Title: Investigating the Applicability of Passive Sampling Devices to Pesticide Monitoring
Author: Claire Wells
Author: Environment Agency
Author: Emma Pemberton
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1558, Representation ID: 547, Object ID: 2702
Abstract:
Passive sampling is an emerging water quality monitoring technique, which may offer several advantages over conventional spot sampling. First, as a continuous monitoring technique, it should increase the chances of detecting transient contamination events. Second, passive sampling involves much larger volumes of water than are normally collected by spot samples, so lower levels of environmental contaminants can be detected. Thirdly, passive sampling devices only sample freely available contaminants; the results therefore provide a useful indication of contaminant bioavailability. A series of small scale field trials tested the practicalities of deploying passive samplers in shallow waters. The deployment cages put a lower bound on the water depth required, but results from the field trials indicated that, even in headwater streams, suitable sampling locations could be found. The study considered the ability of passive sampling devices to provide quantitative results for short pulses of pesticide exposure such as spray drift following application of pesticides to a crop. This scenario is considered to be highest risk, in terms of causing ecological impacts. Laboratory trials demonstrated that whilst the passive samplers were able to accumulate contaminants after short exposures (less than 1 hour), not all the compounds tested would be quantifiable after such short durations. Furthermore, some of the contaminants were lost when the SPMD was placed in ‘clean’ water following accumulation, showing that compounds may depurate from the SemiPermeable Membrane Device (SPMD) after exposure. These results suggest that passive samplers may not be suitable for monitoring the most high risk pesticide exposure scenarios. In conclusion, the report found that passive samplers were not a suitable quantitative monitoring method for transient pesticide contamination caused by spray drift. This is because the short exposure times and the possibility that accumulated contaminants may be depurated from SPMDs lead to a risk of false negatives. Further research to examine how passive samplers accumulate pulsed exposures of contaminants such as pesticides would be beneficial. Passive samplers do offer advantages over spot sampling for the monitoring of continuous contamination by low level pollutants or where qualitative results are sufficient.
Publisher: Environment Agency
Subject Keywords: Pesticides; Sampling; Rivers; Lakes; Agricultural pollution; Measuring instruments
Extent: 53
Permalink: http://www.environmentdata.org/archive/ealit:4855
Total file downloads: 238
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