The Effect of Surfactants On the Transport of Cryptosporidium Parvum Through Soil.

Transport of the pathogenic protozoan Cryptosporidium parvum through soils threatens ground and surface wather. C. parvum may be introduced into soils in the maure of infected calves. The presences of other chemicals in the soil applied as or with amendments may affect the transport of the C. parvum oocysts. Surfactants, in particular, which are used in many herbicide formulations, decrease water tension and may disrupt the air-water interface where oocysts are thought to accumulate. We investigate the effect of the anionic surfactant Aerosol-80 on the transport of C. parvum oocysts through four agricultural soils from Utah and Illinois. We find that the presence of the surfactant accelerated the transport of the oocysts through preferential flow paths. On the otherhand, when connected macropores were not present in the soils, the presence of the surfactant retarded the transport of the oocysts through the soil matrix by straining oocyst-surfactant-Ca flocs.