Incidence and influencing factors of occupational pneumoconiosis: A systematic review and meta-analysis

Objectives: To determine the incidence of pneumoconiosis worldwide and its influencing factors.

Design: Systematic review and meta-analysis.

Setting: Cohort studies on occupational pneumoconiosis.

Participants: PubMed, Embase, the Cochrane Library, and Web of Science were searched until November 2021. Studies were selected for meta-analysis if they involved at least one variable investigated as an influencing factor for the incidence of pneumoconiosis and reported either the parameters and 95% confidence intervals (CIs) of the risk fit to the data, or sufficient information to allow for the calculation of those values.

Primary outcome measures: The pooled incidence of pneumoconiosis and risk ratio (RR) and 95% CIs of influencing factors.

Results: Our meta-analysis included 19 studies with a total of 335,424 participants, of whom 29,972 developed pneumoconiosis. The pooled incidence of pneumoconiosis was 0.093 (95% CI: 0.085~0.135). We identified the following influencing factors: (1) male (RR=3.74; 95%CI 1.31–10.64; P=0.01), (2) smoking (RR=1.80; 95%CI 1.34–2.43; P=0.0001), (3) tunneling category (RR=4.75; 95%CI 1.96–11.53; P<0.0001), (4) helping category (RR=0.07; 95%CI 0.13–0.16; P<0.0001), (5) age (the highest incidence occurs between the ages of 50 and 60), (6) duration of dust exposure ((RR=4.59, 95% CI 2.41–8.74, P<0.01), (7) cumulative total dust exposure (CTD) (RR=34.14, 95% CI 17.50–66.63, P<0.01). A dose-response analysis revealed a significant positive linear dose-response association between the risk of pneumoconiosis and duration of exposure and CTD (P-nonlinearity=0.10, P-nonlinearity=0.16; respectively). The Pearson correlation analysis revealed that silicosis incidence was highly correlated with CSE (r=0.794, P<0.001).

Conclusion: The incidence of pneumoconiosis in occupational workers was 0.093 and seven factors were found to be associated with the incidence, providing some insight into the prevention of pneumoconiosis.

PROSPERO registration number: CRD42022323233.

Abbreviations: NOS: Newcastle Ottawa Scale, CWP: Coal Worker's Pneumoconiosis, CTD: cumulative total dust exposure, CSE: cumulative silica exposure.