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Assessing the ecotoxicological impact to aquatic organisms from pulsed exposures to pesticides - PN0946

Pesticide contamination of surface waters may frequently occur in pulses as a result of repeated applications, spray drift, overland flow and drainage inputs. Continuous exposure, as employed in standard chronic ecotoxicity tests may therefore not provide a true estimate of the ecotoxicity of a compound in the field and could result in both over- and under- estimations of effects. Studies into the effects of pulsed exposures have focused on heavy metals and anions and few data are available for pesticides. There is therefore a need to generate data on the effects of pulsed exposure to a range of pesticides in order to test current assumptions used in the risk assessment process and, where appropriate, to propose new approaches. This proposal is for a series of experimental studies to assess the relative toxicity of a range of pulsed exposure scenarios for a range of pesticide types. The results will be compared with data from standard studies and, where possible, the outputs from currently available modelling approaches. Recommendations will be provided which will enable scientists at PSD to advise on the suitability and design of pulsed exposure studies and to interpret the results of studies submitted by industry.
The objectives of the project are to:

1. Assess the toxicity of pulse exposures to aquatic organisms
2. Compare the results from the pulsed exposure studies with the results from standard ecotoxicity tests and microcosm/mesocosm studies
3. Explore the use of currently available models (i.e. the concentration x time model and the Mancini uptake/depuration model for predicting the toxicity of pulsed exposures)
4. Provide guidance on the use of pulsed exposure studies for environmental risk assessments and on the interpretation of results
5. Identify future research requirements.
Project Documents
• Final Report : Assessing the ecotoxicological impact to aquatic organisms from pulsed exposures to pesticides   (1638k)
Time-Scale and Cost
From: 2002

To: 2005

Cost: £136,183
Contractor / Funded Organisations
University - Cranfield
Environmental Effects              
Environmental Protection              
Peer Review              
Fields of Study
Pesticide Safety