evidence: Dr R. Benson, Region VIII, Environmental Protection Agency, USA [...] It is also plausible that exposure estimate errors are more prominent at higher exposure levels as a result of past industrial hygiene sampling or worker protection practices (Hertz-Picciotto & Smith, 1993), which is consistent with the findings of the sensitivity analysis of the Rönnskär data (Järup, 1992), and the update of the Anaconda cohort (Lubin et al., 2000). [...] Re-analysis of the Anaconda cohort (Lubin et al., 2000) is also in favour of a linear exposure-risk relationship, and ascribes the apparent non-linearity to overestimation of the high exposures (mainly because of use of protective devices).