Risk of lung cancer following exposure to carbon black, titanium dioxide and talc: Results from two case–control studies in Montreal

Abstract

(IARC) recently evaluated the carcinogenicity of three poorly soluble weakly-toxic substances: carbon black, titanium dioxide and talc. Though there is evidence of carcinogenity in experimental animals for these substances, the evidence in humans is sparse and equivocal. In the context of two large population based case-control studies of lung cancer carried out in Montreal, we were able to study the possible relationships between the exposure to each of these substances and subsequent risk of lung cancer. We were able to distinguish talc used for industrial purposes from that used for cosmetic purposes. Interviews for Study I were conducted in 1979-1986 (857 cases, 533 population controls, 1,349 cancer controls) and interviews for Study II were conducted in 1996II were conducted in -2001 (1,236 cases and 1,512 controls). Detailed lifetime job histories were elicited, and a team of hygienists and chemists evaluated the evidence of exposure to a host of occupational substances. Lung cancer risk was analysed in relation to each exposure, adjusting for several potential confounders, including smoking. Subjects with occupational exposure to carbon black, titanium dioxide, industrial talc and cosmetic talc did not experience any detectable excess risk of lung cancer. The results are consistent with the recent evaluations of the IARC Monographs. ' 2007 Wiley-Liss, Inc.Key words: lung cancer; carbon black; talc; titanium dioxide; casecontrol studies; Canada; occupational risks; chemical hazards Lung cancer remains the leading cause of cancer deaths in Canada and other industrialised countries. 1 Prevention of cancer requires identification of modifiable risk factors. Apart from smoking, one of the most fruitful areas for identification of lung cancer risk factors has been the occupational environment. The Monograph Programme of the International Agency for Research on Cancer (IARC) conducts evaluations of carcinogenic risks of different agents, and thereby provides the information base for cancer prevention throughout the world. 2 Recently, an IARC Working Group evaluated the carcinogenicity of three poorly soluble low-toxicity particulate materials: carbon black, titanium dioxide and talc. 3 IARC considered these agents together because they appear to cause tumours in the respiratory tract of rats through similar mechanisms, and because they may share some toxico-kinetic similarities.Carbon blacks are strong black pigments and they have been used extensively in the rubber, paint and printing industries. Carbon blacks do not occur as natural compounds, but are produced by thermal decomposition of hydrocarbons. 4,5 Carbon black dust is mainly composed of elemental carbon. Titanium dioxide is a white pigment, produced from ilmenite ore or from titanium slag. It is primarily used as a whitening and mollifying agent in paints, varnishes, lacquers, paper, plastics, ceramics, rubber and printing ink. 5,6 Mineral talc (Mg, Si, Fe, O) is a member of the silicate family; it can occur in platy form or, exceptionally, in as...

Lung cancer risk associated with occupational exposure to nickel, chromium VI, and cadmium in two population‐based case–control studies in Montreal

“…In Study II, controls were recruited according to the distributions of age, sex, and area of residence of lung cancer cases. Details of subject ascertainment and data collection have been presented in detail previously [Siemiatycki and Richardson, 1991;Ramanakumar et al, 2006Ramanakumar et al, , 2008.…”

The potential health risk of titania nanoparticles

“…Although limited epidemiological studies in U.S. and European TNP production factories showed no significant respiratory carcinogenic risks [11][12][13][14]. TNP toxicity has been observed in diverse models, such as rodents [15][16][17][18], aquatic organisms [19][20][21], and human cells [22][23][24].…”

Characteristics of Carbon Pyrolyzed from Table Sugar and Sucrose for Pt-less DSSC Counter Electrode

“…Research has found that a carbon black counter electrode could achieve a PCE of 8.29%, close to the value produced by a DSSC with a platinum counter electrode: a PCE of 8.35% (Wu et al, 2016). The use of carbon black, however, should be avoided due to its possible carcinogenic effect on humans (Ramanakumar et al, 2008).…”