Estimation of aluminium pollution in oak stands on the Krotoszyn Plateau

Estimation of the degree of aluminium absorption by oak stands on the Krotoszyn Plateau and on reference areas is reported in this paper. Soil pH, the content of exchangeable aluminium in soil and the content of aluminium in the xylem and roots of <em>Quercus robur</em> L. were determined. The performed studies show a very strong acidification of soils from the investigated areas of the Krotoszyn Plateau; pH vs. 1 M KCI did not exceed 4.0, whereas the content of exchangeable Al in some places was 50 mg/100 g. The results also showed an elevated content of aluminium in the wood and roots of oaks growing on the Krotoszyn Plateau as compared to oaks in Zawiercie (near a Steel Mill), where the reaction of soil is neutral. The content of Al in the xylem of oaks from the Krotoszyn Plateau was over the range 3.8-9.9 µg/g, in the roots 198-499 µg/g, that in the xylem and roots of oaks in Zawiercie was 1.5 µg/g and 56 µg/g, respectively

Intestinal Absorption of Trace Amounts of Aluminium in Rats Studied with 26Aluminium and Accelerator Mass Spectrometry

1. Until recently studies of intestinal aluminium absorption used pharmacological amounts of stable 27Al. 2. To examine the intestinal absorption of trace amounts of different chemical compounds of aluminium, in the present study we have employed the long half-life isotope of aluminium, 26Al, and accelerator mass spectrometry. Trace amounts of 26Al (2.7–12.1 ng) as the hydroxide, citrate, citrate plus 1 mmol/kg sodium citrate, or maltolate respectively, were administered to four groups of rats (n = 9 per group) by gavage. Blood and urine samples were collected for 5 h and the 26Al content (as a percentage of the administered dose) determined by accelerator mass spectrometry. 3. The 5 h urinary 26Al excretion amounted to 0.1 ± 0.02, 0.7 ± 0.2, 5.1 ± 1.5 and 0.1 ± 0.1% of administered dose in the four groups respectively. There was a strong positive correlation between peak plasma 26Al (r = 0.98) and urinary 26Al excretion in individual animals (P < 0.001). 4. We conclude that the fractional intestinal absorption of trace oral doses of aluminium hydroxide is at least 0.1% (compared with the previous estimate of 0.01% using large 27Al oral loads). Absorption of aluminium citrate given alone is significantly greater (0.7%) and is further increased to 5% by the accompanying sodium citrate, consistent with an enhancing effect of added citrate upon mucosal aluminium permeability. Aluminium maltolate absorption approximates that of aluminium hydroxide (0.1%).