She has served on several governmental and non-governmental organizations, conducting research and advocacy into effects of pesticides, asbestos, and wireless radiation on human health, especially cancers.

[9] Davis was the oldest of four children;[10] her father was a chemist and machinist in the local steel mills, as well as a brigadier general in the Pennsylvania National Guard and her mother was a homemaker.

[18] As senior adviser to the US Assistant Secretary for Health, Davis claimed that extra doses of estrogen-like compounds in the environment may increase the quantities of hormone some women receive to dangerous levels and can cause serious illness.

"[27] Science writer Fred Pearce in New Scientist called Davis a "a hero with a nose for trouble" and drew comparisons to Rachel Carson, the author of Silent Spring.

[33][34] In it, she argues that medical institutions involved in the "war on cancer" have focused more on cures than on prevention, and that some safety research into environmental toxicity suffers from a conflict of interest due to funding from companies who make products suspected of causing harm.

"[35] Epidemiologist Richard Clapp called the book "a welcome addition to the struggle to correct the imbalance" between curative and preventative research,[36] while science writer Fred Pearce wrote it "is a rattling good read and raises vital issues that remain relevant today.

"[37] In a positive review, science journalist Dan Fagin called Davis "her generation's strongest advocate of the idea that synthetic chemicals are a seriously under-recognized cause of cancer.

[51] Davis was featured prominently in a controversial 2016 episode of the Australian TV program Catalyst, in which she claimed "every single well-designed study ever conducted finds an increased risk of brain cancer with the heaviest users [of mobile phones]".

[52][53][45] The episode drew heavy criticism from researchers, and Davis' claims were refuted by public health scholar Simon Chapman, who claims there is no evidence of increase brain cancer rates in Australians, as well as Rodney Croft, a commissioner with the International Commission on Non-Ionizing Radiation Protection, who called the views of Davis "a fringe position that is not supported by science.

The U.S. Court of Appeals for the District of Columbia ruled in favor of the EHT and plaintiffs, finding the FCC "failed to provide a reasoned explanation for its determination that its guidelines adequately protect against the harmful effects of exposure to radiofrequency radiation unrelated to cancer.

[11] Davis told The New York Times Magazine that, although she decided to devote herself to cancer research shortly after her father's death, his illness was not the reason for that decision.