BACKGROUND Occupational and environmental exposure to crystalline silica may lead to the development of silicosis, which is characterized by inflammation and progressive fibrosis. A substantial number of patients diagnosed with silicosis develop pulmonary hypertension. Pulmonary hypertension associated with silicosis and with related restrictive lung diseases significantly reduces survival in a...

Silica exists in both crystalline and noncrystalline forms, with crystalline silica being the hazard of concern. Silica, or silicon dioxide, exposure is associated with many occupations, including construction workers, laborers, miners, foundry workers, glassmakers, drywall finishers, bricklayers, and tuckpointers.(1) Crystalline silica occurs most commonly in the form of quartz, cristobalite, ...

The formation of reactive oxygen species resulting from the interaction of silica dust particles with red blood cell membranes was investigated; particularly, the effect of surface hydroxyl (silanol) group concentration on the rate of formation of such reactive oxygen species was investigated. The rate of formation was measured indirectly through the effect of catalase, a hemoprotein peroxidase...

Silica is a very common material that can be found in both crystalline and amorphous forms. Well-known toxicities of the lung can occur after exposure to the crystalline form of silica. However, the toxicities of the amorphous form of silica have not been thoroughly studied. The majority of in vivo studies of amorphous silica nanoparticles (NPs) were performed using an inhalation exposure metho...

BACKGROUND Respirable crystalline silica is a highly prevalent occupational exposure and a recognized lung carcinogen. Most previous studies have focused on selected high-exposure occupational groups. This study examines the relationship between occupational exposure to silica and lung cancer in an occupationally diverse male population. METHODS Two large population-based case-control studies...

OBJECTIVES To investigate the risk of silicosis among tin miners and to investigate the relation between silicosis and cumulative exposure to dust (Chinese total dust and respirable crystalline silica dust). METHODS A cohort study of 3010 miners exposed to silica dust and employed for at least 1 year during 1960-5 in any of four Chinese tin mines was conducted. Historical total dust data from...

Crystalline silica has long been well established as a fibrogenic agent, and recent evidence has implicated it as a potential human carcinogen. However, the mechanisms of silica-induced disease development and progression are not well understood. Our previous studies demonstrated that crystalline silica is able to activate activator protein-1 (AP-1) through mitogen-activated protein kinase (MAP...

OBJECTIVE To use various exposure-response models to estimate the risk of mortality from lung cancer due to occupational exposure to respirable crystalline silica dust. METHODS Data from a cohort mortality study of 2342 white male California diatomaceous earth mining and processing workers exposed to crystalline silica dust (mainly cristobalite) were reanalyzed with Poisson regression and Cox...

I am writing this letter on behalf of the International Diatomite Producers Association (“IDPA”), a trade association of producers of diatomaceous earth products that was formed in 1987. IDPA includes in its membership companies both doing business and operating facilities in the state of California. IDPA sponsored one of the principal epidemiology studies relating to crystalline silica exposur...