[color=#231f20][color=#231f20][color=#231f20]i love a ches! you will make a great phn! it depends on the employer, but i encourage you to apply to positions even if the job description reads "bsn preferred".
it varies from employer to employer what the degree requirements are for a phn position. i work at a local health department in va now, and there are ms, bsn, adn, and licensed diploma nurses all holding phn positions. the last local health dept where i was employed in co only hired rns holding bsns or ms/msn degrees. however, they did consider one applicant that was an adn and currently enrolled in a bsn bridge program. maybe you could consider working towards your bsn or ms part-time.
fyi: the ana's phn scope and standards of practice does state "the baccalaureate degree in nursing is the educational credential for entry into public health nursing practice". it's something to bear in mind.
good luck in you job search, and welcome to public health nursing!