Role of Environmental Contaminants in the Etiology of Alzheimer’s Disease: A Review

Abstract

Alzheimer's dis ease (AD) is a leading cause of mortality in the developed world with 70% risk attributable to genetics. The remaining 30% of AD risk is hypothesized to include environmental factors and human lifestyle patterns. Environmental factors possibly include inorganic and organic hazards, exposure to toxic metals (aluminium, copper), pesticides (organochlorine and organophosphate insecticides), industrial chemicals (flame retardants) and air pollutants (particulate matter). Long term exposures to these environmental contaminants together with bioaccumulation over an individual's life-time are speculated to induce neuroinflammation and neuropathology paving the way for developing AD. Epidemiologic associations between environmental contaminant exposures and AD are still limited. However, many in vitro and animal studies have identified toxic effects of environmental contaminants at the cellular level, revealing alterations of pathways and metabolisms associated with AD that warrant further investigations. This review provides an overview of in vitro, animal and epidemiological studies on the etiology of AD, highlighting available data supportive of the long hypothesized link between toxic environmental exposures and development of AD pathology.

Environmental Toxicants-Induced Immune Responses in the Olfactory Mucosa

“…Epidemiological studies have associated exposure to environment toxicants with the incidence of neurodegenerative diseases, including Alzheimer’s and Parkinson’s diseases (15, 16). Since olfactory dysfunction is a common prodromal symptom of these diseases, and because xenobiotics administered into the nasal cavity are often found in the brain, the nasopharynx has attracted attention as a port-of-entry for environmental agents that cause neurological disease (the olfactory vector hypothesis) (17–19).…”

Rationale for the Successful Management of EDTA Chelation Therapy in Human Burden by Toxic Metals

“…Indeed, in some areas, toxicological health risks seem to be higher than in others: in Haiti, ground water shows Pb and Cr contamination [10], whereas significant levels of As, Pb, Cd, Ni, and Cr have been found in edible fish tissue in the Pearl River Delta in China [11]. Furthermore, environmental contaminants, for example, toxic metals such as aluminum (Al), are considered a possible cause of Alzheimer's disease [12]. …”

Polymorphism of genes encoding proteins of DNA repair vs. occupational and environmental exposure to lead, arsenic and pesticides

“…Ekspozycja na pestycydy wiąże się ze wzrostem ryzyka występowania chłoniaka nieziarniczego [17], raka płuca [18], raka trzustki [19], raka prostaty [20], chorób neurodegeneracyjnych [21,22], a także chorób przewlekłych, np. cukrzycy [23,24].…”