This was an incredible expose of corporate greed and devastated communities. It goes into detail in all the ways companies knew PFAs and PFOs were dangerous to humans, covered up that knowledge, and exposed communities to incredibly dangerous levels of the chemicals. It also goes into detail of how the communities were affected by these chemicals and how individuals were forced to become activists to fight back against powerful companies who place profit over all else.

I found it heartbreaking to learn how widespread this problem is, but I was also left hopeful by how much these communities have won already in the fight to ban forever chemicals.

Necessity spurred innovation, but at what cost? They Poisoned the World by journalist Mariah Blake uses the history of one New York town, Hoosick Falls, to detail the development and production of PFAS that had many industrial applications despite growing health concerns. Like many works of advocacy and reveal all, it does not paint a flattering portrait of the companies, focused on profit health and safety.

Blake's chapters are brief in length, reliant on large amounts of direct interviews. Most damning of all is the US's focus on safe until proven harmful, allowing the quick adaption to other similar chemicals when one is find to be harmful. While Blake traces the history of Dupont from its origins, the bulk of the work is unfortunately contemporary, ended with both a cry for action and the role of the national government in supporting accountability or rolling back regulations.

Recommended to readers of current events, social issues or the conflict between ethics and capitalism.

I love journalistic exposes and I love journalistic exposes about environmental catastrophes even more. I am absolutely the target audience for They Poisoned the World and yet, I still loved it more than I could have imagined.

Mariah Blake does an outstanding job breaking down the history of plastics and PFAs, using a human angle, she teaches us the science and policy debate surrounding forever chemicals and how our world has been changed.

Daunting in content, this book is a must-read for anyone who cares about the lives of every living thing on this planet. Exceptionally accessible and filled to the brim with information, The Poisoned the World is one of my favorite reads of 2025. Perfect for fans of Dark Waters and Paradise Falls.

"They Poisoned the World" is an enticing, captivating, and devastating read about the tumultuous downsides of capitalistic greed. Unfortunately, in today's world, this type of occurrence feels all too commonplace, but author Mariah Blake takes readers on an incredible journey of corporate cover-ups dating back to World War II. After losing several friends and family, including his father, to cancer, Michael Hickey began looking into his local water supply in Hoosick Falls, New York and discovered dangerous levels of "forever chemicals" known as PFAS in the town's drinking water caused by illegal dumping, among other factors, of toxic chemicals.

Throughout this book, Blake describes decades of government officials and business executives looking the other way on research into disastrous effects of chemicals used in their production plants, as well as run-off affecting inconspicuous areas of everyday town life. These companies would rather pay hefty fines than admit any wrongdoing or do their part to warn employees or townspeople of the harmful conditions. Blake weaves in historical narratives that read like science fiction. She captivates readers with, at times, unbelievable stories of greed and corruption with personal implications interspersed detailing how these decisions have lasting impacts on everyday people for generations. It's difficult to fathom just how far those in power will go to stay there, even at the cost of human life, and Blake does an excellent job of remaining objective while leading readers to understand the full scope of these chemicals' effects.

An important read to understand how entwined corporations have been in our communities for centuries, poisoning our lives. Blake tells us stories of ordinary people mixed with the Powers That Be maneuvering our lives, getting away with murder from the moment industrialization advanced.

How ubiquitous are forever chemicals? What are the consequences of these dangerous materials? What can you do if your community is heavily affected by pollution? This books answers these questions through facts and stories of everyday Americans affected by forever chemicals. An important read!

"They Poisoned the World" by Mariah Blake is a chilling exposé of the chemical industry's decades-long campaign to conceal the dangers of "forever chemicals." Blake masterfully weaves together the secret history of these toxins with the inspiring story of a small town that dared to challenge powerful corporations. This book is a must-read for anyone concerned about public health and the environment.

This is a stunning exposé of how companies that put forever chemicals into communities are getting away with murder. With compelling interviews and detailed research, this book is easy to read because of its style - yet incredibly difficult to read because of its content. I hope this book becomes our generation’s Silent Spring: a rallying cry for common-sense regulation that protects Americans from unethical agencies and greedy corporations that put profit above people. This is a must-read.

Thank you to NetGalley and Crown Publishing for the free eARC. I post this review with my honest opinions.

This review is cross-posted on Goodreads and will be posted on Amazon and Instagram upon the book’s publication.

PS: even though I got this book for free, it’s going to be the most expensive one I ever read… I’m about to replace my PFA-filled cookware and bakeware with nontoxic options!