For years, findings and insights have accumulated that industrially produced chemicals, as well as natural substances from certain plants and animals, can not only have acute toxic effects on humans but also long-term effects that may lead to chronic diseases. Many of these effects specifically target the brain, the central organ responsible for regulating conscious and unconscious life processes, and only in a healthy state can it ensure optimal management of daily tasks for humans. Chemical effects in the brain, especially those of a chronic nature, can significantly impair a person's quality of life over time. Many chronic diseases that progress slowly and lead to increasing general discomfort have been described in recent years as a consequence of or in connection with ongoing exposure of affected individuals to environmental chemicals, including chronic fatigue syndrome, toxic encephalopathy, solvent and wood preservative syndrome, and multiple chemical sensitivity, to name just a few. Furthermore, the rapidly increasing prevalence of dementia-related diseases in the population, such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, and others, is being linked to a growing body of scientific evidence regarding exposure to environmental chemicals.