Completed Research

Ergonomics and Welding Fume Exposures During Stud Welding (Completed – 2009-2014)

Nathan Fethke, PhD, CPE

University of Iowa
Ph: 319-467-4563
[email protected]

Imagine spending your workday hunched over at a right angle for 20 minutes at a time, bearing heavy tools while at risk of inhaling toxic fumes. That’s the job of ironworkers welding floor-level studs – for instance, while securing floor decks to a new skyscraper’s steel frame. Every year thousands of workers toil at this task while erecting bridges or commercial buildings.

Nate Fethke and his team partnered with an innovative equipment manufacturer to explore an engineering solution. Fethke’s team measured workers’ posture and muscle effort using both the conventional approach and an alternative: a mobile cart to hold the arc welder. This new tool allowed workers to weld from an upright position, reducing back strain and possibly fume inhalation.

The research program was an object lesson in the hurdles to efficient technology transfer. Building a device that was able to meet workers’ demand for safety and contractors’ demand for productivity was a daunting challenge. Initial prototypes relieved strains on workers’ backs but increased demands on their shoulder muscles, and a wheeled cart effective on a flat surface encountered in bridge construction may have less mobility when encountering obstacles like waffle decking.

Meanwhile, the demands of this research design generated important collateral benefits for the field. Industrial hygienists who wanted to establish worker exposure levels to very fine particles (smaller than 300 nanometers) during a particular work task long wished for a personal monitoring system that could measure these in real time. A new device, the DiSCmini, promised to do this – but first scholars had to assess and validate its performance.

The team needed just this technology to assess worker exposure to contaminants in welding fume. They evaluated the DiSCmini aerosol monitor by testing its performance against two reference instruments already in use: a scanning mobility particle sizer (SMPS) and a handheld condensation particle counter (CPC). The results verified that the DiSCmini could be useful in measuring metal aerosols, such as welding fume, for personal task-based exposure monitoring, as well as many other occupational settings where very fine particles of interest are present.

  • Manufacturer New Rule Products used preliminary findings to modify its ergonomically designed welding cart, considerably reducing back and shoulder stresses.
  • The research team published a paper in the Journal of Occupational and Environmental Hygiene describing the validation of a handheld device – the DiSCmini – for measuring welding fume exposures in real time. The paper was cited five times in peer-reviewed scientific journals during that project year, increasing the body of knowledge in this area.