Soil contamination

Soils can contain a wide variety of contaminants (e.g. metals, organic compounds, pharmaceuticals, nanoparticles) which, if present in excessive concentrations, may adversely affect soil function and ecosystem services.

Soils also influence contamination of surface and groundwaters, by controlling the rate at which contaminants transfer. Sources of contamination include deposition from the atmosphere, old industrial sites (e.g. mines, smelters, factories) and agricultural practices such as the spreading of sewage sludge to land.

As an integrated research institute, CEH has a broad range of expertise around soil contamination and its effects, and is in a unique position to conduct sophisticated, integrated research. For example:

  • Our expertise in modelling soil acidification allows us to predict how changes in acidic deposition to soils over time affect the rates at which metals accumulate and are lost from soils
  • Our knowledge of both soil and water chemistry allows us to predict how changes in soil chemistry over time affect how contamination may be leached to surface waters
  • New technologies, such as geophysical sensors are allowing us to image soils in situ to understand spatial patterns at the field scale

Research and monitoring on soil contamination in CEH includes:

 
  • Developing new monitoring methods for assessing exposure and effects of trace organics and metals on soil organisms
  • Integrated modelling of long-term soil metal accumulation and leaching
  • Calculation and mapping of critical loads of atmospherically deposited metal (nickel, copper, zinc, cadmium, lead and mercury) to UK rural soils
  • Development of threshold risk concentrations (critical limits) for metal effects on soil biota and their use to assess the vulnerability of soils to metal contamination
  • Measurement and modelling of the effects of mixtures of chemicals on soil organisms
  • Understanding the toxicokinetics and toxicodynamics of pollutants in exposed soil species
  • Assessment of long-term acclimation and genetic adaptation of soil organisms to pollution, and the consequences for soil function and resilience to change
  • Assessment of emerging risks likely to especially affect soils, e.g. nanoparticles

A key strength of activities such as Countryside Survey is the integration of chemical and biological measurements thus allowing integrated assessment of contaminant effects. All the work is strongly supported by the CEH Analytical Chemistry facilities which include analysers for the measurement of metals and other contaminants in precipitation, soils, waters and biota.