Know Your Environment. Protect Your Health.

Selenium

County Service Area 11

Selenium is an essential element in diets. But too much selenium can decrease thyroid hormone production and cause hair loss, skin lesions and brittle fingernails.

 

5

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND30ND
2019N/A00N/A
2020N/A00N/A
20211.25 ppb221.000 ppb - 1.50 ppb
2022N/A00N/A
2023N/A00N/A

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 30 ppb

The EWG Health Guideline of 30 ppb for selenium was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against hair loss and nail damage.

EPA Maximum Contaminant
Level (MCL): 50 ppb

The legal limit for selenium, established in 1991, was based on human epidemiological studies of populations exposed to naturally occurring selenium in drinking water. This limit does not include any additional consideration of children’s health.

ppb = parts per billion

All test results

Date Lab ID Result
2018-07-10CA4100582_001_001-201807100700ND
2018-08-28CA4100582_004_004-201808281015ND
2018-12-04CA4100582_004_004-201812041211ND
2021-07-08CA4100582_001_001-2021070808001.000 ppb
2021-08-26CA4100582_004_004-2021082608151.50 ppb