from Syngenta Crop Protection

Last January, EPA issued an Interim Re-registration Eligibility Decision (IRED) for atrazine. The IRED detailed the Agency's re-registration decision for this important herbicide, after considering identified risks, public comment and mitigation options. A revised IRED for atrazine, which will take into account further public comment and available data, is expected to be issued on October 31, 2003.  

This is the next step in an EPA Special Review of the triazines-a family of herbicides that includes atrazine-which began in late 1994. Nine years and about 200 studies later, atrazine is poised to be one of the first major pesticides re-registered under what EPA calls a "pilot process to facilitate greater public involvement" during re-registration and/or tolerance re-assessment under the Food Quality Protection Act.

EPA will issue the final re-registration and tolerance reassessment decisions for atrazine once the cumulative risks for all of the triazine herbicides (including simazine) are considered. We expect this to occur in 2005.

The atrazine website, www.atrazine.com, may offer useful information in addition to the bulleted facts below.

Some general facts about atrazine 

*          Farmers use atrazine to control weeds on about two-thirds of all US corn and sorghum acreage. It is also applied to as much as 90 percent of US sugar cane acreage. (Source:  Doane Agricultural Services and commodity groups.)

*          By using atrazine over alternative herbicides, farmers save an average of $35 per acre in herbicide costs and yield advantages. (Refer to  "Atrazine's Value to Agriculture" on www.atrazine.com.)

*          According to the US Department of Agriculture, atrazine is the most widely used herbicide in conservation tillage systems, which can reduce soil erosion by as much as 90 percent.

*          Atrazine is the second most popular herbicide in the US, placing a distant second behind glyphosate, according to Doane.

*          Atrazine is the most thoroughly tested herbicide ever used in crop protection, with more 800 scientific studies and 45 years of use supporting its safety to humans and the environment. 

*          Atrazine is the active ingredient most frequently used by manufacturers in herbicide pre-mix combination products and is now found in more than 45 pre-mixes in the US.

On the recent European Union decision to not re-register atrazine

*          Though we have not seen the final report, the EU decision was most likely based on concerns that past and outdated uses of atrazine at times exceeded an arbitrary 0.1 ppb standard in ground water. This standard is neither health-based nor scientifically supported, and has nothing to do with toxicity or possible health risks.

*          The EU decision to not re-register atrazine ignores its own favorable science review which concluded that, "It is expected that the use of atrazine, consistent with good plant protection practice, will not have any harmful effects on human or animal health or any unacceptable effects on the environment." The EU scientific review also showed that a health-based water standard for atrazine should be set at 15 ppb and further confirmed that proposed uses of atrazine and simazine would not exceed the arbitrary 0.1 ppb standard in most corn-growing regions in Europe.

*          The agricultural need for and safety of atrazine herbicides in the EU are confirmed by the fact that the EU Commission intends to grant "essential uses" which allow continued use of atrazine in some EU states until 2007.

*          Austrian and German farmers have used terbuthylazine, a sister triazine herbicide, for many years. Terbuthylazine is chemically similar to atrazine and simazine, and its uses are nearly identical to those proposed for atrazine in the EU. (Note:  terbuthylazine is not registered for use in the US because it does not offer American farmers the same spectrum of weed control as atrazine.) More than 70 percent of the corn in Germany will be grown with terbuthylazine for effective weed control.

*          In countries with a science-driven regulatory process like that of the US, we expect atrazine and simazine to remain available to growers.

On atrazine's safety to humans

*          EPA classifies atrazine as "not likely" to cause cancer in humans. This echoes a ruling in 1998 by the World Health Organization's International Agency for Research on Cancer (IARC), which re-categorized atrazine as "not classifiable as to carcinogenicity in humans."

*          There is no scientific link between atrazine and prostate cancer. This conclusion was upheld in the recent Agricultural Health Study of farm workers in Iowa and North Carolina conducted by the National Cancer Institute, which shows no association between atrazine exposure and prostate cancer.

*          Since 1995, male workers age 45 or older at our St. Gabriel, La., plant have received annual Prostate Specific Antigen (PSA) tests as part of a wellness program. The increase in prostate cancer detection in workers at the St. Gabriel facility is the result of a screening bias.  EPA has stated "on balance, a role for atrazine seems unlikely because prostate cancer was found primarily in active employees who received intensive PSA screening; there was no increase in advanced tumors or mortality; and proximity to atrazine manufacturing did not appear to be correlated with risk." A Scientific Advisory Panel in July 2003 agreed that "the increase in PSA screening at the St. Gabriel plant likely led to an increase in the detection of cases of prostate cancer" but called for further examination on potential link between atrazine and prostate cancer.

On drinking water

*          Wide safety margins exist for atrazine in US drinking water. Monitoring studies of more than 28,000 community water systems from 1993 to 2002 in the 32 states where atrazine is used most show that average concentrations over the 10-year period were below the lifetime drinking water safety standard (3 ppb) and the seven-year Health Advisory Level for atrazine (200 ppb). Atrazine concentrations continue to decline in these systems due to changes in use and adoption of best management practices, such as buffer strips (plantings used to separate crops from waterways).

*          As required by the atrazine IRED issued in January 2003, Syngenta has launched an innovative monitoring program in community water systems most vulnerable to atrazine.  Part of this program is a website and toll-free number providing updates on atrazine exceedances in these watersheds.
Visit www.atrazine-watershed.info or call 866-365-3014. 

On amphibian research

*          Ongoing lab and field research by university scientists shows atrazine has no effect on survival, growth or limb deformities of frogs. This work supports earlier studies conducted to meet registration requirements for atrazine.

*          In general, Syngenta supports the conclusions of a Scientific Advisory Panel convened in June 2003 to review available research on atrazine's potential effect on frogs. The SAP report upholds the EPA position that:

• "finds the overall weight-of-evidence so uncertain that it does not support any definitive conclusions,"

• that the current data is incomplete and

• that additional studies are needed to adequately test the hypothesis that atrazine affects gonadal development.

*          Syngenta is initiating research based in large part on the recommendations of EPA and the SAP.  This will involve focused lab studies with gonadal abnormalities as the endpoint. Preliminary work will begin in 2003 with the studies commencing in 2004.

On endangered species

*          The NRDC lawsuit requiring EPA to consult with the Fish and Wildlife Service and the National Marine Fisheries Service is unnecessary, as EPA has not yet completed its endangered species assessment for atrazine. Only if EPA determines in its assessment that atrazine may affect endangered species would consultation be required under the Endangered Species Act.

*          There is no scientific evidence to support that atrazine use has any adverse effect on endangered species. Syngenta expects EPA's analyses will concur with this conclusion.