Parasites

Infectious Human Disease, Snail Fever, Worsened by Pesticide Run-Off into Fresh Waterways   (Beyond Pesticides, March 18, 2020) Freshwater habitats are threatened now—more than ever—by the adverse effects of pesticide pollution...Pesticide pollution, attributed to runoff from agricultural farms, indirectly increased the rate of the tropical disease schistosomiasis, which infects over 280 million people (2018).   Increased prevalence of this disease is devastating to socioeconomic development in affected regions, as life expectancy, employment rate, and gross domestic product (GDP) decreases.   Laboratory testing discovered freshwater snails have a higher tolerance toward commonly used agriculture pesticides, like neonicotinoids (neonics) and organophosphates. This tolerance enabled the host snail to persist in an environment where non-tolerant (macro)invertebrates could not. In turn, the population of parasitic flatworms increased with its snail host... Neonicotinoid use eradicates the host snail’s predators and supports destructive planktonic algae (periphyton), a food source for snails.    This study is just one example of pesticide use causing a trophic cascade in unhealthy marine environments.      Dr. Liess confirmed the study’s findings in ScienceDaily, “With our study, we were able to demonstrate that even low pesticide concentrations constitute a serious environmental risk and, in this respect, not only contribute to the decline in insect populations, but also indirectly promote dangerous diseases in humans… The results underline the urgent need for reassessing the environmental risk of low pesticide concentrations and for integrated disease management that includes a focus on the regulation and management of pesticides in areas where schistosomiasis is endemic or might be introduced due to potentially favorable ecological conditions.”