Table 3

Summary of data, methods, and lung cancer unit risk estimates for lifetime exposure to 1 μg/m3 of crystalline silica derived from risk analyses of toxicological or epidemiological data

Reference Data source Exposure metric Statistical model Risk estimate
Collins and Marty19 Geometric mean of risk estimates from rat inhalation studies24-26 Respirable silica (quartz) particlesLinearised multistage (GLOBAL 86)2.9 × 10−4 (95% upper   confidence limit) (with surface area correction factor)
Goldsmith et al 18 Mortality study of diatomaceous earth workers4 Cumulative exposure to respirable   silica (exposure intensity × years) (mainly cristobalite) with 15 year lagLinearised multistage (GLOBAL 86)1.83 × 10−7
Cohort mortality study of South African gold miners21 Gold mining dust containing quartzLinearised multistage (GLOBAL 86)6.75 × 10−5
Goldsmith et al 18 Risk estimates from rat inhalation studies24-26 Respirable silica (quartz) particlesLinearised multistage (GLOBAL 86)6 × 10−3 (95% upper confidence   limit) (highest of 5 estimates) (with surface area correction factor)
Riceet al (this study)Mortality study of diatomaceous earth workers2 Cumulative exposure to respirable silica   with 10 year lag (mainly cristobalite) in mg/m3.yearsPoisson regression: linear relative rate3.8 × 10−4 (white men)