Esswein-EJ; Holmes-EB; Suruda-A
NIOSH 2001 Aug; :1-8
The National Institute for Occupational Safety and Health (NIOSH) received a health hazard evaluation (HHE) request from a representative of the Colorado Department of Public Health and Environment (CDPHE) for assistance in determining if workers' lung problems could be related to exposures encountered while working at the Littleton/Englewood Waste Water Treatment Plant (WWTP). An opening conference and a walkthrough survey were conducted on January 11-12, 2001. Survey monitoring for the presence of hydrogen sulfide gas was conducted. Respiratory health questionnaires were distributed to all current operations and maintenance employees. Results from the medical respiratory questionnaire indicate that the prevalence of self-reported bronchitis in operations and maintenance employees at the WWTP was similar to that in the general population. At the time of the investigation, the Littleton/Englewood WWTP appeared to be a well-controlled workplace that had implemented a combination of dilution ventilation, managerial controls and, where appropriate, respiratory protection (for certain confined space entry procedures) to protect workers from occupational exposures. Hydrogen sulfide was detected at several locations in the plant, and in the ambient air within the plant. The plant has undergone significant expansion over the years. Changes in work practices at the plant, and improvements in dilution ventilation within the plant, were phased in over a period of time in recent years. These changes were implemented to improve occupational safety and health at the Littleton/Englewood WWTP and appear to be effective at the time of this investigation. An occupational health hazard was not determined to exist at the Littleton/Englewood WWTP during the time of this investigation. However, occupational exposures to plant operators with a long history of employment would be expected to vary considerably over the years as the plant underwent enlargement and process changes. Workers with many years of employment at this WWTP may have incurred occupational exposures which could cause chronic irritant bronchitis. But at the time of this investigation, evidence of any overall increased risks for chronic irritant bronchitis were not found.
Hazards-Unconfirmed; Region-8; Waste-disposal; Waste-treatment; Water-purification; Sulfur-compounds; Respiratory-system-disorders; Pulmonary-system-disorders;
Author Keywords: Sewerage Systems; waste water treatment plants; WWTP; sludge
Hazard Evaluation and Technical Assistance; Field Studies
National Institute for Occupational Safety and Health