First, consider the following Wikipedia definition and comments about "junk science":

<<Oftentimes, the term "junk science" is used by opponents of certain advocacy groups who believe that a said group's scientific research is biased, unscientific, and with a special agenda to prove, rather than unbiased, true scientific inquiry.

As with many other ideological terms, there is often no political agreement as to which side of a debate constitutes "junk", and which "real" science, though the scientific community typically has an overwhelming majority opinion. Public debates on environmental and public health issues seem particularly prone to this problem. These debates are further complicated when scientists use mass media to publicize their research.>>

In the case of the Surgeon General's comments, the announcement was made via public media rather than a peer-reviewed scientific journal. However true or admirable, the purpose seems to have been to further the agenda of the anti-smoking lobby by using the power of the Public Health pulpit. Their goal now seems to be to outlaw smoking everywhere, even outdoors and within the private property of others.

The press release contained claims such as "Second-hand smoke is a leading cause of preventable death among adults in the US, and kills at least 53,000 people each year," but no links to the peer-reviewed scientific studies to support that statistical claim. It also fails to define a de minimis level of "exposure" or separate the second-hand tobacco smoke exposure effects from thngs like diesel exhaust, which everyone is exposed to also to some degree.