Beyond Zoonosis: The Mental Health Impacts of Rat Exposure of Inner-City Residents

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This work was one of the 2018 Ron de Burger Student Award winners. 

Author: Raymond Lam, University of British Columbia – Master of Science in Occupational and Environmental Hygiene


  • Rats are a common problem in cities worldwide, but impoverished, inner-city neighborhoods are disproportionately affected because factors associated with poverty promote rat infestations and rat-human contact.
  • Public health has mostly focused on disease transmission associated with rat infestations, but little is known about the non-physical consequences of this environmental exposure.
  • Mental health is often neglected but is receiving increasing attention in public health research and practice.


  • A systematic review and narrative synthesis of the published literature was conducted to explore the effect of rat exposure on mental health among inner-city residents.
  • Titles and abstracts of articles were first reviewed to determine relevance to the research question; full text of included articles were subsequently reviewed and synthesized for evidence between the exposure and outcome.

Results & Discussion

  • Literature addressing this topic was sparse (eight out of seven hundred and fifty-six articles) but the results consistently suggest that rat exposure has a negative impact on mental health.
  • These impacts can be direct or indirect and themselves can be exacerbated by external variables.
  • Evidence of the mental health impact of other pest infestations have been mixed, suggesting pest-specific factors, such as perception, also play a role in determining the outcome.
  • Given the limited literature, many areas for future research remain: how rat infestation elicits stress, if a dose-response relationship exists between rat exposure and poor mental health, if different demographics are disproportionately affected, and possible interventions for the problem.


  • By developing a better understanding of potential rat-related health risks, both mental and physical, public health officials can better evaluate, refine, and develop their policies regarding rats.

The full review is available below.


Publication Date Aug 20, 2018
Author Raymond Lam
Posted by NCCEH Aug 20, 2018