Table 2.
Incidence rate ratios with 95% CI for systemic sclerosis, rheumatoid arthritis, systemic lupus erythematosus, small vessel vasculitis and Sjögren’s syndrome by cumulated styrene exposure in 59 997 male and 12 215 female workers in the Danish reinforced plastics industry, 1979 to 2012
| Styrene exposure level | n | Rate ratio | n | Rate ratio | ||
| Men | Women | |||||
| Crude | Adjusted* | Crude | Adjusted* | |||
| Systemic sclerosis | 22 | 9 | ||||
| ≤17 mg/m3-years | 1 | 1 | 1 | 1 | ||
| 18–67 mg/m3-years | 2.52 (0.68 to 9.30) | 1.90 (0.51 to 7.11) | 1.02 (0.19 to 5.58) | 1.15 (0.20 to 6.52) | ||
| ≥68 mg/m3-years | 2.68 (0.74 to 9.75) | 1.86 (0.50 to 7.00) | 2.13 (0.48 to 9.53) | 2.50 (0.50 to 12.50) | ||
| Per 100 mg/m3-years | 1.05 (0.97 to 1.14) | 1.03 (0.94 to 1.13) | 1.18 (1.01 to 1.38) | 1.19 (1.01 to 1.39) | ||
| Reumatoid arthritis | 359 | 168 | ||||
| ≤17 mg/m3-years | 1 | 1 | 1 | 1 | ||
| 18–67 mg/m3-years | 1.32 (0.99 to 1.76) | 1.12 (0.83 to 1.49) | 0.93 (0.64 to 1.35) | 0.83 (0.57 to 1.20) | ||
| ≥68 mg/m3-years | 1.68 (1.28 to 2.21) | 1.28 (0.96 to 1.70) | 1.17 (0.80 to 1.71) | 0.95 (0.63 to 1.41) | ||
| Per 100 mg/m3-years | 1.04 (1.02 to 1.07) | 1.02 (1.00 to 1.05) | 1.05 (0.97 to 1.13) | 1.01 (0.93 to 1.10) | ||
| Systemic lupus erythematosus | 23 | 15 | ||||
| ≤17 mg/m3-years | 1 | 1 | 1 | 1 | ||
| 18–67 mg/m3-years | 0.94 (0.36 to 2.45) | 0.84 (0.32 to 2.24) | 1.28 (0.42 to 3.90) | 1.50 (0.47 to 4.73) | ||
| ≥68 mg/m3-years | 0.60 (0.21 to 1.74) | 0.55 (0.18 to 1.66) | 0.71 (0.15 to 3.35) | 0.88 (0.18 to 4.35) | ||
| Per 100 mg/m3-years | 0.70 (0.42 to 1.15) | 0.68 (0.40 to 1.14) | 0.65 (0.24 to 1.77) | 0.71 (0.27 to 1.84) | ||
| Small vessel vasculitis | 61 | 19 | ||||
| ≤17 mg/m3-years | 1 | 1 | 1 | 1 | ||
| 18–67 mg/m3-years | 1.01 (0.51 to 2.00) | 0.82 (0.41 to 1.64) | 0.79 (0.28 to 2.20) | 0.71 (0.25 to 2.01) | ||
| ≥68 mg/m3-years | 1.50 (0.80 to 2.81) | 1.06 (0.55 to 2.04) | 0.22 (0.03 to 1.67) | 0.18 (0.02 to 1.38) | ||
| Per 100 mg/m3-years | 1.06 (1.01 to 1.11) | 1.03 (0.99 to 1.09) | 0.39 (0.10 to 1.60) | 0.32 (0.07 to 1.47) | ||
| Sjögren’s syndrome | 18 | 24 | ||||
| ≤17 mg/m3-years | 1 | 1 | 1 | 1 | ||
| 18–67 mg/m3-years | 0.42 (0.13 to 1.39) | 0.40 (0.12 to 1.35) | 1.10 (0.44 to 2.76) | 1.01 (0.40 to 2.55) | ||
| ≥68 mg/m3-years | 0.60 (0.21 to 1.74) | 0.57 (0.19 to 1.70) | 0.88 (0.29 to 2.68) | 0.79 (0.25 to 2.52) | ||
| Per 100 mg/m3-years | 0.75 (0.46 to 1.23) | 0.74 (0.45 to 1.22) | 0.77 (0.42 to 1.42) | 0.73 (0.38 to 1.41) | ||
*Adjusted for age, calendar year of follow-up and educational level.