NeuroToxicology 31 (2010) 575–581 Contents lists available at ScienceDirect NeuroToxicology Review The neurotoxicity of environmental aluminum is still an issue Stephen C. Bondy * Program in Environmental Toxicology, Division Occupational and Environmental Health, Department of Medicine, University of California, Irvine, CA 92697-1825, USA A R T I C L E I N F O A B S T R A C T Article history: Received 18 September 2009 Received in revised form 24 March 2010 Accepted 10 May 2010 Available online 27 May 2010 Evidence for the neurotoxicity of extended exposure to low levels of aluminum salts is described using an animal model treated with aluminum at low levels reﬂecting those found in some water supplies. Emphasis is given to the potential role of aluminum in acceleration and promotion of some indices characteristic of brain aging. These hallmarks include the appearance of excess levels of inﬂammation in speciﬁc brain areas. Aluminum salts can increase levels of glial activation, inﬂammatory cytokines and amyloid precursor protein within the brain. Both normal brain aging and to a greater extent, Alzheimer’s disease are associated with elevated basal levels of markers for inﬂammation. These are not attributable to obvious exogenous stimuli and may reﬂect the lifespan history of the organism’s immune responses. It is possible that aluminum salts can act as a subtle promoter of such apparently unprovoked responses. s 2010 Elsevier Inc. All rights reserved. Keywords: Aluminum Drinking water brain aging Alzheimer’s disease Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aluminum is environmentally prevalent and ingested by humans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . There is an epidemiological relation between chronic aluminum exposure and the incidence of Alzheimer’s disease . . . . . . . . . . . Aluminum exposure may also promote the onset of Parkinson’s disease. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acute exposure to aluminum can cause clinical neurotoxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elevated levels of intrinsic inﬂammation are associated with neural aging and this is exacerbated in several neurodegenerative diseases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Low levels of aluminum in drinking water of experimental animals, elevate basal levels of inﬂammatory activity within the CNS Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. Introduction This review on the potential neurotoxic hazard posed by aluminum focuses on distinguishing between those aspects of aluminum neurotoxicity that are widely accepted and not controversial, and those aspects that are suggestive but not fully established. The work of this laboratory over the past 12 years is described and this falls into the latter classiﬁcation, adding to the body of evidence increasingly implicating aluminum as a potentially hazardous environmental agent. The most accepted facts relating to aluminum include: (i) it’s widespread prevalence and level of human consumption, (ii) the * Correspondence address: Department of Community and Environmental Medicine, University of California at Irvine, Irvine, CA 92697-1825, USA. Tel.: +1 949 824 8077; fax: +1 949 824 2793. E-mail address: scbondy@uci.edu. 0161-813X/$ – see front matter s 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.neuro.2010.05.009 known neurotoxicity of high levels of aluminum, and (iii) a repeated epidemiological correlation between ingested aluminum and the incidence of Alzheimer’s disease. Another relevant area of widespread consensus is the tendency of the aging brain to express elevated levels of inﬂammation and the further exacerbation of this state in several neurodegenerative diseases. Less accepted is the evidence that aluminum can be a causal factor in promoting Alzheimer’s disease. This area has been handicapped by earlier erroneous reports of heightened levels of aluminum in amyloid plaques. Tissue aluminum levels are notoriously difﬁcult to determine and later more reliable ﬁndings leading to similar conclusions have been overshadowed by these original reports. The main objective of our more recent studies has been to study the effects of extended exposure of experimental animals to levels of aluminum that have relevance for the human population. Demon- stration that these can provoke cerebral inﬂammatory responses resembling those that are found with brain senescence, can provide a mechanistic link to epidemiological reports.

/pdf/the-neurotoxicity-of-environmental-aluminum-is-still-an-2gtz0lt99x.pdf

The neurotoxicity of environmental aluminum is still an issue - eScholarship

The photocatalytic reduction of U(VI) into U(IV) by ZIF-8/g-C3N4 composites at visible light

Zeolitic imidazolate framework-based nanomaterials for the capture of heavy metal ions and radionuclides: A review

Impact of metal ions and organic ligands on uranium removal properties by zeolitic imidazolate framework materials

Advances in Zeolite Imidazolate Frameworks (ZIFs) Derived Bifunctional Oxygen Electrocatalysts and Their Application in Zinc–Air Batteries

With the rapid growth of nuclear power generation and fuel processing, the treatment of nuclear industry wastewater has become a major problem, and if not handled properly, it will pose a potential threat to the ecological environment and human health. Herein, a chitosan (CS)/ZIF-8 composite monolithic beads with ZIF-8 loading up to 60 wt% for U(VI) removal was prepared, which can be easily removed after use. It possesses a very high adsorption capacity of 629 mg•g-1 at pH = 3 for U(VI) and a well recyclability is demonstrated for at least four adsorption/desorption cycles. X-ray photoelectron spectroscopy (XPS) was carried out to study the adsorption mechanism between uranium and adsorbent, and the chelation of U(VI) ions with imidazole, hydroxyl, and amino groups was revealed. This work shows that CS/ZIF-8 composite can be used as an effective adsorbent for uranium extraction from aqueous solution, and has a potential application value in wastewater treatment.

/pdf/in-situ-preparation-of-chitosan-zif-8-composite-beads-for-5flwcpo69p.pdf

In Situ Preparation of Chitosan/ZIF-8 Composite Beads for Highly Efficient Removal of U(VI)

A metal–organic gel-based fluorescent chemosensor for selective Al3+ detection

One of the challenges to sustainability is to efficiently and conveniently remove organic dyes from wastewater. Herein, a light ZIF-8@chitosan (CS) composite sponge with bulk density of 0.18 g cm−3 was prepared by an in situ method. The composite sponge possesses a three-dimensional porous structure with abundant chelating sites, which can efficiently and selectively remove congo red (CR). The maximum adsorption capacity (987.01 mg g−1) is higher than most chitosan-based adsorbents. High selective adsorption towards CR over other dyes is also demonstrated. Over 90% adsorption capacity was retained after five adsorption–desorption cycles. In addition, a column-mounted equipment for fixed-bed cycle wastewater treatment was assembled with a freestanding ZIF-8@CS sponge, which exhibited high CR removal efficiency of 99%. Based on the systematic spectroscopy characterization, the dominant role in the superior adsorption performance is attributed to the electrostatic interactions, hydrogen bonds, π–π stacking and metal coordinating interaction between the ZIF-8@CS sponge and CR.

Lijuan Liu

Papers

In Situ Preparation of Chitosan/ZIF-8 Composite Beads for Highly Efficient Removal of U(VI)

A metal–organic gel-based fluorescent chemosensor for selective Al3+ detection

Reusable ZIF-8@chitosan sponge for the efficient and selective removal of congo red