Inhaling certain workplace dusts and fumes may heighten the risk of developing rheumatoid arthritis, a new study has found.
Breathing in such particles — from agents such as vapors, gasses and solvents — may also exacerbate the impacts of smoking and genetic susceptibility to the autoimmune disease, according to the study, published in the Annals of Rheumatic Diseases.
“Our study shows that inhalable, mainly occupational exposures act as important environmental risk factors in [rheumatoid arthritis] development,” wrote the authors, a team of medical researchers from Sweden’s Karolinska Institute.
Rheumatoid arthritis, a chronic joint disorder characterized by painful inflammation, affects up to 1 percent of the global population, the study authors noted.
While scientists are already aware that smoking heightens the risk of developing the disorder, the Karolinska team sought to determine whether breathing in workplace dust and fumes could also have an impact.
To draw their conclusions, the researchers made use of data available through the Swedish Epidemiological Investigation of Rheumatoid Arthritis.
The database includes 4,033 people newly diagnosed with the disease between 1996 and 2017, along with 6,485 individuals matched for age and sex but free of the disease.
Each participant also received a score based on whether they carried genes that could raise their risk of developing the disease, according to the study.
The type of rheumatoid arthritis diagnosis a patient receives is characterized by the presence or absence of a specific type of antibodies — with positivity for these antibodies indicating a worse prognosis, the authors explained.
Patients can still have the disorder while testing negative for these antibodies. But about 60 to 80 percent of those with rheumatoid arthritis do test positive for the antibodies, according to the Arthritis Foundation.
In the Swedish study, patients who tested positive for the antibodies veered slightly younger, tended to be women and were more likely to smoke than those who tested negative.
About 73 percent of those who tested positive for the antibodies were exposed to workplace contaminants, while 72 percent of those who tested negative and 67 percent of control subjects were also exposed.
The researchers found that exposure to any workplace agent was linked to a 25 percent increased risk of developing antibody-positive rheumatoid arthritis. That risk surged to 40 percent in men, according to the study.
Among the agents most strongly associated with that increased risk were quartz, asbestos, diesel fumes, gasoline fumes, carbon monoxide and fungicide, the authors determined.
Only a few agents — quartz, asbestos and detergents — had strong connections to the development of antibody-negative rheumatoid arthritis, per the study.
Stressing that their research was observational only, the authors acknowledged that they could not establish cause for their findings.
However, they called for “extended measures to reduce these exposures as part of international collaborative efforts to reduce morbidities due to working life.”
In an accompanying editorial, two researchers not involved with the study likewise emphasized the need for greater public health efforts to curb the risk of developing this disease.
“First, environmental health initiatives should reduce public exposure to ambient pollutants, including carbon monoxide and gasoline exhaust,” wrote Jeffrey Sparks of Brigham and Women’s Hospital in Boston and Vanessa Kronzer of the Mayo Clinic.
“Second, occupational health initiatives should mitigate occupational hazards, including detergents and asbestos,” the doctors continued.
“Third, public health initiatives should continue to reduce cigarette smoking,” they added.
