TABLE. Demographic, occupational, and clinical features of 18 silicosis cases in stone fabrication workers — California, Colorado, Texas, and Washington, 2017–2019.
| State-Patient no. | Age range (yrs) at diagnosis | Decade of first exposure* (total yrs) | Chest CT abnormalities | Pulmonary function test findings (FEV1, FVC, and DLCO percentage predicted; FEV1/FVC ratio) | Other associated conditions |
|---|---|---|---|---|---|
| CA-1† |
30–39 |
2000s (9 yrs) |
Diffuse ground glass and solid centrilobular nodules; mediastinal lymphadenopathy |
FEV1: 35%§ |
Scleroderma |
| FVC: 33%§ | |||||
| FEV1/FVC: 86% | |||||
| DLCO: 13%§ | |||||
| CA-2†,¶ |
30–39 |
2000s (13 yrs) |
Bilateral ground glass opacities and nodules |
Not performed |
Rheumatoid arthritis |
| CA-3 |
30–39 |
2000s (11 yrs) |
Diffuse, upper lung predominant perilymphatic nodules |
FEV1: 77%§ |
None |
| FVC: 83% | |||||
| FEV1/FVC: 76% | |||||
| DLCO: 70%§ | |||||
| CA-4 |
40–49 |
2000s (14 yrs) |
Subpleural nodules with upper lobe predominance; mild mediastinal lymphadenopathy |
FEV1: 73%§ |
None |
| FVC: 79%§ | |||||
| FEV1/FVC: 75% | |||||
| DLCO: 57%§ | |||||
| CA-5 |
30–39 |
2000s (14 yrs) |
Upper lobe architectural distortion and ground glass micronodules; mediastinal lymphadenopathy. |
FEV1: 58%§ |
None |
| FVC: 71%§ | |||||
| FEV1/FVC: 67%§ | |||||
| DLCO: 73%§ | |||||
| CA-6 |
50–59 |
2000s (16 yrs) |
Bilateral upper lobe fibronodular scarring; calcified mediastinal lymphadenopathy. |
FEV1: 94% |
None |
| FVC: 96% | |||||
| FEV1/FVC: 98% | |||||
| CO-1 |
40–49 |
2000s (12 yrs) |
Upper lung predominant perilymphatic nodules |
FEV1: 86% |
Latent tuberculosis infection |
| FVC: 92% | |||||
| FEV1/FVC: 76% | |||||
| DLCO: 96% | |||||
| CO-2 |
60–69 |
1980s (23 yrs) |
Diffuse perilymphatic nodules; calcified mediastinal lymphadenopathy |
FEV1: 57%§ |
Rheumatoid arthritis |
| FVC: 48%§ | |||||
| FEV1/FVC: 91% | |||||
| DLCO: 62%§ | |||||
| CO-3 |
50–59 |
2000s (13 yrs) |
Upper lung predominant nodules; calcified mediastinal lymphadenopathy |
FEV1: 82% |
Latent tuberculosis infection |
| FVC: 82% | |||||
| FEV1/FVC: 80% | |||||
| DLCO: 102% | |||||
| CO-4 |
40–49 |
2000s (17 yrs) |
Diffuse centrilobular nodules; upper lung ground glass opacities; calcified mediastinal lymphadenopathy |
FEV1: 96% |
None |
| FVC: 92% | |||||
| FEV1/FVC: 82% | |||||
| DLCO: 74%§ | |||||
| CO-5 |
50–59 |
1980s (23 yrs) |
Upper lung predominant nodules; calcified mediastinal lymphadenopathy |
FEV1: 105% |
Rheumatoid arthritis |
| FVC: 104% | |||||
| FEV1/FVC: 80% | |||||
| DLCO: 90% | |||||
| CO-6 |
40–49 |
1990s (22 yrs) |
Upper and middle lung predominant nodules |
FEV1: 105% |
None |
| FVC: 103% | |||||
| FEV1/FVC: 82% | |||||
| DLCO: 102% | |||||
| CO-7 |
40–49 |
1990s (24 yrs) |
Upper lung predominant nodules; mild paraseptal emphysema; calcified mediastinal lymphadenopathy |
FEV1: 90% |
Rheumatoid arthritis |
| FVC: 83% | |||||
| FEV1/FVC: 86% | |||||
| DLCO: 77%§ | |||||
| TX-1 |
50–59 |
2010s (2 yrs) |
Bilateral lower lobe ground glass opacities and scattered nodules |
FEV1: 65%§ |
None |
| FVC: 70%§ | |||||
| FEV1/FVC: 73% | |||||
| TX-2 |
50–59 |
1980s (31 yrs) |
Multiple bilateral pulmonary nodules; ground glass opacities in lower lobes and calcified hilar lymphadenopathy |
FEV1: 118% |
None |
| FVC: 115% | |||||
| FEV1/FVC: 80% | |||||
| TX-3 |
50–59 |
1980s (31 yrs) |
Upper lobe predominant reticular and partially calcified nodular opacities with bilateral partially calcified hilar and mediastinal lymphadenopathy |
FEV1: 89% |
None |
| FVC: 102% | |||||
| FEV1/FVC: 69%§ | |||||
| TX-4 |
40–49 |
2010s (2 yrs) |
Upper lobe predominant nodules with bilateral hilar and mediastinal lymphadenopathy |
FEV1: 54%§ |
None |
| FVC: 55%§ | |||||
| FEV1/FVC: 79% | |||||
| WA-1 | 30–39 | 2010s (6 yrs) | Diffuse, upper lung predominant nodules with early conglomeration; mediastinal lymphadenopathy | FEV1: 41%§ |
None |
| FVC: 44%§ | |||||
| FEV1/FVC: 77% | |||||
| DLCO: 32%§ |
Abbreviations: CA = California; CO = Colorado; CT = computed tomography; DLCO = diffusing capacity for carbon monoxide; FEV1 = forced expiratory volume in 1 second; FVC = forced vital capacity; TX = Texas; WA = Washington.
* Exact years of employment suppressed for patient confidentiality.
† Patient died from silicosis.
§ Abnormal pulmonary function test defined as FEV1<80% predicted, FVC<80% predicted, FEV1/FVC<70%, and DLCO <80% predicted. Global Lung Function Initiative reference values (2012) were used to calculate percentage predicted values for spirometry; DLCO was based on reference values in Crapo RO, Morris AH. Standardized single-breath normal values for carbon monoxide diffusing capacity. Am Rev Respir Dis 1981;123:185–9. For some cases, only spirometry was performed; therefore, DLCO is not reported.
¶ Silicosis diagnosed based on postmortem review of lung tissue.