Another way through which the fine particles diffuse into the
ambience of the workshop is the bag filter. The bag filters had a
good filtering effect on coarse particles, but it was difficult for
them to filter the particles below 2.5 μm diameter. This was
consistent with the monitoring results that the average
concentration of PM2.5 (130.4 μg/m3
) exceeded the risk
threshold at the bag filter outlet. Therefore, we used the Gaussian diffusion model (Figure 5) to analyze the impact of
PM2.5 on the residents near the factory in our study.