Potassium
Cities measured
87
Detected in
87 / 87
Highest
14.2 mg/L — Abu Dhabi
Overview
Potassium is an essential electrolyte critical for heart function and fluid balance. In water it comes from geological dissolution, agricultural runoff (fertilisers), and sewage. Drinking water concentrations are generally low.
Health Relevance
At drinking water concentrations, potassium poses no risk for most people. For individuals with renal disease unable to excrete potassium, food — not water — is the primary concern.
Regulatory Limits
Drinking Water Directive 2020/2184
No EU regulatory limit.
Controversy & Contested Science
Potassium permanganate (KMnO₄), used as an oxidant in some water treatment processes, adds trace potassium and can produce manganese by-products if overdosed. Industrial effluent and agricultural runoff continue to raise potassium in European surface waters, with little attention given to the cumulative effects on downstream ecosystems.