Know Your Environment. Protect Your Health.

Simazine

St John Water District 1

Simazine is a hormone-disrupting herbicide related to atrazine. It affects the male and female reproductive systems. In studies of laboratory animals, simazine increases blood levels of estrogen, decreases prolactin and progesterone, and causes mammary and ovarian tumors.

 

15

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND40ND
2019ND40ND
2020ND10ND
20210.0930 ppb220.0760 ppb - 0.110 ppb
20220.0400 ppb21ND - 0.0800 ppb
2023ND20ND

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 0.1 ppb

The EWG Health Guideline of 0.1 ppb for simazine was defined by EWG based on epidemiological studies of human exposure to atrazine in drinking water. This health guideline protects against harm to the developing fetus, harm to the reproductive system and hormone disruption.

EPA Maximum Contaminant
Level (MCL): 4 ppb

The legal limit for simazine, established in 1992, was based on toxicity studies in laboratory animals conducted in the 1980s. This limit does not fully protect against harm to the reproductive system, harm to the developing fetus, and hormone disruption.

ppb = parts per billion

All test results

Date Lab ID Result
2018-05-1435392327001ND
2018-05-1435392327001ND
2018-07-1735405084001ND
2018-07-1735405084001ND
2019-01-2235444040001ND
2019-01-2235444040001ND
2019-07-2535485228001ND
2019-07-2535485228001ND
2020-10-2235587106001ND
2021-01-28356080680010.110 ppb
2021-11-18356793800010.0760 ppb
2022-02-02356948710010.0800 ppb
2022-09-1535747517001ND
2023-03-2035787603001ND
2023-11-2835844327001ND