Technical report 122


In a retrospective mortality study among employees who were occupationally exposed to toner, it was concluded that the results were consistent with the general mortality patterns among healthy working populations. There was no evidence that toner exposure increases the risk of all-cause mortality or cause-specific mortality for the 23 categories of death analysed (Abraham et al, 2010).

This cohort study examined the effects of occupational exposure to toner, a particulate material with widespread use in today’s society, on mortality. The study included 33,671 employees of a xerographic company employed between 1960 and 1982 as manufacturing workers or customer service engineers. Vital status was tracked through 1999. Standardised mortality ratios (SMRs) were calculated using the US population for comparison. Results: All-cause SMRs for toner-exposed populations were 0.65 and 0.84 for white men and women, respectively, and 0.37 and 0.74 for non-white men and women, respectively. SMRs for all cancers, lung cancer, respiratory disease, and cardiovascular disease in toner-exposed men were lower than 1.0 (Abraham et al, 2010).

This report, using data updated for vital statistics through December 31, 1999, extends the average follow-up time to 26 years and provides strong support that toner exposure does not increase mortality. The exposure to total dust concentrations from the CSE’s ranged from below the limit of detection to 0.34 mg/m3 (average value: 0.33 mg/m3). Field measurements resulted in total dust concentrations of 0.09 to 0.94 mg/m3, with an average of 0.28 mg/m3. One higher value (3.0 mg/m3) was considered suspect and was rejected. The average TWA concentration for total dust measured during worst-case testing was only slightly higher (0.38 mg/m3).

In general, there was a pattern of lower mortality in the Xerox population than expected compared with US mortality rates, consistent with the “healthy worker effect.” The SMRs for all causes were 0.65 and 0.91 for the white male exposed and control populations, respectively; 0.84 and 0.92 for the white females exposed and control populations, respectively. There was a similar indication of the healthy worker effect among non-white men and women. In addition, the SMRs for all cancers, lung cancer, respiratory disease, and cardiovascular disease in white and non-White men were all lower than 1.0 in the toner-exposed population, with the confidence limits not including 1.0. These SMRs suggest that exposure to toner in an occupational setting does not cause an increase in mortality from cancer, respiratory disease, or cardiovascular disease (Abraham et al, 2010).