Measurements of ultrafine particle concentrations and size distribution in an iron foundry

The number and surface area concentration of ultrafine particles in an iron foundry is of interest as freshly generated ultrafine particles are produced by metal melting, pouring and molding processes. This study measured the number and surface area concentrations of ultrafine particles and their size distributions in an iron foundry using a scanning mobility particle sizer (SMPS). The 10-100 nm ultafine particle number concentrations (NC_0.01-0.1) and surface area concentrations (SC_0.01-0.1) measured at the iron foundry were 2.07 × 10⁴ to 2.82 × 10⁵ particles cm^-3 and 67.56 to 2.13 × 10³ μm² cm^-3, respectively. The concentrations changed dramatically depending on on-site manufacturing conditions. The NC_0.01-0.1 levels in the iron foundry were approximately 4.5 times higher on average compared with those in the outdoor ambient environment. These measurement results indicate that the presence of extra particles in the workplace air is within the ultrafine range. Additionally, the analytical results suggest that the number mode diameter can be used to estimate the SC_0.01-0.1 levels using the NC_0.01-0.1 levels. Moreover, the ultrafine particle number mode diameter was found to be about 46.1 nm in the iron foundry.