Are Humans Causing Cancer in Wild Animals?

Several types of bacteria have oncogenic potential, but new research postulates that humans could, in fact, be an oncogenic species—changing the environment in a way that causes cancer in wild animal populations.

Investigators from the Arizona State University (ASU) School of Life Sciences scoured the literature for connections between rapid environmental changes and the rate of neoplasia in wild animals.

“Cancer in wild populations is a completely ignored topic and we wanted to stimulate research on this question,” said Mathieu Giraudeau, PhD, postdoctoral researcher in the ASU Life Sciences Lab and one of the study authors. “We recently published several theoretical papers on this topic, but this time, we wanted to highlight the fact that our species can strongly influence the prevalence of cancer in many other species of our planet.”

RELATED:

• Most Mammals Live Longer in Zoos Than in the Wild
• How Can We Lessen the Negative Impacts of Roads on Wildlife?

It is well known that some viruses can mutate to cause cancer in humans, so the investigators wondered if humans were doing the same to animals.

“Basically, we are doing the same thing,” Tuul Sepp, PhD, postdoctoral researcher in the ASU Life Sciences Lab and one of the study authors, said. “We are changing the environment to be more suitable for ourselves while these changes are having a negative impact on many species on many different levels, including the probability of developing cancer.”

The investigators pointed out various human activities that have been shown to increase cancer rates in wildlife, such as:

• Accidental or intentional wildlife feeding
• Accidental release of radiation into the atmosphere from nuclear plants
• Accumulation of microplastics in both land- and water-based environments
• Artificial light pollution
• Chemical and physical pollution of oceans and waterways
• Exposure to pesticides and herbicides on farmlands
• Reduction of genetic diversity in human-impacted habitats

With this study showing how humans have an oncogenic effect on wild animals, the investigators are urgently calling for further studies on this relationship. They even plan to develop biomarkers to physically measure cancer rates in wild animal populations.

“I think it would be interesting to measure cancer prevalence in wild animals in human-impacted environments and also in more preserved areas for the same species,” Dr. Giraudeau said.

The investigators ended their article with an open-ended question: If humans are causing cancer in wild animal populations, what other species could we also be affecting?