National Drinking Water Database
National Drinking Water Database - Chemical Contaminants
Iodine-131
Status: Unregulated - EPA has not established a maximum legal limit in tapwater for this contaminant.
Iodine-131 is a radioactive tracer used in medical applications, and present in the environment due to radioactive fallout from nuclear power station accidents and nuclear weapons testing.
Detected |
Found above health guidelines |
Found above legal limit |
|
|---|---|---|---|
| States | 1 |
- |
- |
| Water utilities | 2 |
- |
- |
| People Served | 144,628 |
- |
- |
Iodine-131 Exposure by State
Water utilities in 1 states have reported detecting Iodine-131 in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.
| State | Water Suppliers with Iodine-131 contamination | |
|---|---|---|
| Systems | Population | |
| Washington | 2 | 144,628 |
| Total | 2 | 144,628 |
The Most Polluted Communities
2 water utilities reported detecting Iodine-131 in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies
Ranked by highest average Iodine-131 level
| Rank | System | Population Served | Positive test results of total reported tests | Average Level (Range) |
|---|---|---|---|---|
| 1 | Clark Public Utilities Vancouver, WA | 79,948 | 1 of 1 | 545000 ppb (545000 ppb) |
| 2 | City of Kennewick Kennewick, WA | 64,680 | 1 of 3 | 334.44 ppb (0 to 1003.33 ppb) |
Testing Summary for Iodine-131
| Are tests routinely required for Iodine-131 by federal law? | No |
| Water suppliers reporting tests for Iodine-131 (2004-2006): | 3 of 47,576 |
| Average testing rate for water supplier reporting tests (2004-2006): | 0.6 per year |