The influence of welders' protective devices on respiration at rest and during exercise was studied under laboratory conditions. During exercise the devices caused increased ventilation and increased arterial carbon dioxide tension. In the case of the welding helmet the increase was probably a consequence of increased dead space. It is concluded that the physiological affects on respiration are of minor importance in themselves, but they should be taken into account when the degree of exposure to welding fumes is evaluated.

Key terms carbon dioxide; carbon dioxide tension; dust respirator; exercise; experimental physiology; respiration; rest; ventilation; welding helmet