Dusty trades and associated rheumatoid arthritis in a population-based study in the coal mining counties of Appalachia

Abstract

ObjectivesWe previously showed increased coal mining-associated risk of rheumatoid arthritis (RA). Using additional survey data, we sought to delineate this risk further.MethodsWe used data from two cross-sectional, random-digit-dial, population-based surveys (males;≥50 years) in selected counties in the Appalachian region of the inland, mid-Atlantic USA with elevated pneumoconiosis mortality. Surveys ascertained age, smoking, coal mining and non-coal silica exposure jobs. In a subset, we surveyed ergonomic exposures, scored by intensity. We queried diagnosis of RA, corticosteroid use, and, in a subset, use of disease modifying antirheumatic drugs (DMARDs). Multivariable logistic regression modelled RA risk (defined by glucocorticoid or DMARDs use) associated with coal mining employment, other silica exposure, smoking status, and age and ergonomic exposures.ResultsWe analysed data for 2981 survey respondents (mean age 66.6 years; 15% current, 44% ex-smokers). The prevalence of glucocorticoid-treated and DMARD-treated RA was 11% and 4%, respectively. Glucocorticoid-treated RA was associated with coal mining (OR 3.5; 95% CI 2.5 to 4.9) and non-coal mining silica exposure (OR 3.2; 95% CI 2.4 to 4.4). For DMARD-treated RA, the odds associated with coal mining and other silica remained elevated: OR 2.3 (95% CI 1.18, 4.5) and OR 2.7 (95% CI 1.51, 5.0), respectively. In the same model, the highest intensity ergonomic exposure also was associated with increased odds of RA (OR 4.3; 95% CI 1.96 to 9.6).ConclusionsWe observed a strong association between coal mining and other silica-exposing dusty trades and RA. Clinicians and insurers should consider occupational histories in the aetiology of RA.

Assessment of Risk of Rheumatoid Arthritis Among Underground Hard Rock and Other Mining Industry Workers in Colorado, New Mexico, and Utah

“…such a smoking association in our previous studies of coal miners in Appalachia,3,4 a population with similar proportions of current and prior smokers.…”

“…Assessment of Risk of Rheumatoid Arthritis Among Mining Industry Workers previous research focusing on the risk of RA associated with coal mining in the Appalachian region of the US. 3,4…”

“…Our target final number was based on our previous experience surveying coal miners in Appalachia. 3,4 Race and ethnicity data by self-report were collected in the survey and were relevant to this mining population in particular because of past patterns of employment in mining.…”

“…Other aspects of manual labor, in particular in the mining sector, are likely to carry risk for arthritis other than RA, an association we observed in the present study and in our population-based studies in Appalachia. 3,4 An analysis of outpatients from a New Mexico clinic with targeted outreach to miners 18 observed increased relative risks for arthritis among uranium (1.3), metal (1.3), and nonmetal (1.4) miners. This is similar to our estimate for hard rock miners, but less than what we estimated for coal miners and related mining occupations.…”

“…We based both the sampling methods and the survey interview on our previous research focusing on the risk of RA associated with coal mining in the Appalachian region of the US. 3,4…”