Environmental factors are now generally believed to be involved in the causation of nearly all cancers. Further, the World Health Organization has estimated that environmental factors constitute 25-33% of global disease burden. Accordingly, since the creation of organic/inorganic chemicals in the late 19th century, the global community has faced an exponential rise in the production and subsequent exposure to environmental chemicals.
As a result, there has been a relative upsurge in the levels of human exposure to these toxic elements. While the concentrations of these chemicals generally remain below their no-observed-effects concentrations (NOECs) within the environment, researchers are discovering that the combination of such chemicals produces significant health hazards that are not generally seen with isolated concentrations of individual chemicals.
This review investigates the premise that harmless isolated chemicals cause significant health hazards when the chemicals are combined within the environment. Further, exposure to combined toxic chemicals can be neutralized by Chlorella pyrenoidosa, a fresh water species of green algae that contains detoxifying chemicals that function in concert to support the human detoxification system.
Exogenous Toxins and Human Health
Humans are exposed to wide use synthetic/industrial chemicals that produce unfavorable health effects. (1) Figure 1 offers examples of such chemicals.
While it is beyond the scope of this review to provide comprehensive documentation for the specific mechanisms whereby each of these known toxic chemical causes damage to the human body, Figure 3 offers an overview of the most prevalent health challenges associated with exposure to environmental toxins and impaired detoxification mechanisms.
Despite the fact that the relative levels of isolated environmental chemical exposure to humans is low, new data is emerging that elucidates the measurable adverse health effects which may be associated with combined exposure to multiple chemicals at no-observed-effect-concentrations (NOECs).
Combined No-Observed-Effect-Concentrations of Environmental Chemicals
A recent study completed by Dr. Silva and colleagues (31) demonstrated that estrogenic chemicals below their NOECs act together to produce significant effects. These researchers tested multi-component mixtures of eight weak environmental chemicals known to bind to estrogen receptors, including hydroxylated polychlorinated biphenyls, benzophenones, parabenes, bisphenol A and genestein. The mixtures were prepared so that no one chemical would contribute disproportionately to the overall effect based on their known individual potencies. Concentrations of the individual components ranged from 0.004 [micro]M to 1.04 [micro]M The researchers measured the estrogenic effects of the low dose chemical mixture utilizing the Yeast Estrogen Screen. Using this reporter gene assay, they first demonstrated that each chemical tested activated the genetically modified yeast cells' estrogen receptor protein.
The additive combined effects of the weak estrogenic compounds were then calculated using four separate models -- concentration addition, toxicity equivalency factors, effect summation, and independent action. From these estimations, the researchers determined that the concentration addition and toxicity equivalency factor approach were valid methods for the calculation of additive mixture effects, as there was excellent agreement between prediction and observation. Remarkably, there were substantial mixture effects even though each chemical was present at levels well below its NOEC. The researchers concluded that...
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