Dusty Trades: Inorganic Dust Exposure During Military Service May Be an Occupational Risk Factor for RA

Exposure to inorganic dust has been linked to increase the risk of developing rheumatoid arthritis (RA) and other autoimmune conditions. This association between dusty environments and RA has been documented in miners, as well as individuals with silica-exposed vocations, such as stone cutters. Additionally, research has revealed patients with RA have immunological citrullinated targets in their lungs and synovial tissue, which suggests dust may be associated with anti-cyclic citrullinated peptide (CCP) seropositive RA.¹

Military Service as a Dusty Trade

Many military activities, such as welding, abrasive blasting, grinding and polishing metals, vehicle and other maintenance work, earth moving and other construction, as well as explosives detonation, entail inorganic dust exposure. Up until now, however, researchers have not assessed whether exposure to inorganic dust during military service is a risk factor for RA and other autoimmune conditions.

Assessing such an association is challenging because military personnel, generally, tend to be healthier than the general population. This healthy-soldier effect appears to erode over time, which means veterans from the Afghanistan and Iraqi wars may now be vulnerable to exposure-associated diseases. If an association between dust exposure during military service and a risk for RA were to be documented, the findings could influence the healthcare of military personnel and veterans through primary prevention and targeted follow-up surveillance.

Results from a recent, large-scale study indicate dust exposure during military service represents an occupational and environmental risk for a future diagnosis of RA or other autoimmune condition. Dust exposure among military personnel was associated with a 10% increased risk of developing RA compared with military personnel who had minimal to no exposure to inorganic dust. David Ying, MD, a rheumatologist at the San Francisco Veterans Affairs (VA) Health Care Systems, and colleagues suggest their analysis may be relevant for prevention activities. Their findings were published in the July issue of ACR Open Rheumatology.¹

Study Details

The study comprised a large sample (N=438,086) of veterans of the Afghanistan and Iraqi wars. It focused on veterans of Operation Enduring Freedom, Operation Iraqi Freedom and Operation New Dawn who received healthcare through the VA system. The majority (88%) of the cohort was male, 63% were white, non-Hispanic, and 68% had smoked. The study was unique because it did not rely on participant recall, but instead employed a job exposure matrix (JEM) based on military occupation codes to assign risk linked to military duties. These military occupation codes are nine-character codes used in the service personnel system of the U.S. Army and Marine Corps to identify and rack and manage every job performed by military personnel. Almost half (44%) of the veterans were classified as having likely or somewhat likely exposure to dust.