Aluminium cycling in the soil-plant-animal-human continuum

Abstract

A critical review of the literature on Al toxicity in plants, animals and humans reveals a similar mode of Al action in all living organisms, namely interference with the secondary messenger system (phosphoinositide and cytosolic Ca2+ signalling pathways) and enhanced production of reactive oxygen species resulting in oxidative stress. Aluminium uptake by plants is relatively quick (across the intact plasma membrane in < 30 min and across the tonoplast in < 1 h), despite huge proportion of Al being bound in the cell wall. Aluminium absorption in the animal/human digestive system is low (only about 0.1% of daily Al intake stays in the human body), except when Al is complexed with organic ligands (eg. citrate, tartarate, glutamate). Aluminium accumulates in bones and brain, with Al-citrate and Al-transferrin complexes crossing the blood-brain barrier and accumulating in brain cells. Tea plant and other Al-accumulator plant species contain large amounts of Al in the form of non-toxic organic complexes.

Multiwalled carbon nanotubes in alfalfa and wheat: toxicology and uptake

“…Both nano-Fe [40,44,45] and nano-Fe 3 O 4 [41] have been taken up by exposed plants, so both can be bioavailable. Dissolved Al species can cause oxidative stress, interfere with the uptake and metabolism of essential elements, and cause morphological alterations in higher organisms [46][47][48]. In the present system, growth was actually enhanced in some cases, possibly because the impurities could have supplied the plant with Fe, a micronutrient, or have induced a stress response in the plants [39].…”

Aluminium in Acid Soils: Chemistry, Toxicity and Impact on Maize Plants

“…Due to the fact that Al ions in an increased concentration are www.intechopen.com much more dangerous for plants than H + ions in the same concentration at the same value of TEA, plants increasingly suffer if a higher share of Al ions is present in it. Already at the content of 6-10 mg 100 g -1 of readily mobile Al in the soil, plant growth is retarded to a greater or lesser extent depending on the species (Rengel, 2004). High TEA, created predominantly by Al ions, is among the most important causes of the low productive capacity of pseudoglay in the indicated basin where, despite of fertilizer use and application of different agrotechnical measures, average yields of cultivated plants are low and vary fairly greatly depending on weather conditions of the year.…”

The meaning of aluminium exposure on human health and aluminium-related diseases

“…A recent review on aluminium toxicity in plants, animals and humans revealed a similar mode of aluminium action in all living organisms: the enhanced production of reactive oxygen species resulting in oxidative stress and cell death (45) . Aluminium phosphide (AlP) is a potent pesticide, utilised for the protection of stored products and crops, but it has also been shown to be severely toxic to humans (46) .…”