Response to “Letter to Editor: Errors and misunderstandings invalidate estimates of titanium dioxide inhalation risk”

Multiple errors made by authors result in a huge overestimation of potential exposure to particles in the size range 10–30nm in TiO2 nanoparticle production facilities

“…Somewhat surprisingly, Liao et al [7] stated that it was appropriate to describe "mg m −3 yr" as yearly averaged concentration based on "insufficient information" contained in the reports by Boffetta et al [4,8], and they did not correct this obvious error in their earlier risk assessment [2]. However, Table 2.8 of Boffetta et al [8] clearly indicates that 7.75 mg m −3 year is the median "estimated cumulative exposure to respirable TiO 2 dust" of surface treatment workers, and the report contains a long and comprehensive description of how the cumulative exposures of workers were estimated.…”

Response to “Letter to Editor: Multiple errors made by authors result in a huge overestimation of potential exposure to particles in the size range 10–30nm in TiO2 nanoparticle production facilities”

“…The published data from Boffetta et al [3] showed that (cumulative) exposure concentration was estimated to be 7.75 mg m −3 yr for European surface treatment workers. Due to the insufficient information provided by Boffetta et al [3], we have reasonably assumed that the TiO 2 exposure of 7.75 mg m −3 for European surface treatment workers was a year-averaged measurement and have used for risk analysis in our previous studies [1,6,7]. Yet Tomenson and Morfeld [8] considered that (cumulative) exposure (i.e., 7.75 mg m −3 yr) should be treated to be the 1-yr exposure.…”