Airborne Magnetite- and Iron-Rich Pollution Nanoparticles: Potential Neurotoxicants and Environmental Risk Factors for Neurodegenerative Disease, Including Alzheimer’s Disease

作者：Barbara A. Maher · 发表于：Journal of Alzheimer s Disease · 年份：2019 · DOI：10.3233/jad-190204 · 被引用次数：132 · 研究领域：Air Quality and Health Impacts、Heavy Metal Exposure and Toxicity、Nanoparticles: synthesis and applications

Fewer than 5% of Alzheimer's disease (AD) cases are demonstrably directly inherited, indicating that environmental factors may be important in initiating and/or promoting the disease. Excess iron is toxic to cells; iron overload in the AD brain may aggressively accelerate AD. Magnetite nanoparticles, capable of catalyzing formation of reactive oxygen species, occur in AD plaques and tangles; they are thought to form in situ, from pathological iron dysfunction. A recent study has identified in frontal cortex samples the abundant presence of magnetite nanoparticles consistent with high-temperature formation; identifying therefore their external, not internal source. These magnetite particles range from ∼10 to 150 nm in size, and are often associated with other, non-endogenous metals (including platinum, cadmium, cerium). Some display rounded crystal morphologies and fused surface textures, reflecting cooling and crystallization from an initially heated, iron-bearing source material. Precisely-matching magnetite 'nanospheres' occur abundantly in roadside air pollution, arising from vehicle combustion and, especially, frictional brake-wear. Airborne magnetite pollution particles < ∼200 nm in size can access the brain directly via the olfactory and/or trigeminal nerves, bypassing the blood-brain barrier. Given their toxicity, abundance in roadside air, and nanoscale dimensions, traffic-derived magnetite pollution nanoparticles may constitute a chronic and pernicious neurotoxicant,...