a Public Health degree but yes it is marketable. Some types of jobs available:
https://www.mastersportal.com/articles/587/what-can-i-become-with-a-masters-in-public-health.html
The amount of Math depends upon the college curriculum.
For a Cal state like Cal State LA, you only need 1 Statistics class for the major.
For a UC like UC Irvine, you need 1 Statistics class and 2 Calculus classes for the major.
For PA school, it will depend upon the school you are applying but most programs will require at least:
One year of chemistry with labs*
One course each of human anatomy and physiology with labs
One course in microbiology with lab
One course in statistics
One course in psychology
A degree in Public Health should cover all these courses either through major requirements and/or electives. Again it depends upon which school you attend and their major curriculum.
You also have to realize that PA is very competitive, so you will need to get a High GPA at any school you attend.
You do not have to major in Science to apply to Medical school, PA school etc… but it does make it easier to meet the school requirements. You need to go with your strengths.