Related Experiment Video
Updated: Feb 5, 2026

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff
Published on: May 15, 2017
The effect of water source and soil supplementation on parasite contamination in organic vegetable gardens
Fernanda Pinto Ferreira1, Eloiza Teles Caldart1, Roberta Lemos Freire1
1Departamento de Medicina Veterinária Preventiva, Universidade Estadual de Londrina - UEL, Londrina, PR, Brasil.
Abstract:
The objective of this study was to determine factors associated with vegetable contamination with zoonotic protozoan. Samples of water, soil and vegetables were collected from July/2014 to May/2016, totaling 83 samples, 21 properties of Londrina region, Paraná, Brazil. DNA amplification of Toxoplasma gondii, Cryptosporidium spp. and Giardia intestinalis in the samples was conducted using polymerase chain reaction (PCR). The PCR results were positive for T. gondii in 12.9% (8/62), Cryptosporidium spp. in 11.3% (7/62) and G. intestinalis in 25.8% (16/62) of the samples. DNA sequencing identified C. parvum in five samples and G. intestinalis Assemblage E in three. The statistical associations demonstrated greater probability of positive samples for T. gondii and for at least one of the three protozoa when the source of irrigation water was the river; a greater chance of positive samples for Cryptosporidium spp. when deer were present on the property; and a smaller chance of positive samples for at least one of the three etiologic agents when soil was supplemented with limestone. The results expose some critical contamination points, providing support for training farmers on good management practices during the production process.
Related Concept Videos
The Soil Ecosystem
The Water Cycle
Water and Mineral Acquisition
Contaminants and Errors
Another key consideration is determining the appropriate number of samples required to...
Epiphytes, Parasites, and Carnivores
States of Water
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...

