Representing Soil Pollution by Heavy Metals Using Continuous Limitation Scores

The paper suggests a methodology to represent overall soil pollution in a sampled area using continuous limitation scores. The interpolated heavy metal concentrations are first transformed to limitation scores using the exponential transfer function determined by using two threshold values: permissible concentration (0 limitation points) and seriously polluted soil (4 limitation points). The limitation scores can then be summed to produce the map of cumulative limitation scores and visualize the most critically polluted areas. The methodology was illustrated using the 784 soil samples analyzed for Cd, Cr, Cu, Ni, Pb and Zn in central region of Croatia. The samples were taken at 1Ö1 and 2Ö2 km grids and at fixed depths of 20 cm. Heavy metal concentrations in soil were determined by ICP-OES after microwave assisted aqua regia digestion. The sampled concentrations were interpolated using the block regression-kriging with geological, land cover maps, terrain parameters and industrialization parameters as auxiliary predictors. The results showed that the best auxiliary predictors are geological map, ground water depth, NDVI and slope map and distance to urban areas. The spatial prediction was successful for Cd, Ni, Pb and Zn, and somewhat less successful for Cu and Cr. The final map of cumulative limitation scores showed that 33.5% of the total area is suitable for organic agriculture and 7.2% of the total area is seriously polluted by one or more heavy metals. This procedure can be used to assess suitability of soils for agricultural production and as a basis for possible legal commitments to maintain the soil quality.

ROMIć Marija;  HENGL Tomislav;  ROMIć Davor;  HUSNJAK Stjepan; 

2008-12-16

PERGAMON-ELSEVIER SCIENCE LTD

JRC33095

0098-3004,   

http://dx.doi.org/10.1016/j.cageo.2007.05.002,    https://publications.jrc.ec.europa.eu/repository/handle/JRC33095,   

10.1016/j.cageo.2007.05.002,