Two adjacent British Columbia, Canada, watersheds with similar topographical features were studied.
Both the Black Mountain Irrigation District (BMID) and the Vernon Irrigation District (VID) serve rural agricultural communities which are active in cattle ranching.
The present study was carried out in five phases, during which a total of 249 surface water samples were tested in the study watersheds.
The aims of these phases were to determine levels of parasite contamination in raw water samples collected from the intakes as well as from other sites in each watershed and to investigate cattle in the watersheds as potential sources of parasite contamination of surface drinking water supplies.
Giardia cysts were not detected in the raw water samples collected from lake sources at the headwaters of both watersheds but were found in 100% (70 of 70) of water samples collected at the BMID intake and 97% (68 of 70) of water samples collected at the VID intake.
Significantly higher levels (P<0.05) of Giardia cysts were found at the BMID intake (phase 1,7 to 2,215 cysts per 100 liters ; phase 3,4.6 to 1,880 cysts per 100 liters) when compared with that of the VID intake (2 to 114 cysts per 100 liters).
The BMID watershed has a more complex system of surface water sources than the VID watershed.
Cattle have access to creeks in the BMID watershed, whereas access is restricted in the VID watershed. (...)
Mots-clés Pascal : Cryptosporidium, Sporozoa, Protozoa, Isolat, Réservoir eau, Zone rurale, Canada, Amérique du Nord, Amérique, Biotype, Caryotype, Qualité eau, Pouvoir infectant, Eau potable, Contamination biologique, Bétail, Diplomonadida, Giardia
Mots-clés Pascal anglais : Cryptosporidium, Sporozoa, Protozoa, Isolate, Water tank, Rural area, Canada, North America, America, Biotype, Karyotype, Water quality, Infectivity, Drinking water, Biological contamination, Livestock, Diplomonadida
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 96-0426782
Code Inist : 002B30A02A. Création : 10/04/1997.