Table 5

Estimates of cumulative risk, prevalence, and excess lifetime risks of radiographic silicosis due to exposure to respirable crystalline silica at the current OSHA permissable exposure limit

StudyIndustryOutcome and ILO criterionMeasureFollow up after employmen tEstimate (%)
*Cumulative risk based on 40 y at 0.1 mg/m3 quartz; †Cumulative risk based on 40 y at 0.05 mg/m3 cristobalite; ‡Cumulative risk based on 45 y at 0.1 mg/m3 quartz; §Lifetime excess risk based on 45 y at 0.1 mg/m3 quartz.
Studies with little follow up after employment:
    Muir et al40*Hard rock mining (gold)Radiographic, ILO: 1/1Cumulative risk0 y1.2
    Hughes et al20Diatomaceous earth (low exposure intensity)Radiographic, ILO: 1/0Cumulative riskMinimal1.1
Diatomaceous earth (high exposure intensity)Radiographic, ILO: 1/0Cumulative riskMinimal3.7
    Ng and Chan44Granite quarryradiographic, ILO: 1/1PrevalenceMinimal6.0
    LeGrand-Cattan et al45Ceramics industryRadiographic, ILO: 1/0Prevalence0 y31.0
    This studyDiatomaceous earthRadiographic, ILO: 1/0Lifetime excess riskMinimal7.5
Studies with follow up after employment:
    Hnizdo and Sluis-Cremer41Hard rock mining (gold)Radiographic, ILO: 1/1Cumulative risk<43 y77.0
    Kreiss et al43Hard rock miningRadiographic, ILO: 1/0Cumulative risk<40 y82.0
    Steenland and Brown42§Hard rock mining (gold)Radiographic, ILO: 1/1 and mortalityLifetime excess risk11–25 y35.0
    Chen et al46Tin miningRadiographic, ILO:∼1/1Cumulative risk<34 y55.0