Human illness can negatively impact the environment, according to a study published Monday in the Proceedings of the National Academy of Sciences by Kathyrn Fiorella, a former UC Berkeley doctoral student.

In the study, Fiorella focused on investigating a fishing community around Lake Victoria, Kenya, which suffered from high rates of disease and a dwindling fish stock. According to Fiorella, the site gave her an opportunity to witness the relationship between human and environmental health.

“We followed 303 households for a year. and we revisited them four different times to understand what was going on in the health of the fisherman in the households, how their health was changing through the course of the year and how their fishing practices changed over the course of the year,” Fiorella said.

A self-reported questionnaire was used to measure health-related quality of life. Subjects were then assigned an overall score for their mental and physical health. The questionnaire also included questions about how much time the subjects spent fishing and what methods they used, Fiorella said.

When Fiorella looked exclusively at subjects who had been fishing recently and studied their health and fishing techniques, she found that subjects who were ill were more inclined to use illegal fishing practices that were physically less exerting, rather than using sustainable fishing methods that were more physically demanding.

“I hope (the study) encourages us to think about new pathways about how human health and environment are connected,” Fiorella said.

The study was funded in part by the National Science Foundation’s Dynamics of Coupled Natural and Human Systems program. Richard Yuretich, program director for the division of earth sciences at the National Science Foundation, said proposals were funded on a competitive basis, with 10 to 20 percent of the submitted proposals receiving grants.

The program supports research that analyzes the complicated relationship between people and their environments, according to Yuritech.

“Usually, when we think of the environment and human health, we think about the effect of the environment on human health,” Yuretich said. “We never think that the human population in it of itself can have an effect on the environment and ecosystems around us. … It becomes a compelling case to keep people healthy, and it’s also a form of environmental protection.”

Arthur Reingold, campus professor and division head of epidemiology, confirmed the merit of the study. He also emphasized, however, the importance of further research.

“This research should stimulate people to look into other types of illnesses or communities. That would then lead to change in how we support people when they are ill,” Reingold said. “People will be sufficiently concerned about effects on the environment, and that should be motivation to support people to reduce the effect of illness and injury.”