Final answer:
The cited source is a newspaper article from the New York Times.
Step-by-step explanation:
The source represented by the citation 'Kramer, Cosmo F. "A Health Threat Baffling for Its Lack of a Pattern." New York Times 22 June 2003, natl. ed.: A14.' is a newspaper article. The title of the article, 'A Health Threat Baffling for Its Lack of a Pattern,' is placed within quotation marks, indicating that it is an article and not a book or a website. Moreover, it has a specific date and edition (national edition) as well as a page number (A14), which is typical for newspaper citations. The source is from the renowned publication New York Times, known for its journalism and reporting on current events.