Silicosis

Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. It is marked by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs. It is a type of pneumoconiosis. Silicosis, particularly the acute form, is characterized by shortness of breath, cough, fever, and cyanosis (bluish skin). It may often be misdiagnosed as pulmonary edema (fluid in the lungs), pneumonia, or tuberculosis. Using workplace controls, silicosis is almost always a preventable disease.

Silicosis resulted in at least 43,000 deaths globally in 2013, down from at least 50,000 deaths in 1990.

The name silicosis (from the Latin silex, or flint) was originally used in 1870 by Achille Visconti (1836–1911), prosector in the Ospedale Maggiore of Milan. The recognition of respiratory problems from breathing in dust dates to ancient Greeks and Romans. Agricola, in the mid-16th century, wrote about lung problems from dust inhalation in miners. In 1713, Bernardino Ramazzini noted asthmatic symptoms and sand-like substances in the lungs of stone cutters. The negative effects of milled calcined flint on the lungs of workers had been noted less than 10 years after its introduction as a raw material to the British ceramics industry in 1720.

With industrialization, as opposed to hand tools, came increased production of dust. The pneumatic hammer drill was introduced in 1897 and sandblasting was introduced in about 1904, both significantly contributing to the increased prevalence of silicosis. In 1938, the United States Department of Labor, led by then Secretary of Labor Frances Perkins, produced a film titled Stop Silicosis to discuss the results of a year-long study done concerning a rise in the number of silicosis cases across the United States.

In the early 21st century, an epidemic of silicosis was caused by the unsafe manufacturing of engineered stone countertops containing quartz (and obsidian), which became popular.

Because chronic silicosis is slow to develop, signs and symptoms may not appear until years after exposure. Signs and symptoms include:

In advanced cases, the following may also occur:

Patients with silicosis are particularly susceptible to tuberculosis (TB) infection—known as silicotuberculosis. The reason for the increased risk—3 fold increased incidence—is not well understood. It is thought that silica damages pulmonary macrophages, inhibiting their ability to kill mycobacteria. Even workers with prolonged silica exposure, but without silicosis, are at a similarly increased risk for TB.