The British scientists accused groups such as Greenpeace and the World Wildlife Fund of "acting irresponsibly by publishing reports claiming most people have blood swimming with toxic compounds." That old trick should sound familiar to U.S. consumers. Perhaps the most experienced practitioner is the Environmental Working Group (EWG), which continually tries to frighten us about harmless amounts of pesticides in our food, and specifically mercury and PCBs in our fish.

Last year EWG issued a fear-mongering report called "Body Burden," which detailed the number of chemicals found in peoples' bloodstreams. While EWG didn't provide any evidence of actual harm, that didn't stop full-time worrywart and California State Senator Deborah Ortiz from sponsoring legislation that would have taxpayers foot the bill for more "body burden" testing.

EWG, like its activist comrades here and abroad, cares less about good science than it does about good PR. As a spokesperson for Britain's Science Media Centre told the Observer:

These groups are more media savvy than scientists and have given themselves headlines galore by giving "terrifying" results of blood tests to a media they know has an insatiable appetite for scare stories. But it's important the public know most scientists take issue with their alarmist interpretation.

Consider the opinions of leading U.K. toxicology experts, who all told the Observer that the activists' fuzzy math doesn't add up:

• Imperial College professor Alan Boobis, an expert in metabolism and mechanistic studies on chemical carcinogens and chemical risk assessment, noted that many chemicals "can cause diseases but not at the levels found in these tests ... Most chemicals were found at a fraction of a part per billion. There is no evidence such concentrations pose any threat to people's health. This is irresponsible, hysterical scaremongering."

• Imperial College professor John Henry -- a prominent toxicologist and a consultant to Britain's National Poisons Information Service -- offered this retort to hysteria over flame-retardant chemicals in a person's blood stream: "You find flame retardant traces because we have them in our homes. That's why fire deaths have plunged. These chemicals are monuments to mankind's progress."

• Southampton University professor David Coggon, who studies the epidemiology of occupational and environmental causes of disease, warned: "People are being pressed to make decisions on misleading information."