One morning in 2000, Dr. Jane Hightower walked into her exam room to find a patient with disturbing symptoms she couldn’t explain. The woman was nauseated, tired, and had difficulty concentrating, but a litany of tests revealed no apparent cause. She was not alone. Dr. Hightower saw numerous patients with similar, inexplicable ailments, and eventually learned that there were many more around the nation and the world. They had little in common—except a healthy appetite for certain fish. Dr. Hightower’s quest for answers led her to mercury, a poison that has been plaguing victims for centuries and is now showing up in seafood. But this “explanation” opened a Pandora’s Box of thornier questions.

Why did some fish from supermarkets and restaurants contain such high levels of a powerful poison? Why did the FDA base its recommendations for “safe” mercury consumption on data supplied by Saddam Hussein’s Ba’athist extremists? And why wasn’t the government warning its citizens?

In Diagnosis: Mercury, Dr. Hightower retraces her investigation into the modern prevalence of mercury poisoning, revealing how political calculations, dubious studies, and industry lobbyists endanger our health. While mercury is a naturally occurring element, she learns there’s much that is unnatural about this poison’s prevalence in our seafood. Mercury is pumped into the air by coal-fired power plants and settles in our rivers and oceans, and has been dumped into our waterways by industry. It accumulates in the fish we eat, and ultimately in our own bodies.