Ambient air contamination by micron and submicron particles from welding operations

Summary

Impactor sampling and PIXE analysis constitute a good combination in detecting the influence of fugitive emission and ventilation air on ambient air quality. In total filter samples heavier natural particles mask the increase in mass due to the smaller industrial particles. Multielemental analysis of many samples is important in finding unknown sources and in evaluating the effect of all the sources. PIXE is well suited for this kind of analysis.

The health effects of low-concentration air-pollution exposure on large population groups including such sensitive groups as children, elderly and sick people are not well understood, which is encouraging for sampling more basic information for epidemiological studies.

The increases of the concentration of iron, potassium and manganese are evident. Although the reported values are below air-quality limit values, there are some reasons for being careful. Firstly, the increases are most significant in submicron particles. Secondly, with different weather conditions and from other industrial areas, indoor contribution could be orders of magnitude larger. Thirdly, in PIXE analysis only elemental constituents heavier than about sulphur are detected and there may be other lighter constituents. It is, e.g., known that water-soluble fluorine is abundant in fumes from electrodes with basic coatings. Thus considerable attention should be given to the ambient air when planning means of improving work environment and when allocating new industrial areas.