Mitigation of two pyrethroid insecticides in a Mississippi Delta constructed wetland

Environ Pollut. 2009 Jan;157(1):250-6. doi: 10.1016/j.envpol.2008.07.025. Epub 2008 Sep 13.


Constructed wetlands are a suggested best management practice to help mitigate agricultural runoff before entering receiving aquatic ecosystems. A constructed wetland system (180 m x 30 m), comprising a sediment retention basin and two treatment cells, was used to determine the fate and transport of simulated runoff containing the pyrethroid insecticides lambda-cyhalothrin and cyfluthrin, as well as suspended sediment. Wetland water, sediment, and plant samples were collected spatially and temporally over 55 d. Results showed 49 and 76% of the study's measured lambda-cyhalothrin and cyfluthrin masses were associated with vegetation, respectively. Based on conservative effects concentrations for invertebrates and regression analyses of maximum observed wetland aqueous concentrations, a wetland length of 215 m x 30 m width would be required to adequately mitigate 1% pesticide runoff from a 14 ha contributing area. Results of this experiment can be used to model future design specifications for constructed wetland mitigation of pyrethroid insecticides.

MeSH terms

  • Agriculture*
  • Insecticides* / analysis
  • Mississippi
  • Nitriles / analysis
  • Pyrethrins / analysis
  • Rain
  • Water Movements
  • Water Pollutants, Chemical* / analysis
  • Water Purification / methods*
  • Wetlands


  • Insecticides
  • Nitriles
  • Pyrethrins
  • Water Pollutants, Chemical
  • cyfluthrin
  • cyhalothrin