Hi Rebekka,

As far as I am aware, there is no legal precedence for the role of public health nurses and their health education/health promotion role within the countries that you state and, indeed' most Westernised countries. Their are the legislated scopes of practice, ethical codes of conduct, professional boundaries etc that govern all registered nurses practice, such as the UK's Nursing and Midwifery Council, but nothing specific to public/community health roles.

You may want to visit my site - where a lot of my publications relate to the role and function of nurses within health education/health promotion. It would be very difficult, in my mind, to legislate specifically for health promotion roles and public health nurses - because their practices vary widely and their 'interpretation' of what constitutes 'health promotion' is another major hurdle

thank you so much for all these great answers! and I will have a look at your website, I hope I can get at least some answers

thanks a lot!

 In the U.S. many states have their own nursing board certification, so it wouldn't surprise me if every state has different laws about what nurses are "allowed" to do with regard to public health. 

It depends on what you are including in prevention.  Providing flu immunizations would be covered by nursing practice laws but engaging in policy, advocacy, or education would not.   There is voluntary certification of health education/health promotion specialists but they do not require you to be a nurse.