Estimated temporal trends per campaign for respirable dust and quartz exposures for three time periods adjusted for random effects of site, job and worker
| Respirable dust | Respirable quartz | |||||||
| Period | Sites (n) | Observation (n) | Trend (%) | CI (95%) | Sites (n) | Observation (n) | Trend (%) | CI (95%) |
| All | 154 | 25 539 | −4.6*** | −4.8 to −4.3 | 149 | 22 593 | −2.1*** | −2.3 to − 1.8 |
| Summer2002–summer2008 | 69 | 9686 | −7.4*** | −8.3 to −7.1 | 66 | 8416 | −4.0*** | −4.1 to − 3.3 |
| Winter2008–summer2012 | 125 | 8786 | −1.8*** | −2.8 to −0.9 | 119 | 7980 | +4.1 *** | +2.6 to + 5.3 |
| Winter 2012–summer 2016 | 106 | 7067 | −7.1*** | −8.8 to −6.0 | 99 | 6197 | −8.7 *** | −11.0 to − 7.2 |
***p<0.001.