Investigation of occupational exposure to respirable crystalline silica (RCS) among engineered stone fabricators in Chicago—A pilot study

Engineered stone countertops, popularly known as quartz or artificial stone countertops, have gained significant attraction due to their durability and aesthetic appeal. However, due to their high crystalline silica content, the fabrication of these countertops poses severe health risks to workers, as evidenced by numerous global cases of silicosis. The study aimed to assess occupational exposure to respirable crystalline silica (RCS) among fabricators in Chicago and characterize the elemental composition and physical properties of engineered stone dust. Eight professional fabricators from two local stone workshops were recruited for the study. The exposure levels to RCS were assessed using the NIOSH 7500 method. Bulk dust samples were collected on-site, and the elemental composition of the dust was analyzed using X-ray fluorescence (XRF) and reported in stoichiometric oxide units. A set of real-time air monitors was used to measure particle size distribution, particulate matter (PM) concentrations, and ambient conditions in the workplace. A questionnaire was administered, and worker activities were recorded during the visits. Workers were found to be overexposed to respirable quartz in their workplaces, with time-weighted averaged (TWA) concentrations ranging from 11 to 203 µg/m