Barium
Cities measured
87
Detected in
87 / 87
EU limit
2000 μg/L
Highest
88 μg/L — Delhi
Overview
Barium enters water from natural geological dissolution of barite and witherite minerals, and from industrial sources including oil and gas drilling (barium sulfate is used in drilling muds). It is not common in Stockholm's granite-bedrock water.
Health Relevance
Soluble barium compounds interfere with potassium channel function, causing muscle weakness and cardiac arrhythmias. Long-term exposure above 2 mg/L is associated with elevated blood pressure.
Regulatory Limits
Drinking Water Directive 2020/2184
No EU regulatory limit. WHO guideline: 0.7 mg/L.
Controversy & Contested Science
Barium contamination from hydraulic fracturing ('fracking') has been detected in groundwater near fracking sites in the UK, Germany, and the US. The relationship between fracking and drinking water contamination is intensely contested. The EPA's 2016 comprehensive fracking and drinking water study concluded fracking can affect drinking water under specific circumstances — a carefully worded finding interpreted as vindication by both industry and environmentalists.