Tham khảo tài liệu 'health safety and environment_4', kỹ thuật - công nghệ, điện - điện tử phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 316 7 Health Safety and Environment Table Time required to reach OSHA PEL for copper slag Stephenson et al. 2002 Contaminant Time to reach OSHA PEL in min Booth time Outdoor time Room time Total particulate 22 40 15 Arsenic 37 60 15 Lead 37 60 63 Emission of Minerals and Organic Compounds Asbestos Fibres Many old linings contain asbestos. Asbestos fibres are known to be responsible for lung cancer. Results of asbestos emission during the preparation of steel substrates with different methods were reported by Binder 2001 Goergens 2002 and Schroder 2000 . Some results are shown in Figs. and . More information is provided in Table . It can be seen that all preparation methods that contain a liquid phase wet blast cleaning water jetting generate rather low asbestos concentrations. Fig. Results of asbestos monitoring Schroder 2000 . Treatment methods 1 - dry blast cleaning 2 - wet blast cleaning 3 - wet blast cleaning 4 - abrasive water jetting 85 MPa 5 - hydroblasting 200 MPa 6 - abrasive water jetting 120 MPa 7 - hydroblasting and dry blast cleaning 8 - wet blast cleaning 9 - hydroblasting 240 MPa 10 - wet blast cleaning copper slag 11 - water cleaning 13 MPa 12 - water cleaning 15 MPa Emission of Minerals and Organic Compounds 317 preparation method Fig. Emission of asbestos fibres for different treatment methods Goergens 2002 Organic Compounds Tar epoxy coatings contain polycyclic agents namely polycyclic aromatic hydrocarbons PAH . Results of measurements of hydrocarbon exposure during paint Table Asbestos and PAH emissions during the coating removal from steel substrates Schroder 2000 Method Number of measurements Number of fibres per cubic metre PAH-value in pg m3 Flame cutter 8 881 Regulatory limita exceeded Needle hammer 1 5 845 - 1 14 933 - 1 281 000 80-130 Burner 7 30 000-165 000 14-48 Hand-held grinder 1 25 000 50-152 Water jet 13 MPa 1 5 000-10 000 Regulatory limit undercut Grinding 2 20 000-45 000 - .
