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EWG's Tap Water Database — 2021 UPDATE

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2,3,7,8-TCDD (Dioxin)

City of San Luis

Dioxins are contaminants released from chemical manufacturing, pulp and paper bleaching, and incineration of products that contain chlorine. 2,3,7,8-Tetrachlorodibenzodioxin (2,3,7,8-TCDD) is the most toxic chemical in the group of dioxins. Read More.

Dioxins are among the most toxic known environmental pollutants. As a class, dioxins are extremely toxic, persistent and bioaccumulative; these contaminants build up and are stored in fatty tissues and fluids, such as breast milk, and pass from the mother to the child. Most people are exposed to dioxins through the food they eat, primarily from meat, dairy, fish and eggs. In humans, dioxins are associated with cancer, birth defects, damage to the nervous and immune systems, altered metabolism, thyroid disruption, altered menstrual cycling and damage to the cardiovascular system.

 

28

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND40ND
2015ND120ND
2016N/A00N/A
2017N/A00N/A
2018ND60ND
2019ND60ND

ppt = parts per trillion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.0002 ppt

The EWG Health Guideline of 0.0002 ppt for 2,3,7,8-TCDD was defined by the Environmental Protection Agency as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

EPA Maximum Contaminant
Level (MCL) 0.03 ppt

ppt = parts per trillion

All test results

Date Lab ID Result
2014-02-13479281-005DND
2014-02-13479281-005CND
2014-02-13479281-005BND
2014-02-13479281-005AND
2015-05-20201505210191SCND
2015-05-20201505210191SBND
2015-05-20201505210191SAND
2015-05-20201505210177SCND
2015-05-20201505210177SBND
2015-05-20201505210177SAND
2015-11-18201511190130SCND
2015-11-18201511190132SCND
2015-11-18201511190132SBND
2015-11-18201511190132SAND
2015-11-18201511190130SBND
2015-11-18201511190130SAND
2018-03-27201803280610SCND
2018-03-27201803280610SBND
2018-03-27201803280610SAND
2018-03-27201803280609SCND
2018-03-27201803280609SBND
2018-03-27201803280609SAND
2019-03-12201903130096SAND
2019-03-12201903130098SCND
2019-03-12201903130098SBND
2019-03-12201903130098SAND
2019-03-12201903130096SCND
2019-03-12201903130096SBND