Fig. 6. PCA loading plot for Hg in 15 fly ash samples (F12: Exchangeable Hg, F3: organo-chelated Hg, F4: strongly-complexed Hg and F5: mercuric-sulfide).Figure optionsDownload full-size imageDownload as PowerPoint slide
3.6. Health risk assessment
Fly ash was also used in cement kiln for coordination. As this Entinostat process took in a very high temperature, all of the mercury in the fly ash was transformed into Hg vapor. Exposure to Hg vapor and Hg compounds may occur for workers on site during their daily duty. The risks for workers would via three main pathways: inhalation of Hg vapor and particulates emitted from fly ash, dermal contact of Hg in fly ash, and oral ingestion fly ash. The HQ was calculated to evaluate the non-cancer risk, and the results are abiogenesis shown in Fig. 7.
Fig. 7. Non-cancer risks due to exposure to Hg in fly ash for workers.Figure optionsDownload full-size imageDownload as PowerPoint slide
As shown in Fig. 7, much of risk occurs via the inhalation of Hg vapor and re-suspended particles. The risk index HQinh ranged from 0.01 to 0.57, accounting for the major proportion of the three main exposure pathways. HQtotal ranged from 0.02 to 0.75, lower than the “safe” threshold of 1. Therefore, exposure of Hg in fly ash did not exhibit potential health risk for on-site workers. In addition, the inhalation pathway was the main exposure route for workers on site, personal protective equipment could be taken to reduce the risk.