Mortality among mine and mill workers exposed to respirable crystalline silica

• Published in: PloS one Vol. 17; no. 10; p. e0274103
• Main Authors: Kleinschmidt, Sarah E, Andres, Kara L, Holen, Brian M, Buehrer, Betsy D, Durand, Gerardo, Taiwo, Oyebode, Olsen, Geary W
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 14.10.2022; Public Library of Science (PLoS)
• Subjects: Biology and Life Sciences; Chronic obstructive pulmonary disease; Crystal structure; Crystallinity; Disease prevention; Dose-response effects; Employees; Evaluation; Exposure; Fatalities; Health aspects; Health hazards; Health risks; Hygiene; Industrial health and safety; Job titles; Kidney diseases; Lung cancer; Lung diseases; Manufacturing; Manufacturing industry; Medicine and Health Sciences; Miners; Mortality; Occupational exposure; Occupational health and safety; Occupational safety; Quartiles; Regression analysis; Regression models; Respiratory diseases; Roofing; Silica; Silicon dioxide; Silicosis; Social Sciences; Social security; Workers; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0274103

Millions of workers are potentially exposed to respirable crystalline silica (RCS) which has been associated with several diseases. We updated the mortality experience of a cohort of 2,650 mine and mill workers at four manufacturing facilities to assess cause-specific mortality risks associated with estimated cumulative RCS exposure. Study eligibility was defined as any employee who had [greater than or equal to]1 year of service by 2000, with work history experience available from 1945 through 2004. Vital status and cause of death were ascertained from 1945 through 2015. RCS exposure was estimated across plant-, department-, job-, and time-dependent categories using historic industrial hygiene sampling data and professional judgment. Associations between cumulative RCS (mg/m.sup.3 -years) and cause-specific mortality were examined using Cox proportional hazard regression models. In the exposure-response analysis defined on quartiles of cumulative RCS exposure, no increasing trend (p.sub.trend = 0.37) in lung cancer mortality (n = 116 deaths) was observed (Hazard ratio (HR) = 1.00 (referent), 1.20, 1.85, 0.92). Mortality risk for non-malignant respiratory disease was increased across quartiles (HR = 1.00, 1.35, 1.89, 1.70; p.sub.trend = 0.15), based on 83 deaths. Non-malignant renal disease mortality was increased across quartiles (HR = 1.00, 6.64, 3.79, 3.29; p.sub.trend = 0.11), based on 26 deaths. After nearly seven decades of follow-up, the exposure-response analyses showed no evidence of a positive trend for lung cancer, and limited evidence of a trend for non-malignant respiratory disease, and non-malignant renal disease mortality as a result of cumulative RCS exposure in this occupational cohort.