Inhaling crystalline silica can lead to serious, sometimes fatal illnesses including silicosis, lung cancer, tuberculosis (in those with silicosis), and chronic obstructive pulmonary disease (COPD). In addition, silica exposure has been linked to other illnesses including renal disease and other cancers.

Signs & Symptoms

Silica causes permanent lung damage that can be disabling and potentially fatal. When workers inhale crystalline silica, the lung tissue reacts by developing fibrotic nodules and scarring around the trapped silica particles. If these nodules grow too large, breathing becomes difficult;

• Chronic silicosis, which usually occurs after 10 or more years of exposure to crystalline silica at relatively low concentrations;
• Accelerated silicosis, which results from exposure to high concentrations of crystalline silica and develops 5 to 10 years after the initial exposure; and
• Acute silicosis, which occurs where exposure concentrations are the highest and can cause symptoms to develop within a few weeks to 4 or 5 years after the initial exposure.

Silica and other dusts cause COPD. COPD includes chronic bronchitis, emphysema, bronchiectasis, and chronic airway obstruction. In 2021, according to the World Health Organization (WHO), COPD was the “fourth leading cause of death worldwide.” According to a study by the Centers for Disease Control and Prevention (CDC), it was the “fifth leading cause of death in the United States” in 2023.

Symptoms from both silicosis and COPD may not be obvious and can initially include shortness of breath, chest pain, or a persistent cough. Silicosis and COPD can be severe enough to cause respiratory failure, which may eventually lead to death.
In addition, silica exposure has been linked to other illnesses, including lung cancer and kidney disease.

Screening & Treatment

To ensure your doctor is aware that you may have been exposed to silica on the job, and is well informed about the signs, symptoms, and diagnosis of silica related illness, we recommend bringing a Physicians’ Alert (Spanish) to your appointment.

Your medical examinations should include: 

• Chest x-ray – classified according to the International Labour Office (ILO) International Classification of Radiographs for Pneumoconiosis
• Pulmonary function test
• Annual evaluation for tuberculosis – Purified protein derivative (PPD) skin test – for everyone with silicosis

There is no specific treatment for silicosis. Workers are advised to avoid further silica exposure to prevent the disease from worsening, limit exposure to irritants, and quit smoking. Antibiotics are prescribed as needed for respiratory infections. Those with a positive skin test for tuberculosis (TB) generally need treatment with anti-TB drugs. Any change in the appearance of the chest x-ray may be a sign of TB. Patients with severe silicosis may need to have a lung transplant.

Treatment of COPD includes inhaled bronchodilators, anti-cholinergic agents, or steroids, with antibiotics prescribed for respiratory infections as needed. As with silicosis, it is important to limit exposure to irritants and quit smoking. 

Employers must offer medical surveillance to their employees who are highly exposed to respirable crystalline silica at no cost. For more information on how to set up a medical monitoring program or on when it must be offered, see the Medical Monitoring Under the OSHA Silica Standard for the Construction Industry – Guide For Employers.

In 1996, the World Health Organization – International Agency for Research on Cancer (IARC) first classified silica as a known human carcinogen and in 2009, IARC reaffirmed its position, noting “[an] increased risk of lung cancer [from silica exposure] was observed across various industries and processes.” 

The National Cancer Institute completed a study in 2011 showing lung cancer screening saves lives. Based on that study, the American Lung Association began recommending lung cancer screening with low-dose CT scans for current or former smokers ages 55 to 74, with a smoking history of at least 30 pack-years (that is, an average of one pack per day for 30 years) and with no history of lung cancer. 

The National Comprehensive Cancer Network (NCCN) later refined the guidelines, recommending that individuals with significant occupational exposure to a carcinogen be screened beginning at age 50 if they have a smoking history of at least 20 pack-years. People with high silica exposures who also meet these smoking criteria should be screened. 

These American Lung Association documents provide additional information but do not include the NCCN recommendations about occupational exposure: LUNG CANCER CT SCREENING:  IS IT RIGHT FOR ME? and Lung Cancer Screening.

To learn more about the health effects…

• Silicosis Health Effects (video clip), Dr. Linda Rosentock, former Director of NIOSH 1994-2000
• Health Effects of Occupational Exposure to Respirable Crystalline Silica, NIOSH Pub# 2002-129
• Preventing Silicosis and Deaths in Construction Workers, NIOSH Pub# 96-112
• OSHA Fact Sheet: OSHA’s Respirable Crystalline Silica Standard for Construction
• Pulmonary Fibrosis Types, Pulmonary Fibrosis News