Know Your Environment. Protect Your Health.

Simazine

Harris County Municipal Utility District 468

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.

 

6

Samples

0

Samples exceeding legal limit (MCL)

4

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.140 ppb110.140 ppb
2019ND10ND
20200.200 ppb110.200 ppb
20210.110 ppb110.110 ppb
20220.160 ppb110.160 ppb
20230.0800 ppb110.0800 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
2018-02-06AE125880.140 ppb
2019-02-06AE53303ND
2020-02-21AE996130.200 ppb
2021-02-02AF423020.110 ppb
2022-02-15AF850090.160 ppb
2023-02-13AG286570.0800 ppb