In the late 1970s, as a policy advisor for the
Environmental Law Institute, Davis began publishing articles examining links between environmental chemicals and cancer. In 1990, she led a study published in
The Lancet along with
National Institute for Environmental Health Sciences director David Hoel, British census director
John Fox, and
World Health Organization statistician
Alan Lopez, examining cancer rates in the United States, Japan, and several European countries, concluding "all forms of cancer are increasing in persons over age 54 except lung and stomach" and "the changes in cancer other than lung are so great and rapid that their causes demand intensive investigation." Davis was appointed by President Clinton to the
US Chemical Safety and Hazard Investigation Board. In 1997 she was working as a consultant to the
World Health Organization Davis founded the International Breast Cancer Prevention Collaborative Research Group, an organization dedicated to exploring the causes of breast cancer. 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. Davis served five years as the founding director of the Center for Environmental Oncology at the
University of Pittsburgh Cancer Institute (UPCI). In 2009, she stepped down to become professor in the Department of Epidemiology at the
University of Pittsburgh Graduate School of Public Health. She has authored over 200 scientific papers as well as three books. She provides accounts of the
1948 Donora smog in her hometown, the 1952
Great Smog of London, and other events. She also criticizes industry interests who dismiss evidence they dislike as "junk science." The book was a finalist for that year's
National Book Award for Nonfiction. Public health philosopher
Kristin Shrader-Frechette praised it as "the best book on public health and environmental pollution of the last 30 years." 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. Other writers have compared and Davis and Carson, both in their styles and themes of writing and their small town Pennsylvania upbringings. Epidemiologist Bert Brunekreef wrote the book is "at its best when describing how commercial interests have harassed well known environmental health scientists in attempts to downplay the seriousness of, say, the effects of environmental lead on the IQ of children," but found "an alarming number of errors" regarding air pollution.
The Secret History of the War on Cancer Davis' second book,
The Secret History of the War on Cancer, was published in 2007. 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. Epidemiologist
Richard Clapp called the book "a welcome addition to the struggle to correct the imbalance" between curative and preventative research, while science writer Fred Pearce wrote it "is a rattling good read and raises vital issues that remain relevant today." 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." Medical historian Peter Keating, however, found the book "largely unoriginal" and poorly organized. Epidemiologist
Peter Boyle wrote that "devotees of conspiracy theories and aficionados of gossip and innuendo will be drawn towards this book like wasps to a juicy piece of meat" and discussed how the book suggested that
the link between tobacco and cancer was used to distract from other possible sources.
Wireless radiation In 2007 Davis founded the Environmental Health Trust (EHT), The EHT campaigns for safer
cell phone use, and has challenged research that finds no links between cellular phones and cancer, advocated for more research into the effects of wireless radiation on children, Davis has been called a "crusader in the fight over cell phone safety". She claims much research that finds no effects is industry-funded and biased. She summarized her research into health effects of cell phones in her 2010 book,
Disconnect: The Truth about Cell Phone Radiation, What the Industry Has Done to Hide It, and How to Protect Your Family. She has cited the
World Health Organization's 2011 classification of wireless radiation as a
Class 2B agent ("Possibly Carcinogenic to Humans"). while the EHT has been accused of promoting low quality sources. 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]". 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." and
BBC Radio 4 has called Davis one of the most influential scientists in 5G-opposition movements. In 2021, the EHT and other groups filed a lawsuit asserting the
Federal Communications Commission (FCC) failed to consider new scientific evidence when deciding in 2019 not to update its safety guidelines for cellular phone and cellular tower radiation, which had not been updated since 1996. 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." ==Personal life==