1. Is it just another employee complaint?
Tech
Research
Institute
Georgia
Is it just another employee complaint?
A Case Study of Occupational Illness in the Workplace
Jenny Houlroyd, MSPH, Georgia Tech Research Institute, 21d OSHA Consultation Program, contact:
Overview
Discussion
Occupational illnesses are often not documented at the onset of acute symptoms at the time of exposure, even when using classical surveillance methods, such as a medical screening program. This case study highlights an example where an employee reported headaches, breathing problems, and dizziness, which were documented by the employer in the company's Hazard Assessment Plan, but no further action was taken until an outside consultant identified the source of the health complaints.
Several types of administrative and engineering controls were required to be implemented so that employees would no longer be required to wear respirators, although most continued to voluntarily wear N-95 respirators. Changes in production and the number of welders also had an impact on employee exposures. After successful reduction in exposures, the employee who had been experiencing symptoms of welding fume fever reported that the symptoms have subsided.
Materials and Methods
During four on-site OSHA consultation visits, comprehensive program reviews and site assessments were conducted for the facility. Employees performing MIG welding were monitored for exposure to using Gilian GilAir 3500 personal sampling pumps set at 2.0 liters per minute (LPM) with a 37 mm, 0.8 µm preweighed PVC filter. The samples were analyzed by the Wisconsin Occupational Health Laboratory (WOHL), an AIHA accredited laboratory, using in-house method based on NIOSH 0500 and 0600 and for ICP metals by WOHL in-house method based on NIOSH The pumps were pre- and post-calibrated using a Bios calibrator Model DC-1. The first visit was considered the initial survey, and three follow-up visits were conducted to determine the effectiveness and maintenance of engineering controls.
Figure 3. Welding position: standing
out of welding fumes
Figure 4. Welding position: standing in the welding fume plume
Recommended Practices for Health and Safety Professionals
Perform in-depth employee interviews at initial visit.
Conduct comprehensive program reviews.
Predict changes in employee exposure based on current ventilation system for changes in production.
Evaluate and require interim control measures (such as respiratory protection) until follow-up monitoring is conducted.
Conduct follow-up monitoring after each control measure is implemented.
Evaluate the effectiveness of engineering controls and maintenance periodically after exposures are reduced to levels below the Permissible Exposure Limits.
Perform follow-up employee interviews.
Results of On-site Assessments
The program review revealed that the primary welder, who MIG welds on galvanized steel, had reported symptoms of headaches, breathing problems and dizziness; however this employer had classified this documented illness as not being work related. Industrial hygiene monitoring confirmed that exposures to zinc oxide fume ranged from 5.99 mg/m3 to 25.0 mg/m3. The OSHA Permissible Exposure Limit (PEL) for zinc oxide fumes is 5 mg/m3. Initial implementation of general dilution ventilation did not adequately reduce employee exposure to zinc oxide fume. After implementing localized, point source exhaust ventilation and training employees to stand away from the plume of welding fumes, employee exposures to zinc oxide fumes were reduced to the range of 0.6 mg/m3 to 1.6 mg/m3.
Conclusions
This case study highlights the need to educate employers on the identification of symptoms of occupational illnesses based on the known health hazards for individual tasks. Additional research is necessary to determine methods to capture cases of work-related illnesses where the symptoms are not unique to the particular types of exposure.
Figure 5. Welding stations after implementation of point source ventilation
Figure 1. Welding station B during visit 2 on December 8, 2008
Figure 2. Diagram of general dilution ventilation systems and welding stations
during visit 2 on December 8, 2008
Figure 6. Summary of Sampling Results