Occupational exposure and mortality among workers at three titanium dioxide plants

Abstract

There was no indication of a positive association between occupational exposure and death from all causes, all cancers, lung cancers, non-malignant respiratory disease, or all heart disease.

Development of linear and threshold no significant risk levels for inhalation exposure to titanium dioxide using systematic review and mode of action considerations

“…Of the seven studies, two reported that lung cancer risk was significantly elevated among the workers (Boffetta et al, 2004;Ellis et al, 2013). When these positive findings were further investigated, it was apparent that exposure-response relationships were not observed for the exposure metrics evaluated (e.g., duration of employment, cumulative exposure).…”

“…1). Upon further evaluation, seven studies were determined to fulfill the inclusion criteria and quantitatively characterized carcinogenic endpoints in humans (Boffetta et al, 2001(Boffetta et al, , 2004Chen and Fayerweather, 1988;Ellis et al, 2010Ellis et al, , 2013Fryzek et al, 2003;Ramanakumar et al, 2008). These studies were all epidemiologic assessments of workers in TiO 2 production facilities in Europe and in the United States.…”

“…When these positive findings were further investigated, it was apparent that exposure-response relationships were not observed for the exposure metrics evaluated (e.g., duration of employment, cumulative exposure). Ellis et al (2013) contained detailed sampling data for TiO 2 in the workplace; the authors indicated that monitoring data for TiO 2 as well as titanium chloride (TiCl 4 ) (N ¼ 3488 industrial hygiene monitoring records) were collected from 1971 to 2002. The study authors reported the 8-h time weighted average (TWA) TiO 2 concentrations by 5-year calendar intervals and by job types.…”

“…For the calendar year intervals, the 8-h TWA concentrations ranged from 1.75 mg/m 3 in 2001e2005 to 31.5 mg/m 3 in 1971e1975. By job type, the 8-h TWA concentrations ranged from 0.15 mg/m 3 (purification) to 14.70 mg/m 3 (utility) (Ellis et al, 2013). When lung cancer risk was stratified by lagged and unlagged cumulative exposure categories (<5, 5 to 15, 15 to 35, 35 to 80, and >80 mg/m 3 -year), there were no obvious patterns in exposure-response, as those in the lower cumulative exposure categories exhibited higher relative risk estimates compared to those in the higher exposure categories (Table 5 of Ellis et al, 2013).…”

“…By job type, the 8-h TWA concentrations ranged from 0.15 mg/m 3 (purification) to 14.70 mg/m 3 (utility) (Ellis et al, 2013). When lung cancer risk was stratified by lagged and unlagged cumulative exposure categories (<5, 5 to 15, 15 to 35, 35 to 80, and >80 mg/m 3 -year), there were no obvious patterns in exposure-response, as those in the lower cumulative exposure categories exhibited higher relative risk estimates compared to those in the higher exposure categories (Table 5 of Ellis et al, 2013). In Bofetta et al (2004), lung cancer SMR was increased among men, but the study authors noted that lung cancer risk did not increase with duration of employment or estimated cumulative exposure to TiO 2 dust.…”