Wastewater Treatment Plants: Environment, Human Health, and Air Quality Assessment

Details

• Personal Author:
  Lee JA
• Description:
  By looking at air quality, health status, and numeric simulations in wastewater treatment plants (WWTPs), this study aims to investigate (1) exposure levels in various unit operations, (2) health risks posed by workers' job activities and environment, and (3) concentration prediction by computer simulation and mathematical modeling. Hydrogen sulfide (H2S) and endotoxin were measured by area and personal monitoring at unit operations during various job tasks. The area monitoring results showed that levels of H2S were less than 1 ppm and endotoxin ranged from 6 to 1247 EU/m3. The H2S levels were statistically higher in grit-removal and sludge-dewatering unit operations, and were associated with relative humidity and total incoming flow; however, such differences and associations were not found for endotoxin. Personal monitoring measurements of H2S and endotoxin were found to be less than 1 ppm and 1071 EU/m3. The exposure levels of H2S were statistically different between job tasks. Questionnaire results showed increased risks of respiratory, neurological, gastro-intestinal problems and ocular-skin irritations among the WWTP workers. In particular, the prevalence rate (45%) of depression among the workers was significantly higher than that of the controls. Also, an association of job tasks with adverse health effects was found. Several suggestions were made based on these results: (1) different methods for controlling endotoxin and H2S in unit operations are needed to effectively reduce their concentrations, (2) distinctive health surveillance for various job duties should be provided, and (3) medical observation for neuro-psychological health is required. A numerical simulation was also performed to test whether such methods can be used for air quality assessments. In five cases with combinations of different configurations and airflow-rates, gas concentrations predicted by simulation and measured by tracer analysis were compared. The results showed disagreement between the two assessment techniques; however, reasons explaining the disagreement are discussed in this study and further research to decrease the differences in concentration estimation will be necessary. Overall, this study's outcome provided significant information concerning the relationship between exposure levels in WWTPs and workers' job activities, and warrants more research to overcome the limitations of this study. [Description provided by NIOSH]
• Subjects:
  Air Pollution Endotoxins Occupational Health Safety Workplace
• Keywords:
  Air Quality Monitoring Exposure Assessment Health Effects Hydrogen Sulfide Waste Treatment Water Purification Work Environment
• ISBN:
  9780542795701
• Publisher:
  ProQuest LLC.
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Thesis
• Place as Subject:
  Iowa ; OSHA Region 7
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20057337
• Citation:
  Ann Arbor, MI: ProQuest LLC., 2006 May; :3225635
• CAS Registry Number:
  Hydrogen sulfide (CAS RN 7783-06-4)
• Federal Fiscal Year:
  2006
• Performing Organization:
  University of Iowa
• Peer Reviewed:
  False
• Start Date:
  20050701
• Source Full Name:
  Wastewater treatment plants: environment, human health, and air quality assessment
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c0d2d799c10b494c9c8ae9a20e5b8c4bd29a64bbdbb2431b858d8ffe07090c4c08f58e08f5d4a0e67b84f26dfc7566376d584fad4b00f24cc2a357fa07809f5b
• Download URL:
  https://stacks.cdc.gov/view/cdc/214724/cdc_214724_DS1.pdf
• File Type:
  [PDF - 2.96 MB ]