100 Exposure to mineral dust from renovation – are we forgetting an exposed group?

A growing focus on sustainability increases the need for renovation and repurposing of existing building stock to increase energy efficiency without material waste. Indoor demolition and renovation, rather than total demolition and rebuilding, produces an altered exposure situation for the workers involved. The outer shell of the building is often kept intact and protected, while the inner structure is being demolished and rebuilt, leading to an enclosed working environment. In this study personal respirable dust and respirable crystalline silica (RCS) samples were collected at 14 demolition sites. The samples were analyzed with X-ray diffraction using the NIOSH 7500 method for RCS. During the measurements workers did manual demolition and cleaning out silica containing materials. The exposure measurements showed that 18 % of the respirable samples and 57 % of the RCS samples were above the Norwegian occupational exposure limits (OELs) of 5 and 0.05 mg/m3, respectively. In addition, an assessment was performed on indirectly exposed workers, working within the same buildings. These workers showed a substantial exposure to RCS with 15 % of samples being above the Norwegian OEL, despite not working with silica containing materials. Indirectly exposed workers are often overlooked in exposure assessments or regarded as unexposed since they are not producing or resuspending the pollutant. Furthermore, the workers themselves are less aware of the exposure and thereby less likely to use dust protection.