Synergistic Toxicity

1. Synergistic Toxicity

How can 1 + 1 = 100? “Synergistic toxicity” refers to the effect that when exposed to two toxins, the toxicity level is far greater than the additive toxicity levels of the two toxins. A good example demonstrating ‘synergistic toxicity’ is a 1978 study on mice (Shubert et al. Combined Effects in Toxicology – A Rapid systematic Testing Procedure: Cadmium, Mercury & Lead. J. of Toxicology & Environmental Health 4:763, 1978). The study took the amount of mercury salt that kills 1 in 100 mice and 1/20th of the amount of lead salt that kills 1 in 100 mice. When these amounts of mercury salt and lead salt were administered, the synergistic toxicity of these two toxins killed 100 in 100 mice:

If Additive toxicity, one would expect 1 + 0.05 = 1.05 mice to die (1 or 2)
With Synergistic toxicity, the results were: 1 + 0.05 = 100 mice died

It is important to understand the concept of ‘synergistic toxicity’, as research is increasingly showing that different toxins are typically synergistic rather than additive in the human body. However when testing is performed on a toxicity of a substance, the ‘level of harm’ is set based on an assumption that the substance is the only toxin to which he body is being exposed.
Synergistic toxicity is likely highly relevant in the causality of autism. Assume, as example, that a fetus or young infant already has high levels of toxins (e.g. lead and mercury from environmental sources) due to a lessened ability to excrete toxins. Then multiple vaccines are administered which contain an aluminum salt (e.g. aluminum hydroxide) which is specifically included as an “adjuvant” to elicit an abnormally large immune reaction (the adjuvant is essentially what makes a vaccine work as it causes the body to build an immune response to the disease-causing virus or bacteria such as measles, pertussis, etc). Additionally, the vaccines can contain live virus, endotoxins produced by the bacteria, and/or organic mercury. There is significant potential for unexpected ‘synergistic toxicity’ effects from vaccines, particularly for a susceptible population that may already have high toxin levels due to a lessened ability to excrete toxins. Yet synergistic toxicity of vaccines has not been studied – studies have focused on only individual toxicity of a single component of the vaccines (e.g. mercury or measles virus). Further, the toxicity of an environmental toxin is generally studied independently of other toxins, although the few studies on combining toxins typically show a strong synergistic toxicity effect.