Biological and chemical assessments of zinc ageing in field soils.
As zinc (Zn) is both an essential trace element and potential toxicant, the effects of Zn fixation in soil are of practical significance. Soil samples from four field sites amended with ZnSO(4) were used to investigate ageing of soluble Zn under field conditions over a 2-year period. Lability of Zn measured using (65)Zn radioisotope dilution showed a significant decrease over time and hence evidence of Zn fixation in three of the four soils. However, 0.01 M CaCl(2) extractions and toxicity measurements using a genetically modified lux-marked bacterial biosensor did not indicate a decrease in soluble/bioavailable Zn over time. This was attributed to the strong regulatory effect of abiotic properties such as pH on these latter measurements. These results also showed that Zn ageing occurred immediately after Zn spiking, emphasising the need to incubate freshly spiked soils before ecotoxicity assessments.
Donner
Erica
E
Department of Soil Science, The University of Reading, Whiteknights, Reading RG6 6DW, United Kingdom. e.donner@mdx.ac.uk
Broos
Kris
K
Heemsbergen
Diane
D
Warne
Michael St J
MS
McLaughlin
Mike J
MJ
Hodson
Mark E
ME
Nortcliff
Stephen
S
D004784:Environmental Monitoring; D012989:Soil Pollutants / Q000032:analysis*; D015032:Zinc / Q000032:analysis*
D012989:Soil Pollutants; D015032:Zinc