the breathing zone than in the workplaces.'5 The
individual samples may contain higher percentages
of Cr and Mn compared with the stationary samples
but a lower Fe percentage.'5 17
The data published by the International Agency
for Research on Cancer' show that evaluation of
occupational exposure to fumes under some determined
conditions can be estimated by combining
information on the elemental abundance of the
aerosol as determined from a chemical analysis of
welding fumes produced in the laboratory under
controlled conditions,'8 and the total aerosol concentration
expected on the basis of measurements in the
workplace. The disadvantage of this technique,
however, is that the actual composition of specific
welding fumes cannot be determined.
Although the average percentage of elements in
MMA/SS welding fumes found in our study (table 3)
is similar to the percentage reported by some other
authors (Cr 2-9-2; Ni 0-2-3-3; Fe 3-3-15-9; Mn 1-4-
14%),' 'l" mean statistical values of particular
elements in the welders' breathing zone do not form a
real picture of exposure.
The data presented (fig 3) indicate that different
conditions at the workplace may result in variations
in the chemical composition of the fumes. Therefore,