101 Quantitative models for prediction of occupational exposure to respirable dust and quartz within the formulating, metal manufacturing and construction industries

Introduction Stoffenmanager® is a quantitative inhalation exposure tool for OSH and REACH, (inter)nationally recognized by local governments and the EU. Three novel generic models to quantitatively predict exposure to respirable dust and respirable quartz are developed, aiming to protect workers from associated health risks within formulating, metal manufacturing and construction industries. Methods Personal exposure data including comprehensive contextual information were extracted from the IFA exposure database MEGA. Stoffenmanager® scores were calculated for the measurement values. For each quantitative model exposure data were segregated into calibration and validation datasets. Subsequently, mixed effect models were performed to derive quantitative regression equations. Spearman correlation coefficients were calculated to study the relation between concentrations estimated with use of new regression equations and measured exposure concentrations. Results A total of approximately 8000 good quality personal exposure measurements were extracted for all three models. Stoffenmanager® scores were compared with exposure measurements and the calculated spearman coefficients showed a positive relationship for all algorithms. Correlations between observed and estimated exposures ranged between r=0.40 and r=0.71. Proportions of measurements above 50th and 90th percentile were calculated, as a measure for conservatism of the models. They varied around 50% and 10% respectively. Discussion and conclusion The substantial amount of personal exposure data, the good correlation and the level of conservatism indicate that the three innovative models are sufficient to be implemented in Stoffenmanager® to expand its applicability domain. The new models serve to improve workers’ health by reducing occupational exposure to respirable dust and quartz.