Occupational risks for idiopathic pulmonary fibrosis mortality in the United States

Metal and wood dust exposures have been identified as possible occupational risk factors for idiopathic pulmonary fibrosis (IPF). We analyzed mortality data using ICD-10 code J84.1--"Other interstitial pulmonary diseases with fibrosis," derived age-adjusted mortality rates for 1999-2003, and assessed occupational risks for 1999, by calculating proportionate mortality ratios (PMRs) and mortality odds ratios (MORs) using a matched case-control approach. We identified 84,010 IPF deaths, with an age-adjusted mortality rate of 75.7 deaths/million. Mortality rates were highest among males, whites, and those aged 85 and older. Three industry categories with potential occupational exposures recognized as risk factors for IPF were identified: "Wood buildings and mobile homes" (PMR = 4.5, 95% confidence interval (CI) 1.2-11.6 and MOR = 5.3, 95% CI 1.2-23.8), "Metal mining" (PMR = 2.4, 95% CI 1.3-4.0 and MOR = 2.2, 95% CI 1.1-4.4), and "Fabricated structural metal products" (PMR = 1.9, 95% CI 1.1-3.1 and MOR = 1.7, 95% CI 1.0-3.1). Workers in these industry categories may benefit from toxicological studies and improved surveillance for this disease.