Chemical Fate

Chemicals enter the environment via a number of routes, for example, in the application of plant protection products to crops, excretion of veterinary products from livestock, or through use as biocidal products. Chemical uses in Europe are subject to regulation under Directives such as:

  • 91/414/EEC, the Plant Protection Products Authorisations Directive
  • 98/8/EC, the Biocidal Products Directive
  • 2001/82/EC, the Veterinary Medicinal Products Directive
  • 2001/83/EC, the Human Pharmaceuticals Directive

These Directives require that the fate and behaviour of the chemicals in the environment are investigated and assessments made as to the scope for adverse environmental effects. The first step in investigating the fate of chemicals in the environment is to conduct laboratory studies (e.g. soil degradation, adsorption to soil). If these studies indicate a potential issue of persistence or movement of the chemical to water (groundwater or surface water), then further field investigations are often required by the relevant regulatory authorities.

Such field studies are complicated, expensive and often time-critical with respect to regulatory approval. It is essential, therefore, that the appropriate study is conducted and to a very high standard.

CEA has experience in all of the stages required to conduct the most appropriate field study, to satisfy the requirements of the regulatory authorities:

  • Evaluation of first tier laboratory studies; are higher tier studies required? Could appropriate higher tier modelling resolve regulatory concerns/uncertainties?
  • What field study design is most appropriate and where should it be conducted?

We can:

  • Design an appropriate field study to satisfy regulatory requirements
  • Initiate the study and manage all aspects of the ongoing work (GLP compliant facilities)
  • Interpret the results in the context of the regulatory requirements and carry out any modelling required to place the results into an appropriate context

Recent Studies:

  • Farmyard losses - The fate of chemicals from typical farmyard hard surfaces to determine relative losses i.e. concrete, asphalt, ballast
  • Soil dissipation and leaching- Field/semi-field studies to determine mobility and transport processes in a range of soil types representing high leaching risk
  • Drainage study - Losses of Veterinary Medicines applied in slurry, surface water and sediment
  • Catchment scale - Quantifying field losses from diffuse and point source contamination - measurements within fully instrumented agricultural catchment
  • Edge of field - Deposition of spray drift to surface water - monitoring across standard LERAP buffers in Arable and Orchard cropped areas