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EWG's Tap Water Database — 2021 UPDATE

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2,4-D

Missouri American St. Louis County & St. Charles County

2,4-D (2,4-dichlorophenoxyacetic acid) is a herbicide that can be applied directly to GMO corn and soy plants engineered to withstand this toxic chemical. Americans' exposures to 2,4-D from food and drinking water will likely increase in years to come as farmers plant more of these GMO crops. Read More.

2,4-D is an endocrine disruptor that interferes with thyroid hormones. The International Agency for Research on Cancer classifies 2,4-D as possibly carcinogenic to humans. In occupational studies, farmers exposed to 2,4-D tended to have higher incidences of damaged and malformed sperm. Laboratory animals exposed to 2,4-D during gestation are born underdeveloped and are more likely to have birth defects.

 

65

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
20140.0350 ppb203ND - 0.300 ppb
20150.0250 ppb202ND - 0.300 ppb
2016ND100ND
2017ND50ND
20180.1000 ppb53ND - 0.200 ppb
20190.1000 ppb53ND - 0.200 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 20 ppb

The EWG Health Guideline of 20 ppb for 2,4-D 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 harm to internal organs.

EPA Maximum Contaminant
Level (MCL) 70 ppb

The legal limit for 2,4-D, established in 1991, was based on toxicity studies in laboratory animals conducted in the 1980s. This limit may not fully protect against harm to the nervous system, harm to the thyroid, and hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2014-01-1524591701ND
2014-01-1524591301ND
2014-01-15245931010.200 ppb
2014-01-15245924010.300 ppb
2014-01-15245929010.200 ppb
2014-04-1525143101ND
2014-04-1525144001ND
2014-04-1525144301ND
2014-04-1625141301ND
2014-04-1625142201ND
2014-07-2226142901ND
2014-07-2226143601ND
2014-07-2226144401ND
2014-07-2226145201ND
2014-07-2226145501ND
2014-10-0827161801ND
2014-10-0927159601ND
2014-10-0927160901ND
2014-10-0927160101ND
2014-10-0927162101ND
2015-01-0627909801ND
2015-01-0627909601ND
2015-01-0727908401ND
2015-01-0727908001ND
2015-01-0727909101ND
2015-04-2228625501ND
2015-04-22286264010.200 ppb
2015-04-2228624601ND
2015-04-2228627301ND
2015-04-22286276010.300 ppb
2015-07-1329464701ND
2015-07-1329463501ND
2015-07-1329464401ND
2015-07-1629461801ND
2015-07-1629462601ND
2015-10-2630316401ND
2015-10-2630317401ND
2015-10-2630317701ND
2015-10-2730314901ND
2015-10-2730315501ND
2016-01-0530936501ND
2016-01-0530937101ND
2016-01-0530937301ND
2016-01-1130935201ND
2016-01-1130935701ND
2016-04-0531777201ND
2016-04-0531776201ND
2016-04-2031779501ND
2016-04-2031779201ND
2016-04-2031778201ND
2017-04-1135123101ND
2017-04-1135121901ND
2017-04-1135122801ND
2017-04-1935120901ND
2017-04-1935119901ND
2018-04-0639051701ND
2018-04-0639052601ND
2018-04-16390535010.200 ppb
2018-04-16390543010.200 ppb
2018-04-16390546010.1000 ppb
2019-04-0843598201ND
2019-04-0843599201ND
2019-04-09436001010.200 ppb
2019-04-09436011010.200 ppb
2019-04-09436012010.1000 ppb