A bit of googling to find out about science communication in the US and I found this, there are some job descriptions / adverts in there too:
Science Writers in New York
“The membership of Science Writers in New York (SWINY) is composed of editors and writers who cover science and medicine in the print and electronic news media as well as public relations professionals who promote science. Anyone with an interest in science communication is welcome to become a dues paying member, and non-members are encouraged to attend our events.
We invite you to explore our site. You can also find us on LinkedIn, Facebook and Twitter.
For more information, feel free to contact a board member or email email@example.com.
April 11: Grab Your Reader! Writing Tactics That Hook and Hold Your Audience
Regulatory Medical Writer (FT, PA)
Science Writer for Symposium (Freelance, NYC)
Associate Editor, Cancer Today (FT, Philly)
Collaborators, LatinAmericanScience (Freelance, Telecommute)”