Occurrence, impacts and general aspects of pesticides in surface water: A review

A review of the main pesticides employed in agriculture found that the pesticide groups present in the highest amounts are herbicides, fungicides, and insecticides. For this reason, their occurrence in surface waters around the world, as well as their adverse effects on non-target organisms were reviewed for the period 2012–2019. Among the most common vegetal herbicides is atrazine, followed by metalochlor, both of which are widely-used on soybean and corn crops. Insecticides are used to control insects by agonizing them. Although they present low toxicity for mammals, they are toxic to ecosystems and impact the environment when present. Fungicides are employed to prevent fungal infections by damaging the cellular membrane, causing damage to non-target organisms, tebuconazole and carbendazim were the most frequent fungicides identified in surface waters throughout the world. Once pesticides reach water bodies, they can impact the whole ecological food chain, since other animals, including humans, feed on aquatic animals that may be contaminated. Another concern is the mixing of pesticides, in which case the mixture may be more toxic than any one single compound. Because mixtures of pesticides are commonly found in surface water, the need for suitable water treatment is crucial.