Know Your Environment. Protect Your Health.

Simazine

Harris County Municipal Utility District 276

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)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.0800 ppb110.0800 ppb
20190.130 ppb110.130 ppb
2020ND10ND
20210.0800 ppb110.0800 ppb
20220.0700 ppb110.0700 ppb
20230.120 ppb110.120 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
2018-02-07AE128460.0800 ppb
2019-02-04AE527480.130 ppb
2020-01-29AE96116ND
2021-01-21AF404500.0800 ppb
2022-03-03AF875760.0700 ppb
2023-02-09AG284260.120 ppb