Selenium

City of Pearl

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.

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Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2014	ND	2	ND
2015	N/A	0	N/A
2016	ND	8	ND
2017	N/A	0	N/A
2018	ND	10	ND
2019	ND	3	ND

ppb = parts per billion

State and national drinking water standards and health guidelines

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
2014-03-31	140401-001IN	ND
2014-04-02	140403-005IN	ND
2016-12-14	161215-127IN	ND
2016-12-14	161215-126IN	ND
2016-12-14	161215-122IN	ND
2016-12-14	161215-121IN	ND
2016-12-14	161215-120IN	ND
2016-12-14	161215-119IN	ND
2016-12-14	161215-114IN	ND
2016-12-14	161215-112IN	ND
2018-09-04	180905-039IN	ND
2018-09-04	180905-040IN	ND
2018-09-04	180905-038IN	ND
2018-09-04	180905-037IN	ND
2018-09-04	180905-036IN	ND
2018-09-04	180905-035IN	ND
2018-09-04	180905-034IN	ND
2018-09-04	180905-033IN	ND
2018-09-04	180905-032IN	ND
2018-09-04	180905-031IN	ND
2019-01-22	190123-017IN	ND
2019-07-09	190710-003IN	ND
2019-11-06	191114-002IN	ND