Radium (226 + 228)

Category: radiological

Written by WaterFilterMatch Editorial TeamApril 2026

EPA MCL

5 pCi/L

Status

EPA Regulated

NSF Standard

NSF/ANSI 58

Health Effects

Increased risk of bone cancer with long-term exposure. Radium accumulates in bones and emits radiation that can damage surrounding tissue. Both Ra-226 (alpha emitter) and Ra-228 (beta emitter) are regulated together.

Source: EPA National Primary Drinking Water Regulations

Where It Comes From

Erosion of natural deposits. Radium is a naturally occurring radioactive element found in certain rock formations, particularly granite and sandstone aquifers.

Where It's Commonly Found

Groundwater in parts of the Midwest, Great Plains, Texas, and the Mid-Atlantic region. More common in deeper wells tapping certain aquifer formations. Chicago-area water has notably elevated radium levels.

Hundreds of community water systems exceed the EPA MCL. EWG has found that many more systems exceed their health guideline, which is stricter than the EPA standard.

How to Remove It

Effective Technologies

  • reverse osmosis
  • ion exchange
  • water softener
  • distillation

Does NOT Remove It

  • activated carbon
  • carbon block
  • UV
  • KDF
  • mechanical filtration
  • ceramic

Official Sources

Related Contaminants

Learn More

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Informational guidance based on EPA data and NSF standards - not medical advice.