FOOTWAYS for pesticide registration authorities

FOOTPRINT was not initially conceived to derive tools to directly support the registration of active substances in Member States. However, it is evident that several aspects of the FOOTPRINT work appear very useful for registration purposes, notably the facts that:

• an extensive characterisation of all agro-pedo-meteorological conditions in locations where pesticides are applied in all Member States has been undertaken.
• parameterisation routines to automatically parameterise the pesticides fate models MACRO and PRZM, including for the several thousands of agro-environmental scenarios, were developed.
• skills to distribute the modelling work over several hundreds of processors were acquired.

The FOOTPRINT tools derived as part of the EU project have limitations which normally limit their direct application in registration, namely :

1. the fact that the climatic zones in FOOTPRINT are large and do not sufficiently cover the diversity in climates within countries
2. that a Freundlich exponent of one (i.e. linear sorption) had to be assumed in the first-generation tools and,
3. the fact that the user cannot feed advanced pesticide properties (Freundlich exponent, time-dependent sorption, specific value of Q10).

However, all these limitations have been alleviated through the next-generation tools that we are developing.

Due to the demand for tools which directly serve registration purposes, we've engaged into the development of an interactive computerised system (FOOTWAYS Pro) which allows registration authorities (and those interested in undertaking risk assessment for registration purposes) to undertake very detailed risk assessments for all the scenarios covering their country. This takes the form of an on-line web portal where the user can feed his/her pesticide properties, select his/her options (e.g. one agro-environmental scenario only, agro-environmental scenarios covering a specific region or all agro-environmental scenarios covering the entire country or multiple countries). All the instructions are then fed to the FOOTWAYS super-computer which automatically parameterises the pesticide fate models and undertakes the modelling using several hundreds of processors. The results for leaching, drainage, lateral subsurface flow, surface runoff and erosion are then provided back through the web to the user in tabular, statistical, graphical and mapping forms for specific agro-environmental scenarios or for all of them.
Model predictions are typically undertaken for 20 years of historical meteorological data, but this can be adapted to user needs, for instance using the most recent meteorological data available or even met data reflecting climate change projections.

The FOOTWAYS tools are NOT designed to replace the FOCUS procedures which are in place in European registration. It is expected that the FOCUS approach which provides a worst-case approach to risk assessment will remain in use, especially for Annex I listing at the European level. In contrast to FOCUS, FOOTWAYS Pro is specifically designed to help assess risks for NATIONAL registration. The tool is expected to be of major interest in countries whose conditions are not reflected by the FOCUS scenarios and those countries which have little knowledge regarding the representativity of the FOCUS scenarios in relation to their national conditions.
The models we use for risk assessment in FOOTWAYS Pro are MACRO and PRZM which have both been endorsed by the FOCUS groups. The MACRO model is used to simulate leaching, drainage and lateral subsurface flow while we use PRZM to estimate transfers by surface runoff and erosion. The advantage of using MACRO lies in the fact that this model accounts for preferential flow phenomena and can adequately simulate the fate of pesticides in soils ranging from unstructured sandy soils to structured clay soils, in contrast to other models which are typically used for registration purposes (PELMO, PRZM and PEARL).

FOOTWAYS Pro is ideally suited to support national registration (see above), but can also very effectively support trans-boundary and zonal applications. For instance, as part of an evaluation dossier, you could undertake a detailed risk assessment for your country and a more rapid risk assessment for other countries of the zone you are in, allowing risks to be compared within the zone. This is made possible because FOOTWAYS Pro partly relies on the FOOTPRINT agro-environmental scenarios which provide a characterisation of the agricultural land for all countries in Europe. FOOTWAYS Pro is to this day the only tool which can be used to assess risks consistently within and between the 3 zones.

You may want to use FOOTWAYS Pro to :

• undertake a risk assessment for your country based on detailed agro-environmental scenarios and the best available pesticide fate models
• evaluate an overall risk of transfer and impacts on water resources (e.g. using ecotoxicologically-based thresholds or legal limits)
• compare the risks for your country to other countries within the zone
• identify the problematic uses for a given pesticide
• identify the problematic soils and/or locations in your country where you can expect significant transfer to surface water and groundwater
• gain an understanding of the spatial distribution of the risks (where are the problematic and unproblematic areas?)
• identify the modes of transfer in soils (Do we face a groundwater or surface water problem in this particular location?)
• come up with meaningful label restrictions
• evaluate which measures to put in place to decrease the risk in the problematic areas (bridging between risk assessment and risk management).

If you are interested in discussing how you could use FOOTWAYS Pro for national registration and how long it would take / how much it would cost, please contact us at .