Public health information dissemination represents an interesting combination of broadcasting, sharing, and retrieving relevant health information. Social media-based public health information dissemination offers some particularly interesting characteristics, as individual users or members of the public actually carry out the actions that constitute the dissemination. These actions also may inherently provide novel evaluative information from a document computing perspective, providing information in relation to both documents and indeed the social media users or health consumers themselves. This paper discusses the novel aspects of social media-based public health information dissemination, including a comparison of its characteristics with search engine-based Web document retrieval. A preliminary analysis of a sample of public health advice tweets taken from a larger sample of over 4700 tweets sent by Australian health-related organization in February 2012 is described. Various preliminary measures are analyzed from this data to initially suggest possible characteristics of public health information dissemination and document evaluation in micro-blog-based systems based on this sample.