• Posted December 9, 2022

Workplace Fumes, Dust Could Raise Odds for Rheumatoid Arthritis

The air where you work could be increasing your risk of developing rheumatoid arthritis, a new study suggests.

Breathing in the fumes from commercial vapors, gases and solvents -- and even common dusts found in the workplace -- appears to increase chances of the chronic autoimmune joint disorder, researchers reported Dec. 6 in the Annals of the Rheumatic Diseases.

Exposure to any of these workplace pollutants is associated with a 25% increased risk of developing a form of rheumatoid arthritis that is made worse by the presence of anti-citrullinated protein antibodies (ACPA), researchers found.

That risk increased to 40% when looking at men specifically, results showed.

People with ACPA-positive rheumatoid arthritis have a worse prognosis and tend to experience higher rates of damage caused by wear and tear on their joints, researchers said.

For this study, researchers examined data on more than 4,000 people drawn from a Swedish study of rheumatoid arthritis. The people all were newly diagnosed with RA between 1996 and 2017.

The team combed through personal job histories to estimate each person's exposure to 32 airborne workplace agents.

Analysis showed that exposure to fumes and dust was associated with an increased risk of RA. Further, that exposure also appeared to boost the risk from other factors like smoking or genetics.

In all, 17 of 32 agents -- including asbestos, quartz, diesel fumes, gasoline fumes, carbon monoxide and fungicides -- were strongly associated with an increased risk of developing ACPA-positive RA, researchers said.

Only a few agents -- quartz dust (silica), asbestos and detergents -- were strongly associated with ACPA-negative RA.

The risk increased with the number of agents and duration of a person's exposure, with the strongest links seen for exposures lasting between eight and 15 years.

Men appear to have a higher risk than women, because they tended to have been exposed to more agents for longer periods.

People exposed to a workplace agent who also smoked and had a high genetic risk for RA tended to have an extremely high risk of ACPA-positive RA, ranging from 16 to 68 times higher than people not exposed to all three risk factors.

The risk of developing ACPA-positive RA in those who were "triple exposed" was 45 times higher for gasoline engine exhaust fumes; 28 times higher for diesel exhaust; 68 times higher for insecticides; and 32 times higher for quartz dust.

"Our study emphasizes the importance of occupational respiratory protections, particularly for individuals who are genetically predisposed to RA," the researchers said in a journal news release.

Bowen Tang, a doctoral candidate at the Karolinska Institute in Stockholm, Sweden, led the study.

In an accompanying editorial, Boston rheumatologist Dr. Jeffrey Sparks noted that the study points the way to interesting clues about how RA develops.

"Each occupational inhalable agent had a unique profile of the way it interacted with RA risk genes and with smoking," wrote Sparks, who works at Brigham and Women's Hospital. "These unique interactions suggest that if the relationship between inhalable agents and RA is indeed causal, they may do so via distinct pathways."

Noting the stronger associations found for ACPA-positive RA, Sparks said the findings add more support to the growing belief that ACPA-positive disease might be very different from ACPA-negative RA.

More information

The U.S. Centers for Disease Control and Prevention has more about rheumatoid arthritis.

SOURCE: BMJ, news release, Dec. 6, 2022