od used in toxicology is highly flawed because it makes this assumption: lower dosage = lower poisonous effect.
This linear relationship has become the basis for determining the average daily intake (ADI) of many chemicals. At ultra-low levels of dosage, the chemical
is considered too low to cause any health problems.
However, in a 2012 peer reviewed journal Endocrine Reviews, Vandenberg, et. al. showed that there were hundreds of published studies documenting
the exact opposite, i.e. that chemicals became MORE toxic at low and often the lowest doses. It further concluded that
“Experimental data indicate that endocrine disrupting chemicals and hormones do not have any observable adverse effects or threshold doses, and therefore no dose can ever be considered safe.” That means that the tiniest amounts are harmful whether we see any immediate effect or not
or whether they exceed threshold limits set by the government or industry standards.”
Andre Leu explains this counterintuitive concept in his book, The Myths of Safe Pesticides this way: “Many scientists assume a chemical is
relatively safe if it’s found in parts per million in the standard toxicology test, but at parts per billion or trillion they can act much like hormones.
This is because at very low levels they could attach to hormone receptors, whereas at higher levels of dosage they were ‘ignored’ by the hormone receptors.
If and when these chemicals attach themselves to the hormone, they send signals to the endocrine system to act as a hormone, or as an antagonist to the
hormone, or block the normal functioning of the hormone and act as an endocrine disruptor.”
"Hormone receptors can be likened to locks in a door of the cell wall and a very small hormone acts like the key. In large doses, the chemical molecule
is the wrong size and shape to fit into the lock, but the same chemical in a much smaller molecule can fit right into the receptor and unlock the door
sending a false signal to the cell or block normal hormone signals, thereby disrupting the normal functioning of the cell.”
There is a substantial body of published research on endocrine disruption, and
the current methods of toxicology testing used to permit chemical residues in our food and water are based on the assumption that all chemicals lose
their toxicity as they decrease in quantity. This is clearly not correct for many chemicals.
According to the USPCP, numerous published studies link the endocrine disruption caused by common commercially available chemicals to many of the health
problems such as obesity, type 2 diabetes, ADHD, depression, cancers of the sexual tissues and endocrine system, genital-urinary track malformations and
lowered fertility rates and sperm counts.
The vast majority of chemicals have simply not been tested for their long-term affects on humans, pets or the environment. Some 800 chemicals are known or
suspected to be capable of interfering with hormone receptors, hormone synthesis or hormone conversion. However, only a small fraction have been
investigated in tests. Andre Leu says “ Setting low thresholds for chemicals is, therefore, not evidence-based science. It is decision-making based on data-free assumptions.”
Testing chemicals in isolation is not realistic
According to Dr. Leu, “Part of this is due to how most testing is done on single chemicals in isolation in a lab. The reality of most chemicals is that
they are used in combination with other chemicals creating a “chemical cocktail” that makes testing difficult and costly. Regulatory authorities tend to
focus on the active ingredient in a cocktail and if it is below the “acceptable daily intake (ADI)” the cocktail as a whole is considered safe. They do not
test the combinations of chemicals.”
According to a study by the World Health Organization (WHO) and the United Nations Environmental Program (UNEP), chemical cocktails can act
when individual chemicals at low levels combine with others at low levels, their mixture can create much higher levels of chemical toxicity than the
two individually. This “additive effect” has