by The Center for Regulatory Effectiveness on EPA's Preliminary Ecological
Fate and Effects Risk Assessment and Related Documents for Atrazine
The Center for Regulatory Effectiveness ("CRE") is concerned that the above-referenced preliminary atrazine documents ("EcoTox Risk Assessment") do not use and rely on a probabilistic risk assessment. EPA itself acknowledges that probabilistic risk assessments are far more useful and accurate than lower-tier analyses like the one EPA is using for atrazine. EPA’s failure to use and rely on a probabilistic risk assessment is bad science and bad policy. It denies the public accurate, comprehensive and useful information concerning the ecological risks of atrazine. It also violates the new Data Quality Act and OMB’s guidelines implementing the Act.
If EPA believes that methodology or data input changes should be made to the probabilistic risk assessments already submitted by the registrant, then EPA should request that the registrant complete a new probabilistic risk assessment, or EPA should prepare its own, and allow public notice and comment, prior to any risk management decision. In no event should EPA base an atrazine EcoTox risk assessment on the lower-tier, inadequate analysis used by the preliminary risk assessment.
Months before EPA prepared and published its EcoTox Risk Assessment, the atrazine registrant, Syngenta, submitted a refined probabilistic risk assessment for atrazine’s ecological effects and fate entitled Aquatic Ecological Risk Assessment of Atrazine-A Tiered Probabilistic Approach. This probabilistic assessment was prepared by a panel of highly regarded, independent scientists. It concluded that
The integration of an unusually comprehensive data set including laboratory bioassays, field microcosm studies, simulation modeling, and environmental monitoring revealed that atrazine does not pose an ecologically significant risk to most aquatic environments in North America. Although direct toxic effects on aquatic animals are very unlikely to occur, some inhibitory effects on algae, phytoplankton or macrophyte production may occur in certain habitats vulnerable to agricultural runnoff. These effects are likely to be transient and recovery would be rapid.
EPA’s EcoTox Risk Assessment does not use or rely on Syngenta’s probabilistic risk assessment. Instead, EPA only uses and relies on a preliminary, lower tier (Tier I/Tier II) risk analysis of atrazine’s ecological effects and fate. Based on this "initial screening level assessment," EPA concludes that
On page 2 of its response to Syngenta’s comments on a draft of the atrazine EcoTox Risk Assessment, EPA acknowledges that these conclusions and their underlying lower-tier analysis assessment "do not imply any quantification of magnitude or probability of effect."
According to EPA, there are inadequate data to perform a probabilistic risk assessment for atrazine, even though the Agency admits that there are "a relatively large amount of both ecotoxicological data and monitoring data on atrazine...." EcoTox Risk Assessment, pages 4-5.
By contrast, EPA is using probabilistic risk assessments for the Agency’s cumulative risk assessment of the organophosphate pesticides. It is hard to believe that the available data allow valid probabilistic risk assessments in this very complex and novel multiple-pesticide context, but do not allow probabilistic assessment of the ecological effects of the single pesticide atrazine, which is indisputably one of the world’s most studied and tested pesticides.
Everyone Agrees That Probabilistic Risk Assessments Are Necessary To Accurately Assess Ecological Fate And Effects
EPA’s Office of Pesticide Programs explains on its website (emphasis added):
In May 1996 the Environmental Fate and Effects Division (EFED) of the Office of Pesticide programs (OPP) presented two pesticide risk assessment case studies to EPA’s Scientific Advisory Panel (SAP) and asked them to address the agency’s current pesticide risk assessment methodology. The SAP commented that while the current process is believed to be cautious and protective in terms of adverse environmental effects, it best serves as a screen because it provides little information on the likelihood of damage. The SAP recommended that the pesticide risk assessment process be expanded to include probabilistic assessments of risk and to identify the uncertainties associated with the assessment.
EPA’s Ecological Committee on FIFRA Risk Assessment Methods ("ECOFRAM") published in 1999 an Aquatic Report which on page 3 summarized the SAP’s conclusions in part as follows (emphasis added):
The panel suggested that the current test methodologies and specific endpoints used by OPP in its model assessments were designed to support the relative simplistic process of hazard assessment, not risk assessment. The Panel indicated that the current approach has a number of limitations, and its utility in risk assessments is of questionable value. They also pointed out that gaps in the current methodologies must be filled to accomplish effective and comprehensive risk assessments. As a result, they strongly urged OPP EFED to conduct probabilistic assessments (risk assessments) to evaluate the ecological impacts from pesticides.
In sum, the type of lower-tier analyses used by EPA for atrazine have been subject to formal, independent, external peer review and found lacking in this context. By contrast, a probabilistic risk assessment, like the one submitted by Syngenta, is the type of analysis found necessary by formal, independent, external peer review.
The Data Quality Act, P. L. 106-554, § 515, imposes new standards on the quality of information disseminated by federal agencies including EPA’s pesticide risk assessments. As required by the statute, the Office of Management and Budget ("OMB") promulgated guidelines implementing the Act’s new data quality standards. 66 FR 49718 (September 28, 2001). These OMB guidelines apply to EPA’s pesticide risk assessments. EPA now has until October 1, 2002 to promulgate its own Data Quality Act guidelines, which must conform to OMB’s and must include a petition process by which parties can correct information disseminated by EPA that does not comply with the Data Quality Act and OMB’s guidelines: including pesticide risk assessments.
EPA’s atrazine EcoTox Risk Assessment does not meet the Data Quality Act’s standards as implemented by OMB’s guidelines. For example, it lacks "utility" and "objectivity."
EPA’s Current EcoTox Risk Assessment for Atrazine Lacks "Utility"
OMB’s Guidelines under the Data Quality Act require that all information disseminated by EPA to the public have "utility." The OMB definition of "utility" explains that this term "refers to the usefulness of the information to its intended users, including the public."
As noted above, EPA’s own SAP emphasized that the type of lower-tier analyses used by EPA instead of the atrazine probabilistic risk assessment has "utility...of questionable value." EPA’s own SAP urged the Agency "to conduct probabilistic assessments (risk assessments) to evaluate the ecological impacts from pesticides." The SAP further cautioned that the type lower-tier analysis used for atrazine "best serves as a screen because it provides little information on the likelihood of damage." In fact, as the SAP pointed out, this type of lower-tier analysis "is designed to support the relative simplistic process of hazard assessment, not risk assessment." EPA itself admits that its lower-tier analysis does "not imply any quantification of magnitude or probability of effect." Yet EPA is relying on it as the sole ecological fate and effects risk assessment for atrazine. It has little if any "utility" for this purpose
EPA’s Current EcoTox Risk Assessment for Atrazine lacks "Objectivity
OMB’s Guidelines also require "objectivity" in information EPA disseminates to the public. The OMB definition of "objectivity" explains (emphasis added), "In a scientific or statistical context, the original or supporting data shall be generated, and the analytical results shall be developed, using sound statistical and research methods."
EPA’s SAP has concluded that the type of lower-tier analysis used by EPA is not a "sound statistical...method" for pesticide ecological risk assessments. In fact it is only a hazard assessment, not a full-fledged risk assessment. Probabilistic risk assessments are the "sound statistical...method" in this context, especially when one has already been prepared and submitted to the Agency.
In contrast EPA has relied on worst case data to imply or actually state that atrazine will cause indirect ecological effects. This subjective speculation does not rely on any data that remotely satisfies the new OMB Data Quality Act requirements.
EPA should promptly state publicly that it is revising its preliminary EcoTox Risk Assessment for atrazine to incorporate the results of a probabilistic risk assessment:
by The Center bor Regulatory Effectiveness on The Atrazine Environmental
Fate and Effects Risk Assessment
The Center for Regulatory Effectiveness ("CRE") has the following primary comments on the Environmental Fate and Effects Chapter of EPA's Registration Eligibility Science Chapter for Atrazine ("Environmental Risk Assessment").
First, EPA's Environmental Risk Assessment "concluded that the major effects from atrazine use are indirect effects on fish and invertebrate populations...." At the same time, EPA correctly admitted "that there is 'inadequate data' on indirect effects to assess risk..."; and that "[c]urrently, there is no methodology...which can model and statistically analyze indirect effects." EFED Review of Public Comments in Response to the EPA EFED Revised Environmental Risk Assessment for Atrazine, p. 3(April 10, 2002)("Comment Response"). EPA also correctly admittted that there are substantial uncertainties regarding the field and laboratory standards used to support the Environmental Risk Assessment's conclusion of indirect effects: e.g., lack of reproducibility and lack of transparency. Environmental Risk Assessment, pp. 63-64. Given these admissions, EPA obviously cannot publicly disseminate a conclusion that atrazine causes indirect effects. Any such conclusion would violate the objectivity and utility standards of the Data Quality Act amendments to the Paperwork Reduction Act, 44 U.S.C. § 3516 statutory and historical notes ("Data Quality Act"). Consequently, EPA's Environmental Risk Assessment should be revised to delete any conclusion that atrazine causes indirect effects on wildlife.
Second, the Environmental Risk Assessment should be revised to state that EPA cannot use or rely on the Hayes Frog Studies because those studies do not comply with the Data Quality Act for the following and other reasons:
Third, the Environmental Risk Assessment should be revised to state that there is no acceptable evidence of wildlife endocrine disruption from atrazine because there are no validated test methods for endocrine disruption. The objectivity and utility standards of the Data Quality Act preclude any conclusion or suggestion of adverse endocrine effects until and unless there are properly validated test methods.
Fourth, the quotient method EPA used in the Environmental Risk Assessment is arbitrary and lacks utility. Consequently, any conclusions based on the quotient method violate the utility and objectivity standards of the Data Quality Act. EPA should defer any conclusions about the environmental effects of atrazine until EPA has developed a reliable probabilistic risk assessment method for adverse environmental effects.
These and other comments are discussed in more detail below.
Environmental Risk Assessment
EPA's Environmental Risk Assessment determined that the only major environmental risk from atrazine use was indirect effects, not direct effects: e.g.,
Paradoxically, EPA also admits in its Comment Response the Agency is unable to assess indirect environmental effects for atrazine or any other pesticide:
EPA's inability to assess indirect environmental effects is not a new phenomenon. EPA acknowledged this flaw in its risk assessment process over ten years ago:
Although the Agency believes that long-term, indirect effects of pesticide use on aquatic ecosystems may be important, the Agency does not have a testing scheme in place to accurately measure such effects within the time specified for Reregistration. Decisions on the Ecological, Fate, and Effects Task Force, Linda J. Fisher, EPA Assistant Administrator, Attachment: Program Guidance on Ecological Risk Management, p. 1 (Oct. 29, 1992).
Nothing has changed since, as acknowledged by EPA in its atrazine Comment Response.
Moreover, EPA used the quotient method in its Environmental Risk Assessment, and EPA admits: "The quotient method cannot evaluate secondary effects." 61 FR 47552, 47594 (Sept. 9, 1996). EPA defines the term "secondary effects" as an effect where the stressor acts on supporting components of the ecosystem, which in turn have an effect on the ecological component of interest (synonymous with indirect effects...). Id. at 47615.
EPA cannot inform the public that atrazine use causes indirect effects when EPA admits that "there is no methodology...which can model and statistically analyze indirect effects"; and "that there is 'inadequate data' on indirect effects to assess risk...." Comment Response, p. 3. EPA's Environmental Risk Assessment violates the Data Quality Act's objectivity and utility requirements because EPA's conclusion that atrazine has adverse indirect effects has no factual or scientific basis. Consequently, this conclusion is not accurate and reliable; nor is it useful to its intended users. 67 FR 8452, 8453 (Feb. 22, 2002)(OMB's government-wide Data Quality guidelines).
With regard to indirect effects, EPA also relied on some field and laboratory studies. With regard to the quality of these studies, EPA admitted:
Detrimental effects on plants are rapid are rapid and appear to increase as both the atrazine concentration exposure increases. Prolonged exposure results in starvation an ultimately death of plants. Rapid recovery of oxygen evolution (within hours) is observed in aquatic plants if atrazine exposure is removed. Plant recovery and resistence are two complicating issues which add uncertainty to any risk assessment on atrazine, and there is insufficient information to do more than report that both occur.
Environmental Risk Assessment, pp. 63-64
These field and laboratory studies do not meet the Data Quality Act's objectivity and utility standards. EPA itself admits that "the laboratory toxicity data" do not allow the Agency to "determine with certainty that impacts on these or similar species would result in a loss of ecological function or important changes in community structure in natural systems." Moreover, the laboratory and field toxicity tests showing adverse effects are not reproducible: "some studies... showed no effects at similar exposure levels"; and neither EPA nor the public has access to the underlying data. It is also inaccurate to compare monitoring data with field and laboratory data when their "spatial and temporal distributions... do not match." In addition, EPA acknowledges, "Plant recovery and resistence are two complicating issues which add uncertainty to any risk assessment on atrazine, and there is insufficient information to do more than report that both occur." In sum, based on the current data base, and based on the risk assessment methods used by EPA, there is too much "uncertainty" regarding atrazine's indirect environmental effects to reach any accurate, reliable, unbiased and useful conclusion regarding those effects. Consequently, any conclusion regarding those effects cannot meet Data Quality Act standards.
The Hayes Frog Studies Do Not Meet Data Quality Standards
The Environmental Risk Assessment suggests that the Hayes Frog Studies show that atrazine use causes endocrine disruption in frogs at very low concentrations, in particular with regard to reproductive development. The Hayes Frog Studies do not meet the Data Quality Act objectivity and utility requirements for at least two reasons.
First, other laboratories have been unable to reproduce them. Attached as Exhibit A to CRE's comments are a written report and slides from a presentation to EPA by Dr. James A. Carr of Texas Tech University. Dr. Carr was unable to reproduce Dr. Hayes' test results. In addition, CRE understands that Dr. John Giesy, of Michigan State University, has been unable to reproduce Dr. Hayes' test results, but has not yet prepared a written report on his tests. Test results that have been shown not to be reproducible do not meet the Data Quality Act's objectivity and utility standards because they are not accurate, reliable or useful.
Second, Dr. Hayes hypothesizes that atrazine can cause adverse endocrine effects in frogs because atrazine induces aromatase in the frogs. Environmental Risk Assessment, p. 90. There are no validated test methods for aromatase induction. Any mode or mechanism of action that relies on unvalidated test methods does not meet the Data Quality Act's objectivity and utility standards because the unvalidated test methods have not been demonstrated to be accurate, reliable and useful.
In light of the above concerns, the Environmental Risk Assessment should be revised to state that EPA will not use or rely on the Hayes Frog Studies because they do not meet Data Quality Act standards.
EPA Cannot Reach Any Conclusion About Endocrine Disruption Until And Unless There Are Validated Test Methods
EPA's Environmental Risk Assessment at page 90 states:
Atrazine has been reported to cause sub-lethal effects in aquatic organisms and amphibians. These include endocrine effects in frogs at ~0.1 µg/L and in largemouth bass at ~50 µg/L, as well as olfactory effects in salmon at ~50 µg/L. In addition some studies have been conducted where these effects were not demonstrated.
At pages 90-93, the Environmental Risk Assessment contains an extensive discussion of the relevant studies which suggests that some of them support the conclusion that atrazine causes wildlife endocrine effects.
EPA has also acknowledged:
The Endocrine Disruptor Screening program has proposed a number of test protocols for identifying endocrine effects in wildlife species. Some of these protocols are currently in round-robin testing. As of this date, none of them have been approved for regulatory testing.
EFED Review of Comments from Syngenta and its Contractors about the EPA Revised Environmental Risk Assessment for Atrazine, p. 22. (April 22, 2002).
The Environmental Risk Assessment in its current state violates the Data Quality Act's objectivity and utility standards because it indicates that atrazine does cause endocrine effects in wildlife based on studies using unvalidated test methods. EPA should revise its Environmental Risk Assessment to clearly state that EPA cannot reach any conclusions about wildlife endocrine effects from atrazine until and unless there are properly validated test methods for those effects.
The Quotient Risk Assessment Method is Arbitrary and Lacks Utility
As in the case of most if not all pesticides, EPA used the quotient method to assess atrazine's environmental risks:
The standard method used in the EPA Office of Pesticide Programs (OPP) to characterize ecological risk is the ratio or quotient method. "Typically, the ratio (or quotient) is expressed as an exposure concentration divided by an effects concentration: (U.S. EPA, Part A, Section 5.1.3). A risk quotient (RQ) is the ratio of the estimated environmental concentration of a chemical to a toxicity test effect level for a given species. It is calculated by dividing an appropriate exposure estimate (e.g., EEC or estimated environmental concentration) by an appropriate toxicity test effect level (e.g. LC50). Thus, the RQ is an index (an indicator or measure of a condition) of the potential adverse effects. As an index, the risk quotient needs some reference point or bearing to have meaning. Thus, the Agency has established Levels of Concern (LOCs) in order to identify when the potential adverse effects are of concern to the Agency (See Appendix XVI, Table 1). LOCs are criteria used to indicate potential risk to nontarget organisms and the need to consider regulatory action. When an LOC is exceeded, it means that a pesticide, when used as directed, has the potential to cause adverse effects on nontarget organisms.
Environmental Risk Assessment, p. 5
The referenced Appendix Table contains the LOCs that EPA has established for all pesticide environmental risk assessment. These LOCs do not vary from pesticide to pesticide.
EPA's refined risk assessment for atrazine's environmental effects consisted primarily of computer modeling of atrazine concentrations in various surface waters based on the available monitoring data. The model results were then compared to the LOCs. Environmental risk assessment, pp. 4-5, 7-8, 16.
EPA's Office of Pesticide Programs has explained on its website that the quotient risk assessment method lacks utility (emphasis added):
The [SAP] panel suggested that the current test methodologies and specific endpoints used by OPP in its model assessments were designed to support the relative simplistic process of hazard assessment, not risk assessment. The Panel indicated that the current approach has a number of limitations, and its utility in risk assessments is of questionable value. They also pointed out that gaps in the current methodologies must be filled to accomplish effective and comprehensive risk assessments. As a result, they strongly urged OPP EFED to conduct probabilistic assessments (risk assessments) to evaluate the ecological impacts from pesticides.
The SAP has emphasized its concern "with the notion that the frequency of LOC exceedances is a useful measure." The SAP concluded that the LOC-exceedance standard is "essentially an arbitrarily selected threshold." FIFRA Scientific Advisory Panel, Final Report on a Set of Scientific Issues Being Considered by the Environmental Protection Agency Regarding Methodology for Conducting Comparative Ecological Risk Assessments," p. 9 (SAP Report No. 99-01A, Jan. 22, 1999).
EPA's use of the quotient method in the Environmental Risk Assessment violates the Data Quality Act's utility and objectivity requirements because this method is not accurate, reliable or useful in assessing the indirect or other environmental effects of atrazine.