The Committee appreciates the opportunity to respond to these two additional letters. This is also an opportune time to clarify other issues that may be lost in the detail of the Statement. Dr. Martin's letter is entitled "2004 Asbestos disease guidelines ignore mass screening abuse," as if the Statement condoned abusive practices. In fact, the Statement favorably cites both a 2002 white paper from the National Institute of Occupational Safety and Health and a 2000 resolution by the Association of Occupational and Environmental Clinics regarding characteristics of responsible and ethical screening programs. Dr. Martin makes two substantive allegations of error by the Committee in his original letter. One involves the interpretation of 1/0 readings, which the Statement describes, correctly, as "presumptively diagnostic but not unequivocal": this interpretation is inherent in the International Labour Organization (ILO) Classification system. Dr. Martin also requests a reference for the statement that the plain chest film has a sensitivity of no more than 90% and a specificity of about 93% (the source says 90 to 95%): the reference is number 150, cited in the Statement on page 710. To Dr. Smith, the Committee responds that the passages he describes as contradictory simply make reasonable distinctions. With respect to occupational and medical histories, the Committee has made the unexceptional recommendation that a physician take a history to help guide the diagnosis. With respect to his comment on pleural plaques, the Committee stands by what was written and the evidence cited. With respect to the contribution of asbestos exposure to airway obstruction, the Statement says that asbestos exposure might be clinically significant in the presence of low lung function. Dr. Smith writes: "The role of ILO B-Reader chest X-ray interpretation has recently come into question." In point of fact, the B-Reader Program belongs to NIOSH. It is not an activity of the ILO. Although relatively few communications have been received to date, it is unreasonable to expect the members of the Committee to provide individual responses to every future correspondent. In the interest of anticipating the concerns of others, therefore, the Committee offers the following broad overview of the Statement. The key difference between the 1986 criteria and the 2004 criteria is that the 2004 Guidelines present a more explicit approach to diagnosis based on criteria: the need to establish evidence for exposure, to identify a disorder compatible with asbestos as a cause, exclusion of other causes, and a forceful requirement for assessing impairment in the event that the physician makes a diagnosis of nonmalignant asbestos-related disease. Although these elements were mentioned in 1986, they were not given the same emphasis. The 2004 document also broadens the discussion beyond asbestosis, which predominated in 1986, and brings the criteria up to date with respect to modern methods of imaging, such as HRCT and digital radiography, and clinical evaluation. It also provides guidance to the physician on the initial management of the patient once a disease of this type is diagnosed, including what to look for and how to follow up such patients. The disease has to come first, so the identification of a disorder that is compatible with asbestos exposure is first. Then, the connection to asbestos exposure must be made and other plausible causes ruled out. The emphasis in the guidelines is on structural change, not functional change, in making the diagnosis. Functional deficit is not a diagnosis, in the sense of a specific disease entity, and members of the committee thought that functional changes were secondary phenomena, too nonspecific to fulfill a criterion but which may support the diagnosis. A restrictive defect, for example, is consistent with asbestosis (and much else) but may not be present early on and is not required for the diagnosis. The asbestos-related disease entity may of course result in impairment, which should then be measured to guide care and track progression. The document is not a major break with the past. The evidence required to meet each criterion has broadened with the advance of technology but remains conservative in that the emphasis is on the likelihood of a connection to asbestos and excluding other types of conditions, rather than identifying disease at the very earliest possible moment. The criteria are generally more specific than they are sensitive. The Committee prepared these guidelines for the purpose of guiding physicians to the recognition and confirmation of nonmalignant asbestos-related disease for the purpose of treatment and patient care: that was our mandate. The Committee did not formulate the guidelines for other applications and is not encouraging the use of these guidelines outside of clinical diagnosis. The Committee welcomes the comments of ATS members on the Asbestos Statement. An open forum has been scheduled during the ATS annual International Conference in San Diego for 7:00 to 9:00 pm, Sunday, 22 May 2005.