Atrazine Mercapturate Test · Urine

Atrazine is one of the most commonly applied agricultural herbicides in the United States, and it shows up in drinking water, food, and the air around farms. Most people will never know whether their body is processing it. This urine test gives you a window into that question by measuring a specific breakdown product your body creates after atrazine enters your system.

AM (atrazine mercapturate) is an exploratory biomarker. It is not a routine clinical test, and there are no consensus cutoffs that say one number is healthy and another is dangerous. What it does is tell you whether atrazine has recently entered your body in detectable amounts, which is information you cannot get from any standard panel.

What This Test Reveals

When atrazine enters your body, it does not simply sit there. Your liver breaks it down into a series of smaller fragments using one of your built-in detox systems (the glutathione pathway, which attaches a small molecule called glutathione to foreign chemicals so they can be flushed out in urine). AM is one of those fragments. Detecting it in your urine is direct chemical evidence that your body has recently encountered and processed atrazine.

AM is a useful but partial signal. In some people it is the dominant atrazine breakdown product, while in others, related fragments called DACT (diaminochlorotriazine) and desethylatrazine are more abundant. Population-wide research using only AM tends to underestimate true exposure because of this variation. If your AM is undetectable, it does not guarantee you have had zero exposure to atrazine. If it is detectable, it is a meaningful flag.

How Common Detection Is

Detection rates depend heavily on who is being tested and what assay is used. In the general population, fewer than 5% of people had detectable AM when measured at a low detection threshold. In a study of 579 early-pregnancy urine samples from women in France, atrazine or AM was quantifiable in 5.5% of samples. In a UK birth-cohort analysis using gestational urine, AM specifically was detected in only 1% of samples, while the related metabolite desethyl atrazine mercapturate appeared in 3%.

The picture changes for people who work with the herbicide directly. During planting season, farmers had higher average urinary AM than non-farming controls, and the levels tracked closely with how much atrazine they had applied the day before. Even on days without recent application, farmers still showed elevated AM, suggesting ongoing background exposure beyond active spraying.

Pregnancy Outcomes

The clearest human signal connecting AM to a health outcome comes from the PELAGIE birth cohort in France. Among 579 women, the presence of urinary atrazine or AM in early pregnancy was associated with fetal growth restriction and small head circumference at birth. The same study did not find an association with major congenital anomalies. The evidence is observational rather than proof of causation, but it is the strongest signal currently available linking atrazine biomarkers to a clinical outcome in humans.

What this means for you: if you are pregnant or planning to be, and you live, work, or drink water near agricultural areas where atrazine is used, knowing your exposure level is information you can act on. You cannot change a result after the fact, but a measurable reading can prompt practical changes (water filtration, food sourcing, reduced direct contact during planting season) before they matter most.

Reference Ranges

There are no consensus clinical reference ranges for urinary AM. This is a Tier 3 biomarker, meaning it is used primarily in research and biomonitoring rather than routine clinical care. The most useful framework comes from population biomonitoring data, which tells you whether your level is rare or common compared to the general population and to occupationally exposed groups.

The numbers below come from human biomonitoring studies of urinary AM and reflect detection patterns rather than clinical risk thresholds. They are illustrative orientation, not a target. Your lab will likely report values in micrograms per gram of creatinine (a urine concentration unit that adjusts for how dilute or concentrated your sample is).

Compare your results within the same lab over time. Different assays (immunoassay versus HPLC-MS/MS, a precise lab technique that separates and weighs individual molecules) can produce meaningfully different numbers. Immunoassays tend to read consistently higher than HPLC-MS/MS due to cross-reactivity with chemically similar molecules in your urine.

When Results Can Be Misleading

• Recency of exposure: AM reflects atrazine that entered your body in the last few days. A clean result during winter does not rule out exposure during the spring and summer planting season, when atrazine application peaks in agricultural regions.
• Assay choice: Older immunoassay methods give higher readings than newer HPLC-MS/MS methods because antibody-based tests pick up chemically similar molecules along with AM. If you retest, ask whether your lab uses the same method as before.
• Hydration and sample concentration: A very dilute or very concentrated urine sample can shift the absolute number. Most labs adjust for this by reporting AM relative to urinary creatinine, but extreme hydration extremes can still affect interpretation.
• Other atrazine metabolites: AM alone captures only part of total atrazine exposure. Some people break atrazine down primarily into DACT or desethylatrazine instead, so a low AM result alongside elevated levels of those related metabolites would still indicate meaningful exposure.

Tracking Your Trend

AM is a short-term marker. It reflects recent exposure rather than a long-term burden, which makes a single reading less useful in isolation than a series taken across different seasons or after specific exposures. If you live or work in an agricultural area, a baseline reading in late winter (before planting season) and a follow-up during peak spraying season can show whether your environment is actively contributing to your body burden.

If you are making changes (switching water filtration, moving residences, reducing time outdoors during application periods, or shifting food sources), retesting after 2 to 4 weeks can show whether those changes are reaching your body chemistry. For ongoing monitoring, an annual check during the same season each year gives you a comparable baseline to track over time.

What to Do With an Abnormal Result

A detectable or elevated AM result does not require a medical workup the way a high cholesterol number might. There is no medication to lower it. The decision pathway is environmental rather than clinical.

• Investigate your water source: atrazine is a known contaminant in drinking water, particularly in agricultural regions. A water test that screens for atrazine and its degradation products can identify whether your tap is a contributor.
• Order a broader pesticide panel: AM captures only one piece of total exposure. A multi-metabolite urine panel that includes glyphosate, organophosphates, and pyrethroid metabolites gives a fuller picture of what is reaching your body.
• Consider timing and context: if your reading is high during planting season but undetectable in winter, the source is likely seasonal agricultural application. If it is consistently detectable year-round, the source is more likely your water, food, or home environment.
• Retest before drawing conclusions: because AM has high biological variability and depends on recent exposure, a single elevated reading is best confirmed by a second sample taken 2 to 4 weeks later under similar conditions.