Exposure to common agents such as silica and detergents has been identified as a major risk factor for the disease.
Individuals frequently exposed to dust and fumes at work could face a greater risk of developing rheumatoid arthritis (RA), according to the latest international research.
Researchers in Stockholm examined data from around 10,000 participants between 1996 and 2017, 4000 of whom were newly diagnosed with rheumatoid arthritis and 6,000 who were disease free, to estimate the extent to which participants were exposed to 32 airborne workplace agents, and whether their exposure was associated with diagnoses of rheumatoid arthritis.
The findings, published in the Annals of the Rheumatic Diseases, found that close to three quarters of participants with RA were exposed to at least one dust or fume in their workplace, compared to around two thirds of those without the disease.
Quartz, asbestos, gasoline fumes and carbon monoxide, were among the 17 agents strongly linked to a higher risk of the ACPA-positive RA specifically, while quartz dust (silica), asbestos, and detergents were strongly associated with the ACPA-negative subtype.
Overall, exposure to any of the 32 agents assessed was seen to raise the risk of developing ACPA-positive rheumatoid arthritis by 25%, which grew to 40% in men.
The risk of developing RA associated with workplace exposure to these inhalable agents grew as the number of agents and duration of exposure increased, reaching a peak when workers were exposed on a regular basis between eight to 15 years.
In addition to exposure itself being associated with a greater risk of developing rheumatoid arthritis, researchers found that it interacted with smoking and RA-risk genes to further heighten the risk.
Workers who were ‘triple exposed’ to the inhalants, smoking and a genetic risk of developing RA were seen to have a much higher risk of developing the ACPA-positive subtype, ranging from 16 to 68 times greater, compared to those not exposed to any agents.
“Occupational inhalable agents could act as important environmental triggers in RA development and interact with smoking and RA-risk genes leading to excessive risk for ACPA-positive RA,” wrote the authors of the study.
“Our study emphasises the importance of occupational respiratory protections, particularly for individuals who are genetically predisposed to RA.”
The results also showed a gendered disparity regarding inhalant exposure, with men both encountering more agents and being exposed for longer periods than women, 11 years on average compared to seven for female workers.
Despite being limited by a reliance on personal recall from participants, as well as a difficulty identifying the specific agents triggering rheumatoid arthritis when workers were surrounded by many agents at once, the authors hope the findings highlight the importance of limiting workers’ exposure to these harmful inhalants.
“Our data [provides] a novel and quite dramatic emphasis on the role of occupational exposures in the aetiology of seropositive RA, calling for extended measures to reduce these exposures as part of international collaborative efforts to reduce morbidities due to working life,” they concluded.
