of small amounts of poorly soluble beryllium compounds might occur in the lungs to allow persistent low-level beryllium presentation to the immune system. It is clear from these studies that more efforts are required to evaluate the role of intrapulmonary dissolution in beryllium-induced immune system stimulation and subsequent development of CBD.
It is important to consider several exposure parameters in understanding the dose-response relationship between exposure to beryllium and the development of CBD. These parameters include airborne concentration, particle size, particle composition, and particle solubility. In addition, there is now evidence that skin exposure is probably an important contributor to sensitization. Thus, in the second report, the committee will focus its attention on characterizing inhalation and skin exposure contributions to risk of BeS and CBD, and whether differences in the physiochemical properties and bioavailability of beryllium compounds warrant the development of different chronic inhalation exposure levels for different beryllium compounds.