Table 1.
Basic characteristics, PAH metabolites, mtDNAcn and TL for conventional asphalt workers, crumb rubber modified (CRM) asphalt workers and controlsa
| Conventional asphalt workers (n = 116) |
CRM asphalt workers (n = 51) |
All asphalt workers (n = 167) |
Controls (n = 100) |
pb | |
|---|---|---|---|---|---|
| Age | 43 (24–59) | 42 (22–61) | 43 (23–59) | 46 (24–62) | 0.29 |
| BMI (kg/m2) | 28 (22–38) | 28 (23–35) | 28 (23–38) | 27 (22–36) | 0.89 |
| Length of asphalt working (year) | 12 (1–30) | 10 (1–38) | 12 (1–35) | – | – |
| Smoking | 0.066 | ||||
| Never smoker | 84 (74%) | 31 (70%) | 115 (73%) | 65 (65%) | |
| Previous smoker | 24 (21%) | 5 (11%) | 29 (18%) | 23 (23%) | |
| Current smoker | 6 (5%) | 8 (19%) | 14 (9%) | 12 (12%) | |
| Cigarette pack-year if ever smoked | 9 (2–30) | 18 (1–95) | 10 (1–38) | 14 (1–54) | 0.083 |
| Snus | 0.014 | ||||
| Never snus user | 54 (47%) | 25 (57%) | 79 (50%) | 66 (66%) | |
| Previous snus user | 15 (13%) | 2 (5%) | 17 (11%) | 13 (13%) | |
| Current snus user | 45 (40%) | 17 (38%) | 62 (39%) | 21 (21%) | |
| Investigation Season | < 0.001 | ||||
| Spring (Apr-Jun) | 44 (38%) | 17 (40%) | 61 (39%) | 26 (26%) | |
| Summer (Jul-Aug) | 38 (33%) | 10 (24%) | 48 (30%) | 18 (18%) | |
| Early autumn (Sep-Oct) | 34 (29%) | 15 (36%) | 49 (31%) | 3 (3%) | |
| Winter (Jan-Mar) | 0 (0%) | 0 (0%) | 0 (0%) | 53 (53%) | |
| Pre- working 1-OH-PYR (μmol/mol creatinine) | 0.041 (0.018–0.11) | 0.042 (0.011–0.17) | 0.041 (0.017–0.13) | 0.028 (0.0087–0.091) | 0.12 |
| Post- working 1-OH-PYR (μmol/mol creatinine) | 0.068 (0.024–0.24) | 0.11 (0.020–0.76) | 0.076 (0.021–0.27) | 0.028 (0.0092–0.091) | < 0.001 |
| Pre- working 2-OH-PH (μmol/mol creatinine) | 0.13 (0.063–0.55) | 0.14 (0.061–0.51) | 0.13 (0.063–0.52) | 0.095 (0.040–0.65) | 0.18 |
| Post- working 2-OH-PH (μmol/mol creatinine) | 0.20 (0.071–0.62) | 0.24 (0.077–0.90) | 0.21 (0.076–0.69) | 0.082 (0.039–0.47) | < 0.001 |
| Post-working relative mtDNAcn | 0.98 (0.70–1.6) | 0.97 (0.72–1.3) | 0.98 (0.70–1.5) | 0.87 (0.56–1.3) | < 0.001 |
| Post-working relative TL | 1.1 (0.76–1.6) | 1.2 (0.73–1.8) | 1.1 (0.73–1.7) | 1.1 (0.72–1.7) | 0.29 |
aValues are median (5–95 percentile) for continuous variables, or n (%) for categorical variables
bP values for age, BMI, cigarette pack-year, 1-OH-PYR, 2-OH-PH, relative mtDNA copy number and relative telomere length were derived from one-way ANOVA and P values for smoking, snus status and investigation season were derived from Fisher’s exact test to test the differences across three occupational groups