Karley Johnson

Project title: Establishing an Urban Rodent Control Outreach Program Focused on Nontoxic Methods

Degree: MS (Applied) | Program: Applied Toxicology (App Tox) | Project type: Thesis/Dissertation
Completed in: 2022 | Faculty advisor: Tania M Busch Isaksen


Commensal rodents are a widespread problem in densely populated cities, where they live in close proximity to humans. These rodents can transmit numerous diseases to humans and domestic animals and are a threat to public health. Public Health – Seattle & King County’s (PHSKC) rodent program in the Environmental Health Services division works to help Seattle residents know how to clean up their properties to avoid attracting rodents and worsening these issues. They also provide educational resources and workshops to inform the public on how to control rodents and prevent infestations. One important issue that needs to be considered when educating people on how to control rodents is the possible hazards that can come from misuse and overuse of rodenticide products. These products can be especially dangerous for children, pets and wildlife, and should only be used after other rodent control measures have been taken first. During my internship with the PHSKC rodent program during the summer of 2022, I worked on a project creating rodent control and prevention kits that were distributed to Seattle residents upon request. These kits used only nontoxic control methods and products, including traps and rodent exclusion materials. These kits were intended to decrease barriers for people needing to rodent proof their homes, or exterminate rodents on their property, which can be very expensive processes. They can also provide alternative means to avoid purchasing over the counter rodenticides that are commonly misused in homes. I also authored a blog post on the hazards of rodenticides, which promoted using nontoxic options for rodent control. Finally, I created and distributed a survey of Seattle residents to gain perspective on their current knowledge, attitudes and practices regarding rodent control methods and the rodent program at PHSKC. Through a review of the literature, recommendations for how to improve this survey and produce more robust survey tools in the future were made. These three projects encompassed three very important public health skills: learning about the needs of the population that you serve, educating that population on important public health topics, and creating new ways to serve the population by lowering barriers to creating a healthier living environment for everyone.