Characteristics and main results of included cohort studies assessing non-malignant respiratory disease and exposure to cement production dust
| Country | Design | Exposure metric (number), personal dust levels mg/m3 (SD) | Number of exposed workers (response rate, %) | Source of controls | Adjustment for age and smoking | Main effects respiratory symptoms and other findings: OR (95% CI) or percentage (SD) exposed vs non-exposed, p value | Main effects lung function tests: OR (95% CI) or percentage (SD) exposed vs non-exposed, p value | Reference |
|---|---|---|---|---|---|---|---|---|
| Italy | Prospective, 11 years | Stationary total dust: 1973 (13): 7.4 (1.0) 1978 (31): 5.3 (0.8) | 68 (100, 69, 53) | None | Yes | Not reported (NR) | NS reduction in FEV1 or FVC | 20¶ |
| Saudi Arabia | Cross-shift | Respirable dust different departments (97): range of levels: 7–21 (SD range:1.3–1.79) | 149 (99) | Office | Yes | NR | FEV1: −0.05 L (−0.02 to −0.08), FEV1/FVC ratio: −1.32 (−0.59 to −2.06) | 21 |
| Norway | Retrospective cohort study | Total dust (20): 7.4 (13), respirable (20): 0.9 (0.6) | 119 (86) | Non-exposed blue-collar | Yes | NS differences in symptoms | High exposed (exp) vs (vs) low exp: FEV1/FVC : −0.03 (−0.07 to 0.01) | 22 |
| Norway | Cross-shift | Respirable (95): 0.3 (range: 0.02–6.2) | 95 (77) | Preshift | Yes | NR | FEV1: −37 mL (p=0.04), DLCO: −0.17 mmol/min/kPa (p=0.02) | 25 |
| Ethiopia | Cross-shift | Total (40): exposed (exp): 27 (3.0), controls (ctr): 0.4 (1.7) | 40 (95) | Blue-collar low-exposed | Adjusted only for smoke | High exp vs low: cough: NS, wheezing: 35% vs 0% (p=0.002), dyspnoea: 47 vs 5 (p=0.001), stuffy nose: 85–0% (p>0.0005) | Exposure associated with decline in peak expiratory flow: β-coefficient: −1.6 (−3.1 to −0.15) for log total dust | 23 |
| Ethiopia | Prospective, 1 year | Total (262): exp cleaners: 432 (10th–90th percentile: 12–6719), production: 8.2 (0.7–72), ctr: 0.4 (range:0.2–0.9) | 71 (100, 71) | Office | Yes | Elevated prevalence of respiratory symptoms reported for cleaners and production workers but not for ctr from 2009 to 2010 | 2009–10: cleaners: FEV1/FVC: β: −1.7 (3.4) (p=0.004), production workers: −1.8 (4.4), (p=0.02). Ctr: no change | 24 |
| Norway | Prospective, 2 weeks | Thoracic (84): maintenance workers: 0.6 mg/m3 (0.2–8.1), furnace: 1.75 (0.2–15.5) | 35 (78) | Office, non-exposed | Yes | Neutrophil cells in sputum increased: β: 16.7; p<0.001 and neutrophil count increased by 0.4% per year (p=0.02), IL-1β increased by: 28 (25th–75th percentile: 21–36) vs 17 pg/mL (13–21) | Only baseline levels were reported | 28 |
| Iran | Cross-shift | Total (148): exp: 17, ctr: 0.9 | 100 (100) | Office | Yes | Stuffy nose: 52% vs 6% (p<0.001), dyspnoea: 49% vs 2% (p<0.00) | FEV1/FVC: β:−0.8 (−3.9 to −3.1), FVC: β:−0.7 (−3.1 to −2.3) | 26 |
| Denmark | Retrospective cohort study | Total dust (105): 3.3 (25th and 75th quartiles: 2.0;7.8), respirable : 1.5 (1.0; 2.2) | 546 (89) | General population | Yes | Hospitalisation due to chronic obstructive pulmonary disease: 1–10 year exp: OR 1.2 (0.5 to 2.7), 11–20 year: 1.3 (0.5 to 3.4), 21–30 year: 1.6 (0.8 to 3.4), <30 year: 1.0 (0.4 to 2.6) | Only baseline levels were reported | 27 |
| Tanzania | Prospective, 1 year | Total: 2010 (126): 5.0 (range: 0.6–69), 2011 (52): 7.4 (0.3–110) | 134 (81, 78) | Office | Yes | Prevalence 2010 vs 2011 of cough: 21% vs 12% (p<0.05), cough with sputum: 19% vs 10% (p<0.05), dyspnoea: 14% vs 2% (p<0.01), wheeze: 24% vs 7% (p<0.001) | NR | 29 |
| Europe | Prospective, 4 years | Thoracic (6111): non-administration; varied between job types and plants: 0.09–14.6 mg/m3 | 4966 (NR) | Low-exposed workers | Yes | NR | FEV1/m2 per (mg/m3)×year: −3.8 mL (−7.0 to −0.7) for 2.25–3.35 mg/m3, and −7.4 (−10.7 to −4.2) for 3.36–14.6 mg/m3 | 30 |
*Studies supplemented by the authors.
DLCO, diffusion capacity of carbon monoxide; FEV1, Forced expiratory volume in 1 s; FVC, Forced vital capacity; NR, not reported; NS, non-significant; UAE, United Arab Emirates.