Associations between cement dust exposure and annual longitudinal change in dynamic lung volume divided by standing height squared in cement production workers, by exposure category
| Exposure category (thoracic aerosol) | FEV1·h−2# | FEV6·h−2¶ | FVC·h−2+ |
| 1 (0.09–0.88 mg·m−3) | Reference=0 (lowest exposed group) | Reference=0 (lowest exposed group) | Reference=0 (lowest exposed group) |
| 2 (0.89–1.55 mg·m−3) | −1.3 (−4.3–1.7) | −1.5 (−4.7–1.8) | −1.1 (−4.6–2.3) |
| 3 (1.56–2.24 mg·m−3) | −2.0 (−5.1–1.2) | −2.7 (−6.2–0.7) | −2.4 (−6.0–1.2) |
| 4 (2.25–3.35 mg·m−3) | −3.8 (−7.0– −0.7) | −7.9 (−11.3– −4.4) | −6.3 (−9.9– −2.7) |
| 5 (3.36–14.6 mg·m−3) | −7.4 (−10.7– −4.2) | −8.7 (−12.4– −4.9) | −6.6 (−10.3– −2.8) |
| Administration | −4.0 (−7.9–0.0) | −7.6 (−11.9– −3.3) | −7.7 (−12.2– −3.2) |
Data are presented as mL change (95% CI). Estimates are from linear mixed model regression using person identity as a random intercept and other covariates as fixed effects. Adjustments were made for exposure category at baseline (five quintile levels plus administration), age at baseline, smoking status at baseline (0, 1–9, 10–19 or ≥20 cigarettes per day), sex, plant, pack-years of smoking at baseline and during follow-up, allergy (yes/no), physician-diagnosed asthma (yes/no), self-reported use of a respirator most of the time (yes/no), and previous occupational exposure to dust and gases for more than 1 year (yes/no). Bold font indicates estimates that are statistically significant at the 5% level compared with the lowest quintile from 0.09–0.88 mg·m−3. FEV1·h−2: forced expiratory volume in 1 s divided by the standing height squared; FEV6·h−2: forced expiratory volume in 6 s divided by the standing height squared; FVC·h−2: forced vital capacity divided by the standing height squared. #: n=3625; ¶: n=3268; +: n=3364.