Widespread use of pesticides and other agrochemicals can speed the transmission of the debilitating disease schistosomiasis, while also upsetting the ecological balances in aquatic environments that prevent infections, finds a new study led by researchers at the University of California, Berkeley.
Schistosomiasis, also known as snail fever, is caused by parasitic worms that develop and multiply inside freshwater snails and is transmitted through contact with contaminated water. The infection, which can trigger lifelong liver and kidney damage, affects hundreds of millions of people every year and is second only to malaria among parasitic diseases, in terms of its global impact on human health.
The study, published in the July edition of the journal Lancet Planetary Health, found that agrochemicals can increase the transmission of the schistosome worm in myriad ways: by directly affecting the survival of the waterborne parasite itself, by decimating aquatic predators that feed on the snails that carry the parasite and by altering the composition of algae in the water, which provides a major food source for snails.
“We know that dam construction and irrigation expansion increase schistosomiasis transmission in low-income settings by disrupting freshwater ecosystems,” said UC Berkeley’s Christopher Hoover, a doctoral student in environmental health sciences and lead author of the study. “We were shocked by the strength of evidence we found also linking agrochemical pollution to the amplification of schistosomiasis transmission.”
Read more at University of California - Berkeley
Image: A man waters his crops near Lampsar, a community about 12 miles from the city of Saint Louis in the lower Senegal River Basin in West Africa. A new study led by researchers at the University of California, Berkeley finds that use of some agricultural pesticides can speed the transmission of the debilitating disease schistosomiasis, while also upsetting the ecological balances in aquatic environments that prevent infections. (Credit: Planetary Health Alliance photo by Hillary Duff)