RATIONALE: Outbreaks of fungal infections (mycoses) can occur among workers disrupting soil and/or bird droppings. The National Institute for Occupational Safety and Health (NIOSH) received two requests for investigation of whether increased risk of mycosis exists in workers with concomitant exposure to both silica and fungi. Although, silicosis is thought to increase risk for mycosis, no quantification of this risk exists. METHODS: To quantify the risk of dying with both mycosis and pneumoconiosis, we explored the coincidence of mortality from mycosis with silicosis, coal workers' pneumoconiosis (CWP), or asbestosis among US residents using the National Occupational Respiratory Mortality System. We evaluated mycosis mortality in people who died at age 45 or older with any multiple cause-of-death mention of each pneumoconiosis from 1979 to 2004, in comparison to those dying without any mention of these pneumoconioses. RESULTS: Those dying with silicosis have 4.4-fold risk of dying with mycosis compared to those dying without pneumoconiosis (prevalence ratio 4.4, 95% CI 3.4-5.9). The respective prevalence ratio for decedents with asbestosis is 1.5 (95% CI 1.2-2.0) and for decedents with CWP is 1.0 (95% CI 0.8-1.2). Silicosis decedents were 2.9 (95% CI 2.0-4.3) times more likely to have mycosis at death compared to asbestosis decedents. Silicotics were 4.6 (95% CI 3.2-6.6) times more likely to have mycosis than persons dying with CWP. CONCLUSIONS: Health professionals should consider this enhanced risk of disease when co-exposure to fungi and silica exists. Although there are no specific OSHA or NIOSH exposure limits for fungi, measures to protect silica-exposed workers with potential fungal exposure include good hygiene practices, wetting soil and bird droppings to suppress dust, using enclosed cabs with high-efficiency particulate air filtered air-conditioning, respiratory protection, worker education, and access to medical care.
Respiratory-system-disorders; Pulmonary-system-disorders; Lung-disease; Lung-disorders; Epidemiology; Statistical-analysis; Coal-workers-pneumoconiosis; Pneumoconiosis; Silicosis; Mycology; Mycotoxins; Microorganisms; Asbestosis; Fungi; Fungal-diseases; Fungal-infections; Mortality-rates; Mortality-data; Mortality-surveys