The link between sarcoidosis and work has not been established. Some studies show that residents of rural areas have an increased risk of developing sarcoidosis. Some researchers propose that environmental factors may be associated with the disease but no studies to date support this hypothesis.

One study also noted that people living close to granite rocks with high beryllium content had a high incidence of sarcoidosis. Beryllium lung disease is very similar in its clinical and radiographic appearance to sarcoidosis but the chemical element has not yet been identified as the direct cause of the disease.

Other studies considered occupational risk factors by comparing workers of the lumbering industry who are thought to have a high incidence of sarcoidosis with other workers not in this industry but no difference in the incidence of sarcoidosis was found.

Several attempts have been made to link bacteria and viruses with sarcoidosis but none of these microorganisms were found to have a relation with the disease. Other factors like genetics, allergies and smoking have been investigated but no positive results have been found.

Even though studies have been carried our worldwide for many years, sarcoidosis is still a disease of unknown cause.