Ecological Risk Assessment of Agricultural Pesticides throughout the Shadegan Wetland, Iran

Abstract

As a major ecosystem type, wetland provides invaluable ecological services. Environmental pollution, especially pesticide runoffs should be paid more attention to keep wetlands healthy. This paper proposes two methodologies namely, deterministic and probabilistic approaches. Deterministic approach or risk quotient (RQ) was calculated using the water concentration and toxicant reference values of five pesticides (DDT, Aldrine, Dieldrin, Ametryn, Lindane). For probabilistic approach, hazardous concentrations for 5% of species (HC5) were estimated. The results of deterministic approach showed that the RQ for shirbot or large scaled barb (Barbus grypus), benni (Barbus sharpeyi), golden barb (Barbus luteus) and insect larvae (Chironomus sp.) is high and the environment is exposed to higher risk. However, the results of probabilistic approach and HC5 showed that DDT and Lindane are the most harmful pesticides and can create unsuitable environment. It is recommended that proper countermeasures should be implemented to reduce the risks.