Occupational Dust Exposure and Chronic Obstructive Pulmonary Disease: A Systematic Overview of the Evidence

Abstract

The object of this study was to assess the relationship between occupational dust exposure and chronic obstructive pulmonary disease (COPD). Studies were identified using MEDLINE (January 1966 to July 1991), SCISEARCH, manual review of reference lists, and personal contact with more than 30 international experts. Studies of COPD, lung function, emphysema, chronic bronchitis, or mortality in workers exposed to nonorganic dust were retrieved. Studies were included if dust exposure was measured quantitatively, and a quantitative relationship between dust exposure and one of the outcomes of interest was calculated while controlling at least for smoking and age. Methodological rigor was assessed, and data regarding the study populations, prognostic factors, and outcomes were extracted independently by two reviewers. Thirteen reports derived from four cohorts of workers met our inclusion criteria. Three of the cohorts were of coal miners and one was of gold miners. All of the studies found a statistically significant association between loss of lung function and cumulative respirable dust exposure. It was estimated that 80 (95% CI, 34 to 137) of 1,000 nonsmoking coal miners with a cumulative respirable dust exposure of 122.5 gh/m3 (considered equivalent to 35 years of work with a mean respirable dust level of 2 mg/m3) could be expected to develop a clinically important (> 20%) loss of FEV1 attributable to dust. Among 1,000 smoking miners the comparable estimate was 66 (95% CI, 49 to 84). The risk of a clinically important loss of lung function attributable to dust among nonsmoking gold miners was estimated to be three times as large as for coal miners at less than one fifth of the cumulative respirable dust exposure (21.3 gh/m3), the maximal exposure observed among the cohort of gold miners. We conclude that occupational dust is an important cause of COPD, and the risk appears to be greater for gold miners than for coal miners. One possible explanation of the greater risk among gold miners is the higher silica content in gold mine dust.

Occupational chronic obstructive pulmonary disease: a systematic literature review

“…The induction time from exposure to the detection of early COPD is often long (decades). Identification and measurements of relevant exposures over a prolonged period of time are generally not performed and thus are unavailable for research with few exceptions (8).…”

Silicose

“…(25)(26) As alterações clínicas e funcionais observadas, embora guardem certa relação com as alterações radiográficas, podem ser encontradas em indiví-duos expostos sem evidências radiográficas de silicose.…”

Assessment of Lifetime Occupational Exposure in an Epidemiologic Study of COPD

“…Although cigarette smoking is the most important risk factor worldwide for COPD, occupational exposures to mineral and organic dusts, irritant gases and fumes, and to other industrially produced or used agents have been established as risk factors for COPD [2][3][4][5][6][7][8][9][10][11][12][13][14]. Industryand population-based epidemiological studies have reported increased risk of COPD due to occupational exposures or due to employment in certain industries or job categories.…”

“…Industryand population-based epidemiological studies have reported increased risk of COPD due to occupational exposures or due to employment in certain industries or job categories. Occupational groups reported to have increased risk of COPD include coal miners, hard rock miners, tunnel workers, concretemanufacturing workers, construction workers, agricultural workers, and some manufacturing workers [2,3,[6][7][8][9]. COPD etiology is multi-factorial in nature and is strongly associated with non-occupational factors such as tobacco smoking.…”