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Pesticide Mixtures in the Water-Column Versus Bottom-Sediments of Prairie Rivers
Mauli Gamhewage1, Claudia Sheedy2, Sirajum Munira3
1Department of Soil Science, University of Manitoba, Ellis Building, 13 Freedman Crescent, Winnipeg, MB, R3T 2N2, Canada.
Summary
Pesticide mixtures, primarily current-use herbicides, contaminate river water and sediments, especially in intensively managed areas. These mixtures pose the greatest risk to aquatic plants, indicating widespread herbicide pollution.
Area of Science:
- Environmental Chemistry
- Ecotoxicology
- Aquatic Ecology
Background:
- Pesticide contamination in aquatic ecosystems is a growing concern.
- Understanding pesticide distribution in water and sediment is crucial for risk assessment.
Purpose of the Study:
- To compare pesticide presence in river water-column versus bottom-sediments.
- To investigate pesticide distribution in rivers traversing intensively-managed and semi-natural habitats.
- To assess the ecotoxicological risk posed by detected pesticide mixtures.
Main Methods:
- Screening of river water-column and bottom-sediment samples for 160 pesticide compounds.
- Analysis of pesticide types, concentrations, and mixtures.
- Calculation of Pesticide Toxicity Index (PTI) values for different trophic levels.
Main Results:
- 35 pesticide compounds were detected, with current-use pesticides dominating (96% in water, 76% in sediment).
- Pesticide mixtures were prevalent in 72% of water samples and 51% of sediment samples.
- Intensively managed river segments showed a wider range of pesticides in both water and sediment, including fungicides.
Conclusions:
- River ecosystems, particularly those in agricultural areas, are significantly impacted by current-use pesticides.
- Herbicides were the dominant component of detected pesticide mixtures in the water-column, leading to high PTI values for plants.
- Fungicides were found in contaminated water and sediments, but not in rivers within semi-natural habitats.
Keywords:
Auxin herbicidesBottom sedimentsPesticide Toxicity IndexPesticide mixturesRiversWater-columnMore Related Videos
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