Fig. 1

Scatter plot of weighted tenure in years (x-axis) and cumulative silica exposure in mg/m3-year (y-axis) among the study participants (Spearman’s correlation coefficient = 0.69, P < 0.0001). Each data point represents the cumulative exposure level of an individual worker. The regression line shows the positive association between weighted tenure and cumulative silica exposure (Estimated coefficient = 0.19, P < 0.0001)