Table 1. Various microcystin health advisory concentrations from the USEPA and World Health Organization.

Source	Type	Concentration
USEPA	Child Drinking Water Advisory	0.3 µg/L
WHO	Drinking Water	1 µg/L
USEPA	Adult Drinking Water Advisory	1.6 µg/L
WHO	Recreational: Low Prob. of Effect	2–4 µg/L
WHO	Recreational: Moderate Prob. of Effect	10–20 µg/L
WHO	Recreational: High Prob. of Effect	20–2000 µg/L
WHO	Recreational: Very High Prob. of Effect	>2000 µg/L