Giardia lamblia cysts
Craik 2001
Test conditions & context
Type Protozoan cyst / oocyst
Medium Water
Test wavelength —
Author Craik
Year 2001
UV-C dose–response (D-values)
A D-value is the UV-C dose (in mJ/cm²) needed for a given log-reduction. D90 = 90 % inactivation = 1-log; D99 = 99 % = 2-log; D99.9 = 99.9 % = 3-log, and so on. Values come from the cited study under its specific test conditions.
Reduction log Dose (mJ/cm²)
D90 90 % 1-log 1 mJ/cm²
D99 99 % 2-log 2 mJ/cm²
D99.9 99.9 % 3-log 3 mJ/cm²
D99.99 99.99 % 4-log 4 mJ/cm²
D99.999 99.999 % 5-log 5 mJ/cm²
D99.9999 99.9999 % 6-log 6 mJ/cm²
Morphology & UV-C resistance
Morphology class Protozoan cyst
Protozoen-Zyste/-Oozyste mit dicker, mehrschichtiger Wand — vergleichsweise UV-empfindlich (ein DNA-Schaden genügt, da in der Zyste keine Replikation stattfindet), aber resistent gegen Chlor und Ozon → UV-Bestrahlung ist die bevorzugte Inaktivierungsmethode.
Primary source
Craik (2001). scholar.google.com/scholar