Evaluating polar pesticide pollution with a combined approach: a survey of agricultural practices and POCIS passive samplers in a Tunisian lagoon watershed

A study of pesticides in the Bizerte lagoon watershed on the Mediterranean coast of Tunisia showed that herbicides and fungicides are the most commonly used compounds. A survey was made of selected farmers. Pesticide contamination was monitored in the water column and sediments at four selected sampling sites (lagoon (A) and in three oueds—Chegui (B), Garaa (C), and Tinja (D)). Polar organic chemical integrative samplers (POCIS) were used to assess pesticide contamination. Thirty-two pesticides were investigated; the total concentration of active ingredients ranged from 35.9 ng L−1 in Tinja oued to 1246 ng L−1 in Chegui oued. In the lagoon, the total concentration of pesticides was 67.7 ng L−1. In the sediments, the highest concentration was measured in Chegui oued in the spring (31 ng g−1 dw). The main compounds found in the analyzed sediments were prosulfocarb and tebuconazole molecules.