Potential Risk to Human from Environmental Aluminum Exposure

The element Aluminum (Al) is found in relatively high amounts in the earth’s crust (about 7%) despite being non-essential for life. [1] However, Al is present mostly in its water insoluble form unless the pH of the soil is highly acidic (pH<5.0). Under acidic conditions, Al converts to its soluble form [1] and is mostly found in soluble fluoride or organic complexes.[2] Drinking water also contains an appreciable amount of Al, however its quantity in water varies with the region (Figure 1). [3] The presence of Al in drinking water is perhaps due to acid rain in industrial regions that permits insoluble Al to become soluble and enter the underground water reservoir.[4] Moir et al. proposed an empirical formula for estimating the concentration of exchangeable soil Al as a function of soil pH (this was based on soil found in Lees Valley, North Canterbury, New Zealand.) This relationship describes the amount of Al available for exchange with plants grown in soil, and it can be used as an indirect measure to quantify the amount of soluble Al in soil: [5]