They tell you that environmental toxins are all around you, making you sick. Ever wonder why you've never seen a victim of these so-called toxins? This will tell you.
It's true that as human activity on the planet increases, residue from nearly everything we do contaminates the water, the air, the ground, even our food supply. At the same time, we're always working to minimize this. But along the way, there are always going to be reports in the news of high levels of some toxic substance found somewhere. Heavy metals, pesticides, and BPA are among the many compounds that ends up in our environment.
We all want to know if our safety is in danger. To determine this, start with a basic understanding of our world: Every compound you can name, no matter how scary, has a safe level; and every compound, no matter how natural, has a toxic level.
A good example is plutonium, one of the most dangerous substances known. Suppose you heard on the news that plutonium was found in your drinking water at ten times the normal level, even a hundred times the normal level. Should you be concerned? Yes, we should probably address it; but would those levels put anyone's health at risk? Not even remotely. No matter how scary the media might try to make that sound, plutonium occurs naturally on Earth, and every person and animal that ever lived has an average of about 20,000,000 plutonium atoms in their bone marrow, simply because we live on this planet. This most toxic of compounds has a normal, safe, background level that is way, way below the level at which it becomes dangerous.
This is what's so hard for many people to accept: You hear "pesticides" and you think "Oh my gosh, there is no safe level of that." Not true. Anything can be diluted below hazardous levels, and the reverse is also true. Any compound can be concentrated above hazardous levels. You can die from drinking too much pure water (we call this water intoxication), and you can die from breathing too much pure oxygen (we call this oxygen toxicity). Everything can be a poison (like soy beans), and everything can be safe (like box jellyfish neurotoxin): the only thing that differentiates them is the dose.
The bottom line is simple. Don't accept sensationalized news articles that only tell you how far above normal levels some toxin has been found. The only thing that matters is how that level compares to a safe level.
References & Further Reading
Chappel, M. "Colon Therapeutics 23-Oct-03." FDA.gov. US Food and Drug Administration, 23 Oct. 2003. Web. 25 Dec. 2009. <http://www.fda.gov/ICECI/EnforcementActions/WarningLetters/2003/ucm147792.htm>
Fang, Hsai-Yang. Introduction to environmental geotechnology. Boca Raton: CRC Press, 1997. 434-437.
Goldacre, Ben. "Be fit: The detox myth." The Guardian. 8 Jan. 2005, Newspaper: 9.
Lordan, Betsy. "FTC Charges Marketers of Kinoki Foot Pads With Deceptive Advertising; Seeks Funds for Consumer Redress." Federal Trade Commission. Federal Trade Commission, 28 Jan. 2009. Web. 25 Dec. 2009. <http://www.ftc.gov/opa/2009/01/xacta.shtm>
Moores, S. "Experts Warn of Detox Diet Dangers." NBC News. NBCNews.com, 18 May 2007. Web. 3 Nov. 2012. <http://www.msnbc.msn.com/id/18595886/ns/health-diet_and_nutrition/t/experts-warn-detox-diet-dangers/>
Singh, S., Ernst, E. Trick or treatment: the undeniable facts about alternative medicine. New York: W. W. Norton & Company, 2008. 226-227,308.