Irrigation Workers’ Exposures to Antibiotic-Resistant Bacteria and Antimicrobials

Details

• Personal Author:
  Gibbs S ; Joseph S ; Rosenberg Goldstein R ; Sapkota A ; Sapkota AR
• Description:
  Spray irrigation of reclaimed wastewater is an attractive alternative for wastewater disposal and an economic method of irrigation. However, as reclaimed wastewater use expands, it is necessary to evaluate the extent of potential human exposures to emerging wastewater contaminants such as antibiotic-resistant bacteria and antimicrobials, particularly among wastewater irrigation workers. Thus, the goal of our study was to advance understanding of wastewater irrigation workers' exposures to antibiotic-resistant bacteria and antimicrobials in the Mid-Atlantic and Midwest regions of the U.S. To accomplish this goal, we studied four wastewater treatment plants and four of their associated reclaimed wastewater spray irrigation sites. We collected environmental samples from each site in 2009 and 2010. Nostril and skin swab samples were also collected from spray irrigation workers and office workers (control group). All samples were tested for antibiotic-resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomyin-resistant Enterococcus (VRE). Wastewater samples were also tested for antimicrobial residues, including ciprofloxacin and tetracycline. We detected MRSA in 50% of wastewater samples from the four treatment plants and 93% of MRSA isolates were multidrug resistant (resistant to approximately 2 classes of antibiotics). We also detected VRE in 32% of wastewater samples from the treatment plants. While both MRSA and VRE were detected in a few of the unchlorinated effluent samples (finished water coming out of the plants), MRSA was not detected at any of the wastewater spray irrigation sites, and VRE was detected in only one sample from one spray irrigation site. Similarly, we did not detect MRSA or VRE in nostril or skin swabs from any of the spray irrigation workers. However, we did detect 5. aureus in nostril swabs from 26% of spray irrigation workers and 29% of office workers. A greater percentage of spray irrigation workers carried multidrug resistant 5. aureus in their nostrils compared to office workers. Moreover, a range of antimicrobial residues, including azithromycin, linezolid and ciprofloxacin, were detected in raw wastewater, effluent and reclaimed wastewater used at spray irrigation sites. Levels of antimicrobials declined throughout the wastewater treatment process; however, concentrations were still elevated in wastewater used at spray irrigation sites. To our knowledge, this is the first report of the detection of MRSA at wastewater treatment plants in the U.S. It is also the first study to 1) analyze reclaimed wastewater at reuse sites in the U.S. for antibiotic-resistant bacteria and antimicrobial residues; and 2) assess the rate of 5. aureus carriage among spray irrigation workers. Our findings suggest that implementing tertiary treatments (e.g. chlorination, filtration) for wastewater intended for reuse applications could reduce the potential risk of exposures to antibiotic-resistant bacteria and antimicrobial residues among individuals working with reclaimed wastewater. However, reclaimed wastewater spray irrigation workers, as well as wastewater treatment plant workers, could still potentially be exposed to these emerging contaminants through skin contact and inhalation. Encouraging frequent handwashing and the use of gloves, as well as changing clothes before going home, could reduce the potential risks associated with these exposures among spray irrigation workers and wastewater treatment plant workers. [Description provided by NIOSH]
• Subjects:
  Agriculture Anti-Bacterial Agents Occupational Health Safety
• Keywords:
  Agricultural Industry Antibacterial Agents Antibiotics Antimicrobials Bacteria Methicillin Resistant Staphylococcus Aureus MRSA Waste Disposal Water Sprays
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Maryland ; OSHA Region 3
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-27
• NIOSHTIC Number:
  nn:20056751
• NTIS Accession Number:
  PB2019-101414
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, R03-OH-009598, 2012 Dec; :1-27
• Contact Point Address:
  Amy R. Sapkota, PhD, MPH, Assistant Professor, Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, 2234P SPH Building #255, College Park, MD 20742
• Email:
  ars@umd.edu
• Federal Fiscal Year:
  2013
• NORA Priority Area:
  Agriculture, Forestry and Fishing ; Services
• Performing Organization:
  University of Maryland College Park Campus
• Peer Reviewed:
  False
• Start Date:
  20090901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20120831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:b030a2dc70a32fdc90d7f00853edb648bae3df1e8ef1f4e3f51697b72494ac7809028b2ff339ac102f712b5993e61d27d65946abe0f9aec53b5468c9110e2609
• Download URL:
  https://stacks.cdc.gov/view/cdc/218910/cdc_218910_DS1.pdf
• File Type:
  [PDF - 3.99 MB ]