The Dose Makes the Poison?

Up on ISSUU is a free publication titled, Pesticides, Food and You: The Dose Makes the Poison?, produced by Friends of the Earth, here in Melbourne, Australia, and funded by The City of Yarra. Now, as some of you who already know (possibly from harsh experiences, yourself), the ‘dose’ of a chemical, allergen or irritant is not determined by the actual dosage. Rather, it’s a matter or ‘the dose + the host makes the poison’, a phrase coined by Dr Pamela Reed Gibson. Do you have a dysfunctional immune system? Has an exposure to a toxic dose of poisonous chemicals? Worked with substances you’ve become sensitised to? Got allergies? Then, as you’ve possibly already discovered, chemicals effect you differently (from Joe and Jane Doe who are out spraying there lawn with herbicide bi-monthly). In The Dose Makes the Poison, this point is discussed further:

“All substances are poisons; there is none which is not a poison. The right dose differentiates a poison….” ~ Paracelsus (1493-1541)

“This quotation essentially defines how our society deals with the issue of toxicants. The quote means that the body will experience a harmful event only when one is exposed to a high enough dose of a particular substance. The toxic effect of a substance will increase depending on the amount that one is exposed to. For example caffeine or alcohol consumed in high enough quantities will kill a person, yet millions of people drink varying amounts of caffeine or alcohol ‘safely’ every day.

On a dose response curve, chemicals typically reveal a graded effect between no effect and a toxic effect. The theory states that even a highly toxic substance will not cause an unhealthy response if the exposure level is small enough and a practically non toxic substance can cause an unhealthy response if a person is exposed to enough of it. The potency of a chemical is therefore determined by the dose that one is exposed to.

Public Health Authorities use the Paracelsus philosophy as the basis of their various health standards which specify how much of a particular substance is safe in food, water and the environment. To do this, a substance must first be tested, usually by a pesticide registration applicant, for its short term, or acute toxicity. This is done with toxicity (dose response) experiments, where the amount of physically impaired, sick or dead laboratory organisms (usually mice, rats, rabbits and dogs) are counted after they are exposed to differing concentrations of a particular substance.

A dose refers to the organism’s exposure via inhaling, eating and absorption through the skin. It can include a single dose, or doses which resemble the effects of a lifetime exposure. Response refers to the changes to animals as a result of the exposure. Normally as the dose increases, the amount of death or health impairment in the test animals will also increase. Threshold concentrations are then set which then take into account acute toxicity and also a search for evidence of long term effects of exposure to low level doses either in humans or animals. A safety factor of between 10 and 1000 is then applied based on the degree of confidence of existing information that provides an accurate estimate of the effect of the substance on human health. From this process, regulators determine an Acceptable Daily Intake. (ADI) which is effectively the health standard…

The theory “The Dose Makes the Poison” does not properly define modern toxicology. Firstly it assumes that people react in the same way to chemical exposure and that tests carried out in animals also cross over to humans.

It also does not factor in sensitivities at different life ages (e.g. young children and foetuses react differently to chemicals than adults do), nor does it factor in issues concerning disease sensitivities of people suffering diseases such as Multiple Chemical Sensitivity.

Tests on laboratory animals to determine effects do not adequately measure chronic (long term) toxicity, or the effects of average chemical exposure per day over many years, nor do they factor in the synergistic impact of a cocktail of pesticides that a person may be exposed to, as tests are carried out on individual chemicals only. It also does not properly take into account the impacts on endocrine disruption or the toxicity of substances on the immune system.”

You can click on the image below and read the full body of text from Friends of the Earth, The Dose Makes the Poison? 0n ISSUU or enlarge or download the magazine below:

In the recent past, paid MCS skeptics have attempted to paint a picture of this illness being of a psychogenic (like, all-in-our-heads, yeah?) nature. I mean, surely because most people are fine with small doses of pesticide or fragrance chemicals, then those who do have physical symptoms caused from a minute dose must be manifesting symptoms caused, perhaps by, oh I don’t know… something missing from our lives on an emotional level? Oh, please, paid skeptics! stop attempting to suggest a quasi-diagnosis based on Woo as a theory. It’s getting old (like the year 1980 kind of old).

Previous studies on MCS, and recent discoveries in genetic polymorphisms show that people with MCS have detoxification mechanisms and immune systems that have been seriously compromised, most likely from a combination of environmental insults superimposed on inefficient genetic detoxification pathways. (MTHFR gene anyone?) Also, if there are nutrient deficiencies or enzyme depletion issues, people with MCS who have chemical exposures will find it more difficult than others to process that exposure. More about pesticides and MCS from An Inconvenient Truth, an article on MCS from Arizona Advanced Medicine:

One reason pesticides cause so much trouble for the human body in general, and those with MCS in particular, is that the manufacturer often adds an enzyme blocker to the formulation so that the poison cannot be metabolized properly. This means that the chemical remains in the body (of insect or human) longer, making it even more toxic. That may be desirable if we are talking about killing cockroaches. It is definitely not good for the human beings who share the same air and end up inhaling or absorbing the same toxic chemicals through their skin.

Luckily, there are many doctors who are willing and able to help and support us with our medical problems. However, a medically recognised case definition for MCS is something many of us are still waiting for. Resistance has loomed large in this issue. Arizona Advanced Medicine, point out one well known case of opposition in regards to completely accepting this diagnosis into mainstream medicine:

Mainstream medical resistance remains robust. Just ask the esteemed Dr. William J. Rea of Dallas, a Board certified surgeon and one of the earliest medical professionals to recognize MCS. He has been a target of the medical establishment for the last 25 years. He has treated sick Exxon Valdez cleanup workers and people sick from the toxic chemicals in crude oil and dispersants released during the BP oil spill. In August of 2007, the Texas Medical Board challenged his recognition and treatment of MCS and threatened to revoke his medical license. After three years in court, it was finally proven that the Board’s claims were unsubstantiated and he was exonerated of all charges; he is left with a boatload of legal bills. The Board said that from now on, Dr. Rea must simply inform patients that his treatment is not FDA approved. Many parties have a vested interest in keeping all manner of chemicals a large part of the world economy. It is sobering to know that in 1990 for example, the Chemical Manufacturers Association vowed to work with state medical associations to block the recognition of MCS. (See accompanying article from Dr. Ann McCampbell.)

The Dose Makes the Poison leaves us with this final point:

Current pesticide regulation has not yet evolved to keep up with recent scientfic research that reveals pesticides can have significant impact at very low doses, well below the levels currently regarded as being safe. The ‘dose makes the poison philosophy’ needs to be overhauled to include the full impacts of pesticides and chemicals that can, for example, impact on endocrine function.

And, in conclusion to this post, I’ll leave you with the ending of Rachel Carson’s poem from A Silent Spring, which sums up the answer to this situation a whole lot better than I ever could:

“If …we have at last asserted our ‘right to know’, and if, knowing, we have concluded that we are being asked to take senseless and frightening risks, then we should no longer accept the counsel of those who tell us that we must fill our world with poisonous chemicals; we should look about and see what other course is open to us.”

(A list of endocrine disrupting chemicals (including pesticides) can be found at this link. Most worrying is that many of the endocrine disrupting substances on this list are commonly detected on food in Australia including some of the most commonly detected pesticides such as: Iprodione, Procymidone, Fenithrothion, Endosulfan, Permethrin, Pyrimethanil, Dicofol, Carbaryl, Cypermethrin, Fenvalerate, Vinclozolin, Fipronil, Dieldrin, Malathion are all regarded as suspected Endocrine Disruptors by the Pesticide Action Network.)

Donate: Friends of the Earth, Melbourne

Another Aussie, Sara Wilson, writes: Could you have chemical intolerance? what next?

Green Biz: Why the Adage ‘the Dose Makes the Poison’ Can Be Toxic to Corporate Chemicals Policy

The Right Chemistry: Silent Spring+50: What’s Really Changed?

The Book: Our Stolen Future

NCBI: Evaluation of Genetic Polymorphisms in Patients with Multiple Chemical Sensitivity