Know Your Environment. Protect Your Health.

Simazine

Harris County Municipal Utility District 23

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND20ND
2019ND20ND
20200.0600 ppb21ND - 0.120 ppb
2021ND20ND
2022ND20ND
20230.0550 ppb21ND - 0.110 ppb

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
2018-02-08AE13108ND
2018-02-08AE13129ND
2019-02-25AE55741ND
2019-11-19AE89832ND
2020-03-11AF023660.120 ppb
2020-03-11AF02367ND
2021-01-13AF39249ND
2021-01-13AF39250ND
2022-01-25AF81765ND
2022-12-19AG22228ND
2023-01-17AG248220.110 ppb
2023-04-06AG35945ND