8126826 Results of extended follow-up of the German porcelain workers study: lung cancer and silicosis

<h3>Objective</h3> To quantify silicosis and lung cancer risks among 17,644 German porcelain workers occupationally exposed to respirable crystalline silica (RCS) after extending follow-up 15 years through Dec 31st, 2020. <h3>Material and Methods</h3> Porcelain workers enrolled in a mandatory medical surveillance program including triennial chest x-rays between 1985-1987 and alive at the end of the previous study follow-up (2005) were followed through 2020 for all-cause mortality and silicosis incidence. Cause of death was determined from death certificates. New silicosis cases were identified by re-reading x-rays of individuals included in the medical surveillance program and of individuals who filed insurance claims for silicosis. Cause-specific standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were estimated by RCS exposure group based on work histories and about 8,000 industrial hygiene measurements. Cox proportional hazards ratios (HRs) were estimated by cumulative and average exposure groups. <h3>Results</h3> Deaths from all causes increased from 1,610 (9.1%) to 4,586 (26%). No statistically significant increased mortality risks were seen due to lung cancer, renal cancer, or non-malignant renal disease. Lung cancer mortality also was unrelated to RCS exposure. In contrast, silicosis risk was strongly and statistically significantly associated with average exposure intensity &gt; 0.10 mg/m3 and cumulative exposure &gt;3.0 mg/m3-years; however, exposures below these thresholds were not associated with increased silicosis risk.