Response to Tomenson’s letter on ‘Lung cancer mortality in the French cohort of titanium dioxide workers: some aetiological insights’

Abstract

We thank the editor for the giving us the opportunity to respond to the points raised by Tomenson. Further, we would like to thank Tomenson for making publicly available parts of the so far unpublished report to the sponsors (the Titanium Dioxide Manufacturers Association, for which he provides consultancy services), including particularly the positive dose-response data for the French sub-cohort (re-analysed in our paper). 1 As clearly described in Methods and in Results of our short report, the cumulative exposure to TiO2 was lagged by 10 years. Obviously, this also affects the number of unexposed and exposed workers as reported in the supplemental Table S3. 2 We recognize that we should have specified this also in the footnotes of that table.Regarding tobacco smoking, data were available for 201 (not only 33) workers at the second French plant and the combined crude smoking prevalence for the two French plants was 34%, compatible with the age-standardized prevalence of 42% reported by Boffetta et al. 1 As discussed in our paper, 2 we recognize that the reported prevalence of smoking was low, and lower than that estimated on the national level.