Know Your Environment. Protect Your Health.

Simazine

Harris County Municipal Utility District 233

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.

 

9

Samples

0

Samples exceeding legal limit (MCL)

1

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND10ND
2019ND10ND
20200.200 ppb110.200 ppb
2021ND10ND
20220.1000 ppb110.1000 ppb
20230.0350 ppb42ND - 0.0700 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
2018-10-02AE42415ND
2019-07-31AE76672ND
2020-03-12AF027210.200 ppb
2021-06-07AF56781ND
2022-04-06AF923020.1000 ppb
2023-02-14AG289430.0700 ppb
2023-05-23AG41743ND
2023-08-16AG52912ND
2023-11-20AG642380.0700 ppb